Bearings

A-6

Technical Data

Retainer

NTN

BallRetainer

Inner ring

Outer ring

Outer ring

Inner ring

Retainer

Roller

Ball

Inner ring

Outer ring

Outer ring

Roller

Retainer

Outer ring

Inner ring

Roller

Retainer

Deep groove ball bearingFig. 1.1

Angular contact ball bearingFig. 1.2

Outer ring

Roller

Retainer

Inner ring

Cylindrical roller bearingFig. 1.3

Needle roller bearingFig. 1.4

Inner ring

Outer ring

Retainer

Ball

Spherical roller bearingFig. 1.6

Tapered roller bearingFig. 1.5

Inner ring

Outer ring

Retainer

Roller

Thrust roller bearingFig. 1.8

Thrust ball bearingFig. 1.7

1. Classification and Characteristics of Rolling Bearings

1.1 Rolling bearing construction

Most rolling bearings consist of rings with raceways (an innerring and an outer ring), rolling elements (either balls or rollers)and a rolling element retainer. The retainer separates therolling elements at regular intervals, holds them in place withinthe inner and outer raceways, and allows them to rotate freely.See figures 1.1-1.8.

Rolling elements come in two general shapes: ball or rollers.Rollers come in four basic styles: cylindrical, needle, tapered,and spherical.

Balls geometrically contact the raceway surfaces of the innerand outer rings at “points”, while the contact surface of rollersis a “line” contact.

Theoretically, rolling bearings are so constructed as to allowthe rollling elements to rotate orbitally while also rotating ontheir own axes at the same time.

While the rolling elements and the bearing rings take anyload applied to the bearings (at the contact point betweenthe rolling elements and raceway surfaces), the retainer takesno direct load. The retainer only serves to hold the rolllingelements at equal distances from each other and preventthem from falling out.

1.2 Classification of rolling bearings

Rolling element bearings fall into two main classifications:ball bearings and roller bearings. Ball bearings are classifiedaccording to their bearing ring configurations: deep groove,angular contact and thrust types. Roller bearings on the otherhand are classified according to the shape of the rollers:cylindrical, needle, taper and spherical.

Rolling element bearings can be further classified accordingto the direction in which the load is applied; radial bearingscarry radial loads and thrust bearings carry axial loads.

Other classification methods include: 1) number of rollingrows (single, multiple, or 4-row), 2) separable and non-separable, in which either the inner ring or the outer ring canbe detached, 3) thrust bearings which can carry axial loadsin only one direction, and double direction thrust bearingswhich can carry loads in both directions.

There are also bearings designed for special applications,such as: railway car journal roller bearings (RCT bearings),ball screw support bearings, turntable bearings, as well asrectilinear motion bearings (linear ball bearings, linear rollerbearings and linear flat roller bearings).

A-7

Rolling bearings

Ball bearings

Radial ball bearings

Single row deep groove ball bearings

Maximum capacity type ball bearings

Single row angular contact ball bearings

Duplex angular contact ball bearings

Double row angular contact ball bearings

Four-point contact ball bearings

Self-aligning ball bearings

Single direction thrust ball bearings with flat back face

Double direction thrust ball bearings with flat back face

Single direction thrust ball bearings with seating ring

Double direction thrust ball bearings with seating ring

Double direction angular contact thrust ball bearings

Single row cylindrical roller bearings

Cylindrical roller thrust bearings

Needle roller thrust bearings

Tapered roller thrust bearings

Spherical roller thrust bearings

Fig. 1.9 Classification of rolling bearings

Double row cylindrical roller bearings

Needle roller bearings

Single row tapered roller bearings

Double row tapered roller bearings

Spherical roller bearings

Thrust ball bearings

Roller bearings

TechnicalData

A-8

Technical Data

1.3 Characteristics of rolling bearings

1.3.1. Characteristics of rolling bearings

Rolling bearings come in many shapes and varieties, eachwith its own distinctive features.

However, when compared with sliding bearings, rollingbearings all have the followings advantages:

(1) The starting friction coefficient is lower and only alittle difference between this and the dynamic frictioncoefficient is produced.

(2) They are internationally standardized, interchange-able and readily obtainable.

(3) Ease of lubrication and low lubricant consumption.

(4) As a general rule, one bearing can carry both radialand axial loads at the same time.

(5) May be used in either high or low temperatureapplications.

(6) Bearing rigidity can be improved by preloading.

Construction, classes, and special features of rolling bearingsare fully described in the boundary dimensions and bearingnumbering system section.

1.3.2. Ball bearings and roller bearings

Generally speaking, when comparing ball and roller bearingsof the same dimensions, ball bearings exhibit a lower frictionalresistance and lower face run-out in rotation than rollerbearings.

This makes them more suitable for use in applications whichrequire high speed, high precision, low torque and lowvibration. Conversely, roller bearings have a larger loadcarrying capacity which makes them more suitable forapplications requiring long life and endurance for heavy loadsand shock loads.

1.3.3. Radial and thrust bearings

Almost all types of rollling bearings can carry both radial andaxial loads at the same time.

Generally, bearings with a contact angle of less than 45° havea much greater radial load capacity and are classed as radialbearings; whereas bearings which have a contact angle over45° have a greater axial load capacity and are classed asthrust bearings. There are also bearings classed as complexbearings which combine the loading characteristics of bothradial and thrust bearings.

1.3.4. Standard bearings and special bearings

Bearings which are internationally standardized for shape andsize are much more economical to use, as they areinterchangeable and available on a worldwide basis.

However, depending on the type of machine they are to beused in, and the expected application and function, a non-standard or specially designed bearing may be best to use.Bearings that are adapted to specific applications, and “unitbearings” which are integrated (built-in) into a machine’scomponents, and other specially designed bearings are alsoavailable.

A-10

Technical Data

2. Bearing Selection

2.1 Operating conditions and environment

When selecting a bearing, having an accurate andcomprehensive knowledge of which part of the machine orequipment it is to be installed in and the operatingrequirements and environment in which it will function, is thebasis for selecting just the right bearing for the job. In theselection process, the following data is needed.

(1) The equipment’s function and construction.

(2) Bearing mounting location (point).

(3) Bearing load (direction and magnitude).

(4) Bearing speed.

(5) Vibration and shock load.

(6) Bearing temperature (ambient and frictiongenerated).

(7) Environment (corrosion, lubrication, cleanliness ofthe environment, etc.).

2.2 Demand factors

The required performance capacity and function demandsare defined in accordance with the bearing applicationconditions and operating conditions. A list of general demandfactors to be considered is shown in Table 2.1.

Rolling bearings come in a wide variety of types, shapes anddimensions. The most important factor to consider in bearingselection is a bearing that will enable the machine or part inwhich it is installed to satisfactorily perform as expected.

To facilitate the selection process and to be able to select themost suitable bearing for the job, it is necessary to analyzethe prerequisites and examine them from various standpoints.While there are no hard-and-fast rules in selecting a bearing,the following list of evaluation steps is offered as a generalguideline in selecting the most appropriate bearing.

(1) Thoroughly understand the type of machine thebearing is to be used in and the operatingconditions under which it will function.

(2) Clearly define all demand factors.

(3) Select bearing shape.

(4) Select bearing arrangement.

(5) Select bearing dimensions.

(6) Select bearing specifications.

(7) Select mounting method, etc.

2.3 Design selection

By comparing bearing functions and performance demandswith the characteristics of each bearing type, the most suitablebearing design can be selected. For easy reference, thecharacteristics of general bearing types are compared in Table2.2 on page A-12.

2.4 Arrangement selection

Shaft assemblies generally require two bearings to supportand locate the shaft both radially and axially relative to thestationary housing. These two bearings are called the fixedand floating bearings. The fixed bearing takes both radial andaxial loads and “locates” or aligns the shaft axially in relationto the housing. Being axially “free”, the floating bearing relievesstress caused by expansion and contraction of the shaft dueto fluctuations in temperature, and can also allow formisalignment caused by fitting errors.

Bearings which can best support axial loads in both directionsare most suitable for use as fixed bearings. In floating bearingsthe axial displacement can take place in the raceway (forexample: cylindrical roller bearings) or along the fittingsurfaces (for example: deep groove ball bearings). There isalso the “cross location” arrangement in which both bearings(for example: angular contact ball bearings) act as fixing andnon-fixing bearings simultaneously, each bearing guiding andsupporting the shaft in one axial direction only. Thisarrangement is used mainly in comparatively short shaftapplications.

These general bearing arrangements are shown in Table 2.3on pages A-14 and A-15.

Table 2.1 Bearing Demand Factors

Demand factor Ref. page

Dimension limitations A-16Durabliity (life span) A-40Running accuracy A-22Allowable speed A-77Rigidity A-74Noise/vibration —Friction torque A-78Allowable misalignment for inner/outer rings —Requirements for mounting-dismounting A-97Bearing availability and economy —

A-11

2.5 Dimension selection

Bearing dimension selection is generally based on theoperating load and the bearing’s life expectancy requirements,as well as the bearing’s rated load capacity (P.A-40-A-53).

2.6 Specification determination

Specifications for rolling bearings which are designed for thewidest possible use have been standardized. However, to meetthe diversity of applications required, a bearing of non-standard design specifications may be selected. Items relatingto bearing specification determination are given in Table 2.4.

2.7 Handling methods

If bearings are to function as expected, appropriate methodsof installation and handling must be selected andimplemented. See Table 2.5.

When selecting a bearing, frequently all the data required forthe selection of the bearing is not necessarily clearly specified.Thus, some elements governing selection must be “factoredin” on an estimated basis. Also, the order of priority and weightof each factor must be evaluated. For this reason it is essentialto have ample experience as well as abundant, integrated,data base upon which the bearing selection can be based.

Over the years, NTN has gained considerable expertise inbearings selection. Please consult NTN for advice andassistance with any bearing selection problem.

Table 2.4 Bearing specifications

Specification item Ref. page

Bearing tolerance (dimensional and running) A-22Bearing internal clearance and preload A-64Bearing material and heat treatment A-92Cage design and material A-93

Table 2.5 Bearing handling

Treatment Ref. page

Fitting methods A-54Lubrication methods and lubricants A-79Sealing methods and seals A-88Shaft and housing construction anddimensions A-94

Bearing types

Table 2.2 Types and characteristics of rolling bearings

Characteristics

Load Carrying Capacity

High speed1)

High rotating accuracy1)

Low noise/vibration1)

Low friction torque1)

High rigidity1)

Vibration/shockresistance1)

For fixed bearings2)

For floating bearings1)

Tapered bore bearings5)

Remarks

Reference page

Non-separable orseparable4)

Allowable misalignment forinner/outer rings1)

Radial load

Axial load

Deepgroove

ballbearings

Angularcontact

ballbearings

Double rowangularcontact

ballbearings

Duplexangularcontact

ballbearings

Self-aligning

ballbearings

Cylindricalroller

bearings

Single-flange

cylindricalroller

bearings

Double-flange

cylindricalroller

bearings

Double rowcylindrical

rollerbearings

Needleroller

bearings

Taperedroller

bearings

Sphericalroller

bearings

Thrustball

bearings

Thrustball

bearingswith

seatingring

Double rowangularcontact

thrust ballbearings

Cylindricalrollerthrust

bearings

Sphericalrollerthrust

bearings

Referencepage

A-77

A-22

A-77

A-78

A-74

—

—

A-94

A-94

—

A-99

B-218B-218B-218B-218B-218B-186B-118B-112B-85B-84B-84B-84B-74B-44B-44B-6 B-68

For DB and DFarrangment

For DBarrangment

For duplexarrangment

NU, N type NJ, NF type NUP, NP,NH type

NNU, NN,type

For duplexarrangment

Includingthrust needleroller bearings

3) Indicates movement at raceway. Indicates movement at mated surface of inner or outer ring.4) Indicates both inner ring and outer ring are detachable.5) Indicates inner ring with tapered bore is possible.

Note 1) The number of stars indicate the degree to which that bearing type displays that particular characteristic. Not applicable to that bearing type. 2) Indicates dual direction. Indicates single direction axial movement only.

A-12 A-13

Technical Data

A-14

Technical Data

Table 2.3 (1) Bearing arrangement (Fixed and Floating)

Arrangement

Fixed Floating

1. General arrangement for small machinery Small pumps, small electric2. For radial loads, but will also accept axial loads. motors, auto-mobile3. Preloading by springs or shims on outer ring transmissions, etc.

face.

1. Suitable for high speed. Widely used. Medium-sized electric2. Even with expansion and contraction of shaft, motors, ventilators, etc.

non-fixing side moves smoothly.

1. Withstands heavy loading and some axial Railway vehicle electricloading. motors, etc.

2. Inner and outer ring shrink-fit suitable.3. Easy mounting and dismounting.

1. Radial loading plus dual direction axial loading Wormgear speed reducers,possible. etc.

2. In place of duplex angular contact ball bearings,double-row angular contact ball bearings arealso used.

1. Heavy loading capable. Machine tool spindles, etc.2. Shafting rigidity increased by preloading the two

back-to-back fixed bearings.3. Requires high precision shafts and housings,

and minimal fitting errors.

1. Allows for shaft deflection and fitting errors. Counter shafts for general2. By using an adaptor on long shafts without industrial equipment, etc.

screws or shoulders, bearing mounting anddismounting can be facilitated.

3. Not suitable for axial load applications.

1. Widely used in general industrial machinery Reduction gears for generalwith heavy and shock load demands. industrial equipment, etc.

2. Allows for shaft deflection and fitting errors.3. Accepts radial loads as well as dual direction

axial loads.

1. Widely used in general industrial machinery Industrial machinerywith heavy and shock loading. reduction gears, etc.

2. Radial and dual directional axial loading.

Comment Application

A-15

Table 2.3 (3) Bearing arrangement (Vertical shaft)

Arrangement Comment Application

When fixing bearing is a duplex angular contact Machine tool spindles,ball bearing, non-fixing bearing is a cylindrical vertical mounted electricrollerbearing. motors, etc.

1.Most suitable arrangement for very heavy axial Crane center shafts, etc.loads.

2.Depending on the relative alignment of thespherical surface of the rollers in the upper andlower bearings, shaft deflection and fittingerrors can be absorbed.

3.Lower self-aligning spherical roller thrustbearing pre-load is possible.

Table 2.3 (2) Bearing arrangement (Placed oppositely)

Arrangement Comment Application

General arrangement for use in small machines. Small electric motors, smallreduction gears, etc.

1. This type of back-to-back arrangement well Spindles of machine tools,suited for moment loads. etc.

2. Preloading increases shaft rigidity.3. High speed reliable.

1. Accepts heavy loading. Construction equipment,2. Suitable if inner and outer ring shrink-fit is mining equipment sheaves,

required. agitators, etc.3. Care must be taken that axial clearance does

not become too small during operation.

1. Withstands heavy and shock loads. Wide Reduction gears, automotiverange application. axles, etc.

2. Shafting rigidity increased by preloading.3. Back-to-back arrangement for moment loads,

and face-to-face arrangement to alleviatefitting errors.

4. With face-to-face arrangement, inner ringshrink-fit is facilitated.

Back-to-back arrangement

Face-to-face arrangement

A-16

Technical Data

3. Boundary Dimensions and Bearing Number Codes

3.1 Boundary dimensions

To facilitate international interchangeability and economicbearing production, the boundary dimensions of rollingbearings have been internationally standardized by theInternational Organization for Standardization (ISO) ISO 15(radial bearings-except tapered roller bearings), ISO 355(tapered roller bearings), and ISO 104 (thrust bearings).

In Japan, standard boundary dimensions for rolling bearingsare regulated by Japanese Industrial Standards (JIS B 1512)in conformity with the ISO standards.

Those boundary dimensions which have been standardized;i.e. bore diameter, outside diameter, width or height andchamfer dimensions are shown in cross-section in Figs. 3.1-3.4. However, as a general rule, bearing internal constructiondimensions are not covered by these standards.

The 90 standardized bore diameters (d ) for rolling bearingsunder the metric system range from 0.6 mm - 2500 mm andare shown in Table 3.1.

For all types of standard bearings there has been establisheda combined series called the dimension series. In all radialbearings (except tapered roller bearings) there are eight majoroutside diameters (D ) for each standard bore diameter. Thisseries is called the diameter series and is expressed by thenumber sequence (7, 8, 9, 0, 1, 2, 3, 4) in order of ascendingmagnitude (7 being the smallest and 4 being the largest).

For the same bore and outside diameter combination thereare eight width designations (B ). This series is called the widthseries and is expressed by the number sequence (8, 0, 1, 2,3, 4, 5, 6) in order of ascending size (i.e. 8 narrowest and 6widest). The combination of these two series, the diameterseries and the width series, forms the dimension series.

Table 3.1 Standardized bore diameter

Bore diameter for Standardized Standardnominal bearing bore diameterd mm mm

over include— 1.0 0.6 —

1.0 3.0 1, 1.5, 2.5 Every 0.5 mm

3.0 10 3, 4,...9 Every 1 mm

10 20 10, 12, 15, 17 —

20 35 20, 22, 25, 28, 30, 32 Stanard number R20 series

35 110 35, 40, ....105 Every 5 mm

110 200 110, 120, ....190 Every 10 mm

200 500 200, 220, ....480 Every 20 mm

500 2500 500, 530, 2500 Standard number R40 series

Boundary dimension ofradial bearings

Fig. 3.1

Boundary dimension of single direction thrust bearingsFig. 3.3

Boundary dimension of double direction of thrust bearings

Fig. 3.4

Boundary dimension oftapered roller bearings

Fig. 3.2

d1

D1

D

d

T

rr

rr

D

B

Dd

r r

rr

r r

r r

T

E

C

d D

r

r1 r1 α

B

r

d3

D1

D1

T1

d2

r

Br

r

r

r

r

r

A-17

The relationship of these three series is illustrated in Fig. 3.5.

For tapered roller bearings, the standard bore (d ) and outsidediameter (D ) combined series (i.e. diameter series) has sixmajor divisions and is expressed by the letter sequence (B, C,D, E, F, G) in ascending order of the outside diameter size (Bis the smallest outside diameter and G is the largest outsidediameter). The width (T ) is expressed in the width series by afour letter sequence (B, C, D, E) in ascending order; i.e. Ebeing the widest.

The contact angle (∝) is shown by a six number contact angleseries (2, 3, 4, 5, 6, 7) in ascending order (i.e. 2 being thesmallest angle and 7 the largest angle). The combination ofthe contact angle series, the diameter series and the widthseries form the dimension series for tapered roller bearings(example: 2FB). This series relationship is shown in Fig. 3.6.

For thrust bearings, the standard bore diameter (d ) and theoutside diameter (D ) relationship is expressed by the five majornumber diameter series (0, 1, 2, 3, 4). For the same bore andoutside diameter combination, the height dimensions (T ) isstandardized into 4 steps and is expressed by the numbersequence (7, 9, 1, 2). This relationship is shown in Fig. 3.7.

Width series

Diameter series

Dimension series

8432 10 98

82

0 1 2 3 4 5 6

8308

0900

0102 03 04

1819

1011

12 13

2829

2021

22 23 24 38 39 30 31 32 33 48 49 40 41 42 58 59 50 68 69 60

FIg. 3.5 Comparison of dimension series (Except tapered roller bearings) for radial bearings of same bore diameter

Fig. 3.6 Comparison of dimension series for tapered roller bearings

GFE

DCB

BC

DE

BC

DE

BC

DE

BC

DE

B

CD

E

B

CD

E

Fig. 3.7 Comparison of dimension series forthrust bearing of the same bore diameter

Dimensionseries

Diameterseries Height

series

0 1 2 3 4

7071

7273

74

9091

9293

94

101112

13

14

22

23

24

2

1

9

7

A-18

Technical Data

Chamfer dimensions (r ) are covered by ISO standard 582and JIS standard B1512 (rs min: minimum allowable chamferdimension). There are twenty-two standardized dimensions forchamfers ranging from 0.1 mm to 19 nn (0.05, 0.08, 0.1, 0.15,0.2, 0.3, 0.6, 1, 1.1, 1.5, 2, 2.1, 2.5, 3, 4, 5, 6, 7.5, 9.5, 12, 15,19).

Not all of the above mentioned standard boundary dimensionsand size combinations (bore diameter, diameter series, widthor height series) are standardized. Moreover, there are manystandard bearing sizes which are not manufactured. Pleaserefer to the bearing dimension tables in this catalog.

3.2 Bearing numbers

The bearing numbers indicate the bearing design, dimensions,accuracy, internal construction, etc.

The bearing number is derived from a series of number andletter codes, and is composed of three main groups of codes;i.e. two supplementary codes and a basic number code. Thesequence and definition of these codes is shown in Table 3.2.

The basic number indicates general information such asbearing design, boundary dimensions, etc.: and is composedof the bearing series code, the bore diameter number and thecontact angle code. These coded series are shown in Tables3.4, 3.5, and 3.6 respectively.

The supplementary codes are derived from a prefix code seriesand a suffix code series. These codes designate bearingaccuracy, internal clearance and other factors relating tobearing specifications and internal construction. These twocodes are shown in Tables 3.3 and 3.7.

Special application codeMaterial/heat treatment code

Bearingseries

Design code

Width/height series code

Diameter series code

Bore diameter number

Contact angle code

Internal modification code

Number and code arrangement

Table 3.2 Bearing number sequence

Cage codes

Seal/Shield code

Ring configuration code

Duplex arrangement code

Internal clearance code

Tolerances code

Lubrication code

Basic num

berS

upplementary suffix code

Dimensionseries code

Supple-mentary

prefixcode

TS2 - 7 3 05 B L1 DF+10 C3 P5

A-19

329X 2 9320X 2 0302 0 2322 2 2 Tapered roller303 3 0 3 bearings

303D 0 3313X 1 3323 2 3

239 3 9230 3 0240 4 0231 3 1241 2 4 1 Spherical222 2 2 roller bearings232 3 2213 0 3223 2 3

511 1512 2 Single-thrust513 5 1 3 ball bearings514 4

522 2523 5 2 3 Double-thrust524 4 ball bearings

811 1 1 Cylindrical812 8 1 2 roller thrust893 9 3 bearings

292 2293 2 9 3 Spherical roller294 4 thrust bearings

Table 3.3 Supplementary prefix code

Code Definition

TS- Dimension stabilized bearing for hightemperature use

M- Hard chrome plated bearings

F- Stainless steel bearings

H- High speed steel bearings

N- Special material bearings

TM- Specially treated long-life bearings

EC- Expansion compensation bearings

4T- NTN 4 Top tapered roller bearings

ET- ET Tapered roller bearings

Table 3.4 Bearing series symbol

Bearingseries

Typesymbol

Dimension series

widthseries

diameterseries

Bearing type

67 (1) 768 (1) 869 (1) 9 Single row60 6 (1) 0 deep groove62 (0) 2 ball bearings63 (0) 3

78 (1) 879 (1) 9 Single row70 7 (1) 0 angular contact72 (0) 2 ball bearings73 (0) 3

12 1 (0) 213 1 (0) 3 Self-aligning22 2 (2) 2 ball bearings23 2 (2) 3

NU10 1 0NU2 (0) 2NU22 2 2NU3 NU (0) 3NU23 2 3NU4 (0) 4 Cylindrical

N10 1 0 roller bearingsN2 (0) 2N3 N (0) 3N4 (0) 4

NF2 (0) 2NF3 NF (0) 3

NA48 4 8NA49 NA 4 9 Needle rollerNA59 5 9 bearings

Bearingseries

Typesymbol

Dimension series

widthseries

diameterseries

Bearing type

A-20

Technical Data

Table 3.5 Bore diameter number

Bore Borediameter diameter Remarknumber d mm

/0.6 0.6/1.5 1.5 Slash (/) before bore diameter/2.5 2.5 number

1 1Bore diameter expressed in

9 9 single digits without code

00 1001 12 __________02 1503 17

/22 22/28 28 Slash (/) before bore diameter/32 32 number

04 2005 2506 30 Bore diameter number in double

digits after dividing bore88 440 diameter by 592 46096 480

/500 500/530 530/560 560 Slash (/) before bore diameter

number/2360 2360/2500 2500

Table 3.6 Contact angle code

Code Nominal contact angle Bearing type

A1) Standard 30°B Standard 40° Angular contactC Standard 15° ball bearings

B1) Over 10° Incl. 17°C Over 17° Incl. 24° Tapered rollerD Over 24° Incl. 32° bearings

Note 1) A and B are not usually included in bearing numbers....

