bookpower.pdf

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Transmission

Power takeoff


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Preface

This training module introduces the concept of power

take-off. The training module is part of a series of

modules 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, its

function, types, and operation.

Contedo

Introduction 3

Types of power take-off 4

Clutch type of power takeoff - description 5Clutch 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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Global TrainingTP95850 3

Introduction

A power takeoff is part of the transmission system included in vehicles supplied with auxiliary

equipment, 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 the

operation of the hydraulic pump.


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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 and

use:

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 a

hydraulic 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 used

to 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 the

power takeoff.

From the input shaft, the power is transferred through the power takeoff intermediate shaft (4) to

the output shaft (5).

This type of power takeoff permit the movement of different joints through hydraulic pumps or

drive shafts.

Depending on the type of connection between the power takeoff and the intermediate shaft or

output 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 the

coupling shaft (2) to the power takeoff input shaft. The engaging ring is controlled by the gear

lever (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 the

compressed air used for the cylinder operation.

Attention:

Do not connect this type of power takeoff while driving. If, for any reason, the power takeoff has

been 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 the

gearbox and a switch box (2) where the coupling assembly and the flange or hydraulic pump are

located.

A connecting disc called the plate flange (3) is installed on the crankshaft. The power is

transferred from the plate flange through a disc flange (4) to the input shaft (5). An intermediate

gear (6) transfers the input shaft power to the power takeoff drive gear (7) installed in the switch

box. 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 drive

equipment. The engines flywheel is installed inside the power takeoff intermediate house, and

operates the power takeoff input shaft. Thus, the power takeoff is located between the engine

and the clutch, making it independent on the clutch. The input shafts (5) flange is the connecting

point 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-off

points 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. Flange

2. Seal

3. Dust shield

4. Rear cover

5. Shims

6. Ball bearing7. Power takeoff output shaft

8. O ring

9. Upper housing

10. Cylindrical roller bearing

11. Circlip

12. Seal ring

13. Front cover

14. Seal ring

15. Pulley cap

16. Seal ring

17. Piston

18. Spring

19. Clutch coupling hub

20. Steel disc21. Friction disc

22. Pressure plate

23. Circlip

24. Circlip

25. Thrust washer

26. Needle bearing inner race

27. Needle bearing

28. Pulley

29. Thrust washer


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Power takeoff not dependent on clutch - main components

Control valve

1. Valve body

2. Cap

3. O ring

4. Oil filter

5. Plug6. Copper washer

7. Seal ring

8. Piston

9. Spring

10. Valve

11. 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 of

compressed air acting on the control valve (11). When the power takeoff is connected, the valve

opens 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) that

compresses the clutch blade set and causes the output shaft to rotate. Its design makes it

possible for the power takeoff to be connected and disconnected with the engine running, while

driving 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 the

gearbox.

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 level

depends on the power takeoff position.

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