D
ESCRIPTION
C
HAPTER
4
THP 94/42 R 4 XXT
THP 125/42 R 4 XXT
THP 140 H/42 R 4 XXT
GB-07.2005
4-5
4.2.2.5
Function of the concrete pump
The concrete pump is hydraulically driven by the vehicle engine through a transfer shift gearbox and hydraulic
pump.
The controls are electric and fully automatic. In addition a back-up function can be engaged by a selection
switch; this allows the concrete pump to continue to be run at a reduced speed should the control system or the
sensors fail. The stroke rate can be varied between minimum and maximum.
The drive cylinders (
1
) are fitted with an automatic leakage compensation. The S-valve automatically compensates
for wear at the wear plate and wear ring.
2
3
4
5
1
S12
S11
S13
S14
C
D
Y5a
Y5b
Y3
B
A
9
8
7
10
6
1
Right drive cylinder
2
Control block
3
Wash-out tank
4
Conveying piston
5
Slide housing with agitator
6
S-valve
7
Wear plate
8
Slewing drive
9
Conveying cylinder II
10
Left drive cylinder
Y4a
Y4b
Fig. 4.3 Operation of the concrete pump