...

......

...

A-21

Internalm

odificationsC

ageS

eal orshield

Ring

configurationD

uplexarrangem

ent

Internal clearanceTolerance standard

Lubrication

Code Explanation

C2 Radial internal clearance less than NormalC3 Radial internal clearance greater than NormalC4 Radial internal clearance greater than C3CM Radial internal clearance for electric motor

bearingsNA Non-interchangeable clearance (shown after

clearance code)/GL Light preload/GN Normal preload/GM Medium preload/GH Heavy preload

P6 JIS standard Class 6P6X JIS standard Class 6X (tapered roller brg.)P5 JIS standard Class 5P4 JIS standard Class 4P2 JIS standard Class 22 Class 2 for inch series tapered roller bearings3 Class 3 for inch series tapered roller beaings0 Class 0 for inch series tapered roller bearings

00 Class 00 for inch series tapered roller bearings

/2A Shell Alvania 2 grease/5C Chevron SRI 2/3E ESSO Beacon 325 grease/5K MUL-TEMP SRL

Table 3.7 Supplementary suffix code

Code Explanation

U Internationally interchangeable tapered rollerbearings

R Non-internationally interchangeable taperedroller bearings

ST Low torque tapered roller bearingsHT High axial load use cylindrical roller bearings

L1 Machined Brass cageF1 Machined steel cageG1 Machined brass cage for cylindrical roller

bearings, rivetlessG2 Pin-type steel cage for tapered roller bearingsJ Pressed steel cage

T1 Phenolic cageT2 Plastic cage, nylon or teflon

LLB Synthetic rubber seal (non-contact type)LLU Synthetic rubber seal (contact type)ZZ Shield

ZZA Removable shield

K Tapered inner ring bore, taper 1 : 12K30 Tapered inner ring bore, taper 1 : 30

N Snap ring groove on outer ring, but withoutsnap ring

NR Snap ring on outer ringD Bearings with oil holes

DB Back-to-back arrangementDF Face-to-face arrangementDT Tandem arrangementD2 Two identical paired bearingsG Single bearings, flush ground side face for DB,

DF and DT+α Spacer, (α=nominal width of spacer, mm)

A-22

Technical Data

4. Bearing TolerancesBearing tolerances; i.e., dimensional accuracy, runningaccuracy, etc., are regulated by standards such as ISO andJIS. For dimensional accuracy these standards prescibetolerances and allowable error limitations for those boundrydimensions (bore diameter, outside diameter, width, assembledbearing width, chamfer, and taper) necessary when installingbearings on shafts or in housings. For machining accuracy thestandards provide allowable variation limits on bore, mean bore,outside diameter, mean outside diameter and raceway widthor wall thickness (for thrust bearings). Running accuracy isdefined as the allowable limits for bearing runout. Bearingrunout tolerances are included in the standards for inner andouter ring radial and axial runout; inner ring side runout withbore; and outer ring outside surface runout with side.

Tolerances and allowable error limitations are established foreach tolerance grade or class. For example, JIS standard B1514 (tolerances for rolling bearings) establishes five toleranceclassifications (classes 0, 6, 5, 4, 2).

Starting with class 0 (normal precision class bearings), thebearing precision becomes progressively greater as the classnumber becomes smaller.

A comparison of relative tolerance class standards betweenthe JIS B1514 standard classes and other standards is shownin the comparative Table 4.1.

Table 4.2 indicates which standard and tolerance class isapplicable to each bearing type.

Table 4.1 Comparison of tolerance classifications of national standards

Standard Tolerance Class Bearing Types

Japanese Industrial Class 0Standard JIS B 1514 Class 6X Class 6 Class 5 Class 4 Class 2 All types

Normal classISO 492 Class 6X Class 6 Class 5 Class 4 Class 2 Radial bearings

International ISO 199 Normal class Class 6 Class 5 Class 4 — Thrust ball bearings

Organization for Tapered roller

Standardization ISO 578 Class 4 — Class 3 Class 0 Class 00 bearings (Inch series)

Precision instrumentISO 1224 — — Class 5A Class 4A — bearings

Deutsches Institut

fur Normung DIN 620 P0 P6 P5 P4 P2 All types

Radial bearingsANSI/AFBMA ABEC-1 ABEC-3 ABEC-5 ABEC-7 ABEC-9 (Except tapered

Std. 201) RBEC-1 RBEC-3 RBEC-5 roller bearings)

American National ANSI/AFBMA Tapered roller bear-

Standards Institute Std. 19.1 Class K Class N Class C Class B Class A ings (Metric series)

(ANSI) ANSI B 3.19 Tapered roller

AFBMA Std. 19 Class 4 Class 2 Class 3 Class 0 Class 00 bearings (Inch series)

Anti-Friction Bearing Precision instrument

Manufacturers ANSI/AFBMA __ Class 5P Class 7P ball bearings

(AFBMA) Std. 12.1 Class 3P Class 5T Class 7T Class 9P (Metric series)

Precision instrument

ANSI/AFBMA Class 5P Class 7P ball bearings

Sts. 12.2 — Class 3P Class 5T Class 7T Class 9P (Inch series)

1) “ABEC” is applied for ball bearings and “RBEC” for roller bearings.Notes: 1. JIS B 1514, ISO 492 and 199, and DIN 620 have the same specification level.

2. The tolerance and allowance of JIS B 1514 are a little different from those of AFBMA standards.

A-23

Table 4.2 Bearing types and applicable tolerance

Applicable ToleranceBearing Typestandard

Applicable tolerancetable

Deep groove ball bearing class 0 class 6 class 5 class 4 class 2

Angular contact ball bearings class 0 class 6 class 5 class 4 class 2

Self-aligning ball bearings class 0 — — — —

Cylindrical roller bearings ISO 492 class 0 class 6 class 5 class 4 class 2 Table 4.3

Needle roller bearings class 0 class 6 class 5 class 4 —

Spherical roller bearings class 0 — — — —

Tapered metric ISO 492 class 0,6X class 6 class 5 class 4 — Table 4.4

roller inch AFBMA Std. 19 class 4 class 2 class 3 class 0 class 00 Table 4.5

bearings J series ANSI/AFBMA Std.19.1 class K class N class C class B class A Table 4.6

Thrust ball bearings ISO 199 class 0 class 6 class 5 class 4 — Table 4.7

Page B-219Thrust roller bearings NTN standard class 0 class 6 class 5 class 4 —

Table 2

Spherical roller thrust bearings ISO 199 class 0 — — — — Table 4.8

Double direction angularcontact thrust ball bearings NTN standard — — class 5 class 4 — Table 4.9

The following is a list of codes and symbols used in the bearingtolerance standards tables. However, in some cases the codeor symbol definition has been abbreviated.

(1) Dimension

d : Nominal bore diameterd 2 : Nominal bore diameter (double direction thrust

ball bearing)D : Nominal outside diameterB : Nominal inner ring width or nominal center

washer heightC : Nominal outer ring width1)

Note 1) For radial bearings (except taperedroller bearings) this is equivalent tothe nominal bearing width.

T : Nominal bearing width of single row taperedroller bearing, or nominal height of singledirection thrust bearing

T1 : Nominal height of double direction thrust ballbearing, or nominal effective width of innerring and roller assembly of tapered rollerbearing

T2 : Nominal height from back face of housingwasher to back face of center washer ondouble direction thrust ball bearings, ornominal effective outer ring width of taperedroller bearing

r : Chamfer dimensions of inner and outer rings(for tapered roller bearings, large end of innerrilng only)

r1 : Chamfer dimensions of center washer, orsmall end of inner and outer ring of angularcontact ball bearing, and large end of outerring of tapered roller bearing

r2 : Chamfer dimensions of small end of inner andouter rings of tapered roller bearing

A-24

Technical Data

(2) Dimension deviation

∆ds : Single bore diameter deviation∆dmp : Single plane mean bore diameter deviation

∆d2mp : Single plane mean bore diameter deviation(double direction thrust ball bearing)

∆Ds : Single outside diameter deviation∆Dmp : Single plane mean outside diameter deviation

∆Bs : Inner ring width deviation, or center washerheight deviation

∆Cs : Outer ring width deviation∆Ts : Overall width deviation of assembled single

row tapered roller bearing, or height deviationof single direction thrust bearing

∆T1s : Height deviation of double direction thrust ballbearing, or effective width deviation of rollerand inner ring assembly of tapered rollerbearing

∆T2s : Double direction thrust ball bearing housingwasher back face to center washer back faceheight deviation, or tapered roller bearingouter ring effective width deviation

(3) Chamfer boundry

rs min : Minimum allowable chamfer dimension forinner/outer ring, or small end of inner ring ontapered roller bearing

rs max : Maximum allowable chamfer dimension forinner/outer ring, or large end of inner ring ontapered roller bearing

r1s min : Minimum allowable chamfer dimension fordouble direction thrust ball bearing centerwasher, small end of inner/outer ring ofangular contact ball bearing, large end ofouter ring of tapered roller bearing

r1s max : Maximum allowable chamfer dimension fordouble direction thrust ball bearing centerwasher, small end of inner/outer ring ofangular contact ball bearing, large end ofouter ring of tapered roller bearing

r2s min : Minimum allowable chamfer dimension forsmall end of inner/outer ring of tapered rollerbearing

r2s max : Maximum allowable chamfer dimension forsmall end of inner/outer ring of tapered rollerbearing

(4) Dimension variation

Vdp : Single radial plane bore diameter variationVd2p : Single radial plane bore diameter variation

(double direction thrust ball bearing)Vdmp : Mean single plane bore diameter variation

VDp : Single radial plane outside diameter variationVDmp : Mean single plane outside diameter variation

VBs : Inner ring width variationVCs : Outer ring width variation

(5) Rotation tolerance

Kia : Inner ring radial runoutSia : Inner ring axial runout (with side)Sd : Face runout with bore

Kea : Outer ring radial runoutSea : Outer ring axial runoutSD : Outside surface inclinationSi : Thrust beaing shaft washer raceway (or

center washer raceway) thickness variationSe : Thrust bearing housing washer raceway

thickness variation

A-25

A-26

Technical Data

Table 4.3 Tolerance for radial bearings (Except tapered roller bearings)

Table 4.3 (1) Inner rings

Nominal bore diameter

∆dmp Vdp

d diameter series 7,8,9 diameter series 0,1 diameter series 2,3,4(mm) class 0 class 6 class 5 class 4 1) class 2 1) class 0 class 6 class 5 class 4 class 2 class 0 class 6 class 5 class 4 class 2 class 0 class 6 class 5 class 4 class 2

over inc. high low high low high low high low high low max max max

0.61) 2.5 0 –8 0 –7 0 –5 0 –4 0 –2.5 10 9 5 4 2.5 8 7 4 3 2.5 6 5 4 3 2.52.5 10 0 –8 0 –7 0 –5 0 –4 0 –2.5 10 9 5 4 2.5 8 7 4 3 2.5 6 5 4 3 2.5

10 18 0 –8 0 –7 0 –5 0 –4 0 –2.5 10 9 5 4 2.5 8 7 4 3 2.5 6 5 4 3 2.518 30 0 –10 0 –8 0 –6 0 –5 0 –2.5 13 10 6 5 2.5 10 8 5 4 2.5 8 6 5 4 2.530 50 0 –12 0 –10 0 –8 0 –6 0 –2.5 15 13 8 6 2.5 12 10 6 5 2.5 9 8 6 5 2.550 80 0 –15 0 –12 0 –9 0 –7 0 –4 19 15 9 7 4 19 15 7 5 4 11 9 7 5 480 120 0 –20 0 –15 0 –10 0 –8 0 –5 25 19 10 8 5 25 19 8 6 5 15 11 8 6 5

120 150 0 –25 0 –18 0 –13 0 –10 0 –7 31 23 13 10 7 31 23 10 8 7 19 14 10 8 7150 180 0 –25 0 –18 0 –13 0 –10 0 –7 31 23 13 10 7 31 23 10 8 7 19 14 10 8 7180 250 0 –30 0 –22 0 –15 0 –12 0 –8 38 28 15 12 8 38 28 12 9 8 23 17 12 9 8250 315 0 –35 0 –25 0 –18 — — — — 44 31 18 — — 44 31 14 — — 26 19 14 — —315 400 0 –40 0 –30 0 –23 — — — — 50 38 23 — — 50 38 23 — — 30 23 18 — —400 500 0 –45 0 –35 — — — — — — 56 44 — — — 56 44 — — — 34 26 — — —500 630 0 –50 0 –40 — — — — — — 63 50 — — — 63 50 — — — 38 30 — — —630 800 0 –75 — — — — — — — — 94 — — — — 94 — — — — 55 — — — —800 1000 0 –100 — — — — — — — — 125 — — — — 125 — — — — 75 — — — —

1000 1250 0 –125 — — — — — — — — 155 — — — — 155 — — — — 94 — — — —1250 1600 0 –160 — — — — — — — — 200 — — — — 200 — — — — 120 — — — —

1600 2000 0 –200 — — — — — — — — 250 — — — — 250 — — — — 150 — — — —

1) The dimensional difference ∆ds of bore diameter to be applied for classes 4 and 2 is the same as the tolerance ofdimensional difference ∆dmp

of average bore diameter. However, the dimensional difference is applied to diameter series0,1,2,3 and 4 against Class 4, and also to all the diameter series against Class 2.

Table 4.3 (2) Outer rings

Nominal outside diameter

∆Dmp VDp6)

D diameter series 7,8,9 diameter series 0,1 diameter series 2,3,4(mm) class 0 class 6 class 5 class 4 5) class 2 5)

class 0 class 6 class 5 class 4 class 2 class 0 class 6 class 5 class 4 class 2 class 0 class 6 class 5 class 4 class 2

over inc. high low high low high low high low high low max max max

2.5 8) 6 0 –8 0 –7 0 –5 0 –4 0 –2.5 10 9 5 4 2.5 8 7 4 3 2.5 6 5 4 3 2.56 18 0 –8 0 –7 0 –5 0 –4 0 –2.5 10 9 5 4 2.5 8 7 4 3 2.5 6 5 4 3 2.5

18 30 0 –9 0 –8 0 –6 0 –5 0 –4 12 10 6 5 4 9 8 5 4 4 7 6 5 4 430 50 0 –11 0 –9 0 –7 0 –6 0 –4 14 11 7 6 4 11 9 5 5 4 8 7 5 5 450 80 0 –13 0 –11 0 –9 0 –7 0 –4 16 14 9 7 4 13 11 7 5 4 10 8 7 5 480 120 0 –15 0 –13 0 –10 0 –8 0 –5 19 16 10 8 5 19 16 8 6 5 11 10 8 6 5

120 150 0 –18 0 –15 0 –11 0 –9 0 –5 23 19 11 9 5 23 19 8 7 5 14 11 8 7 5150 180 0 –25 0 –18 0 –13 0 –10 0 –7 31 23 13 10 7 31 23 10 8 7 19 14 10 8 7180 250 0 –30 0 –20 0 –15 0 –11 0 –8 38 25 15 11 8 38 25 11 8 8 23 15 11 8 8250 315 0 –35 0 –25 0 –18 0 –13 0 –8 44 31 18 13 8 44 31 14 10 8 26 19 14 10 8315 400 0 –40 0 –28 0 –20 0 –15 0 –10 50 35 20 15 10 50 35 15 11 10 30 21 15 11 10400 500 0 –45 0 –33 0 –23 — — — — 56 41 23 — — 56 41 17 — — 34 25 17 — —500 630 0 –50 0 –38 0 –28 — — — — 63 48 28 — — 63 48 21 — — 38 29 21 — —630 800 0 –75 0 –45 0 –35 — — — — 94 56 35 — — 94 56 26 — — 55 34 26 — —800 1000 0 –100 0 –60 — — — — — — 125 75 — — — 125 75 — — — 75 45 — — —

1000 1250 0 –125 — — — — — — — — 155 — — — — 155 — — — — 94 — — — —1250 1600 0 –160 — — — — — — — — 200 — — — — 200 — — — — 120 — — — —1600 2000 0 –200 — — — — — — — — 250 — — — — 250 — — — — 150 — — — —2000 2500 0 –250 — — — — — — — — 310 — — — — 310 — — — — 190 — — — —

5) The dimensional difference ∆Ds of outer diameter to be applied for classes 4 and 2 is the same as the tolerance of

dimensional difference ∆Dmp of average outer diameter. However, the dimensional difference is applied to diameter series

0,1,2,3 and 4 against Class 4, and also to all the diameter series against Class 2.

open type

maxmaxmax

A-27

Unit µm

Vdp

class0

max

class6

class5

class4

class2

Kia

max

Sd

max

Sia2)

max

class0

class6

class5

class4

class2

class5

class4

class2

class5

class4

class2

VBs

max

class0

class6

class5

class4

class2

high low

class 0,6

∆Bs

high low

class 5,4

high low

class 2

high low

class 0,6

high low

class 5,4normal modified 3)

6 5 3 2 1.5 10 5 4 2.5 1.5 7 3 1.5 7 3 1.5 0 –40 0 –40 0 –40 — — 0 –250 12 12 5 2.5 1.56 5 3 2 1.5 10 6 4 2.5 1.5 7 3 1.5 7 3 1.5 0 –120 0 –40 0 –40 0 –250 0 –250 15 15 5 2.5 1.56 5 3 2 1.5 10 7 4 2.5 1.5 7 3 1.5 7 3 1.5 0 –120 0 –80 0 –80 0 –250 0 –250 20 20 5 2.5 1.58 6 3 2.5 1.5 13 8 4 3 2.5 8 4 1.5 8 4 2.5 0 –120 0 –120 0 –120 0 –250 0 –250 20 20 5 2.5 1.59 8 4 3 1.5 15 10 5 4 2.5 8 4 1.5 8 4 2.5 0 –120 0 –120 0 –120 0 –250 0 –250 20 20 5 3 1.5

11 9 5 3.5 2 20 10 5 4 2.5 8 5 1.5 8 5 2.5 0 –150 0 –150 0 –150 0 –380 0 –250 25 25 6 4 1.515 11 5 4 2.5 25 13 6 5 2.5 9 5 2.5 9 5 2.5 0 –200 0 –200 0 –200 0 –380 0 –380 25 25 7 4 2.519 14 7 5 3.5 30 18 8 6 2.5 10 6 2.5 10 7 2.5 0 –250 0 –250 0 –250 0 –500 0 –380 30 30 8 5 2.519 14 7 5 3.5 30 18 8 6 5 10 6 4 10 7 5 0 –250 0 –250 0 –300 0 –500 0 –380 30 30 8 5 423 17 8 6 4 40 20 10 8 5 11 7 5 13 8 5 0 –300 0 –300 0 –350 0 –500 0 –500 30 30 10 6 526 19 9 — — 50 25 13 — — 13 — — 15 — — 0 –350 0 –350 — — 0 –500 0 –500 35 35 13 — —30 23 12 — — 60 30 15 — — 15 — — 20 — — 0 –400 0 –400 — — 0 –630 0 –630 40 40 15 — —34 26 — — — 65 35 — — — — — — — — — 0 –450 — — — — — — — — 50 45 — — —38 30 — — — 70 40 — — — — — — — — — 0 –500 — — — — — — — — 60 50 — — —55 — — — — 80 — — — — — — — — — — 0 –750 — — — — — — — — 70 — — — —75 — — — — 90 — — — — — — — — — — 0 –1000 — — — — — — — — 80 — — — —94 — — — — 100 — — — — — — — — — — 0 –1250 — — — — — — — — 100 — — — —

120 — — — — 120 — — — — — — — — — — 0 –1600 — — — — — — — — 120 — — — —150 — — — — 140 — — — — — — — — — — 0 –2000 — — — — — — — — 140 — — — —

2) To be applied for deep groove ball bearings and angular contact ball bearings.3) To be applied for individual raceway rings manufactured for combined bearing use.4) Nominal bore diameter of bearings of 0.6 mm is included in this dimensional division.

Unit µm

VDmp

class0

max

class6

class5

class4

class2

Kea

max

SD

max

Sea

max

class0

class6

class5

class4

class2

class5

class4

class2

class5

class4

class2

VCs∆CsVDp6)

capped bearingsdiameter series

class 6 class 0max

all type

Identical to

∆Bs of innerring of samebearing

Identical to

∆Bs and VBsof inner ring ofsame bearing

max

class5

class4

class2class 0,6

10 9 6 5 3 2 1.5 15 8 5 3 1.5 8 4 1.5 8 5 1.5 5 2.5 1.510 9 6 5 3 2 1.5 15 8 5 3 1.5 8 4 1.5 8 5 1.5 5 2.5 1.512 10 7 6 3 2.5 2 15 9 6 4 2.5 8 4 1.5 8 5 2.5 5 2.5 1.516 13 8 7 4 3 2 20 10 7 5 2.5 8 4 1.5 8 5 2.5 5 2.5 1.520 16 10 8 5 3.5 2 25 13 8 5 4 8 4 1.5 10 5 4 6 3 1.526 20 11 10 5 4 2.5 35 18 10 6 5 9 5 2.5 11 6 5 8 4 2.530 25 14 11 6 5 2.5 40 20 11 7 5 10 5 2.5 13 7 5 8 5 2.538 30 19 14 7 5 3.5 45 23 13 8 5 10 5 2.5 14 8 5 8 5 2.5— — 23 15 8 6 4 50 25 15 10 7 11 7 4 15 10 7 10 7 4— — 26 19 9 7 4 60 30 18 11 7 13 8 5 18 10 7 11 7 5— — 30 21 10 8 5 70 35 20 13 8 13 10 7 20 13 8 13 8 7— — 34 25 12 — — 80 40 23 — — 15 — — 23 — — 15 — —— — 38 29 14 — — 100 50 25 — — 18 — — 25 — — 18 — —— — 55 34 18 — — 120 60 30 — — 20 — — 30 — — 20 — —— — 75 45 — — — 140 75 — — — — — — — — — — — —— — 94 — — — — 160 — — — — — — — — — — — — —— — 120 — — — — 190 — — — — — — — — — — — — —— — 150 — — — — 220 — — — — — — — — — — — — —— — 190 — — — — 250 — — — — — — — — — — — — —

6) To be applied in case snap rings are not installed on the bearings.7) To be applied for deep groove ball bearings and angular contact ball bearings.8) Nominal outer diameter of bearings of 2.5 mm is included in this dimensional division.

A-28

Technical Data

18 30 0 –12 0 –8 0 –6 12 8 6 5 9 6 5 4 18 9 6 4 8 430 50 0 –14 0 –9 0 –7 14 9 7 5 11 7 5 5 20 10 7 5 8 450 80 0 –16 0 –11 0 –9 16 11 8 7 12 8 6 5 25 13 8 5 8 480 120 0 –18 0 –13 0 –10 18 13 10 8 14 10 7 5 35 18 10 6 9 5

120 150 0 –20 0 –15 0 –11 20 15 11 8 15 11 8 6 40 20 11 7 10 5150 180 0 –25 0 –18 0 –13 25 18 14 10 19 14 9 7 45 23 13 8 10 5180 250 0 –30 0 –20 0 –15 30 20 15 11 23 15 10 8 50 25 15 10 11 7250 315 0 –35 0 –25 0 –18 35 25 19 14 26 19 13 9 60 30 18 11 13 8315 400 0 –40 0 –28 0 –20 40 28 22 15 30 21 14 10 70 35 20 13 13 10400 500 0 –45 — — — — 45 — — — 34 — — — 80 — — — — —500 630 0 –50 — — — — 50 — — — 38 — — — 100 — — — — —630 800 0 –75 — — — — 75 — — — 56 — — — 120 — — — — —800 1000 0 –100 — — — — 100 — — — 75 — — — 140 — — — — —

1000 1250 0 –125 — — — — 125 — — — 84 — — — 165 — — — — —1250 1600 0 –160 — — — — 160 — — — 120 — — — 190 — — — — —

Table 4.4 Tolerance for tapered roller bearings (Metric system)


1) The dimensional difference ∆ds of bore diameter to be applied for class 4 is the same as the tolerance of dimensionaldifference ∆dmp

of average bore diameter.

∆dmpNominal borediameter Kia

max

Sd

class0, 6X

class6

class5

class4

high low

class 0,6X

low

class 5,6

high low

class 41)d

(mm)over incl.

