presentation on clutches

Clutches

Presented by

Pratyush ranjnan karM-tech manufacturing technologyRegd no.- 163510

Basic idea

Clutches are useful devices with two rotating shafts It connects the driving shaft to a driven shaft, so that the driven

shaft may be started or stopped at will, without stopping the driving shaft

In a drill,,one shaft is driven by a motor and the other is driving a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed, or be decoupled and spin at different speeds

Types

Types of Clutches

Positive Clutch

Friction Clutch

Plate Or Disc

Clutch

Single plate clutch

Multiplate Clutch

Cone Clutch

Centrifugal Clutch

Positive Clutch/ dog clutch

It couples two rotating shafts or other rotating components not by friction but by interference.

It is Simple to construct, No heat generated , No slip, Compact ,Low cost.

But it Must be connected when shaft is unloaded. Uses- power press and rolling mills

Friction clutches

Single plate clutch

Multiplate clutch

Centrifugal clutch

Driving shaft

Driven shaft

F=mrω2

ω

ω

Cone clutch

Design and torque transmitted

Area of the ring on contacting surface rrA 2

Axial load on the ring rrpW 2

Frictional resistance offered by ring

rprWFr 2

Frictional torque acting on ring rprrFT rr 22

Torque transmitted is obtained by considering following two assumptions:

a) Uniform pressure theory

b) Uniform wear theory

p = Constant

T R

Rr rprT

0

21

2

2

rrpTR

R

T

r 1

2

2

0

2

Torque transmitted

3231

3

32

32

1

2

RRprpTR

R

32312

2213

2 RRRR

WT

22

21

32

31

32

RRRRWT

Uniform pressure theory

Uniform wear theory In this theory, we are considering that wear which take place

is uniform over the entire contacting surface i.e. p.r = Constant So, p = C/r We know that axial loading acting on the ring is,

Integrating above equation within limits we get, rCW

rrrCrrpW

2

...2...2.

21

21

0

2

22

2

1

2

1

2

RRWC

RRCrCW

rCW

RR

R

R

W

We know that, frictional torque acting on the ring is,

Torque transmitted by single plate clutch can be obtained by integrating the equation within the limits R2 to R1 we get,

rCrrrrCT

rprT

r

r

22

2

2

2

2221

22

21

2

0

0

22

22

2

2

1

2

1

2

1

2

RRCT

RRCrCT

rrCT

rrCT

R

R

R

R

T

r

R

R

T

r

• Power transmitted by single plate clutch is given by,

Where, N = Speed of driving shaft

WattNTP

TP

602.

Any questions