Swash Plate Principle, Pump - Fayat Bomag BW 900-50 Service Manual

5.1.2 Swash plate principle, pump

Description of function
Hydraulic system – Basic principles
Fig. 82
The swash plate pump is a positive displacement machine with oil
displacing pistons arranged axially to the drive shaft. The pistons
are thereby supported by the swash plate.
Axial piston units based on the swash plate principle with fixed or
variable displacement can be used as hydraulic pumps or hydraulic
motors. In pump mode the mechanical energy is converted to
hydrostatic energy, when used in motor mode the hydrostatic
energy is converted to mechanical energy. When used as a pump,
the flow volume is proportional to the drive speed and the
swashing angle. The available (pump) torque increases with the
pressure drop between high and low pressure side.
Variable displacement pumps and motors can be change their dis-
placement, i.e. the pump delivery rate or motor throughput, by
simply changing the angle of the swash plate.
Fig. 83
1 Drive shaft
2 Piston
3 Piston area
4 Piston stroke
5 Slipping disc
6 Adjusting angle
7 Cylinder
BW 900-50 99