Vdp

high max

class0, 6X

class6

class5

class4

Vdmp

max

class0, 6X

class6

class5

class4

max

class5

class4

10 18 0 –12 0 –7 0 –5 12 7 5 4 9 5 5 4 15 7 5 3 7 318 30 0 –12 0 –8 0 –6 12 8 6 5 9 6 5 4 18 8 5 3 8 430 50 0 –12 0 –10 0 –8 12 10 8 6 9 8 5 5 20 10 6 4 8 450 80 0 –15 0 –12 0 –9 15 12 9 7 11 9 6 5 25 10 7 4 8 580 120 0 –20 0 –15 0 –10 20 15 11 8 15 11 8 5 30 13 8 5 9 5

120 180 0 –25 0 –18 0 –13 25 18 14 10 19 14 9 7 35 18 11 6 10 6180 250 0 –30 0 –22 0 –15 30 22 17 11 23 16 11 8 50 20 13 8 11 7250 315 0 –35 — — — — 35 — — — 26 — — — 60 — — — — —315 400 0 –40 — — — — 40 — — — 30 — — — 70 — — — — —400 500 0 –45 — — — — 45 — — — 34 — — — 80 — — — — —500 630 0 –50 — — — — 50 — — — 38 — — — 90 — — — — —630 800 0 –75 — — — — 75 — — — 56 — — — 105 — — — — —800 1000 0 –100 — — — — 100 — — — 75 — — — 120 — — — — —


2) The dimensional difference ∆Ds of outside diameter to be applied for class 4 is the same as the tolerance of dimensional

difference ∆Dmp of average outside diameter.

∆Dmp Kea

max

SD

class0, 6X

class6

class5

class4

high low

class 0,6X

low

class 5,6

high low

class 42)D

(mm)over incl.

VDp

high max

class0, 6X

class6

class5

class4

VDmp

max

class0, 6X

class6

class5

class4

max

class5

class4

Nominal borediameter

A-29

5 0 –1005 0 –1005 0 –1006 0 –1007 0 –1008 0 –100

10 0 –10010 0 –10013 0 –100— 0 –100— 0 –100— — —— — —— — —— — —

Unit µm

∆Bs

high low

class 0,6

low

class 6X

high low

class 4, 5

high

Sia

class 4

max

∆Ts

high low

class 0,6

low

class 6X

high low

class 4, 5

high

∆B1s, ∆C1s

high low

class 4, 5

∆B2s, ∆C2s

high low

class 4, 5

3 0 –120 0 –50 0 –200 +200 0 +100 0 +200 –200 — — — —4 0 –120 0 –50 0 –200 +200 0 +100 0 +200 –200 — — — —4 0 –120 0 –50 0 –240 +200 0 +100 0 +200 –200 +240 –240 — —4 0 –150 0 –50 0 –300 +200 0 +100 0 +200 –200 +300 –300 — —5 0 –200 0 –50 0 –400 +200 –200 +100 0 +200 –200 +400 –400 +500 –5007 0 –250 0 –50 0 –500 +350 –250 +150 0 +350 –250 +500 –500 +600 –6008 0 –300 0 –50 0 –600 +350 –250 +150 0 +350 –250 +600 –600 +750 –750— 0 –350 0 –50 — — +350 –250 -200 0 — — +700 –700 +900 –900— 0 –400 0 –80 — — +400 –400 +200 0 — — +800 –800 +1000 –1000— 0 –450 — — — — — — — — — — +900 –900 +1200 –1200— 0 –500 — — — — — — — — — — +1000 –1000 +1200 –1200— 0 –750 — — — — — — — — — — +1500 –1500 +1500 –1500— 0 –1000 — — — — — — — — — — +1500 –1500 +1500 –1500

high

∆Cs

high low

class 0, 6, 5, 4

low

class 6X

high

Sea

class 4

max

Identical to

∆Bs of innerring of samebearing

Table 4.4 (3) Effective width of outer and inner rings with roller Unit µm

d(mm)

over incl.


low

class 0

high low

class 6X

high low

class 0

high low

class 6X

high

∆T1s ∆T2s

10 18 +100 0 +50 0 +100 0 +50 018 30 +100 0 +50 0 +100 0 +50 030 50 +100 0 +50 0 +100 0 +50 0

50 80 +100 0 +50 0 +100 0 +50 080 120 +100 -100 +50 0 +100 -100 +50 0

120 180 +150 -150 +50 0 +200 -100 +100 0

180 250 +150 -150 +50 0 +200 -100 +100 0250 315 +150 -150 +100 0 +200 -100 +100 0315 400 +200 -200 +100 0 +200 -200 +100 0

Master cupsub-unit

Master conesub-unit

T1 T2

d d

A-30

Technical Data

— 101.6 +203 0 +203 0 +203 –203 +203 –203 +1520 –1520— 4 +80 0 +80 0 +80 –80 +80 –80 +599 –599

101.6 304.8 +356 –254 +203 0 +203 –203 +203 –203 +1520 –15204 12 +140 –100 +80 0 +80 –80 +80 –80 +599 –599

304.8 609.6 — 508.0 +381 –381 +381 –381 +203 –203 — — +1520 –152012 24 — 20 +150 –150 +150 –150 +80 –80 — — +599 –599

304.8 609.6 508.0 — +381 –381 +381 –381 +381 –381 — — +1520 –152012 24 20 — +150 –150 +150 –150 +150 –150 — — +599 –599

Table 4.5 Tolerance for tapered roller bearings of inch system


d(mm, inch)

over incl.


low

Class 4

high

∆ds

low

Class 2

high low

Class 3

high low

Class 0

high low

Class 00

high

— 76.2 +13 0 +13 0 +13 0 +13 0 +8 0— 3 +5 0 +5 0 +5 0 +5 0 +3 0

76.2 304.8 +25 0 +25 0 +13 0 +13 0 +8 03 12 +10 0 +10 0 +5 0 +5 0 +3 0


D(mm, inch)

over incl.

Nominal outsidediameter

incl.

Class 4

over

∆Ds

incl.

Class 2

over incl.

Class 3

over incl.

Class 0

over incl.

Class 00

over

Unit µm0.0001 inch

Unit µm0.0001 inch

— 304.8 +25 0 +25 0 +13 0 +13 0 +8 0— 12 +10 0 +10 0 +5 0 +5 0 +3 0

304.8 609.6 +51 0 +51 0 +25 0 — — — —12 24 +20 0 +20 0 +10 0 — — — —

Table 4.5 (3) Effective width of inner rings with roller and outer rings

d(mm, inch)

over incl.


low

Class 4

∆Ts

low

Class 2

high low

Class 3

high low

Class 0, 00

high

Unit µm0.0001 inch

D(mm, inch)

over incl.

Nominal outsidediameter ∆B2s, ∆C2s

low

Class 4, 2, 3, 0

highhigh

Table 4.5 (4) Radial deflection of inner and outer rings

D(mm, inch)

over incl.


Class 4

K ia, Kea

Class 2 Class 3 Class 0 Class 00

Unit µm0.0001 inch

— 304.8 51 38 8 4 2— 12 20 15 3 1.5 0.75

304.8 609.6 51 38 18 — —12 24 20 15 7 — —

A-31

low

Class 4

high

∆T1s

low

Class 2

high low

Class 3

high

Unit µm0.0001 inch

low

Class 4

high

∆T2s

low

Class 2

high low

Class 3

high

+102 0 +102 0 +102 –102 +102 0 +102 0 +102 –102+40 0 +40 0 +40 –40 +40 0 +40 0 +40 –40

+152 –152 +102 0 +102 –102 +203 –102 +102 0 +102 –102+60 –60 +40 0 +40 –40 +80 –40 +40 0 +40 –40

— — +178 –1781) +102 –1021) — — +203 –2031) +102 –1021)

— — +70 –70 +40 –40 — — +80 –80 +40 –40

— — — — — — — — — — — —— — — — — — — — — — — —

1) To be applied for nominal bore diameters of 406.400 mm 16 inch or less.

Master cupsub-unit

Master conesub-unit

T1 T2

d d

A-32

Technical Data

10 18 0 –12 0 –12 0 –7 0 –5 12 12 4 3 9 9 5 418 30 0 –12 0 –12 0 –8 0 –6 12 12 4 3 9 9 5 430 50 0 –12 0 12 0 –10 0 –8 12 12 4 3 9 9 5 550 80 0 –15 0 –15 0 –12 0 –9 15 15 5 3 11 11 5 580 120 0 –20 0 –20 0 –15 0 –10 20 20 5 3 15 15 5 5

120 180 0 –25 0 –25 0 –18 0 –13 25 25 5 3 19 19 5 7180 250 0 –30 0 –30 0 –22 0 –15 30 30 6 4 23 23 5 8

Table 4.6 Tolerance of tapered roller bearings of J series (Metric system)


d(mm)

over incl.


low

Class K

high

∆dmp

low

Class N

high low

Class C

high low

Class B

high max

Class K Class N Class C Class B

max


Vdp Vdmp

Note: Please consult NTN for bearings of Class A


D(mm)

over incl.


low

Class K

high

∆Dmp

low

Class N

high low

Class C

high low

Class B

high max


max


VDp VDmp

Note: Please consult NTN for bearings of Class A

18 30 0 –12 0 –12 0 –8 0 –6 12 12 4 3 9 9 5 430 50 0 –14 0 –14 0 –9 0 –7 14 14 4 3 11 11 5 550 80 0 –16 0 –16 0 –11 0 –9 16 16 4 3 12 12 6 580 120 0 –18 0 –18 0 –13 0 –10 18 18 5 3 14 14 7 5

120 150 0 –20 0 –20 0 –15 0 –11 20 20 5 3 15 15 8 6150 180 0 –25 0 –25 0 –18 0 –13 25 25 5 3 19 19 9 7180 250 0 –30 0 –30 0 –20 0 –15 30 30 6 4 23 23 10 8250 315 0 –35 0 –35 0 –25 0 –18 35 35 8 5 26 26 13 9315 400 0 –40 0 –40 0 –28 0 –20 40 40 10 5 30 30 14 10

Table 4.6 (3) Effective width of inner and outer rings

d(mm)

over incl.


low

Class K

high

∆T1s

low

Class N

high low

Class C

high low

Class B

high

Note: 1) “❋” mark are to be manufactured only for combined bearings.2) Please consult NTN for the bearings of Class A.

low

Class K

high

∆T2s

low

Class N

high low

Class C

high low

Class B

high

10 80 +100 0 +50 0 +100 –100 ❋ ❋ +100 0 +50 0 +100 –100 ❋ ❋

80 120 +100 –100 +50 0 +100 –100 ❋ ❋ +100 –100 +50 0 +100 –100 ❋ ❋

120 180 +150 –150 +50 0 +100 –100 ❋ ❋ +200 –100 +100 0 +100 –150 ❋ ❋

180 250 +150 –150 +50 0 +100 –150 ❋ ❋ +200 –100 +100 0 +100 –150 ❋ ❋

A-33

15 15 5 3 3 +200 0 +100 0 +200 –200 +200 –20018 18 5 3 4 +200 0 +100 0 +200 –200 +200 –20020 20 6 4 4 +200 0 +100 0 +200 –200 +200 –20025 25 6 4 4 +200 0 +100 0 +200 –200 +200 –20030 30 6 5 5 +200 –200 +100 0 +200 –200 +200 –20035 35 8 6 7 +350 –250 +150 0 +200 –250 +200 –25050 50 10 8 8 +350 –250 +150 0 +200 –300 +200 –300

Class K

K ia

Unit µm

max

Class N Class C Class B

low

Class K

high

∆Ts

low

Class N

high low

Class C

high

Class B

high low

K ia

max

Class B

Class K

K ea

Unit µm

max

Class N Class C Class B

Sea

max

Class B

18 18 5 3 320 20 6 3 325 25 6 4 435 35 6 4 440 40 7 4 445 45 8 4 550 50 10 5 660 60 11 5 670 70 13 5 6

Master cupsub-unit

Master conesub-unit

T1 T2

d d

A-34

Technical Data

10 18 0 –11 0 –7 8 518 30 0 –13 0 –8 10 630 50 0 –16 0 –9 12 750 80 0 –19 0 –11 14 880 120 0 –22 0 –13 17 10

120 180 0 –25 0 –15 19 11180 250 0 –30 0 –20 23 15250 315 0 –35 0 –25 26 19315 400 0 –40 0 –28 30 21400 500 0 –45 0 –33 34 25500 630 0 –50 0 –38 38 29630 800 0 –75 0 –45 55 34

— 18 0 –8 0 –7 6 5 10 5 3 218 30 0 –10 0 –8 8 6 10 5 3 230 50 0 –12 0 –10 9 8 10 6 3 250 80 0 –15 0 –12 11 9 10 7 4 380 120 0 –20 0 –15 15 11 15 8 4 3

120 180 0 –25 0 –18 19 14 15 9 5 4180 250 0 –30 0 –22 23 17 20 10 5 4250 315 0 –35 0 –25 26 19 25 13 7 5315 400 0 –40 0 –30 30 23 30 15 7 5400 500 0 –45 0 –35 34 26 30 18 9 6500 630 0 –50 0 –40 38 30 35 21 11 7

Table 4.7 Tolerance of thrust ball bearings


d or d2(mm)

over incl.


low

Class 0, 6, 5

high

∆dmp, ∆d2mp

low

Class 4

max

Class 0, 6, 5 Class 4

max

Class 0 Class 6 Class 5 Class 4

Vdp, Vd2p S i1 )

1) The division of double direction type bearings will be in accordance with division “d” of single direction type bearingscorresponding to the identical nominal outer diameter of bearings, not according to division “d2”.

Unit µm

high


D(mm)

over incl.


low

Class 0, 6, 5

high

∆Dmp

low

Class 4

max

Class 0, 6, 5 Class 4

max

Class 0, Class 6, Class 5, Class 4

VDp Se2)

2) To be applied only for bearings with flat seats.

Unit µm

high

According to the toleranceof S1 against “d” or “d2”of the same bearings

Class K

A-35

120 180 0 –25180 250 0 –30250 315 0 –35315 400 0 –40400 500 0 –45500 630 0 –50630 800 0 –75800 1000 0 –100

— 30 0 –75 +50 –150 0 –75 0 –5030 50 0 –100 +75 –200 0 –100 0 –7550 80 0 –125 +100 –250 0 –125 0 –10080 120 0 –150 +125 –300 0 –150 0 –125

120 180 0 –175 +150 –350 0 –175 0 –150180 250 0 –200 +175 –400 0 –200 0 –175250 315 0 –225 +200 –450 0 –225 0 –200315 400 0 –300 +250 –600 0 –300 0 –250400 500 0 –350 — — — — — —500 630 0 –400 — — — — — —

Table 4.7 (3) Height of bearings center washer

d(mm)

over incl.


lowhigh low

3) To be in accordance with division “d” of single direction type bearings corresponding to the identical outer diameter ofbearings in the same bearing series.

Note: The specifications will be applied for the bearings with flat seats of Class 0.

Unit µm

high

∆Ts

Single direction type

lowhigh lowhigh

∆T1s3)

Double direction type

∆T2s3) ∆Cs

3)

Table 4.8 Tolerance of spherical thrust roller bearings


d(mm)

over incl.


lowhigh

∆dmp

lowmax max

Vdp Sd

Unit µm

high

∆Ts

50 80 0 –15 11 25 +150 –15080 120 0 –20 15 25 +200 –200

120 180 0 –25 19 30 +250 –250180 250 0 –30 23 30 +300 –300250 315 0 –35 26 35 +350 –350315 400 0 –40 30 40 +400 –400400 500 0 –45 34 45 +450 –450


D(mm)

over incl.


lowhigh

∆Dmp

Unit µm

A-36

Technical Data

30 50 –30 –40 8 4 5 2.550 80 –40 –50 8 4 6 380 120 –50 –60 9 5 8 4

120 150 –60 –75 10 5 8 5150 180 –60 –75 10 5 8 5180 250 –75 –90 11 7 10 7250 315 –90 –105 13 8 11 7315 400 –110 –125 13 10 13 840 500 –120 –140 15 13 15 10

18 30 0 –6 0 –5 8 4 5 3 5 2.5 0 –30030 50 0 –8 0 –6 8 4 5 3 5 3 0 –40050 80 0 –9 0 –7 8 5 6 5 6 4 0 –50080 120 0 –10 0 –8 9 5 6 5 7 4 0 –600

120 180 0 –13 0 –10 10 6 8 6 8 5 0 –700180 250 0 –15 0 –12 11 7 8 6 10 6 0 –800250 315 0 –18 0 –15 13 8 10 8 13 7 0 –900315 400 0 –23 0 –18 15 9 13 10 15 9 0 –1000

Table 4.9 Tolerance of double direction type angular contact thrust ball bearings

Table 4.9 (1) Inner rings and bearing height

d(mm)

over incl.


lowhigh lowmax

VBsSd

Unit µm

high

∆Ts∆dmp, ∆ds

Class 5lowhigh

Class 4 Class 5 Class 4max

S ia

Class 5 Class 4max

Class 5 Class 4 Class 5, Class 4


D(mm)

over incl.


lowhigh max

VCsSD

Unit µm

∆Dmp, ∆Ds

Class 5 Class 4 Class 5 Class 4max

S ea

Class 5 Class 4max

Class 5 Class 4

According totolerance of S

ia

against “d” of thesame bearings

A-37

0.05 — — 0.1 0.20.08 — — 0.16 0.30.1 — — 0.2 0.40.15 — — 0.3 0.60.2 — — 0.5 0.80.3 — 40 0.6 1

40 — 0.8 10.6 — 40 1 2

40 — 1.3 21 — 50 1.5 3

50 — 1.9 31.1 — 120 2 3.5

120 — 2.5 41.5 — 120 2.3 4

120 — 3 5— 80 3 4.5

2 80 220 3.5 5220 — 3.8 6

2.1 — 280 4 6.5280 — 4.5 7

— 100 3.8 62.5 100 280 4.5 6

280 — 5 73 — 280 5 8

280 — 5.5 84 — — 6.5 95 — — 8 106 — — 10 137.5 — — 12.5 179.5 — — 15 19

12 — — 18 2415 — — 21 3019 — — 25 38

Table 4.10 Allowable critical-value of bearing chamfer

Table 4.10 (1) Radial bearings(Except tapered roller bearings)

dover incl.


Unit mm

Radialdirection

r s max

Axialdirection

r s min1)

1) These are the allowable minimum dimensions of thechamfer dimension “r” and are described in thedimensional table.

rs min or r1s min

rs min r1s min

rs max r1s max

r s m

inr 1

s m

in

r s m

axr 1

s m

ax

or

or

or

or

(Axial direction)

(Rad

ial d

irect

ion)

Bore diameter face ofbearing or outer diameter

face of bearing

Side face of inner ring orcenter washer, or sideface of outer ring

A-38

Technical Data

0.3 — 40 0.7 1.4

40 — 0.9 1.6

0.6 — 40 1.1 1.7

40 — 1.3 2

1 — 50 1.6 2.5

50 — 1.9 3

— 120 2.8 4

1.5 120 250 2.8 3.5

250 — 3.5 4

— 120 2.8 4

2 120 250 3.5 4.5

250 — 4 5

— 120 3.5 5

2.5 120 250 4 5.5

250 — 4.5 6

— 120 4 5.5

3 120 250 4.5 6.5

250 400 5 7

400 — 5.5 7.5

— 120 5 7

4 120 250 5.5 7.5

250 400 6 8

400 — 6.5 8.5

5 — 180 6.5 8

180 — 7.5 9

6 — 180 7.5 10

180 — 9 11

0.05 0.1

0.08 0.16

0.1 0.2

0.15 0.3

0.2 0.5

0.3 0.8

0.6 1.5

1 2.2

1.1 2.7

1.5 3.5

2 4

2.1 4.5

3 5.5

4 6.5

5 8

6 10

7.5 12.5

9.5 15

12 18

15 21

19 25

Table 4.10 (2) Tapered roller bearings of metric system

over incl.

Nominal borediameter of

bearing “d” ornominal outside

diameter “D”

Unit mm

Radialdirection

r s max or r1s max

Axialdirection

r s min2)

or r1s min

2) These are the allowable minimum dimensions of thechamfer dimension “r” or “r1” and are described in thedimensional table.

3) Inner rings shall be in accordance with the division of“d” and outer rings with that of “D”.

Note: This standard will be applied to the bearings whosedimensional series (refer to the dimensional table)specified in the standard of ISO 355 or JIS B 1512.Further, please consult NTN for bearings other thanthose represented here.

Table 4.10 (3) Thrust bearings Unit mm

Radial and axial direction

r s max or r 1s maxr s min or r1s min

4)

4) These are the allowable minimum dimensions of thechamfer dimension “r” or “r1” and are described in thedimensional table.

rs min or r1s min

rs min r1s min

rs max r1s max

r s m

inr 1

s m

in

r s m

axr 1

s m

ax

or

or

or

or

(Axial direction)

(Rad

ial d

irect

ion)

Bore diameter face ofbearing or outer diameter

face of bearing

Side face of inner ring orcenter washer, or sideface of outer ring

A-39

— 10 +15 0 +15 0 1010 18 +18 0 +18 0 1018 30 +21 0 +21 0 1330 50 +25 0 +25 0 1550 80 +30 0 +30 0 1980 120 +35 0 +35 0 25

120 180 +40 0 +40 0 31180 250 +46 0 +46 0 38250 315 +52 0 +52 0 44315 400 +57 0 +57 0 50400 500 +63 0 +63 0 56

Table 4.11 Tolerance and allowable values (Class 0) of taperedbore of radial bearings

d(mm)

over incl.


lowhigh

Vdp1)

Unit µm

∆dmp

lowhigh

∆d1mp–∆dmp

max

1) To be applied for all radial flat surfaces of tapered bore.

Note: 1. To be applied for tapered bores of 1/12.2. Symbols of quantity or valuesd1: Basic diameter at the theoretically large end

of the tapered bore

∆dmp: Dimensional difference of the average bore diameterwithin the flat surface at the theoretical small-end ofthe tapered bore.

∆d1mp: Dimensional difference of the average bore diameterwithin the flat surface at the theoretical large-end ofthe tapered bore.

Vdp: Inequality of the bore diameter within the flat surfaceB: Nominal width of inner ringα: Half of the nominal tapered angle of the tapered bore

α = 2°23’9.4” = 2.38594° = 0.041643 RAD

d d B1

112

= +

d+∆dm d+∆dmpd1+∆d1mp

2α

B

2α

B

d d1

Tapered bore with dimensionalwithin a flat plane tolerance

Theoretical tapered hole

A-40

Technical Data

5. Load Rating and Life

5.1 Bearing life

Even in bearings operating under normal conditions, thesurfaces of the raceway and rollling elements are constantlybeing subjected to repeated compressive stresses whichcauses flaking of these surfaces to occur. This flaking is dueto material fatigue and will eventually cause the bearings tofail. The effective life of a bearing is usually defined in terms ofthe total number of revolutions a bearing can undergo beforeflaking of either the raceway surface or the rolling elementsurfaces occurs.

Other causes of bearing failure are often attributed to problemssuch as seizing, abrasions, cracking, chipping, gnawing, rust,etc. However, these so called “causes” of bearing failure areusually themselves caused by improper installation, insufficientor improper lubrication, faulty sealing or inaccurate bearingselection. Since the above mentioned “causes” of bearingfailure can be avoided by taking the proper precautions, andare not simply caused by material fatigue, they are consideredseparately from the flaking aspect.

5.2 Basic rated life and basicdynamic load ratingA group of seemingly identical bearings when subjected toindentical load and operating conditions will exhibit a widediversity in their durability.

This “life” disparity can be accounted for by the difference inthe fatigue of the bearing material itself. This disparity isconsidered statistically when calculating bearing life, and thebasic rated life is defined as follows.

The basic rated life is based on a 90% statistical model whichis expressed as the total number of revolutions 90% of thebearings in an identical group of bearings subjected to identicaloperating conditions will attain or surpass before flaking dueto material fatigue occurs. For bearings operating at fixedconstant speeds, the basic rated life (90% reliability) isexpressed in the total number of hours of operation.

The basic dynamic load rating is an expression of the loadcapacity of a bearing based on a constant load which thebearing can sustain for one million revolutions (the basic liferating). For radial bearings this rating applies to pure radialloads, and for thrust bearings it refers to pure axial loads. Thebasic dynamic load ratings given in the bearing tables of thiscatalog are for bearings constructed of NTN standard bearingmaterials, using standard manufacturing techniques. Pleaseconsult NTN for basic load ratings of bearings constructed ofspecial materials or using special manufacturing techniques.

