DAF LF45, LF55 Series. Manual — part 267

©

200508

2-3

General

CLUTCH

ΛΦ45/55 series

3

9

2.3 OVERVIEW DRAWING, CLUTCH LEVER ATTACHMENT TO CLUTCH

HOUSING

V300397

1

2

3

4

6

7

5

1.

Screw adapter

2.

Ball joint

3.

Clutch lever

4.

Thrust bearing

5.

Clip

6.

Claw

7.

Yoke pin

CLUTCH

2-4

©

200508

General

9

ΛΦ45/55 series

3

©

200508

3-1

Description of components

CLUTCH

ΛΦ45/55 series

3

9

3. DESCRIPTION OF COMPONENTS

3.1 CLUTCH SERVO

Declutching
Depressing the clutch pedal results in a build-up

of hydraulic pressure.

This causes the servo piston (1) to push the air

valve (2) away from the valve seat, against the

force of the springs (3) and (7).

3

2

7

1

10

8

9

A-A

4

5

6

A

V300352-2

A

CLUTCH

3-2

©

200508

Description of components

9

ΛΦ45/55 series

3

Air pressure now flows into the cylinder.

The pressure pin (4) is pushed forward by the air

pressure building up on air piston (5) and the

hydraulic pressure on fluid piston (6).

The pressure pin (4) pushes against the clutch

lever, which results in declutching.

State of equilibrium
When the hydraulic pressure and pneumatic

support push the pressure pin (4) forwards, a

state of equilibrium is achieved between the air

pressure and the hydraulic pressure (status when

the clutch pedal is not depressed any further).

The servo piston (1) again seals off against the

valve seat, closing the air supply and stopping the

build-up of pneumatic pressure.

Clutching
When the clutch pedal is released, there is no

longer any hydraulic pressure and the servo

piston (1) will be pushed back into its original

position by pressure spring (7) and any remaining

pneumatic support.

As a result, the bleed bore (8) in the servo piston

(1) is no longer closed, and venting takes place

via bleed vent (9).

Vent opening
The function of the vent opening (10) is to prevent

a build up of pressure between both piston seals.