Service Training
BW 156/177 D-3/PD-3
- E 7 -
BW 178/179 D-3/PD-3
Since the heavy mass of the vibrator shaft must be set into motion during the acceleration of the
vibration, very high pressure peaks will occur in the high pressure side of the closed circuit during this
phase. The high pressure relief valve reduces these pressure peaks to a value of max. 374 bar
(pressure difference between high and low pressure side = 345 bar + charge pressure = 29 bar).
The screw-type cartridges of the high pressure relief valves contain also the boost check valves for the
closed vibration circuit. The function of these valves has already been described in the chapter “travel
system”.
Charge pump
The charge pump for travel circuit and vibration works also as steering pump The pump is an internal
gear pump with fixed displacement.
The oil flow generated by the charge pump is joined together with the return flow from the steering valve
before the hydraulic oil filter and flows through the filter to the charge ports on travel pump and vibration
pump.
Summary of Contents for BW 156 D-3
Page 143: ...Service Training BW 156 177 D 3 PD 3 G 2 BW 178 179 D 3 PD 3 Supply Fig 1 Power supply...
Page 152: ...Service Training BW 156 177 D 3 PD 3 G 11 BW 178 179 D 3 PD 3 Brakes Fig 5 Brake...
Page 159: ...Service Training BW 156 177 D 3 PD 3 G 18 BW 178 179 D 3 PD 3 Vibration Fig 7 Vibration...
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