The relationship between the basic rated life, the basic dynamicload rating and the bearing load is given in formula (5.1).

………………………………………(5.1)

where,LC

P

p

10 =

40000

4.6

60000

80000

30000

20000

15000

3

100002.5

8000

6000

4000

3000

2000

3.5

4.5

2

4

1500

1000

1.0

0.76200

100

60000

40000

30000

20000

15000

100000.20

8000

6000

4000

3000

2000

1500

1000

1.0

1.4410

60000

5.480000

5

40000

430000

20000

150003

10000

6000

24000

3000

2000

1500

1000

1.0

0.742001.4910

40000

60000

300000.10

20000

15000

100008000

8000

6000

4000

3000

2000

1500

1000

0.20

100

1.0

1.9

1.8

1.7

1.6

1.5

1.4

1.3

1.2

1.1

900

800

700

600

500

4000.95

0.90

300 0.85

0.80

0.6

0.106

0.12

0.14

0.16

0.18

0.22

0.24

0.26

0.28

0.30

0.35

0.4800

600

0.5

400

300

200

150

0.7

80

600.8

0.9

40

30

1.1

1.3

20

15

1.4

1.2

4.5

3.5

2.5

1.9

1.8

1.7

1.6

1.5

1.4

1.3

1.2

800

900

7001.1

600

500

4000.95

0.90

0.85300

0.80

0.75

0.082

0.09

0.12

0.14

0.16

0.18

800

600

400

300

200

150

0.22

0.24

0.26

0.28

0.30

0.35

0.4

0.5

0.6

0.7

0.8

80

60

40

30

20

0.9

1.1

1.2

1.3

1.4

15

fnn L10h

rpm hfh n L10hfn

rpm hfh

Ball bearings Roller bearings

Fig. 5.1 Bearing life rating scale

A-41

p = 3………………………For ball bearings

p = 10/3………………………For roller bearings

L10 : Basic rated life 10 revolutions

C : Basic dynamic rated load N(Cr : radial bearings, Ca : thrust bearings)

P : Equivalent dynamic load N(Pr : radial bearings, Pa : thrust bearings)

The basic rated life can also be expressed in terms of hours ofoperation (revolution), and is calculated as shown in formula(5.2).

where,

L f

f fC

P

fn

p

p

10

1

500 5 2

5 3

33 35 4

h h

h n

n

=

=

=

LLLLLLLLLL

LLLLLLLLLLL

LLLLLLLLL

( . )

( . )

.( . )

L : Basic rated life h

fn : Life factor

fn : Speed

n : Rotational speed, r/min

Formula (5.2) can also be expressed as shown in formula (5.5).

The relation between Rotational speed n and speed factor fnas well as the relation between the basic rated life L10h andthe life factor fh is shown in Fig. 5.1.

When several bearings are incorporated in machines orequipment as complete units, all the bearings in the unit are

L

n

C

P

p

10

61060

5 5h =

LLLLLLLLLL( . )

Table 5.1 Machine application and requisite life

Serviceclassification

Life factor fh and machine application

~2.0 2.0~3.0 3.0~4.0 4.0~5.0 5.0~

Machines used forshort periods orused onlyoccasionally

Electric hand toolsHouseholdappliances

Farm machineryOffice equipment

Short period orintermittent use, butwith high reliabilityrequirements

Medical appliancesMeasuringinstruments

Home air-conditioning motorConstructionequipmentElevatorsCranes

Crane (sheaves)

Machines not inconstant use, butused for longperiods

AutomobilesTwo-wheeledvehicles

Small motorsBuses/trucksDriversWoodworkingmachines

Machine spindlesIndustrial motorsCrushersVibrating screens

Main gear drivesRubber/plasticCalender rollsPrinting machines

Machines inconstant use over 8hours a day

Rolling millsEscalatorsConveyorsCentrifuges

Railway vehicleaxlesAir conditionersLarge motorsCompressor pumps

Locomotive axlesTraction motorsMine hoistsPressed flywheels

PapermakingmachinesPropulsionequipment formarine vessels

24 hour continuousoperation,non-interruptable

Water supplyequipmentMine drainpumps/ventilatorsPower generatingequipment

A-42

Technical Data

Table 5.2 Reliability adjustment factor values a1

Reliability % Ln Reliabiltiy factor a1

90 L10

1.00

95 L5

0.62

96 L4 0.53

97 L3

0.44

98 L2

0.33

99 L1 0.21

considered as a whole when computing bearing life (seeformula 5.6). The total bearing life of the unit is a life ratingbased on the viable lifetime of the unit before even one of thebearings fails due to rolling contact fatigue.

where,

When the load conditions vary at regular intervals, the life canbe given by formula (5.7).

where,

Φj : Frequency of individual load conditions

Lj : Life under individual conditions

L

L L Le en

e

e=+ + +

1

1 1 15 6

1 2

1

LL

LLLL( . )

e

e

L

L L Ln

==

10 9

9 8

1 2

LLLLLLL

LLLLLLL

L L

For ball bearings

For roller bearings

Total basic rated life of entire unit h

Basic rated life of individual bearing 1, 2

n h

:

, :

L Lm = ∑

−φ j

j

1

5 7LLLLLLLLLL( . )

5.3 Machine applications andrequisite lifeWhen selecting a bearing, it is essential that the requisite lifeof the bearing be established in relation to the operatingconditions. The requisite life of the bearing is usuallydetermined by the type of machine the bearing is to be usedin, and duration of service and operational reliabilityrequirements. A general guide to these requisite life criteria isshown in Table 5.1. When determining bearing size, the fatiguelife of the bearing is an important factor; however, besidesbearing life, the strength and rigidity of the shaft and housingmust also be taken into consideration.

5.4 Adjusted life rating factorThe basic life rating (90% reliability factor) can be calculatedthrough the formulas mentioned earlier in Section 5.2.However, in some applications a bearing life factor of over 90%reliability may be required. To meet these requirements,bearing life can be lengthened by the use of specially improvedbearing materials or special construction techniques.Moreover, according to elastohydrodynamic lubrication theory,

it is clear that the bearing operating conditions (lubrication,temperature, speed, etc.) all exert an effect on bearing life. Allthese adjustment factors are taken into consideration whencalculating bearing life, and using the life adjustment factor asprescribed in ISO 281, the adjusted bearing life can be arrivedat.

where,

Lna

= Adjusted life rating in millions of revolutions(106) (adjusted for reliability, material andoperating conditions)

a1

= Reliability adjustment factor

a2 = Material adjustment factor

a3

= Operating condition adjustment factor

5.4.1. Life adjustment factor for reliability a1

The values for the reliability adjustment factor a1 (for a reliabilityfactor higher than 90%) can be found in Table 5.2.

L a a a

C

P

p

na =

1 2 3 5 8LLLLLLLLL( . )

5.4.2. Life adjustment factor for material a2

The values for the basic dynamic load ratings given in thebearing dimension tables are for bearings constructed fromNTN’s continued efforts at improving the quality and life of itsbearings.

Accordingly, a2=1 is used for the life adjustment factor in formula(5.8). For bearings constructed of specially improved materialsor with special manufacturing methods, the life adjustmentfactor a

2 in formula (5.8) can have a value greater than one.

Please consult NTN for special bearing materials or specialconstruction requirements.

When high carbon chromium steel bearings, which haveundergone only normal heat treatment, are operated for longperiods of time at temperatures in excess of 120°C,considerable dimensional deformation may take place. Forthis reason, there are special high temperature bearings whichhave been treated for dimensional stability. This specialtreatment allows the bearing to operate at its maximum

A-43

operational temperature without the occurrence of dimensionalchanges. However, these dimensionally stabilized bearings,designated with a “TS”, prefix have a reduced hardness with aconsequent decrease in bearing life. The adjusted life factorvalues used in formula (5.8) for such heat-stabilized bearingscan be found in Table 5.3.

Table 5.3 Dimension stabilized bearings

Max. operating temperature Adjustment factorCode °C a

TS2 160 0.87TS3 200 0.68TS4 250 0.30

5.4.3. Life adjustment factor a 3 for operating conditions

The operating conditions life adjustment factor a3 is used toadjust for such conditions as lubrication, operating temperature,and other operation factors which have an effect on bearinglife.

Generally speaking, when lubricating conditions aresatisfactory, the a

3 factor has a value on one; and when

lubricating conditions are exceptionally favorable, and all otheroperating conditions are normal, a

3 can have a value greater

than one.

However, when lubricating conditions are particularlyunfavorable and the oil film formation on the contact surfacesof the raceway and rolling elements is insufficient, the value ofa3 becomes less than one. This insufficient oil film formationcan be caused, for example, by the lubricating oil viscositybeing too low for the operating temperature (below 13 mm2/sfor ball bearings; below 20 mm2/s for roller bearings); or byexceptionally low rotational speed (n r/min x dp mm less than10,000). For bearings used under special operating conditions,please consult NTN.

As the operating temperature of the bearing increases, thehardness of the bearing material decreases. Thus, the bearinglife correspondingly decreases. The operating temperatureadjustment values are shown in Fig. 5.2.

5.5 Basic static load ratingWhen stationary rolling bearings are subjected to static loads,they suffer from partial permanent deformation of the contactsurfaces at the contact point between the rolling elements andthe raceway. The amount of deformity increases as the loadincreases, and if this increase in load exceeds certain limits,the subsequent smooth operation of the bearings is impaired.

It has been found through experience that a permanentdeformity of 0.0001 times the diameter of the rolling element,occuring at the most heavily stressed contact point betweenthe raceway and the rolling elements, can be tolerated withoutany impairment in running efficiency.

The basic rated static load refers to a fixed static load limit atwhich a specified amount of permanent deformation occurs.It applies to pure radial loads for radial bearings and to pureaxial loads for contact stress occurring at the rollling elementand raceway contact points are given below.

For ball bearings 4200 MPa

(except self-aligning ball bearings

For self-aligning ball bearings 4600MPa

For roller bearings 4000MPa

5.6 Allowable static equivalentloadGenerally the static equivalent load which can be permitted(See Section 6.4.2. page A-50) is limited by the basic staticrated load as stated in Section 5.5. However, depending onrequirements regarding friction and smooth operation, theselimits may be greater or lesser than the basic static rated load.

In the following formula (5.9) and Table 5.4 the safety factor So

can be determined considering the maximum static equivalentload.

where,

So : Safety factor

Co : Basic static rated load N(radial bearings: Cor, thrust bearings: Coa)

Po max : Maximum static equivalent load N(radial: Por max, thrust Poa max)

S

C

Poo

o max

= LLLLLLLLLLLL( . )5 9

300250200150100

1.0

0.8

0.6

0.4

0.2

Operating temperature °C

Fig. 5.2 Life adjustment value for operating temperature

Life

adj

ustm

ent v

alue

a 3

A-44

Technical Data

Table 5.4 Minimum safety factor values So

Ball RollerOperating conditions bearings bearings

High rotational accuracy demand 2 3

Normal rotating accuracy demand(Universal application) 1 1.5

Slight rotational accuracydeterioration permitted 0.5 1

(Low speed, heavy loading, etc.)

Note 1. For spherical thrust roller bearings, min.So value = 4.

2. For shell needle roller bearings, min. So value = 3.

3. When vibration and/or shock loads are present, aload factor based on the shock load needs to beincluded in the Po max value.

A-46

Technical Data

6. Bearing Load Calculation

6.1 Loads acting on shafts

To compute bearing loads, the forces which act on the shaftbeing supported by the bearing must be determined. Theseforces include the inherent dead weight of the rotating body(the weight of the shafts and components themselves), loadsgenerated by the working forces of the machine, and loadsarising from transmitted power.

It is possible to calculate theoretical values for these loads;however, there are many instances where the load acting onthe bearing is usually determined by the nature of the loadacting on the main power transmission shaft.

6.1.1. Gear load

The loads operating on gears can be divided into three maintypes according to the direction in which the load is applied;i.e. tangential (K

t), radial (K

s), and axial (K

a). The magnitude

and direction of these loads differ according to the types ofgears involved. The load calculation methods given hereinare for two general-use gear and shaft arrangements: parallelshaft gears, and cross shaft gears. For load calculation methodsregarding other types of gear and shaft arrangements, pleaseconsult NTN.

(1)Loads acting on parallel shaft gears

The forces acting on spur and helical parallel shaft gearsare depicted in Figs. 6.1, 6.2, and 6.3. The loadmagnitude can be found by using formulas (6.1), through(6.4).

KHP

D n

K K

K

K K

K K

pt

s t

t

r t2

s2

a t

Spur gear a

Helical gear b)

K

Helical gear

= × ••

= • ( )

= • ( )

= +

= • ( )

19 1 106 1

6 2

6 2

6 3

6.( . )

tan ( . )

tancos

( .

( . )

tan (

LLLLLLLL

LLLLLL

LLLLL

LLLLLLLLLLL

LLLLL

ααβ

β 66 4. )

where,

Kt : Tangential gear load (tangential force) NKs : Radial gear load (separating force) NKr : Right angle shaft load (resultant force of

tangential force and separating force) NKa : Parallel load on shaft NHP : Transmission force kW

n : Rotational speed, r/minDp : Gear pitch circle diameter mm

α : Gear pressure angleβ : Gear helix angle

Because the actual gear load also contains vibrations andshock loads as well, the theoretical load obtained by the aboveformula should also be adjusted by the gear factor fz as shownin Table 6.1.

Table 6.1 Gear factor fz

Gear type fz

Precision ground gears(Pitch and tooth profile errors of less 1.05~1.1

than 0.02 mm)

Ordinary machined gears(Pitch and tooth profile errors of less 1.1~1.3

than 0.1 mm)

Ks

Kt

Fig. 6.1 Spur gear loads

Kt

KaKs

Fig. 6.2 Helical gear loads

Fig. 6.3 Radial resultant forces

Kt

Kr Ks

Dp

A-47

(2)Loads acting on cross shafts

Gear loads acting on straight tooth bevel gears and spiralbevel gears on cross shafts are shown in Figs. 6.4 and6.5. The calculation methods for these gear loads areshown in Table 6.2. Herein, to calculate gear loads forstraight bevel gears, the helix angle β = 0. The symbolsand units used in Table 6.2 are as follows:

Kt : Tangential gear load (tangential force) NKs : Radial gear load (separating force) NKa : Parallel shaft load (axial load) NHP : Transmission force kW

n : Speed in rpmDpm : Mean pitch circle diameter mm

α : Gear pressure angleβ : Helix angleδ : Pitch cone angle

In general, the relationship between the gear load and thepinion gear load, due to the right angle intersection of the twoshafts, is as follows:

Ksp = Kag ................................................... (6.5)

Kap = Ksg ................................................... (6.6)

where,

Ksp, Ksg : Pinion and gear separating force N

Kap, Kag : Pinion and gear axial load N

For spiral bevel gears, the direction of the load varies dependingon the direction of the helix angle, the direction of rotation,and which side is the driving side or the driven side. The

Table 6.2 Loads acting on bevel gears Unit N

PinionRotation direction

Right

Clockwise

Tangential load Kt

Separating force Ks

Driving side

Helix direction Left

Counter clockwise

Right

Clockwise

Left

Counter clockwise

KHP

D ntp

= × ••

19 1 106.

m

K Ks t= +

tancoscos

tan sinα δβ

β δ K Ks t= −

tancoscos

tan sinα δβ

β δ

Driven side K Ks t= −

tancoscos

tan sinα δβ

β δ K Ks t= +

tancoscos

tan sinα δβ

β δ

Axial load Ka

Driving side

Driven side

K Ks t= −

tansincos

tan cosα δβ

β δ K Ka t= +

tansincos

tan cosα δβ

β δ

K Ka t= +

tansincos

tan cosα δβ

β δ K Ka t= −

tansincos

tan cosα δβ

β δ

directions for the separating force (Ks) and axial load (Ka)shown in Fig. 6.5 are positive directions. The direction ofrotation and the helix angle direction are defined as viewedfrom the large end of the gear. The gear rotation direction inFig. 6.5 is assumed to be clockwise (right).

Kap

Ksp

Kag

Ktp

Ksg

Ktg

Fig. 6.4 Loads on bevel gears

βδ

Ka

KsDpm

2

Kt

Fig. 6.5 Bevel gear diagram

A-48

Technical Data

6.1.2. Chain/belt shaft load

The tangential loads on sprockets or pulleys when power (load)is transmitted by means of chains or belts can be calculatedby formula (6.7).

where,

Kt : Sprocket/pulley tangential load NHP : Transmitted force kWDp : Sprocket/pulley pitch diameter mm

K

HP

D ntp

= × ••

19 1 106 7

6.( . )LLLLLLLLL

Table 6.3 Chain or belt factor fb

Chain or belt type fb

Chain (single) 1.2~1.5V-belt 1.5~2.0

Timing belt 1.1~1.3Flat belt (w/ tension pulley) 2.5~3.0

Flat belt 3.0~4.0

For belt drives, and initial tension is applied to give sufficientconstant operating tension on the belt and pulley. Taking thistension into account, the radial loads acting on the pulley areexpressed by formula (6.8). For chain drives, the same formulacan also be used if vibrations and shock loads are taken intoconsideration.

where,

Kr : Sprocket or pulley radial load Nfb : Chain or belt factor (Table 6.3)

6.1.3 Load factor

There are many instances where the actual operational shaftload is much greater than the theoretically calculated load,due to machine vibration and/or shock. This actual shaft loadcan be found by using formula (6.9).

K f Kr b t= • LLLLLLLLLLLL( . )6 8

where,

K : Actual shaft load NKc : Theoretically calculated value Nfw : Load factor (Table 6.4)

K f Kw c= • LLLLLLLLLLLL( . )6 9

Table 6.4 Load factor fw

Amount ofshock fw Application

Very little or Electric machines, machineno shock 1.0 ~ 1.2 tools, measuring instruments

Railway vehicles, automobiles,rolling mills, metal workingmachines, paper making

Light shock 1.2 ~ 1.5 machines, rubber mixingmachines, printing machines,

aircraft, textile machines,electrical units, office machines

Crushers, agricultural equipment,Heavy shock 1.5 ~ 3.0 constuction equipment, cranes

6.2 Bearing load distributionFor shafting, the static tension is considered to be supportedby the bearings, and any loads acting on the shafts aredistributed to the bearings.

For example, in the gear shaft assembly depicted in Fig. 6.7,the applied bearing loads can be found by using formulas (6.10)and (6.11).

where,

FrA : Radial load on bearing A NFrB : Radial load on bearings B NKrI : Radial load on gear I NKa : Axial load on gear I N

KrII : Radial load on gear II NDp : Gear I pitch diameter mm

l : Distance between bearings mm

F Kb

lK

c

lK

D

l

F Ka

lK

a b c

lK

D

l

p

p

rA rI rII a

rB rI rII a

2

2

= − −

= + + + +

LLLLLL

LLL

( . )

( . )

6 10

6 11

F1 Loose side

KrDp

F2 Tension side

Fig. 6.6 Chain/belt loads

A-49

6.3 Mean loadThe load on bearings used in machines under normalcircumstances will, in many cases, fluctuate according to afixed time period or planned operation schedule. The load onbearings operating under such conditions can be converted toa mean load (F

m), this is a load which gives bearings the same

life they would have under constant operating conditions.

(1)Fluctuating stepped load

The mean bearing load, Fm, for stepped loads is

calculated from formula (6.12). F1, F2 … Fn are the loads

acting on the bearing; n1, n

2….n

n and t

1, t

2 … t

n are the

bearing speeds and operating times respectively.

where,

p = 3 : For ball bearingsp = 10/3 : For roller bearings

FF n t

n t

p

mip

i i

i i

=∑( )

∑( )

1

6 12LLLLLLLLL( . )

(2) Consecutive series load

Where it is possible to express the function F(t) interms of load cycle to and time t, the mean load is foundby using formula (6.13).

F

tF t dt p

p

m0

t= ∫ ( )

16 130

0

1

LLLLLLLL( . )

(3) Linear fluctuating load

The mean load, Fm, can be approximated by formula(6.14).

F

F Fm = +min max ( . )

23

6 14LLLLLLLLL

(4) Sinusoidal fluctuating load

The mean load, Fm, can be approximated by formula(6.15) and (6.16).

(a) Fm = 0.75 Fmax ................................ (6.15)

(b) Fm = 0.65 Fmax ................................ (6.16)

l

a b c

Dp

KaKrIFrA

FrB

Bearing A Bearing B

Gear I

Gear II

KrII

F

Fm

F(t)

2to0 to t

Fig. 6.9 Time function series load

F

Fmax

Fmin

Fm

Fig. 6.10 Linear fluctuating load

Fmax

Fm

t

F

F

Fmax

Fm

t(a)

(b)

Fig. 6.11 Sinusoidal variable load

F

F1

FmF2

Fn

nn tnn1 t1 n2t2Fig. 6.8 Stepped load

A-50

Technical Data

6.4 Equivalent load

6.4.1 Dynamic equivalent load

When both dynamic radial loads and dynamic axial loads acton a bearing at the same time, the hypothetical load acting onthe center of the bearing which gives the bearings the samelife as if they had only a radial load or only an axial load iscalled the dynamic equivalent load.

For radial bearings, this load is expressed as pure radial loadand is called the dynamic equivalent radial load. For thrustbearings, it is expressed as pure axial load, and is called thedynamic equivalent axial load.

(1)Dynamic equivalent radial load

The dynamic equivalent radial load is expressed byformula (6.17).

where,

Pr : Dynamic equivalent radial load NFr : Actual radial load NFa : Actual axial load NX : Radial load factorY : Axial load factor

The values for X and Y are listed in the bearing tables.

(2) Dynamic equivalent axial load

As a rule, standard thrust bearings with a contact angle of90° cannot carry radial loads. However, self-aligning thrustroller bearings can accept some radial load. The dynamicequivalent axial load for these bearings is given in formula(6.18).

where,

Pa : Dynamic equivalent axial load NFa : Actual axial load NFr : Actual radial load N

Provided that only.

6.4.2. Static equivalent load

The static equivalent load is a hypothetical load which wouldcause the same total permanent deformation at the mostheavily stressed contact point between the rolling elementsand the raceway as under actual load conditions; that is whenboth static radial loads and static axial loads are simultaneouslyapplied to the bearing.

P XF YFr r a= + LLLLLLLLLLL( . )6 17

P F Fa a r= + 1 2 6 18. ( . )LLLLLLLLLLL

F Fr a ≤ 0 55.

For radial bearings this hypothetical load refers to pure radialloads, and for thrust bearings it refers to pure centric axialloads. These loads are designated static equivalent radial loadsand static equivalent axial loads respectively.

(1)Static equivalent radial load

For radial bearings the static equivalent radial load canbe found by using formula (6.19) or (6.20). The greaterof the two resultant values is always taken for Por.

where,

Por : Static equivalent radial load NXo : Static radial load factorYo : Static axial load factorFr : Actual radial load NFa : Actual axial load N

The values for Xo and Yo are given in the respective bearingtables.

(2)Static equivalent axial load

For spherical thrust roller bearings the staticequivalent axial load is expressed by formula (6.21).

where,

Poa : Static equivalent axial load NFa : Actual axial load NFr : Actual radial load N

Provided that only.

P X F Y F

P For o r o a

or r

= +=

LLLLLLLLLL

LLLLLLLLLLLLLL

( . )

( . )

6 19

6 20

P F Foa a r= + 2 7 6 21. ( . )LLLLLLLLLLL

F Fr a ≤ 0 55.

6.4.3 Load calculation for angular ball bearings andtapered roller bearings

For angular ball bearings and tapered roller bearings thepressure cone apex (load center) is located as shown in Fig.6.12, and their values are listed in the bearing tables.

a a

α αLoadcenter

Loadcenter

Fig. 6.12 Pressure cone apex

A-51

When radial loads act on these types of bearings thecomponent force is induced in the axial direction. For thisreason, these bearings are used in pairs (either DB or DFarrangements). For load calculation this component force mustbe taken into consideration and is expressed by formula (6.22).

