Bomag BW 156 D-3, Service Manual

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Service Training
BW 156/177 D-3/PD-3 - D 19 -
BW 178/179 D-3/PD-3
Fig. 13 Function of radial piston motor
Piston position 1:
The oil enters into the oil distributor under pressure, flows through the distributor and presses against
the piston. This is the start of a rotation. Due to the pressure on the back of the piston the roller will
move along the cam, thereby causing a rotary movement of the cylinder block.
Piston position 2:
At this point the oil flow to the piston has reached its largest cross section. The piston continues his travel
along the cam race towards the valley between two cams. The opening cross section decreases with
continuing rotary movement.
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