Book Power

Transmission

Power takeoff

Preface

This training module introduces the concept of powertake-off. The training module is part of a series ofmodules designed for the Transmission Basic Train-ing.

This module should be studied right after the mod-ules: Rear axle, Clutch, Torque, and General In-formation

While studying this module, you will have the oppor-tunity to learn the meaning of a power take-off, itsfunction, types, and operation.

ContedoIntroduction 3Types of power take-off 4

Clutch type of power takeoff - description 5

Clutch type of power takeoff - models 6

Clutch type of power takeoff - main components 7

Clutch power takeoff - driving and operation 8

Power takeoff non-dependent on a

clutch - description 9

Power takeoff not dependent on clutch

- main components 10

Power takeoff not dependent on clutch

- main components 11

Power takeoff not dependent on a clutch -

driving and operation 12

Koblan power takeoff - lubrication 13

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Introduction

A power takeoff is part of the transmission system included in vehicles supplied with auxiliaryequipment, such as: dump trucks, concrete mixers, cranes, refrigerated trucks, etc.

The power takeoff provides the driving power to the auxiliary equipment.

For example:In a vehicle equipped with a crane, the power takeoff is the equipment responsible for theoperation of the hydraulic pump.

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Types of power take-off

A power takeoff are divided into two categories:

-Power takeoff that are dependent on a clutch (1)

This type of power takeoff is usually used in dump trucks and cranes.The clutch type of power takeoff is driven through the gearbox with the use of a coupling shaft. Itcan used only when the vehicle is parked.

-Power takeoff that are not dependent on a clutch (2)

This type of power takeoff is usually used in refrigerated trucks and concrete mixers.

The clutchless power takeoff is directly driven from the engine flywheel and operates wheneverthe engine is running.

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Clutch type of power takeoff - description

The speed of a clutch type of power takeoff varies according to the engine speed.The power is taken from the intermediate shaft in the gearbox. The K-profile coupling _(polygonal) is used, allowing a larger and better distribution of the torque transferred to the axle.The power takeoff is installed on the right rear side of the gearbox.

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Clutch type of power takeoff - models

Clutch type of power takeoffs come in many different models, each with its own function anduse:

DBKU 1 (1): This is a double rear power takeoff with an individual detachable flange.

BKUH 1071 (2): This is a rear power takeoff directly installed on the gearbox. It is used to run ahydraulic pump.

DBKUH 2 (3): This is a double rear power takeoff with two individual detachable flanges.

DBKUH (4): This is a double rear power takeoff directly installed on the gearbox. It can be usedto run two pumps in the same shaft, one facing forward and the other, backward.

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Clutch type of power takeoff - main components

The power takeoff is contained in a box (1) installed on the rear of the gearbox.The coupling shaft (2) transfers the gearbox intermediate shaft power to the input shaft (3) of thepower takeoff.From the input shaft, the power is transferred through the power takeoff intermediate shaft (4) tothe output shaft (5).This type of power takeoff permit the movement of different joints through hydraulic pumps ordrive shafts.Depending on the type of connection between the power takeoff and the intermediate shaft oroutput shaft, different torque and speeds are obtained.

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Clutch power takeoff - driving and operation

In order to connect or disconnect a power takeoff, there is an engaging ring (6) that connects thecoupling shaft (2) to the power takeoff input shaft. The engaging ring is controlled by the gearlever (7) which, by its turn, is controlled by the piston (8) of a pneumatic cylinder (9).An electrical valve that is operated by a switch installed on the instrument panel supplies thecompressed air used for the cylinder operation.

Attention:Do not connect this type of power takeoff while driving. If, for any reason, the power takeoff hasbeen connected while driving, do not shift gears during its operation, otherwise the gearboxsynchronisers may be submitted to a severe wear.

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Power takeoff non-dependent on a clutch - description

A power takeoff not dependent on a clutch is also known as a Koblan power takeoff.This power takeoff is contained an intermediate box (1) installed between the engine and thegearbox and a switch box (2) where the coupling assembly and the flange or hydraulic pump arelocated.

A connecting disc called the plate flange (3) is installed on the crankshaft. The power istransferred from the plate flange through a disc flange (4) to the input shaft (5). An intermediategear (6) transfers the input shaft power to the power takeoff drive gear (7) installed in the switchbox. To engage and disengage the power takeoff there is a disc clutch (8) in the power takeoffoutput shaft (9).

The output shaft allows the installation of a hydraulic pump or a flange for the mechanical driveequipment. The engines flywheel is installed inside the power takeoff intermediate house, andoperates the power takeoff input shaft. Thus, the power takeoff is located between the engineand the clutch, making it independent on the clutch. The input shafts (5) flange is the connectingpoint for the second flywheel that the clutch is operating on.The input shaft also controls an oil pump (10) that carries the lubrication oil to all power take-offpoints in need of lubrication and, also, creates an oil pressure used to control the disc clutch.

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Power takeoff not dependent on clutch - main components

Upper housing

1. Flange2. Seal3. Dust shield4. Rear cover5. Shims6. Ball bearing7. Power takeoff output shaft8. O ring9. Upper housing10. Cylindrical roller bearing11. Circlip12. Seal ring13. Front cover14. Seal ring15. Pulley cap

16. Seal ring17. Piston18. Spring19. Clutch coupling hub20. Steel disc21. Friction disc22. Pressure plate23. Circlip24. Circlip25. Thrust washer26. Needle bearing inner race27. Needle bearing28. Pulley29. Thrust washer

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Power takeoff not dependent on clutch - main components

Control valve

1. Valve body2. Cap3. O ring4. Oil filter5. Plug6. Copper washer7. Seal ring8. Piston9. Spring10. Valve11. Spring

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Power takeoff not dependent on a clutch - driving and operation

The power take-off is connected and disconnected through a switch that controls the supply ofcompressed air acting on the control valve (11). When the power takeoff is connected, the valveopens the oil flow in the pump to the disc clutch.

The oil passes through a gallery in the input shaft to a space behind a piston (12) thatcompresses the clutch blade set and causes the output shaft to rotate. Its design makes itpossible for the power takeoff to be connected and disconnected with the engine running, whiledriving or at rest.

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Koblan power takeoff - lubrication

A Koblan power takeoff contains an oil pump that supplies oil for its own lubrication.The oil quality and the intervals between the oil changes should be the same used for thegearbox.

Oil level

Check the oil level for the power takeoff regularly.

A Koblan power takeoff contains two level plugs. The plug used to check the power takeoff leveldepends on the power takeoff position.