Table 6.5 Bearing arrangement and dynamic equivalent load

Bearing arrangement Load condition Axial load Equivalent radial load

0 5 0 5. .F

Y

F

YFrII

II

rI

Ia≤ +

0 5 0 5. .F

Y

F

YFrII

II

rI

Ia> +

0 5 0 5. .F

Y

F

YFrI

I

rII

IIa≤ +

0 5 0 5. .F

Y

F

YFrI

I

rII

IIa> +

FF

Y

FF

YF

aIrI

I

aIIrI

Ia

=

= +

0 5

0 5

.

.

FF

YF

FF

Y

aIrII

IIa

aIIrII

II

= −

=

0 5

0 5

.

.

FF

YF

FF

Y

aIrII

IIa

aIIrII

II

= +

=

0 5

0 5

.

.

FF

Y

FF

YF

aIrI

I

aIIrI

Ia

=

= −

0 5

0 5

.

.

P F

P XF Y FrI rI

rII rII II aII

== +

P XF Y F

P FrI rI I aI

rII rII

= +=

P XF Y F

P FrI rI I aI

rII rII

= +=

P F

P XF Y FrI rI

rII rII II aII

== +

Note: 1) The above are valid when the bearing internal clearance and preload are zero.2) Radial forces in the opposite direction to the arrow in the above illustration are also regarded as positive.

6.5 Bearing rated life and load calculationexamples

In the examples given in this section, for the purpose ofcalculation, all hypothetical load factors as well as all calculatedload factors may be presumed to be included in the resultantload values.

(Example 1)

What is the rating life in hours of operation (L10h) for deep grooveball bearing 6208 operating at 650 r/min, with a radial load F

r

of 3.2 kN?

The equivalent radial loads for these bearing pairs are givenin Table 6.5.

F

F

Yar= 0 5

6 22.

( . )LLLLLLLLLLLL

For formula (6.17) the dynamic equivalent radial load Pr is:

The basic dynamic rated load for bearing 6208 (from bearingtable) is 29.1 kN, and the speed factor (fn)for ball bearings at650 r/min (n) from Fig. 5.1 is 0.37. The life factor, fh, from formula(5.3) is:

P Fr r kN= = 3 2.

f fC

Ph nr

r

= = × =0 3729 13 2

3 36..

..

Fa

FrII FrI

Fa

FrIIFrI

III

III

DB arrangement

DF arrangement

Fa

FrII FrI

Fa

FrIIFrI

III

III

DB arrangement

DF arrangement

A-52

Technical Data

Therefore, with fh=3.36 from Fig. 5.1 the rated life, L10h, isapproximately 19,000 hours.

(Example 2)

What is the life rating L10h for the same bearing and conditionsas in Example 1, but with an additional axial load F

a of 1.8 kN?

To find the dynamic equivalent radial load value for Pr, the radialload factor X and axial load factor Y are used. The basic staticload rating, Cor, for bearing 6208 is 17.8 kN.

Therefore, from the bearing tables e=0.29.For the operating radial load and axial load:

From the bearing tables X=0.56 and Y=1.48, and from formula(6.17) the equivalent radial load, Pr, is:

From Fig. 5.1 and formula (5.3) the life factor, fh, is:

Therefore, with life factor fh=2.41, from Fig. 5.1 the rated life,

L10h, is approximately 7,000 hours.

(Example 3)

Determine the optimum model number for a cylindrical rollerbearing operating at 450 r/min, with a radial load F

r of 200 kN,

and which must have a life of over 20,000 hours.

From Fig. 5.1 the life factor fh=3.02 (L10h at 20,000), and thespeed factor f

n=0.46 (n=450 r/min). To find the required basic

dynamic load rating, Cr, formula (5.3) is used.

From the bearing table, the smallest bearing that fulfills all therequirements is NU2336 (C

r=1,380 kN).

F

Ca

or

= =1 817 8

0 10..

.

F

Fea

r

= = > =1 83 2

0 56 0 29..

. .

P XF YFr r a kN= + = × + × =0 56 3 2 1 48 1 8 4 46. . . . .

f fC

Ph nr

r

= = × =0 3729 14 46

2 41..

..

Cf

fPr

h

nr kN= = × =3 02

0 46200 1313

.

.

(Example 4)

What are the rated lives of the two tapered roller bearingssupporting the shaft shown in Fig. 6.13?

Bearing II is an ET-32206 with a Cr=54.5 kN, and bearing I isan ET-32205 with a C

r=42.0 kN. The spur gear shaft has a

pitch circle diameter Dp of 150 mm, and a pressure angle α of20°. The gear transmitted force HP=150 kW at 2,000 r/min(speed factor n).

The gear load from formula (6.1), (6.2a) and (6.3) is:

KHP

D n

K K

K K K

tp

s t

r t2

s2

19 100 150150 2 000

kN

kN

kN

= × ••

= ××

=

= • = × ° =

= + = + =

19 1 109 55

9 55 20 3 48

9 55 3 48 10 16

6

2 2

..

tan . tan .

. . .

α

The radial loads for bearings I and II are:

F K

F K

F

Y

F

Y

rI r

rII r

rI

I

rII

II

kN

kN

= = × =

= = × =

= > =

100170

100170

10 16 5 98

70170

70170

10 16 4 18

0 51 87

0 51 31

. .

. .

..

..

The equivalent radial load is:

P F

P XF YF

Y

rI rI

rII rII IIrI

I

kN

kN

= =

= + • = × + ×

=

5 98

0 50 4 4 18 1 60 1 87

4 66

.

.. . . .

.

From formula (5.3) and Fig. 5.1 the life factor, fh, for each bearing

is:

70 100170

150

Bearing I(ET-32206)

Bearing II(ET-32205)

Fig. 6.13 Spur gear diagram

A-53

Therefore,

LhI =13,200 hours

LhII

=12,700 hours

The combined bearing life, Lh, from formula (5.6) is:

f fC

P

f fC

P

hI nrI

rI

hII nrII

rII

= = × =

= = × =

0 29354 55 98

2 67

0 29342 04 66

2 64

..

..

..

..

(Example 5)

Find the mean load for spherical roller bearing 23932 (Cr=320kN) when operated under the fluctuating conditions shown inTable 6.6.

Table 6.6

Condition No. Operating time % radial axial revolutionload load

i φi Fri Fai ni

kN kN r/min

1 5 10 2 12002 10 12 4 10003 60 20 6 8004 15 25 7 6005 10 30 10 400

The equivalent radial load, Pr, for each operating condition is

found by using formula (6.17) and shown in Table 6.7. Becauseall the values for F

ri and F

ai from the bearing tables

are greater thanF

Fe X Ya

r

and > = = =0 18 0 67 5 502. , . . .

Table 6.7

Condition No. Equivalent radial loadi P

ri

kN

1 17.72 30.03 46.44 55.35 75.1

From formula (6.12) the mean load, Fm, is:

FP n

nmri10 3

i i

i i

kN=∑ • •( )

∑ •( )

=φ

φ

3 10

48 1.

L

L Le e

eh

hI hII

9 8 9 813 200 12 700

6 990 hours

=+

=+

=

1

1 1

11 11 8 9/

P XF Y F F Fri ri ai ri ai= + = +2 0 67 5 50. .

A-79

Name of grease Lithium greaseSodium grease Calcium grease(Fiber grease) (Cup grease)

Thickener Li soap Na soap Ca soap

Base oil Mineral oil Diester oil Silicone oil Mineral oil Minera oil

Dropping point °C 170~190 170~190 200~250 150~180 80~90

Applicable Tempe-–30~+130 –50~+130 –50~+160 –20~+130 –20~+70rature range °C

MechanicalExcellent Good Good Excellent or Good Good or Impossible

properties

Pressure resistance Good Good Impossible Good Good or Impossible

Water resistance Good Good Good Good or Impossible Good

The widest range Excellent in low Suitable for high Some of the grease Excellent in waterof application temperature and and low tempera- is emulsified resistance, but in-

wear characterist- tures when mixed in water ferior in heat resis-Grease generally stics tance

Applications used in roller Unsuitable for Relatively excellentbearings heavy load use high temperature Low speed and

because of low oil resistance heavy load usefilm strength

11. Lubrication

11.1 Lubrication of rolling bearings

The purpose of bearing lubrication is to prevent direct metalliccontact between the various rolling and sliding elements. Thisis accomplished through the formation of a thin oil (or grease)film on the contact surfaces. However, for rolling bearings,lubrication has the following advantages.

(1) Friction and wear reduction(2) Friction heat dissipation(3) Prolonged bearing life(4) Prevention of rust(5) Protection against harmful elements

In order to achieve the above effects, the most effectivelubrication method for the operating conditions must beselected. Also, a good quality, reliable lubricant must beselected. In addition, an effectively designed sealing systemprevents the intrusion of damaging elements (dust, water, etc.)into the bearing interior, removes dust and other impuritiesfrom the lubricant, and prevents the lubricant from leaking fromthe bearing.

Almost all rolling bearings use either grease or oil lubricationmethods, but in some special applications, a solid lubricantsuch as molybdenum disulfide or graphite may be used.

11.2 Grease lubrication

Grease type lubricants are relatively easy to handle and requireonly the simplest sealing devices—for these reasons, greaseis the most widely used lubricant for rolling bearings.

11.2.1 Type and characteristics of grease

Lubricating grease are composed of either a mineral oil baseor a synthetic oil base. To this base a thickener and otheradditives are added. The properties of all greases are mainlydetermined by the kind of base oil used by the combination ofthickening agent and various additives.

Standard greases and their characteristics are listed in Table11.1. As performance characteristics of even the same type ofgrease will vary widely from brand to brand, it is best to checkthe manufacturers’ data when selecting a grease.

Table 11.1 Types and characteristics of greases

A-80

Technical Data

Calcium compound grease Sodium grease Aluminum grease Non-soap based grease(Complex grease) (Non-soap grease)

Ca compound soapCa+Na soap

Al soapBentone, Silica gel, Urea,

Ca+Li soap Carbon Black

Mineral oil Mineral oil Mineral oil Mineral oil Synthetic oil

200~280 150~180 70~90 250 or more 250 or more

–20~+150 –20~+120 –10~+80 –10~+130 –50~+200

Good Excellent or Good Good or Impossible Good Good

Good Excellent or Good Good Good Good

Good Good or Impossible Good Good Good

Some of the grease Excellent in pressure Excellent in stickiness These can be applied to the range fromcontaining extreme resistance and mechanical (adhesiveness) low to high temperatures. Excellentpressures additives are stability characteristics are obtained in heat andsuitable for heavy load use Suitable for bearings which by suitably arranging the thickening

Suitable for bearings which receive vibrations agents and base oilsFor general roller bearings receive vibrations

Grease for general roller bearings.

11.2.2 Base oil

Natural mineral oil or synthetic oils such as diester oil, siliconeoil and fluorocarbon oil are used as grease base oils.

Mainly, the properties of any grease is determined by theproperties of the base oil. Generally, greases with a lowviscosity base oil are best suited for low temperatures andhigh speeds; while greases made from high viscosity baseoils are best suited for heavy loads.

11.2.3 Thickening agents

Thickening agents are compounded with base oils to maintainthe semi-solid state of the grease. Thickening agents consistof two types of bases, metallic soaps and non-soaps. Metallicsoap thickeners include: lithium, sodium, calcium, etc.

Non-soap base thickeners are divided into two groups;inorganic (silica gel, bentonite, etc.) and organic (poly-urea,fluorocarbon, etc.)

The various special characteristics of a grease, such as limitingtemperature range, mechanical stability, water resistance, etc.depend largely on the type of thickening agent is used. For

example, a sodium based grease is generally poor in waterresistance properties, while greases with bentone, poly-ureaand other non-metallic soaps as the thickening agent aregenerally superior in high temperature properties.

11.2.4 Additives

Various additives are added to greases to improve variousproperties and efficiency. For example, there are anti-oxidents,high-pressure additives (EP additives), rust preventives, andanti-corrosives.

For bearing subject to heavy loads and/or shock loads, a greasecontaining high-pressure additives should be used. Forcomparatively high operating temperatures or in applicationswhere the grease cannot be replenished for long periods, agrease with an oxidation stabilizer is best to use.

11.2.5 Consistency

The consistency of a grease, i.e. the stiffness and liquidity, isexpressed by a numerical index.

A-81

The NLGI values for this index indicate the relative softness ofthe grease; the larger the number, the stiffer the grease. Theconsistency of a grease is determined by the amount ofthickening agent used and the viscosity of the base oil. For thelubrication of rolling bearings, greases with the NLGIconsistency numbers of 1,2, and 3 are used.

General relationships between consistency and application ofgrease are shown in Table 11.2.

11.2.6 Mixing of greases

When greases of different kinds are mixed together, theconsistency of the greases will change (usually softer), theoperating temperature range will be lowered, and otherchanges in characteristics will occur. As a general rule, greaseswith different bases oil, and greases with different thickeneragents should never be mixed.

Also, greases of different brands should not be mixed becauseof the different additives they contain.

However, if different greases must be mixed, at least greaseswith the same base oil and thickening agent should be selected.But even when greases of the same base oil and thickeningagent are mixed, the quality of the grease may still changedue to the difference in additives.

For this reason, changes in consistency and other qualitiesshould be checked before being applied.

11.2.7 Amount of grease

The amount of grease used in any given situation will dependon many factors relating to the size and shape of the housing,space limitations, bearing’s rotating speed and type of greaseused.

As a general rule, housings and bearings should be only filledfrom 30% to 60% of their capacities.

Where speeds are high and temperature rises need to be keptto a minimum, a reduced amount of grease should be used.Excessive amount of grease cause temperature rise which inturn causes the grease to soften and may allow leakage. Withexcessive grease fills oxidation and deterioration may causelubricating efficiency to be lowered.

11.2.8 Replenishment

As the lubricating efficiency of grease declines with the passageof time, fresh grease must be re-supplied at proper intervals.The replenishment time interval depends on the type ofbearing, dimensions, bearing’s rotating speed, bearingtemperature, and type of grease.

An easy reference chart for calculating grease replenishmentintervals is shown in Fig. 11.1

This chart indicates the replenishment interval for standardrolling bearing grease when used under normal operatingconditions.

As operating temperatures increase, the grease re-supplyinterval should be shortened accordingly.

Generally, for every 10°C increase in bearing temperatureabove 80°C, the relubrication period is reduced by exponent“1/1.5”.

(Example)

Find the grease relubrication time limit for deep groove ballbearing 6206, with a radial load of 2.0 kN operating at 3,600 r/min.

Cr/P

r=19.5/2.0 kN=9.8, from Fig. 9.1 the adjusted load, f

L, is

0.96.

From the bearing tables, the allowable speed for bearing 6206is 11,000 r/min and the numbers of revolutions permissible ata radial load of 2.0 kN are

therefore,

Using the chart in Fig. 11.1, find the point corresponding tobore diameter d=30 (from bearing table) on the vertical line forradial ball bearings. Draw a straight horizontal line to verticalline I. Then, draw a straight line from that point (A in example)to the point on line II which corresponds to the no/n value(2.93 in example). The point, C, where this line intersectsvertical line III indicates the relubrication interval h. In this casethe life of the grease is approximately 5,500 hours.

no r/min A= × =0 96 11000 10560. LLLLL

n

no B= =10560

36002 93. LLLLLLLLLLL

Table 11.2 Consistency of grease

NLGI JIS (ASTM)Consis- Worked Applications

tency No. penetration

0 355 ~ 385 For centralized greasing use

1 310 ~ 340 For centralized greasing use

2 265 ~ 295 For general use and sealedbearing use

3 220 ~ 250 For general and hightemperature use

4 175 ~ 205 For special use

A-82

Technical Data

11.3 Oil lubrication

Generally, oil lubrication is better suited for high speed andhigh temperature applications than grease lubrication. Oillubrication is especially effective for those application requiringthe bearing generated heat (or heat applied to the bearingfrom other sources) to be carried away from the bearing anddissipated to the outside.

11.3.1 Oil lubrication methods

1) Oil bathOil lubrication is the most commonly used method forlow to moderate speed applications. However, themost important aspect of this lubrication method is oilquantity control.For most horizontal shaft applications, the oil level isnormally maintained at approximately the center of thelowest rolling elements when the bearing is at rest.With this method, it is important that the housingdesign does not permit wide fluctuations in the oillevel, and that an oil gauge be fitted to allow easy

inspection of the oil level with the bearing at rest or inmotion (Fig. 11.2).

400300200

1005040302010

7

200

100

50

30

2010

500300200

100

50

3020

500

300200

100

50

3020

I

30 000

20 000

10 000

5 0004 000

3 000

2 000

1 000

500400

300

20.0

15.0

10.09.08.07.06.0

5.0

4.0

3.0

2.0

1.5

1.0

0.9

0.8

0.7

B

A

no/nII

C

Bearing bore d, mmRelubrication interval, h

III

Radial ball bearings

Thrust ball bearings

Cylindrical roller bearings

Tapered roller bearingsSpherical roller bearings

no = factor ƒL × limiting speed for grease see Fig. 9.1 and bearing tablesn = actual rotational speed, r/min

Fig. 11.1 Diagram for relubrication interval of greasing

Fig. 11.2 Oil bath lubrication

A-83

For vertical shafts at low speeds, the oil level shouldbe up to 50% to 80% submergence of the rollingelements. However, for high speeds or for bearingsused in pairs or multiple rows, other lubricationmethods, such as drip lubrication or circulationlubrication, should be used (see below).

2) Oil splashIn this method the bearing is not directly submerged inthe oil, but instead, an impeller or similar device ismounted on the shaft and the impeller picks up the oiland sprays it onto the bearing. This splash method oflubrication can be utilized for considerably highspeeds.As shown in the vertical shaft example in Fig. 11.3, atapered rotor is attached to the shaft just below thebearing. The lower end of this rotor is submerged inthe oil, and as the rotor rotates, the oil climbs up thesurface of the rotor and is thrown as spray onto thebearing.

3) Drip lubricationUsed for comparatively high speeds and for light tomedium load applications. an oiler is mounted on thehousing above the bearing and allows oil to drip downon the bearing, striking the rotating parts, turning theoil to mist (Fig. 11.4). Another method allows onlysmall amounts of oil to pass through the bearing at atime. The amount of oil used varies with the type ofbearing and its dimensions, but, in most cases, therate is a few drops per minute.

4) Circulating lubricationUsed for bearing cooling applications or for automaticoil supply systems in which the oil supply is centrallylocated.The principal advantage of this method is that oilcooling devices and filters to maintain oil purity can beinstalled within the system.

With this method however, it is important that thecirculating oil definitely be evacuated from the bearingchamber after it has passed through the bearing. Forthis reason, the oil inlets and outlets must be providedon opposite sides of the bearing, the drain port mustbe as large as possible, or the oil must be forciblyevacuated from the chamber (Fig. 11.5). Fig. 11.6illustrates a circulating lubrication method for verticalshafts using screw threads.

5) Disc lubricationIn this method, a partially submerged disc rotates athigh speed pulling the oil up by centrifugal force to anoil reservoir located in the upper part of the housing.The oil then drains down through the bearing. Disclubrication is only effective for high speed operations,such as supercharger or blower bearing lubrication(Fig. 11.7).

Fig. 11.3 Oil spray lubrication

Fig. 11.4 Drip lubrication

Fig. 11.5 Circulating lubrication (Horizontal shaft)

A-84

Technical Data

6) Oil mist lubricationUsing pressurized air, the lubrication oil is atomizedbefore it passes through the bearing. This method isespecially suited for high speed lubrication due to thevery low lubricant resistance. As shown in Fig. 11.8,one lubricating device can lubricate several bearingsat one time. Also, oil consumption is very low.

7) Air-oil lubricationWith the air-oil lubrication system, an exact measuredminimum required amount of lubricating oil is fed toeach bearing at correct intervals. As shown in Fig.11.9, this measured amount of oil is continuously sentunder pressure to the nozzle.

A fresh lubricating oil is constantly being sent to thebearing, there is no oil deterioration, and with thecooling effect of the compressed air, bearingtemperature rise can be kept to a minimum. Thequantity of oil required to lubricate the bearing is alsovery small, and this infinitesimal amount of oil fed tothe bearing does not pollute the surroundingenvironment.Note: This air-oil lubrication unit is now available fromNTN.

8) Oil jet lubricationThis method lubricates the bearing by injecting thelubricating oil under pressure directly into the side ofthe bearing. This is the most reliable lubricatingsystem for severe (high temperature, high speed, etc.)operating conditions.This is used for lubricating the main bearings of jetengines and gas turbines, and all types of high speedequipment. This system can be used in practice for dnvalues up to approximately 2.5 × 106.Usually the oil lubricant is injected into the bearing bya nozzle adjacent to the bearing, however in someapplications, oil holes are provided in the shaft, andthe oil is injected into the bearing by centrifugal forceas the shaft rotates.

Fig. 11.6 Circulating lubrication (Vertical shaft)

Fig. 11.7 Disc lubrication

Fig. 11.8 Oil mist lubrication

T

Reservoir (Level switch)

Oil

Air oil line

NozzleAir

Timer

Solenoid valvePressure switch

Air filter

Mist separator

Air

Fig. 11.9 Air-Oil lubrication supply system

Fig. 11.10 Oil jet lubrication

A-85

11.3.2 Lubricating oil

Under normal operating conditions, spindle oil, machine oil,turbine oil and other minerals are widely used for the lubricationof rolling bearings. However, for temperatures above 150°C orbelow –30°C, synthetic oils such as diester, silicone andfluorosilicone are used.

For lubricating oils, viscosity of the oil is one of the mostimportant properties and determines the oil’s lubricatingefficiency. If the viscosity is too low, the oil film will not besufficiently formed, and it will damage the load carrying surfaceof the bearing. On the other hand, if the viscosity is too high,the viscosity resistance will also be high and cause temperatureincreases and friction loss. In general, for higher speed, a lowerviscosity oil should be used, and for heavy loads, a higherviscosity oil should be used.

In regard to operating temperature and bearing lubrication,Table 11.3 lists the minimum required viscosity for variousbearings. Fig. 11.11 is a lubricating oil viscosity-temperaturecomparison chart is used in the selection of lubricating oil.

It shows which oil would have the appropriate viscosity at agiven temperature. For lubricating oil viscosity selectionstandards relating to bearing operating conditions, see Table11.4.

Table 11.3 Minimum viscosity of lubricating oil forbearings

Bearing typeDynamic viscosity

mm2/s

Ball bearings, cylindrical roller13bearings, needle roller bearings

Spherical roller bearings, taperedroller bearings, thrust needle roller 20

bearings

Spherical roller thrust bearings 30

30002000

1000

500

300200

100

50

30

2015

10

8

6

5

4

3

-30 -20 0-10 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160

1:ISOVG320

7:ISOVG15

2:ISOVG1503:ISOVG684:ISOVG465:ISOVG326:ISOVG22

Temperature °C

Vis

cosi

ty

mm

2 /s

1

2

34

56

7

Fig. 11.11 Relation between viscosity and temperature

A-86

Technical Data

–30 to 0Up to the allowable

22 32 46 All typerevolution

Up to 15,000 46 68 100 All type

0 to 60 15,000 to 80,000 32 46 68 All type

80,000 to 150,000 22 32 32 Except thrust ball bearings

150,000 to 500,000 10 22 32Single row radial ball bearings,

cylindrical roller bearings

Up to 15,000 150 220 All type

60 to 100 15,000 to 80,000 100 150 All type

80,000 to 150,000 68 100 150 Except thrust ball bearings

150,000 to 500,000 32 68Single row radial ball bearings,

cylindrical roller bearings

100 to 150 320 All type

0 to 60Up to the allowable

46 68Spherical roller bearings

60 to 100revolution

150

Table 11.4 Selection standards for lubricating oils

Operating temperatureof bearings

°Cdn–value Heavy or

Impact loadOrdinary load

Viscosity grade of lubricating oil

Bearing type

Notes: 1. In case of oil drip or circulating lubrication2. In case the usage conditions’ range is not listed in this table, please refer to NTN.

11.3.3 Oil quality

In forced oil lubrication systems, the heat radiated away byhousing and surrounding parts plus the heat carried away bythe lubricating oil is approximately equal to the amount of heatgenerated by the bearing and other sources.

