Bomag BW 156 D-3, Service Manual

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Service Training
BW 156/177 D-3/PD-3 - E 5 -
BW 178/179 D-3/PD-3
Fig. 5 Cross-section of vibration pump
1 Control
2 Servo piston
3 Friction free swash plate bearing
4 Attachment plate
5 Spool valve
The engine drives the drive shaft with the cylinder block. The cylinder block carries the working pistons.
The slipper pads rest against the sliding surface of the swash plate and are at the same time held on
the sliding surface by a retaining device.
During each rotation the piston pass through their upper and lower dead centre back to their initial
position. Between both dead centres each piston performs a full working stroke. During this stroke
movement oil is drawn in from the low pressure side of the closed circuit and pressed out through the
slots in the valve plate into the high pressure side. The oil quantity depends on the piston area and the
length of the working stroke.
1
2
3
4
5