For standard housing applications, the quantity of oil requiredcan be found by formula (11.1).

where,

Q : Quantity of oil for one bearing cm3/minK : Allowable oil temperature rise factor (Table 11.5)q : Minimum oil quantity cm3/min (From chart)

Because the amount of heat radiated will vary according tothe shape of the housing, for actual operation it is advisablethat the quantity of oil calculated by formula (11.1) be multipliedby a factor of 1.5 to 2.0. Then, the amount of oil can be adjustedto correspond to the actual machine operating conditions. If itis assumed for calculation purposes that no heat is radiatedby the housing and that all bearing heat is carried away by theoil, then the value for shaft diameter, d, (second vertical linefrom right in Fig. 11.12) becomes zero, regardless of the actualshaft diameter.

(Example)

For tapered roller bearing 30220U mounted on a flywheel shaftwith a radial load of 9.5 kN, operating at 1,800 rpm; what is theamount of lubricating oil required to keep the bearingtemperature rise below 15°C?

d=100 mm, dn=100×1,800=18×104 mm r/min

from Fig. 11.12, q=180 cm3/min.

Assume the bearing temperature is approximately equal tothe outlet oil temperature, from Table 11.5, since K=1,Q=1×180=180 cm3/min.

Q K q= • LLLLLLLLLLLLL( . )11 1

Table 11.5 Factor K

Temperature rise, °C K

10 1.515 120 0.7525 0.6

A-87

11.3.4 Relubrication interval

The interval of oil change depend on operating conditions, oilquantity, and type of oil used. A general standard for oil bathlubrication is that if the operating temperature is below 50°C,the oil should be replaced once a year. For higher operatingtemperatures, 80°C to 100°C for example, the oil should bereplaced at least every three months.

In critical applications, it is advisable that the lubricatingefficiency and oil deterioration be checked at regular intervalsin order to determine when the oil should be replaced.

140

160

1008060

200

40

300200

30 000

20 000

100 10 000

70 7 000

60 6 000

40 4 000

30 3 000

20 2 000

15 1 500

10 1 000

8 8

00

6 6

00

4 4

00

2 2

00

1

2

3

4

56

8

10

15

2030

40

100

200

300

400

500

600

700

800

900

1 000

1 100

1 200

Shaft diameter dmm

cm2/minkN

kgfLoad Pr

d n, ×

104

mm

/min

Basic oilquantity q

Needle roller bearingsSpherical roller bearings

Tapered roller bearingsAngular contact ball bearings

Deep groove ball bearingsCylindrical roller bearings

Fig. 11.12 Guidance for oil quantity

A-88

Technical Data

12. Sealing Devices

Bearing seals have two main functions: 1) to prevent lubricantfrom leaking out and 2) to prevent dust, water and othercontaminants from entering the bearing. When selecting a sealthe following factors need to be taken into consideration: thetype of lubricant (oil or grease), seal sliding speed, shaft fittingerrors, space limitations, seal friction and resultant heat, andcost.

Sealing devices for rolling bearings fall into two mainclassifications: contact and non-contact types.

12.1 Non-contact seals

Non-contact seals utilize a small clearance between the sealand the sealing surface; therefore, there is no wear, and frictionis negligible.

Consequently, very little frictional heat is generated makingnon-contact seals very suitable for high speed applications.

As shown in Fig. 12.1, non-contact seals can have the simplestof designs. With its small radial clearance, this type of seal isbest suited for grease lubrication, and for use in dry, relativelydust free environments.

When several concentric oil grooves (Fig. 12.2) are providedon the shaft or housing, the sealing effect can be greatlyimproved. If grease is filled in the grooves, the intrusion ofdust, etc. can be prevented.

For oil lubrication, if helical concentric oil grooves are providedin the direction opposite to the shaft rotation (horizontal shaftsonly), lubricating oil that flows out along the shaft can bereturned to the inside of the housing (see Fig. 12.3). The samesealing effect can be achieved by providing helical grooves onthe circumference of the shaft.

Labyrinth seals employ a multistage labyrinth design whichelongates the passage, thus improving the sealingeffectiveness. Labyrinth seals are used mainly for greaselubrication, and if grease is filled in the labyrinth, protectionefficiency (or capacity) against the entrance of dust and waterinto the bearing can be enhanced.

The axial labyrinth passage seal shown in Fig. 12.4 is used onone-piece housings and the radial seal shown in Fig. 12.5 isfor use with split housings.

In applications where the shaft is set inclined, the labyrinthpassage is slanted so as to prevent contact between the shaftand housing projections of the seal (Fig. 12.6).

Fig. 12.3 Helical oil groove seal

Fig. 12.1 Clearance seal

Fig. 12.2 Oil groove seal

Fig. 12.4 Axial labyrinth seal

Fig. 12.5 Radial labyrinth seal

A-89

Table 12.1 Clearance for labyrinth seals

Shaft diameter Radial clearance Axial clearanceon diameter

mm mm mm

~50 0.20~0.40 1~250~200 0.50~1.00 3~5

Axial and radial clearance values for labyrinth seals are givenin Table 12.1.

For oil lubrication, if projections are provided on the sleeve asshown in Fig. 12.7 (a), oil that flows out along the sleeve willbe thrown off by centrifugal force and returned through ducts.In the example shown in Fig. 12.7 (b) oil leakage is preventedby the centrifugal force of the slinger.

Also, in Fig. 12.7 (c), a slinger can be mounted on the outsideto prevent dust and other solid contaminants from entering.

12.2 Contact seals

Contact seals accomplish their sealing action through theconstant pressure of a resilient part of the seal on the sealingsurface. Contact seals are generally far superior to non-contactseals in sealing efficiency, although their friction torque andtemperature rise coefficients are somewhat higher.

The simplest of all contact seals are felt seals. Used primarilyfor grease lubrication (Fig. 12.8), felt seals work very well forkeeping out fine dust, but are subject to oil permeation andleakage to some extent. Therefore, the Z type rubber sealshown in Fig. 12.9 and GS type shown in Fig. 12.10, havebeen used more widely.

Fig. 12.9 Z Grease seal

Fig. 12.8 Felt seal

Fig. 12.10 GS Grease seal

Fig. 12.6 Aligning labyrinth seal

(b)(a)

(c)

Fig. 12.7 Slinger

A-90

Technical Data

Oil seals are used very widely and commonly, so their shapesand dimensions are standardized under JIS B2402. Using aring shaped coil spring in the lip to exert optimum contactpressure and also to allow the seal lip to follow the shaft runout,gives this type of seal excellent sealing efficiency.

The direction of the sealing action changes depending on whichdirection the lip faces. If the lip faces outward (Fig. 12.11 (a)),it will protect against dust, water and other contaminantsentering the bearing. If the lip faces inward (Fig. 12.11 (b)), itcan prevent lubricant leakage from the housing.

For needle roller bearings, NTN’s special seals are nowavailable (see page E-82). Depending upon usage conditions,the seal lip may be made of nitrile rubber, silicone rubber,fluorinated rubber or PTFE resin etc.

V-ring seals shown in Fig. 12.12 are used for either oil or greaselubrication. As only the edge of the V-ring makes contact withthe comparatively large seal lip, it is able to follow any siderunout.

V-ring seals are very suitable for high speeds as the V-ringcontacts the seal lip with only light contact pressure. For lipsliding speeds in excess of 12 m/s, the fit of the seal ring islost and it needs to be held in place with a clamping band.

These seals are made of elastic, high polymer material, and,depending on the type of material, they can be used for widerange of operational temperatures. The limiting operatingtemperature ranges for various materials are shown in Table12.2.

Table 12.2 Permissible temperature of seals

Seal materialPermissible operatingtemperature range °C

nitrile –25 to 100

Synthetic rubberacrylic –15 to 160silicone –70 to 230

fluorinated –30 to 220

PTFE synthetic resin –50 to 220

Felt –40 to 120

Allowable speeds for contact seals vary with the type oflubrication, operating temperature, roughness of the sealingcontact surface, etc. A general reference chart showingallowable speeds for seal types is shown in Table 12.3.

Table 12.3 Allowable rubbing speed for seals

Type Allowable speed, m/s

Felt 4Grease seal 6

Oil seal, nitrile rubber 15Oil seal, fluorinated rubber 32

V-ring 40

The general relationship between the shaft contact sealingsurface roughness (Ra) and seal lip speed is shown in Table12.4. In order to increase water resistance of the shaft, it shouldbe heat treated or hard chrome plated, etc. The surfacehardness of the shaft should be at least HRC40 or above, andif possible over HRC55.

Table 12.4 Surface roughness of shafts

Circumferential speedm/s Surface roughness

over incl. Ra

5 0.8a5 10 0.4a10 0.2a

(a)

Fig. 12.11 Oil seal

(b)

Fig. 12.12 V-Ring seal

A-91

12.3 Combination seals

Where operating conditions are especially severe (largeamounts of water, dust, etc.), or in places where pollutioncaused by lubricant leakage cannot be tolerated; seals maybe used in combination. Fig. 12.13 shows a combined labyrinthand oil groove slinger seal, and Fig. 12.14 shows a contactand non-contact seal combination.

Fig. 12.13 Non-contact combination seal

Fig. 12.14 Combined seal

B-8

10

12

15

17

20

d 10～20mm

15 3 0.1 ― 0.855 0.435 87 44 15.7 10 000 12 000 ― ― 6700 ― ― ― ―19 5 0.3 ― 1.83 0.925 187 94 14.8 32 000 38 000 ― 24 000 6800 ZZ LLB ― LLU22 6 0.3 0.3 2.7 1.27 275 129 14.0 30 000 36 000 ― 21 000 6900 ZZ LLB ― LLU26 8 0.3 ― 4.55 1.96 465 200 12.4 29 000 34 000 25 000 21 000 6000 ZZ LLB LLH LLU30 9 0.6 0.5 5.10 2.39 520 244 13.2 25 000 30 000 21 000 18 000 6200 ZZ LLB LLH LLU35 11 0.6 0.5 8.20 3.50 835 355 11.4 23 000 27 000 20 000 16 000 6300 ZZ LLB LLH LLU

18 4 0.2 ― 0.930 0.530 95 54 16.2 8 300 9 500 ― ― 6701 ― LLF ― ―21 5 0.3 ― 1.92 1.04 195 106 15.3 29 000 35 000 ― 20 000 6801 ZZ LLB ― LLU24 6 0.3 0.3 2.89 1.46 295 149 14.5 27 000 32 000 ― 19 000 6901 ZZ LLB ― LLU28 7 0.3 ― 5.10 2.39 520 244 13.2 26 000 30 000 ― ― 16001 ― ― ― ―28 8 0.3 ― 5.10 2.39 520 244 13.2 26 000 30 000 21 000 18 000 6001 ZZ LLB LLH LLU32 10 0.6 0.5 6.10 2.75 620 280 12.7 22 000 26 000 20 000 16 000 6201 ZZ LLB LLH LLU37 12 1 0.5 9.70 4.20 990 425 11.1 20 000 24 000 19 000 15 000 6301 ZZ LLB LLH LLU

21 4 0.2 ― 0.940 0.585 96 59 16.5 6 600 7 600 ― ― 6702 ― LLF ― ―24 5 0.3 ― 2.08 1.26 212 128 15.8 26 000 31 000 ― 17 000 6802 ZZ LLB ― LLU28 7 0.3 0.3 3.65 2.00 375 204 14.8 24 000 28 000 ― 16 000 6902 ZZ LLB ― LLU32 8 0.3 ― 5.60 2.83 570 289 13.9 22 000 26 000 ― ― 16002 ― ― ― ―32 9 0.3 0.3 5.60 2.83 570 289 13.9 22 000 26 000 18 000 15 000 6002 ZZ LLB LLH LLU35 11 0.6 0.5 7.75 3.60 790 365 12.7 19 000 23 000 18 000 15 000 6202 ZZ LLB LLH LLU42 13 1 0.5 11.4 5.45 1 170 555 12.3 17 000 21 000 15 000 12 000 6302 ZZ LLB LLH LLU

23 4 0.2 ― 1.00 0.660 102 67 16.3 5 000 6 700 ― ― 6703 ― LLF ― ―26 5 0.3 ― 2.23 1.46 227 149 16.1 24 000 28 000 ― 15 000 6803 ZZ LLB ― LLU30 7 0.3 0.3 4.65 2.58 475 263 14.7 22 000 26 000 ― 14 000 6903 ZZ LLB ― LLU35 8 0.3 ― 6.80 3.35 695 345 13.6 20 000 24 000 ― ― 16003 ― ― ― ―35 10 0.3 0.3 6.80 3.35 695 345 13.6 20 000 24 000 16 000 14 000 6003 ZZ LLB LLH LLU40 12 0.6 0.5 9.60 4.60 980 465 12.8 18 000 21 000 15 000 12 000 6203 ZZ LLB LLH LLU47 14 1 0.5 13.5 6.55 1 380 665 12.2 16 000 19 000 14 000 11 000 6303 ZZ LLB LLH LLU62 17 1.1 ― 22.7 10.8 2 320 1 100 11.1 14 000 16 000 ― ― 6403 ― ― ― ―

27 4 0.2 ― 1.04 0.730 106 74 16.1 5 000 5 700 ― ― 6704 ― LLF ― ―32 7 0.3 0.3 4.00 2.47 410 252 15.5 21 000 25 000 ― 13 000 6804 ZZ LLB ― LLU37 9 0.3 0.3 6.40 3.70 650 375 14.7 19 000 23 000 ― 12 000 6904 ZZ LLB ― LLU42 8 0.3 ― 7.90 4.50 810 455 14.5 18 000 21 000 ― ― 16004 ― ― ― ―42 12 0.6 0.5 9.40 5.05 955 515 13.9 18 000 21 000 13 000 11 000 6004 ZZ LLB LLH LLU47 14 1 0.5 12.8 6.65 1 310 680 13.2 16 000 18 000 12 000 10 000 6204 ZZ LLB LLH LLU52 15 1.1 0.5 15.9 7.90 1 620 805 12.4 14 000 17 000 12 000 10 000 6304 ZZ LLB LLH LLU

●Deep Groove Ball Bearings

Shielded type(ZZ)

Non-contactsealed type(LLB, LLF)

Contactsealed type

(LLU)

Low torquesealed type

(LLH)

Open type

B

r

r

φD φd

Boundary dimensions Basic load ratings Factor Limiting speeds Bearing numbersdynamic static dynamic static

min-1 non- lowmm kN kgf grease oil contact torque contact

rNS open type open type open shielded sealed sealed sealedd D B rs min

1） min Cr Cor Cr Cor fo ZZ LLB Z LB LLH LLU type type type type type

1）Smallest allowable dimension for chamfer dimension r.

B-9

― ― ― ― ― ― ― ― 10.8 ― 14.2 ― ― ― 0.1 ― 0.0015― ― ― ― ― ― ― ― 12 12.5 17 ― ― ― 0.3 ― 0.005N NR 20.8 1.05 0.8 0.2 24.8 0.7 12 13 20 25.5 1.5 0.7 0.3 0.3 0.009

―5） ―5） ― ― ― ― ― ― 12 13.5 24 ― ― ― 0.3 ― 0.019N NR 28.17 2.06 1.35 0.4 34.7 1.12 14 16 26 35.5 2.9 1.2 0.6 0.5 0.032N NR 33.17 2.06 1.35 0.4 39.7 1.12 14 17 31 40.5 2.9 1.2 0.6 0.5 0.053

― ― ― ― ― ― ― ― 13.6 13.8 16.4 ― ― ― 0.2 ― 0.002― ― ― ― ― ― ― ― 14 14.5 19 ― ― ― 0.3 ― 0.006N NR 22.8 1.05 0.8 0.2 26.8 0.7 14 15 22 27.5 1.5 0.7 0.3 0.3 0.011― ― ― ― ― ― ― ― 14 ― 26 ― ― ― 0.3 ― 0.019

―5） ―5） ― ― ― ― ― ― 14 16 26 ― ― ― 0.3 ― 0.021N NR 30.15 2.06 1.35 0.4 36.7 1.12 16 17 28 37.5 2.9 1.2 0.6 0.5 0.037N NR 34.77 2.06 1.35 0.4 41.3 1.12 17 18.5 32 42 2.9 1.2 1 0.5 0.06

― ― ― ― ― ― ― ― 16.6 16.8 19.4 ― ― ― 0.2 ― 0.0025― ― ― ― ― ― ― ― 17 17.5 22 ― ― ― 0.3 ― 0.007N NR 26.7 1.3 0.95 0.25 30.8 0.85 17 17.5 26 31.5 1.9 0.9 0.3 0.3 0.016― ― ― ― ― ― ― ― 17 ― 30 ― ― ― 0.3 ― 0.025N NR 30.15 2.06 1.35 0.4 36.7 1.12 17 19 30 37.5 2.9 1.2 0.3 0.3 0.03N NR 33.17 2.06 1.35 0.4 39.7 1.12 19 20 31 40.5 2.9 1.2 0.6 0.5 0.045N NR 39.75 2.06 1.35 0.4 46.3 1.12 20 23 37 47 2.9 1.2 1 0.5 0.082

― ― ― ― ― ― ― ― 18.6 18.8 21.4 ― ― ― 0.2 ― 0.0025― ― ― ― ― ― ― ― 19 19.5 24 ― ― ― 0.3 ― 0.008N NR 28.7 1.3 0.95 0.25 32.8 0.85 19 20 28 33.5 1.9 0.9 0.3 0.3 0.018― ― ― ― ― ― ― ― 19 ― 33 ― ― ― 0.3 ― 0.032N NR 33.17 2.06 1.35 0.4 39.7 1.12 19 21 33 40.5 2.9 1.2 0.3 0.3 0.039N NR 38.1 2.06 1.35 0.4 44.6 1.12 21 23 36 45.5 2.9 1.2 0.6 0.5 0.066N NR 44.6 2.46 1.35 0.4 52.7 1.12 22 25 42 53.5 3.3 1.2 1 0.5 0.115― ― ― ― ― ― ― ― 23.5 ― 55.5 ― ― ― 1 ― 0.27

― ― ― ― ― ― ― ― 21.6 22.3 25.4 ― ― ― 0.2 ― 0.0045N NR 30.7 1.3 0.95 0.25 34.8 0.85 22 22.5 30 35.5 1.9 0.9 0.3 0.3 0.019N NR 35.7 1.7 0.95 0.25 39.8 0.85 22 24 35 40.5 2.3 0.9 0.3 0.3 0.036― ― ― ― ― ― ― ― 22 ― 40 ― ― ― 0.3 ― 0.051N NR 39.75 2.06 1.35 0.4 46.3 1.12 24 26 38 47 2.9 1.2 0.6 0.5 0.069N NR 44.6 2.46 1.35 0.4 52.7 1.12 25 28 42 53.5 3.3 1.2 1 0.5 0.106N NR 49.73 2.46 1.35 0.4 57.9 1.12 26.5 28.5 45.5 58.5 3.3 1.2 1 0.5 0.144

Bearing Snap ring groove Snap ring Abutment and fillet dimensions Mass4）numbers dimensions dimensions

mm mm mmsnap2） snap2）

kg

ring ring D1 a b ro D2 f da Da DX CY CZ ras rNas

groove max max min max max max min max3） max (approx.) max min max max (approx.)


a

b

ro ro

f

φD2

rNa

CY

ra

φdaφDaφDXφdφD1 φD

B

rrN

r

CZ

With snap ringWith snap ring groove

0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e

Dynamic equivalent radial loadPr＝XFr＋YFa

Static equivalent radial loadPor＝0.6Fr＋0.5Fa

When Por＜Fr use Por＝Fr

2）Sealed and shielded bearings are also available. 3）This dimension applies to sealed and shielded bearings. 4）Does not include bearings with snap rings. 5）See page B-40.

B-10

20

22

25

28

30

32

35

d 20～35mm

72 19 1.1 ― 28.5 13.9 2 900 1 420 11.4 12 000 14 000 ― ― 6404 ― ― ― ―

44 12 0.6 0.5 9.40 5.05 955 515 13.9 17 000 20 000 13 000 10 000 60/22 ZZ LLB LLH LLU50 14 1 0.5 12.9 6.80 1 320 690 13.5 14 000 17 000 12 000 9 700 62/22 ZZ LLB LLH LLU56 16 1.1 0.5 18.4 9.25 1 880 945 12.4 13 000 15 000 11 000 9 200 63/22 ZZ LLB LLH LLU

32 4 0.2 ― 1.10 0.840 112 86 15.8 4 000 4 600 ― ― 6705 ― LLF ― ―37 7 0.3 0.3 4.30 2.95 435 300 16.1 18 000 21 000 ― 10 000 6805 ZZ LLB ― LLU42 9 0.3 0.3 7.05 4.55 715 460 15.4 16 000 19 000 ― 9 800 6905 ZZ LLB ― LLU47 8 0.3 ― 8.35 5.10 855 520 15.1 15 000 18 000 ― ― 16005 ― ― ― ―47 12 0.6 0.5 10.1 5.85 1 030 595 14.5 15 000 18 000 11 000 9 400 6005 ZZ LLB LLH LLU52 15 1 0.5 14.0 7.85 1 430 800 13.9 13 000 15 000 11 000 8 900 6205 ZZ LLB LLH LLU62 17 1.1 0.5 21.2 10.9 2 160 1 110 12.6 12 000 14 000 9 700 8 100 6305 ZZ LLB LLH LLU80 21 1.5 ― 34.5 17.5 3 550 1 780 11.6 10 000 12 000 ― ― 6405 ― ― ― ―

52 12 0.6 0.5 12.5 7.40 1 270 755 14.5 14 000 16 000 10 000 8 400 60/28 ZZ LLB LLH LLU58 16 1 0.5 17.9 9.75 1 830 995 13.4 12 000 14 000 9 700 8 100 62/28 ZZ LLB LLH LLU68 18 1.1 0.5 26.7 14.0 2 730 1 430 12.4 11 000 13 000 8 900 7 400 63/28 ZZ LLB LLH LLU

37 4 0.2 ― 1.14 0.950 117 97 15.7 3 300 3 800 ― ― 6706 ― LLF ― ―42 7 0.3 0.3 4.70 3.65 480 370 16.5 15 000 18 000 ― 8.800 6806 ZZ LLB ― LLU47 9 0.3 0.3 7.25 5.00 740 510 15.8 14 000 17 000 ― 8 400 6906 ZZ LLB ― LLU55 9 0.3 ― 11.2 7.35 1 150 750 15.2 13 000 15 000 ― ― 16006 ― ― ― ―55 13 1 0.5 13.2 8.3 1 350 845 14.8 13 000 15 000 9 200 7 700 6006 ZZ LLB LLH LLU62 16 1 0.5 19.5 11.3 1 980 1 150 13.8 11 000 13 000 8 800 7 300 6206 ZZ LLB LLH LLU72 19 1.1 0.5 26.7 15.0 2 720 1 530 13.3 10 000 12 000 7 900 6 600 6306 ZZ LLB LLH LLU90 23 1.5 ― 43.5 23.9 4 400 2 440 12.3 8 800 10 000 ― ― 6406 ― ― ― ―

58 13 1 0.5 11.8 8.05 1 200 820 15.4 12 000 15 000 8 700 7 200 60/32 ZZ LLB LLH LLU65 17 1 0.5 20.7 11.6 2 110 1 190 13.6 11 000 12 000 8 400 7 100 62/32 ZZ LLB LLH LLU75 20 1.1 0.5 29.8 16.9 3 050 1 730 13.1 9 500 11 000 7 700 6 500 63/32 ZZ LLB LLH LLU

47 7 0.3 0.3 4.90 4.05 500 410 16.4 13 000 16 000 ― 7 600 6807 ZZ LLB ― LLU55 10 0.6 0.5 9.55 6.85 975 695 15.8 12 000 15 000 ― 7 100 6907 ZZ LLB ― LLU62 9 0.3 ― 11.7 8.20 1 190 835 15.6 12 000 14 000 ― ― 16007 ― ― ― ―62 14 1 0.5 16.0 10.3 1 630 1 050 14.8 12 000 14 000 8 200 6 800 6007 ZZ LLB LLH LLU72 17 1.1 0.5 25.7 15.3 2 620 1 560 13.8 9 800 11 000 7 600 6 300 6207 ZZ LLB LLH LLU80 21 1.5 0.5 33.5 19.1 3 400 1 950 13.1 8 800 10 000 7 300 6 000 6307 ZZ LLB LLH LLU

100 25 1.5 ― 55.0 31.0 5 600 3 150 12.3 7 800 9 100 ― ― 6407 ― ― ― ―


Shielded type(ZZ)

Non-contactsealed type(LLB, LLF)

Contactsealed type

(LLU)

Low torquesealed type

(LLH)

Open type

B

r

r

φD φd






B-11

― ― ― ― ― ― ― ― 26.5 ― 65.5 ― ― ― 1 ― 0.4

N NR 41.75 2.06 1.35 0.4 48.3 1.12 26 26.5 40 49 2.9 1.2 0.6 0.5 0.074N NR 47.6 2.46 1.35 0.4 55.7 1.12 27 29.5 45 56.5 3.3 1.2 1 0.5 0.117N NR 53.6 2.46 1.35 0.4 61.7 1.12 28.5 31 49.5 62.5 3.3 1.2 1 0.5 0.176

― ― ― ― ― ― ― ― 26.6 27.3 30.4 ― ― ― 0.2 ― 0.005N NR 35.7 1.3 0.95 0.25 39.8 0.85 27 28 35 40.5 1.9 0.9 0.3 0.3 0.022N NR 40.7 1.7 0.95 0.25 44.8 0.85 27 29 40 45.5 2.3 0.9 0.3 0.3 0.042― ― ― ― ― ― ― ― 27 ― 45.0 ― ― ― 0.3 ― 0.06N NR 44.6 2.06 1.35 0.4 52.7 1.12 29 30.5 43 53.5 2.9 1.2 0.6 0.5 0.08N NR 49.73 2.46 1.35 0.4 57.9 1.12 30 32 47 58.5 3.3 1.2 1 0.5 0.128N NR 59.61 3.28 1.9 0.6 67.7 1.7 31.5 35 55.5 68.5 4.6 1.7 1 0.5 0.232― ― ― ― ― ― ― ― 33 ― 72 ― ― ― 1.5 ― 0.53

N NR 49.73 2.06 1.35 0.4 57.9 1.12 32 34 48 58.5 2.9 1.2 0.6 0.5 0.098N NR 55.6 2.46 1.35 0.4 63.7 1.12 33 35.5 53 64.5 3.3 1.2 1 0.5 0.171N NR 64.82 3.28 1.9 0.6 74.6 1.7 34.5 38.5 61.5 76 4.6 1.7 1 0.5 0.284

― ― ― ― ― ― ― ― 31.6 32.3 35.4 ― ― ― 0.2 ― 0.006N NR 40.7 1.3 0.95 0.25 44.8 0.85 32 33 40 45.5 1.9 0.9 0.3 0.3 0.026N NR 45.7 1.7 0.95 0.25 49.8 0.85 32 34 45 50.5 2.3 0.9 0.3 0.3 0.048― ― ― ― ― ― ― ― 32 ― 53 ― ― ― 0.3 ― 0.091N NR 52.6 2.08 1.35 0.4 60.7 1.12 35 37 50 61.5 2.9 1.2 1 0.5 0.116N NR 59.61 3.28 1.9 0.6 67.7 1.7 35 39 57 68.5 4.6 1.7 1 0.5 0.199N NR 68.81 3.28 1.9 0.6 78.6 1.7 36.5 43 65.5 80 4.6 1.7 1 0.5 0.36― ― ― ― ― ― ― ― 38 ― 82 ― ― ― 1.5 ― 0.735

N NR 55.6 2.08 1.35 0.4 63.7 1.12 37 39 53 64.5 2.9 1.2 1 0.5 0.129N NR 62.6 3.28 1.9 0.6 70.7 1.7 37 40 60 71.5 4.6 1.7 1 0.5 0.226N NR 71.83 3.28 1.9 0.6 81.6 1.7 38.5 43.5 68.5 83 4.6 1.7 1 0.5 0.382

N NR 45.7 1.3 0.95 0.25 49.8 0.85 37 38 45 50.5 1.9 0.9 0.3 0.3 0.029N NR 53.7 1.7 0.95 0.25 57.8 0.85 39 40 51 58.5 2.3 0.9 0.6 0.5 0.074― ― ― ― ― ― ― ― 37 ― 60 ― ― ― 0.3 ― 0.11N NR 59.61 2.08 1.9 0.6 67.7 1.7 40 42 57 68.5 3.4 1.7 1 0.5 0.155N NR 68.81 3.28 1.9 0.6 78.6 1.7 41.5 45 65.5 80 4.6 1.7 1 0.5 0.288N NR 76.81 3.28 1.9 0.6 86.6 1.7 43 47 72 88 4.6 1.7 1.5 0.5 0.457

― ― ― ― ― ― ― 43 ― 92 ― ― ― 1.5 ― 0.952



kg




a

b

ro ro

f

φD2

rNa

CY

ra


B

rrN

r

CZ


0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e




2）Sealed and shielded bearings are also available. 3）This dimension applies to sealed and shielded bearings. 4）Does not include bearings with snap rings.

B-12

40

45

50

55

60

d 40～60mm

52 7 0.3 0.3 5.10 4.40 520 445 16.3 12 000 14 000 ― 6 700 6808 ZZ LLB ― LLU62 12 0.6 0.5 12.2 8.90 1 240 910 15.8 11 000 13 000 ― 6 300 6908 ZZ LLB ― LLU68 9 0.3 ― 12.6 9.65 1 290 985 16.0 10 000 12 000 ― ― 16008 ― ― ― ―68 15 1 0.5 16.8 11.5 1 710 1 170 15.2 10 000 12 000 7 300 6 100 6008 ZZ LLB LLH LLU80 18 1.1 0.5 29.1 17.8 2 970 1 820 14.0 8 700 10 000 6 700 5 600 6208 ZZ LLB LLH LLU90 23 1.5 0.5 40.5 24.0 4 150 2 450 13.2 7 800 9 200 6 400 5 300 6308 ZZ LLB LLH LLU

110 27 2 ― 63.5 36.5 6 500 3 750 12.3 7 000 8 200 ― ― 6408 ― ― ― ―

58 7 0.3 0.3 5.35 4.95 550 500 16.1 11 000 12 000 ― 5 900 6809 ZZ LLB ― LLU68 12 0.6 0.5 13.1 10.4 1 330 1 060 16.1 9 800 12 000 ― 5 600 6909 ZZ LLB ― LLU75 10 0.6 ― 12.9 10.5 1 320 1 070 16.2 9 200 11 000 ― ― 16009 ― ― ― ―75 16 1 0.5 21.0 15.1 2 140 1 540 15.3 9 200 11 000 6 500 5 400 6009 ZZ LLB LLH LLU85 19 1.1 0.5 32.5 20.4 3 350 2 080 14.1 7 800 9 200 6 200 5 200 6209 ZZ LLB LLH LLU

100 25 1.5 0.5 53.0 32.0 5 400 3 250 13.1 7 000 8 200 5 600 4 700 6309 ZZ LLB LLH LLU120 29 2 ― 77.0 45.0 7 850 4 600 12.1 6 300 7 400 ― ― 6409 ― ― ― ―

65 7 0.3 0.3 6.60 6.10 670 620 16.1 9 600 11 000 ― 5 300 6810 ZZ LLB ― LLU72 12 0.6 0.5 13.4 11.2 1 370 1 140 16.3 8 900 11 000 ― 5 100 6910 ZZ LLB ― LLU80 10 0.6 ― 13.2 11.3 1 350 1 150 16.4 8 400 9 800 ― ― 16010 ― ― ― ―80 16 1 0.5 21.8 16.6 2 230 1 690 15.5 8 400 9 800 6 000 5 000 6010 ZZ LLB LLH LLU90 20 1.1 0.5 35.0 23.2 3 600 2 370 14.4 7 100 8 300 5 700 4 700 6210 ZZ LLB LLH LLU

110 27 2 0.5 62.0 38.5 6 300 3 900 13.2 6 400 7 500 5 000 4 200 6310 ZZ LLB LLH LLU130 31 2.1 ― 83.0 49.5 8 450 5 050 12.5 5 700 6 700 ― ― 6410 ― ― ― ―

72 9 0.3 0.3 8.80 8.10 900 825 16.2 8 700 10 000 ― 4 800 6811 ZZ LLB ― LLU80 13 1 0.5 16.0 13.3 1 630 1 350 16.2 8 200 9 600 ― 4 600 6911 ZZ LLB ― LLU90 11 0.6 ― 18.6 15.3 1 900 1 560 16.2 7 700 9 000 ― ― 16011 ― ― ― ―90 18 1.1 0.5 28.3 21.2 2 880 2 170 15.3 7 700 9 000 ― 4 500 6011 ZZ LLB ― LLU

100 21 1.5 0.5 43.5 29.2 4 450 2 980 14.3 6 400 7 600 ― 4 300 6211 ZZ LLB ― LLU120 29 2 0.5 71.5 45.0 7 300 4 600 13.2 5 800 6 800 ― 3 900 6311 ZZ LLB ― LLU140 33 2.1 ― 89.0 54.0 9 050 5 500 12.7 5 200 6 100 ― ― 6411 ― ― ― ―

78 10 0.3 0.3 11.5 10.6 1 170 1 080 16.3 8 000 9 400 ― 4 400 6812 ZZ LLB ― LLU85 13 1 0.5 16.4 14.3 1 670 1 450 16.4 7 600 8 900 ― 4 300 6912 ZZ LLB ― LLU95 11 0.6 ― 20.0 17.5 2 040 1 780 16.3 7 000 8 300 ― ― 16012 ― ― ― ―95 18 1.1 0.5 29.5 23.2 3 000 2 370 15.6 7 000 8 300 ― 4 100 6012 ZZ LLB ― LLU

110 22 1.5 0.5 52.5 36.0 5 350 3 700 14.3 6 000 7 000 ― 3 800 6212 ZZ LLB ― LLU130 31 2.1 0.5 82.0 52.0 8 350 5 300 13.2 5 400 6 300 ― 3 600 6312 ZZ LLB ― LLU150 35 2.1 ― 102 64.5 10 400 6 550 12.6 4 800 5 700 ― ― 6412 ― ― ― ―







B-13

N NR 50.7 1.3 0.95 0.25 54.8 0.85 42 43 50 55.5 1.9 0.9 0.3 0.3 0.033N NR 60.7 1.7 0.95 0.25 64.8 0.85 44 45 58 65.5 2.3 0.9 0.6 0.5 0.11― ― ― ― ― ― ― ― 42 ― 66 ― ― ― 0.3 ― 0.125N NR 64.82 2.49 1.9 0.6 74.6 1.7 45 47 63 76 3.8 1.7 1 0.5 0.19N NR 76.81 3.28 1.9 0.6 86.6 1.7 46.5 51 73.5 88 4.6 1.7 1 0.5 0.366N NR 86.79 3.28 2.7 0.6 96.5 2.46 48 54 82 98 5.4 2.5 1.5 0.5 0.63― ― ― ― ― ― ― ― 49 ― 101 ― ― ― 2.0 ― 1.23

N NR 56.7 1.3 0.95 0.25 60.8 0.85 47 48 56 61.5 1.9 0.9 0.3 0.3 0.04N NR 66.7 1.7 0.95 0.25 70.8 0.85 49 51 64 72 2.3 0.9 0.6 0.5 0.128― ― ― ― ― ― ― ― 49 ― 71 ― ― ― 0.6 ― 0.171N NR 71.83 2.49 1.9 0.6 81.6 1.7 50 52.5 70 83 3.8 1.7 1 0.5 0.237N NR 81.81 3.28 1.9 0.6 91.6 1.7 51.5 55.5 78.5 93 4.6 1.7 1 0.5 0.398N NR 96.8 3.28 2.7 0.6 106.5 2.46 53 61.5 92 108 5.4 2.5 1.5 0.5 0.814― ― ― ― ― ― ― ― 54 ― 111 ― ― ― 2 ― 1.53

N NR 63.7 1.3 0.95 0.25 67.8 0.85 52 54 63 68.5 1.9 0.9 0.3 0.3 0.052N NR 70.7 1.7 0.95 0.25 74.8 0.85 54 55.5 68 76 2.3 0.9 0.6 0.5 0.132― ― ― ― ― ― ― ― 54 ― 76 ― ― ― 0.6 ― 0.18N NR 76.81 2.49 1.9 0.6 86.6 1.7 55 57.5 75 88 3.8 1.7 1 0.5 0.261N NR 86.79 3.28 2.7 0.6 96.5 2.46 56.5 60 83.5 98 5.4 2.5 1 0.5 0.454N NR 106.81 3.28 2.7 0.6 116.6 2.46 59 68.5 101 118 5.4 2.5 2 0.5 1.07― ― ― ― ― ― ― ― 61 ― 119 ― ― ― 2 ― 1.88

N NR 70.7 1.7 0.95 0.25 74.8 0.85 57 59 70 76 2.3 0.9 0.3 0.3 0.083N NR 77.9 2.1 1.3 0.4 84.4 1.12 60 61.5 75 86 2.9 1.2 1 0.5 0.18― ― ― ― ― ― ― ― 59 ― 86 ― ― ― 0.6 ― 0.258N NR 86.79 2.87 2.7 0.6 96.5 2.46 61.5 64 83.5 98 5 2.5 1 0.5 0.388N NR 96.8 3.28 2.7 0.6 106.5 2.46 63 67 92 108 5.4 2.5 1.5 0.5 0.601N NR 115.21 4.06 3.1 0.6 129.7 2.82 64 74 111 131.5 6.5 2.9 2 0.5 1.37― ― ― ― ― ― ― ― 66 ― 129 ― ― ― 2 ― 2.29

N NR 76.2 1.7 1.3 0.4 82.7 1.12 62 64.5 76 84 2.5 1.2 0.3 0.3 0.106N NR 82.9 2.1 1.3 0.4 89.4 1.12 65 66.5 80 91 2.9 1.2 1 0.5 0.193― ― ― ― ― ― ― ― 64 ― 91 ― ― ― 0.6 ― 0.283N NR 91.82 2.87 2.7 0.6 101.6 2.46 66.5 69 88.5 103 5 2.5 1 0.5 0.414N NR 106.81 3.28 2.7 0.6 116.6 2.46 68 75 102 118 5.4 2.5 1.5 0.5 0.783N NR 125.22 4.06 3.1 0.6 139.7 2.82 71 80.5 119 141.5 6.5 2.9 2 0.5 1.73― ― ― ― ― ― ― ― 71 ― 139 ― ― ― 2 ― 2.77





kg



B-14

65

70

75

80

85

d 65～85mm

85 10 0.6 0.5 11.6 11.0 1 180 1 120 16.2 7 400 8 700 4 100 6813 ZZ LLB LLU90 13 1 0.5 17.4 16.1 1 770 1 640 16.6 7 000 8 200 4 000 6913 ZZ LLB LLU

100 11 0.6 ― 20.5 18.7 2 090 1 910 16.5 6 500 7 700 ― 16013 ― ― ―100 18 1.1 0.5 30.5 25.2 3 100 2 570 15.8 6 500 7 700 3 900 6013 ZZ LLB LLU120 23 1.5 0.5 57.5 40.0 5 850 4 100 14.4 5 500 6 500 3 600 6213 ZZ LLB LLU140 33 2.1 0.5 92.5 60.0 9 450 6 100 13.2 4 900 5 800 3 300 6313 ZZ LLB LLU160 37 2.1 ― 111 72.5 11 300 7 400 12.7 4 400 5 200 ― 6413 ― ― ―

90 10 0.6 0.5 12.1 11.9 1 230 1 220 16.1 6 900 8 100 3 800 6814 ZZ LLB LLU100 16 1 0.5 23.7 21.2 2 420 2 160 16.3 6 500 7 700 3 700 6914 ZZ LLB LLU110 13 0.6 ― 24.4 22.6 2 480 2 300 16.5 6 100 7 100 ― 16014 ― ― ―110 20 1.1 0.5 38.0 31.0 3 900 3 150 15.6 6 100 7 100 3 600 6014 ZZ LLB LLU125 24 1.5 0.5 62.0 44.0 6 350 4 500 14.5 5 100 6 000 3 400 6214 ZZ LLB LLU150 35 2.1 0.5 104 68.0 10 600 6 950 13.2 4 600 5 400 3 100 6314 ZZ LLB LLU180 42 3 ― 128 89.5 13 100 9 100 12.7 4 100 4 800 ― 6414 ― ― ―

95 10 0.6 0.5 12.5 12.9 1 280 1 310 16.0 6 400 7 600 3 600 6815 ZZ LLB LLU105 16 1 0.5 24.4 22.6 2 480 2 300 16.5 6 100 7 200 3 500 6915 ZZ LLB LLU115 13 0.6 ― 25.0 24.0 2 540 2 450 16.6 5 700 6 700 ― 16015 ― ― ―115 20 1.1 0.5 39.5 33.5 4 050 3 400 15.8 5 700 6 700 3 300 6015 ZZ LLB LLU130 25 1.5 0.5 66.0 49.5 6 750 5 050 14.7 4 800 5 600 3 200 6215 ZZ LLB LLU160 37 2.1 0.5 113 77.0 11 600 7 850 13.2 4 300 5 000 2 900 6315 ZZ LLB LLU190 45 3 ― 138 99.0 14 000 10 100 12.7 3 800 4 500 ― 6415 ― ― ―

100 10 0.6 0.5 12.7 13.3 1 290 1 360 16.0 6 000 7 100 3 400 6816 ZZ LLB LLU110 16 1 0.5 24.9 24.0 2 540 2 450 16.6 5 700 6 700 3 200 6916 ZZ LLB LLU125 14 0.6 ― 25.4 25.1 2 590 2 560 16.4 5 300 6 200 ― 16016 ― ― ―125 22 1.1 0.5 47.5 40.0 4 850 4 050 15.6 5 300 6 200 3 100 6016 ZZ LLB LLU140 26 2 0.5 72.5 53.0 7 400 5 400 14.6 4 500 5 300 3 000 6216 ZZ LLB LLU170 39 2.1 0.5 123 86.5 12 500 8 850 13.3 4 000 4 700 2 700 6316 ZZ LLB LLU200 48 3 ― 164 125 16 700 12 800 12.3 3 600 4 200 ― 6416 ― ― ―

110 13 1 0.5 18.7 19.0 1 910 1 940 16.2 5 700 6 700 3 100 6817 ZZ LLB LLU120 18 1.1 0.5 32.0 29.6 3 250 3 000 16.4 5 400 6 300 3 000 6917 ZZ LLB LLU130 14 0.6 ― 25.9 26.2 2 640 2 670 16.4 5 000 5 900 ― 16017 ― ― ―130 22 1.1 0.5 49.5 43.0 5 050 4 400 15.8 5 000 5 900 2 900 6017 ZZ LLB LLU150 28 2 0.5 83.5 64.0 8 500 6 500 14.7 4 200 5 000 2 800 6217 ZZ LLB LLU180 41 3 0.5 133 97.0 13 500 9 850 13.3 3 800 4 500 2 600 6317 ZZ LLB LLU

B

r

r

φD φd

Shielded type(ZZ)

Non-contactsealed type

(LLB)

Contactsealed type

(LLU)

Open type



min-1 non- low-mm kN kgf grease oil contact torque contact

rNS open type open type open shielded sealed sealedd D B rs min

1） min Cr Cor Cr Cor fo ZZ LLB Z LB LLU type type type type


B-15

N NR 82.9 1.7 1.3 0.4 89.4 1.12 69 70 81 91 2.5 1.2 0.6 0.5 0.128N NR 87.9 2.1 1.3 0.4 94.4 1.12 70 71.5 85 96 2.9 1.2 1 0.5 0.206― ― ― ― ― ― ― ― 69 ― 96 ― ― ― 0.6 ― 0.307N NR 96.8 2.87 2.7 0.6 106.5 2.46 71.5 74 93.5 108 5 2.5 1 0.5 0.421N NR 115.21 4.06 3.1 0.6 129.7 2.82 73 80.5 112 131.5 6.5 2.9 1.5 0.5 0.99N NR 135.23 4.9 3.1 0.6 149.7 2.82 76 86 129 152 7.3 2.9 2 0.5 2.08― ― ― ― ― ― ― ― 76 ― 149 ― ― ― 2 ― 3.3

N NR 87.9 1.7 1.3 0.4 94.4 1.12 74 75.5 86 96 2.5 1.2 0.6 0.5 0.137N NR 97.9 2.5 1.3 0.4 104.4 1.12 75 77.5 95 106 3.3 1.2 1 0.5 0.334― ― ― ― ― ― ― ― 74 ― 106 ― ― ― 0.6 ― 0.441N NR 106.81 2.87 2.7 0.6 116.6 2.46 76.5 80.5 103.5 118 5 2.5 1 0.5 0.604N NR 120.22 4.06 3.1 0.6 134.7 2.82 78 85 117 136.5 6.5 2.9 1.5 0.5 1.07N NR 145.24 4.9 3.1 0.6 159.7 2.82 81 92.5 139 162 7.3 2.9 2 0.5 2.52― ― ― ― ― ― ― ― 83 ― 167 ― ― ― 2.5 ― 4.83

N NR 92.9 1.7 1.3 0.4 99.4 1.12 79 80 91 101 2.5 1.2 0.6 0.5 0.145N NR 102.6 2.5 1.3 0.4 110.7 1.12 80 82.5 100 112 3.3 1.2 1 0.5 0.353― ― ― ― ― ― ― ― 79 ― 111 ― ― ― 0.6 ― 0.464N NR 111.81 2.87 2.7 0.6 121.6 2.46 81.5 85.5 108.5 123 5 2.5 1 0.5 0.649N NR 125.22 4.06 3.1 0.6 139.7 2.82 83 90.5 122 141.5 6.5 2.9 1.5 0.5 1.18N NR 155.22 4.9 3.1 0.6 169.7 2.82 86 99 149 172 7.3 2.9 2 0.5 3.02― ― ― ― ― ― ― ― 88 ― 177 ― ― ― 2.5 ― 5.72

N NR 97.9 1.7 1.3 0.4 104.4 1.12 84 85 96 106 2.5 1.2 0.6 0.5 0.154N NR 107.6 2.5 1.3 0.4 115.7 1.12 85 88 105 117 3.3 1.2 1 0.5 0.373― ― ― ― ― ― ― ― 84 ― 121 ― ― ― 0.6 ― 0.597N NR 120.22 2.87 3.1 0.6 134.7 2.82 86.5 91.5 118.5 136.5 5.3 2.9 1 0.5 0.854N NR 135.23 4.9 3.1 0.6 149.7 2.82 89 95.5 131 152 7.3 2.9 2 0.5 1.4N NR 163.65 5.69 3.5 0.6 182.9 3.1 91 105 159 185 8.4 3.1 2 0.5 3.59― ― ― ― ― ― ― ― 93 ― 187 ― ― ― 2.5 ― 6.76

N NR 107.6 2.1 1.3 0.4 115.7 1.12 90 91 105 117 2.9 1.2 1 0.5 0.27N NR 117.6 3.3 1.3 0.4 125.7 1.12 91.5 94 113.5 127 4.1 1.2 1 0.5 0.536― ― ― ― ― ― ― ― 89 ― 126 ― ― ― 0.6 ― 0.626N NR 125.22 2.87 3.1 0.6 139.7 2.82 91.5 97 123.5 141.5 5.3 2.9 1 0.5 0.89N NR 145.24 4.9 3.1 0.6 159.7 2.82 94 103 141 162 7.3 2.9 2 0.5 1.79N NR 173.66 5.69 3.5 0.6 192.9 3.1 98 112 167 195 8.4 3.1 2.5 0.5 4.23

a

b

ro ro

f

φD2

rNa

CY

ra


B

rrN

r

CZ





kg



0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e





B-16

d 90～120mm

90

95

100

105

110

120

115 13 1 0.5 19.0 19.7 1 940 2 010 16.1 5 400 6 300 3 000 6818 ZZ LLB LLU125 18 1.1 0.5 33.0 31.5 3 350 3 200 16.5 5 100 6 000 2 900 6918 ZZ LLB LLU140 16 1 ― 33.5 33.5 3 400 3 400 16.5 4 700 5 600 ― 16018 ― ― ―140 24 1.5 0.5 58.0 49.5 5 950 5 050 15.6 4 700 5 600 2 800 6018 ZZ LLB LLU160 30 2 0.5 96.0 71.5 9 800 7 300 14.5 4 000 4 700 2 600 6218 ZZ LLB LLU190 43 3 0.5 143 107 14 500 10 900 13.3 3 600 4 200 2 400 6318 ZZ LLB LLU

120 13 1 0.5 19.3 20.5 1 970 2 090 16.1 5 000 5 900 2 800 6819 ZZ LLB LLU130 18 1.1 0.5 33.5 33.5 3 450 3 400 16.6 4 800 5 700 2 800 6919 ZZ LLB LLU145 16 1 ― 34.5 35.0 3 500 3 550 16.5 4 500 5 300 ― 16019 ― ― ―145 24 1.5 0.5 60.5 54.0 6 150 5 500 15.8 4 500 5 300 2 600 6019 ZZ LLB LLU170 32 2.1 0.5 109 82.0 11 100 8 350 14.4 3 700 4 400 2 500 6219 ZZ LLB LLU200 45 3 0.5 153 119 15 600 12 100 13.3 3 300 3 900 2 300 6319 ZZ ― LLU

125 13 1 0.5 19.6 21.2 2 000 2 160 16.0 4 800 5 600 2 700 6820 ZZ LLB LLU140 20 1.1 0.5 41.0 39.5 4 200 4 050 16.4 4 500 5 300 2 600 6920 ZZ LLB LLU150 16 1 ― 35.0 36.5 3 600 3 750 16.4 4 200 5 000 ― 16020 ― ― ―150 24 1.5 0.5 60.0 54.0 6 150 5 500 15.9 4 200 5 000 2 600 6020 ZZ LLB LLU180 34 2.1 0.5 122 93.0 12 500 9 450 14.4 3 500 4 200 2 300 6220 ZZ LLB LLU215 47 3 ― 173 141 17 600 14 400 13.2 3 200 3 700 2 200 6320 ZZ ― LLU

130 13 1 0.5 19.8 22.0 2 020 2 240 15.9 4 600 5 400 ― 6821 ― ― ―145 20 1.1 0.5 42.5 42.0 4 300 4 300 16.5 4 300 5 100 2 500 6921 ZZ LLB LLU160 18 1 ― 52.0 50.5 5 300 5 150 16.3 4 000 4 700 ― 16021 ― ― ―160 26 2 0.5 72.5 65.5 7 400 6 700 15.8 4 000 4 700 2 400 6021 ZZ LLB LLU190 36 2.1 0.5 133 105 13 600 10 700 14.4 3 400 4 000 2 300 6221 ZZ ― LLU225 49 3 ― 184 153 18 700 15 700 13.2 3 000 3 600 2 100 6321 ZZ ― LLU

140 16 1 0.5 24.9 28.2 2 540 2 880 16.0 4 300 5 100 ― 6822 ― ― ―150 20 1.1 0.5 43.5 44.5 4 450 4 550 16.6 4 100 4 800 2 400 6922 ZZ LLB LLU170 19 1 ― 57.5 56.5 5 850 5 800 16.3 3 800 4 500 ― 16022 ― ― ―170 28 2 0.5 82.0 73.0 8 350 7 450 15.6 3 800 4 500 2 300 6022 ZZ LLB LLU200 38 2.1 0.5 144 117 14 700 11 900 14.3 3 200 3 800 2 200 6222 ZZ ― LLU240 50 3 ― 205 179 20 900 18 300 13.1 2 900 3 400 1 900 6322 ZZ ― LLU

150 16 1 0.5 28.9 33.0 2 950 3 350 16.0 4 000 4 700 ― 6824 ― ― ―165 22 1.1 0.5 53.0 54.0 5 400 5 500 16.5 3 800 4 400 ― 6924 ― ― ―180 19 1 ― 63.0 63.5 6 450 6 450 16.4 3 500 4 100 ― 16024 ― ― ―180 28 2 0.5 85.0 79.5 8 650 8 100 15.9 3 500 4 100 2 100 6024 ZZ LLB LLU

B

r

r

φD φd

Shielded type(ZZ)

Non-contactsealed type

(LLB)

Contactsealed type

(LLU)

Open type




min-1 non- low-mm kN kgf grease oil contact torque contact

rNS open type open type open shielded sealed sealedd D B rs min

1） min Cr Cor Cr Cor fo ZZ LLB Z LB LLU type type type type

B-17

N NR 112.6 2.1 1.3 0.4 120.7 1.12 95 96 110 122 2.9 1.2 1 0.5 0.285N NR 122.6 3.3 1.3 0.4 130.7 1.12 96.5 99 118.5 132 4.1 1.2 1 0.5 0.554― ― ― ― ― ― ― ― 95 ― 135 ― ― ― 1 ― 0.848N NR 135.23 3.71 3.1 0.6 149.7 2.82 98 102 132 152 6.1 2.9 1.5 0.5 1.02N NR 155.22 4.9 3.1 0.6 169.7 2.82 99 109 151 172 7.3 2.9 2 0.5 2.15N NR 183.64 5.69 3.5 0.6 202.9 3.1 103 118 177 205 8.4 3.1 2.5 0.5 4.91

N NR 117.6 2.1 1.3 0.4 125.7 1.12 100 101 115 127 2.9 1.2 1 0.5 0.3N NR 127.6 3.3 1.3 0.4 135.7 1.12 101.5 104 123.5 137 4.1 1.2 1 0.5 0.579― ― ― ― ― ― ― ― 100 ― 140 ― ― ― 1 ― 0.885N NR 140.23 3.71 3.1 0.6 154.7 2.82 103 109 137 157 6.1 2.9 1.5 0.5 1.08N NR 163.65 5.69 3.5 0.6 182.9 3.1 106 116 159 185 8.4 3.1 2 0.5 2.62N NR 193.65 5.69 3.5 0.6 212.9 3.1 108 125 187 215 8.4 3.1 2.5 0.5 5.67

N NR 122.6 2.1 1.3 0.4 130.7 1.12 105 106 120 132 2.9 1.2 1 0.5 0.313N NR 137.6 3.3 1.9 0.6 145.7 1.7 106.5 110 133.5 147 4.7 1.7 1 0.5 0.785― ― ― ― ― ― ― ― 105 ― 145 ― ― ― 1 ― 0.91N NR 145.24 3.71 3.1 0.6 159.7 2.82 108 110 142 162 6.1 2.9 1.5 0.5 1.15N NR 173.66 5.69 3.5 0.6 192.9 3.1 111 122 169 195 8.4 3.1 2 0.5 3.14N NR 208.6 5.69 3.5 1 227.8 3.1 113 133 202 230 8.4 3.1 2.5 0.5 7

N NR 127.6 2.1 1.3 0.4 135.7 1.12 110 ― 125 137 2.9 1.2 1 0.5 0.33N NR 142.6 3.3 1.9 0.6 150.7 1.7 111.5 115 138.5 152 4.7 1.7 1 0.5 0.816― ― ― ― ― ― ― ― 110 ― 155 ― ― ― 1 ― 1.2N NR 155.22 3.71 3.1 0.6 169.7 2.82 114 119 151 172 6.1 2.9 2 0.5 1.59N NR 183.64 5.69 3.5 0.6 202.9 3.1 116 125 179 205 8.4 3.1 2 0.5 3.7N NR 217.0 6.5 4.5 1 237 3.5 118 134 212 239 9.6 3.5 2.5 0.5 8.05

N NR 137.6 2.5 1.9 0.6 145.7 1.7 115 ― 135 147 3.9 1.7 1 0.5 0.515N NR 147.6 3.3 1.9 0.6 155.7 1.7 116.5 120 143.5 157 4.7 1.7 1 0.5 0.849― ― ― ― ― ― ― ― 115 ― 165 ― ― ― 1 ― 1.46N NR 163.65 3.71 3.5 0.6 182.9 3.1 119 126 161 185 6.4 3.1 2 0.5 1.96N NR 193.65 5.69 3.5 0.6 212.9 3.1 121 132 189 215 8.4 3.1 2 0.5 4.36N NR 232.0 6.5 4.5 1 252 3.5 123 149 227 254 9.6 3.5 2.5 0.5 9.54

N NR 147.6 2.5 1.9 0.6 155.7 1.7 125 ― 145 157 3.9 1.7 1 0.5 0.555N NR 161.8 3.7 1.9 0.6 171.5 1.7 126.5 ― 158.5 173 5.1 1.7 1 0.5 1.15― ― ― ― ― ― ― ― 125 ― 175 ― ― ― 1 ― 1.56N NR 173.66 3.71 3.5 0.6 192.9 3.1 129 136 171 195 6.4 3.1 2 0.5 2.07

a

b

ro ro

f

φD2

rNa

CY

ra


B

rrN

r

CZ





kg



0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e





B-18

d 120～170mm

120

130

140

150

160

170

215 40 2.1 ― 155 131 15 900 13 400 14.4 2 900 3 400 2 000 6224 ZZ LLU260 55 3 ― 207 185 21 100 18 800 13.5 2 600 3 100 ― 6324 ― ―

165 18 1.1 0.5 37.0 41.0 3 750 4 200 16.1 3 700 4 300 ― 6826 ― ―180 24 1.5 0.5 65.0 67.5 6 650 6 850 16.5 3 500 4 100 ― 6926 ― ―200 22 1.1 ― 80.0 79.5 8 150 8 100 16.2 3 200 3 800 ― 16026 ― ―200 33 2 0.5 106 101 10 800 10 300 15.8 3 200 3 800 1 900 6026 ZZ LLU230 40 3 ― 167 146 17 000 14 900 14.5 2 700 3 100 ― 6226 ― ―280 58 4 ― 229 214 23 400 21 800 13.6 2 400 2 800 ― 6326 ― ―

175 18 1.1 0.5 38.5 44.5 3 900 4 550 16.0 3 400 4 000 ― 6828 ― ―190 24 1.5 0.5 66.5 71.5 6 800 7 300 16.6 3 200 3 800 ― 6928 ― ―210 22 1.1 ― 82.0 85.0 8 350 8 650 16.4 3 000 3 500 ― 16028 ― ―210 33 2 ― 110 109 11 200 11 100 15.9 3 000 3 500 1 800 6028 ZZ LLU250 42 3 ― 166 150 17 000 15 300 14.8 2 500 2 900 ― 6228 ― ―300 62 4 ― 253 246 25 800 25 100 13.6 2 200 2 600 ― 6328 ― ―

190 20 1.1 0.5 47.5 55.0 4 850 5 600 16.1 3 100 3 700 ― 6830 ― ―210 28 2 ― 85.0 90.5 8 650 9 200 16.5 3 000 3 500 ― 6930 ― ―225 24 1.1 ― 96.5 101 9 850 10 300 16.4 2 800 3 200 ― 16030 ― ―225 35 2.1 ― 126 126 12 800 12 800 15.9 2 800 3 200 1 700 6030 ZZ LLU270 45 3 ― 176 168 18 000 17 100 15.1 2 300 2 700 ― 6230 ― ―320 65 4 ― 274 284 28 000 28 900 13.9 2 100 2 400 ― 6330 ― ―

200 20 1.1 0.5 48.5 57.0 4 950 5 800 16.1 2 900 3 400 ― 6832 ― ―220 28 2 ― 87.0 96.0 8 850 9 800 16.6 2 800 3 300 ― 6932 ― ―240 25 1.5 ― 99.0 108 10 100 11 000 16.5 2 600 3 000 ― 16032 ― ―240 38 2.1 ― 143 144 14 500 14 700 15.9 2 600 3 000 1 600 6032 ZZ LLU290 48 3 ― 185 186 18 900 19 000 15.4 2 100 2 500 ― 6232 ― ―340 68 4 ― 278 286 28 300 29 200 13.9 1 900 2 300 ― 6332 ― ―

215 22 1.1 ― 60.0 70.5 6 100 7 200 16.1 2 700 3 200 ― 6834 ― ―230 28 2 ― 86.0 95.5 8 750 9 750 16.5 2 600 3 100 ― 6934 ― ―260 28 1.5 ― 119 128 12 100 13 100 16.4 2 400 2 800 ― 16034 ― ―260 42 2.1 ― 168 172 17 200 17 600 15.8 2 400 2 800 ― 6034 ― ―310 52 4 ― 212 223 21 700 22 800 15.3 2 000 2 400 ― 6234 ― ―360 72 4 ― 325 355 33 500 36 000 13.6 1 800 2 100 ― 6334 ― ―




min-1

mm kN kgf grease oil contactrNS open type open type open shielded sealed

d D B rs min1） min Cr Cor Cr Cor fo ZZ Z LLU type type type

B

r

r

φD φd

Shielded type(ZZ)

Contactsealed type

(LLU)

Open type

B-19

N NR 217.0 6.5 4.5 1 227.8 3.1 131 143 204 230 9.2 3.1 2 0.5 5.15― ― ― ― ― ― ― ― 133 ― 247 ― ― ― 2.5 ― 12.4

N NR 161.8 3.3 1.9 0.6 171.5 1.7 136.5 ― 158.5 173 4.7 1.7 1 0.5 0.8N NR 176.8 3.7 1.9 0.6 186.5 1.7 138 ― 172 188 5.1 1.7 1.5 0.5 1.52― ― ― ― ― ― 136.5 ― 193.5 ― ― ― 1 ― 2.31N NR 193.65 5.69 3.5 0.6 212.9 3.1 139 148 191 215 8.4 3.1 2 0.5 3.16N NR 222.0 6.5 4.5 1 242 3.5 143 ― 217 244 9.6 3.5 2.5 0.5 5.82― ― ― ― ― ― ― ― 146 ― 264 ― ― ― 3 ― 15.3

N NR 171.8 3.3 1.9 0.6 181.5 1.7 146.5 ― 168.5 183 4.7 1.7 1 0.5 0.85N NR 186.8 3.7 1.9 0.6 196.5 1.7 148 ― 182 198 5.1 1.7 1.5 0.5 1.62― ― ― ― ― ― ― ― 146.5 ― 203.5 ― ― ― 1 ― 2.45― ― ― ― ― ― ― ― 149 158 201 ― ― ― 2 ― 3.35N NR 242.0 6.,5 4.5 1 262 3.5 153 ― 237 264 9.6 3.5 2.5 0.5 7.57― ― ― ― ― ― ― ― 156 ― 284 ― ― ― 3 ― 18.5

N NR 186.8 3.3 1.9 0.6 196.5 1.7 156.5 ― 183.5 198 4.7 1.7 1 0.5 1.16― ― ― ― ― ― ― ― 159 ― 201 ― ― ― 2 ― 2.47― ― ― ― ― ― ― ― 156.5 ― 218.5 ― ― ― 1 ― 3.07― ― ― ― ― ― ― ― 161 169 214 ― ― ― 2 ― 4.08― ― ― ― ― ― ― ― 163 ― 257 ― ― ― 2.5 ― 9.41― ― ― ― ― ― ― ― 166 ― 304 ― ― ― 3 ― 22

N NR 196.8 3.3 1.9 0.6 206.5 1.7 166.5 ― 193.5 208 4.7 1.7 1 0.5 1.23― ― ― ― ― ― ― ― 169 ― 211 ― ― ― 2 ― 2.61― ― ― ― ― ― ― ― 168 ― 232 ― ― ― 1.5 ― 3.64― ― ― ― ― ― ― ― 171 183 229 ― ― ― 2 ― 5.05― ― ― ― ― ― ― ― 173 ― 277 ― ― ― 2.5 ― 11.7― ― ― ― ― ― ― ― 176 ― 324 ― ― ― 3 ― 26

― ― ― ― ― ― ― ― 176.5 ― 208.5 ― ― ― 1 ― 1.63― ― ― ― ― ― ― ― 179 ― 221 ― ― ― 2 ― 2.74― ― ― ― ― ― ― ― 178 ― 252 ― ― ― 1.5 ― 4.93― ― ― ― ― ― ― ― 181 ― 249 ― ― ― 2 ― 6.76― ― ― ― ― ― ― ― 186 ― 294 ― ― ― 3 ― 14.5― ― ― ― ― ― ― ― 186 ― 344 ― ― ― 3 ― 30.7




kg




a

b

ro ro

f

φD2

rNa

CY

ra


B

rrN

r

CZ


0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e




B-20

d 180～260mm

180

190

200

220

240

260

225 22 1.1 60.5 73.0 6 200 7 450 16.1 2 600 3 000 6836250 33 2 110 119 11 200 12 200 16.5 2 400 2 900 6936280 31 2 117 134 11 900 13 600 16.5 2 300 2 700 16036280 46 2.1 189 199 19 300 20 300 15.6 2 300 2 700 6036320 52 4 227 241 23 200 24 600 15.1 1 900 2 200 6236380 75 4 355 405 36 000 41 500 13.9 1 700 2 000 6336

240 24 1.5 73.0 88.0 7 450 9 000 16.1 2 400 2 900 6838260 33 2 113 127 11 500 13 000 16.6 2 300 2 700 6938290 31 2 134 156 13 700 15 900 16.6 2 100 2 500 16038290 46 2.1 197 215 20 100 21 900 15.8 2 100 2 500 6038340 55 4 255 281 26 000 28 700 15.0 1 800 2 100 6238400 78 5 355 415 36 000 42 500 14.1 1 600 1 900 6338

250 24 1.5 74.0 91.5 7 550 9 300 16.1 2 300 2 700 6840280 38 2.1 157 168 16 000 17 100 16.2 2 200 2 600 6940310 34 2 142 160 14 400 16 300 16.6 2 000 2 400 16040310 51 2.1 218 243 22 200 24 800 15.6 2 000 2 400 6040360 58 4 269 310 27 400 31 500 15.2 1 700 2 000 6240420 80 5 410 500 42 000 51 000 13.8 1 500 1 800 6340

270 24 1.5 76.5 98.0 7 800 10 000 16.0 2 100 2 400 6844300 38 2.1 160 180 16 400 18 400 16.4 2 000 2 300 6944340 37 2.1 181 216 18 500 22 000 16.5 1 800 2 200 16044340 56 3 241 289 24 600 29 400 15.8 1 800 2 200 6044400 65 4 297 365 30 500 37 000 15.3 1 500 1 800 6244460 88 5 410 520 42 000 53 000 14.3 1 400 1 600 6344

300 28 2 85.0 112 8 650 11 400 15.9 1 900 2 200 6848320 38 2.1 170 203 17 300 20 700 16.5 1 800 2 100 6948360 37 2.1 178 217 18 200 22 100 16.5 1 700 2 000 16048360 56 3 249 310 25 400 32 000 16.0 1 700 2 000 6048

320 28 2 87.0 120 8 900 12 200 15.8 1 700 2 000 6852360 46 2.1 222 280 22 600 28 500 16.3 1 600 1 900 6952400 44 3 227 299 23 200 30 500 16.5 1 500 1 800 16052400 65 4 291 375 29 700 38 500 15.8 1 500 1 800 6052



Boundary dimensions Basic load ratings Factor Limiting speeds Bearingdynamic static dynamic static numbers

min-1

mm kN kgfgrease oil open

d D B rs min1） Cr Cor Cr Cor fo lubrication lubrication type

B

r

r

φD φd

ra

φdaφDa

ra

Open Type

186.5 218.5 1 2.03189 241 2 4.76189 271 2 6.49191 269 2 8.8196 304 3 15.1196 364 3 35.6

198 232 1.5 2.62199 251 2 4.98199 281 2 6.77201 279 2 9.18206 324 3 18.2210 380 4 41

208 242 1.5 2.73211 269 2 7.1209 301 2 8.68211 299 2 11.9216 344 3 21.6220 400 4 46.3

228 262 1.5 3231 289 2 7.69231 329 2 11.3233 327 2.5 15.7236 384 3 30.2240 440 4 60.8

249 291 2 4.6251 309 2 8.28251 349 2 12.1253 347 2.5 16.8

269 311 2 5271 349 2 13.9273 387 2.5 18.5276 384 3 25

B-21


Abutment and fillet Massdimensions

mm kg

da Da ras

min max max (approx.)

0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e




B-22

d 280～440mm

440

280

300

320

340

360

380

400

420

350 33 2 137 177 13 900 18 100 16.1 1 600 1 900 6856380 46 2.1 227 299 23 200 30 500 16.5 1 500 1 800 6956420 44 3 232 315 23 700 32 500 16.5 1 400 1 600 16056420 65 4 325 420 33 000 43 000 15.5 1 400 1 600 6056

380 38 2.1 162 210 16 500 21 500 16.1 1 500 1 700 6860420 56 3 276 375 28 200 38 500 16.2 1 400 1 600 6960460 50 4 292 410 29 800 42 000 16.3 1 300 1 500 16060460 74 4 355 480 36 000 49 000 15.6 1 300 1 500 6060

400 38 2.1 168 228 17 200 23 200 16.1 1 400 1 600 6864440 56 3 285 405 29 000 41 000 16.4 1 300 1 500 6964480 50 4 300 440 30 500 45 000 16.4 1 200 1 400 16064480 74 4 370 530 38 000 54 000 15.7 1 200 1 400 6064

420 38 2.1 170 236 17 400 24 000 16.0 1 300 1 500 6868460 56 3 293 430 29 800 44 000 16.5 1 200 1 400 6968520 57 4 340 515 35 000 52 500 16.3 1 100 1 300 16068520 82 5 420 610 42 500 62 500 15.6 1 100 1 300 6068

440 38 2.1 187 258 19 100 26 300 16.0 1 200 1 400 6872480 56 3 300 455 30 500 46 500 16.5 1 100 1 300 6972540 57 4 350 550 36 000 56 000 16.4 1 100 1 200 16072540 82 5 440 670 44 500 68 000 15.7 1 100 1 200 6072

480 46 2.1 231 340 23 600 34 500 16.1 1 100 1 300 6876520 65 4 325 510 33 000 52 000 16.6 1 100 1 200 6976560 82 5 455 725 46 500 74 000 15.9 990 1 200 6076

500 46 2.1 226 340 23 100 34 500 16.0 1 100 1 200 6880540 65 4 335 535 34 000 54 500 16.5 990 1 200 6980600 90 5 510 825 52 000 84 000 15.7 930 1 100 6080

520 46 2.1 260 405 26 500 41 500 16.1 1 000 1 200 6884560 65 4 340 560 35 000 57 000 16.4 940 1 100 6984620 90 5 530 895 54 000 91 000 15.8 880 1 000 6084

540 46 2.1 264 420 26 900 43 000 16.0 950 1 100 6888600 74 4 365 615 37 500 63 000 16.4 890 1 000 6988




min-1



B

r

r

φD φd

ra

φdaφDa

ra

Open Type

B-23

289 341 2 7.4291 369 2 14.8293 407 2.5 23296 404 3 31

311 369 2 10.5313 407 2.5 23.5316 444 3 32.5316 444 3 43.8

331 389 2 10.9333 427 2.5 24.8336 464 3 34.2336 464 3 46.1

351 409 2 11.5353 447 2.5 26.2356 504 3 47.1360 500 4 61.8

371 429 2 12.3373 467 2.5 27.5376 524 3 49.3380 520 4 64.7

391 469 2 19.7396 504 3 39.8400 540 4 67.5

411 489 2 20.6416 524 3 41.6420 580 4 87.6

431 509 2 21.6436 544 3 43.4440 600 4 91.1

451 529 2 22.5456 584 3 60



mm kg

da Da ras


0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e




B-24

d 460～600mm

530

560

600

460

480

500

580 56 3 315 515 32 000 52 500 16.2 900 1 100 6892620 74 4 375 645 38 500 66 000 16.4 850 1 000 6992

600 56 3 320 540 32 500 55 000 16.1 860 1 000 6896650 78 5 430 770 44 000 78 500 16.5 810 950 6996

620 56 3 325 560 33 500 57 000 16.1 820 970 68/500670 78 5 445 805 45 500 82 500 16.5 770 910 69/500

650 56 3 330 580 34 000 59 500 16.0 770 900 68/530

680 56 3 335 600 34 000 61 500 16.0 710 840 68/560

730 60 3 375 705 38 500 72 000 16.0 660 780 68/600




min-1



B

r

r

φD φd

ra

φdaφDa

ra

Open Type

B-25

473 567 2.5 34.8476 604 3 62.2

493 587 2.5 36.2500 630 4 73.0

513 607 2.5 37.5520 650 4 75.5

543 637 2.5 39.5

573 667 2.5 41.5

613 717 2.5 51.7



mm kg

da Da ras


0.1720.3450.6891.031.382.073.455.176.89

0.190.220.260.280.300.340.380.420.44

1 0 0.56

2.301.991.711.551.451.311.151.041.00

Fa

FreX Y X Y

≦efo・Fa

Cor

Fa

Fr＞e




Bearings

Documents

airii rii

tooth profile

transmission

fp fri ri

shafting rigidity

ring orcenter

average bore

basic rated