User Manual

000 293 646 0 - SYS-H XERION 3300 - 04/05 21
1 Overall hydraulic system
PFC pump
391
Description of function When operating a consumer with a constant load (e.g. a hydraulic motor), the
volume flow controller (772) is actuated to a stable position. This keeps both the
pressure on the top face of the variable-displacement pump hydraulic cylinder
(377) and the position of the swash plate (17) constant. As long as the position of
the swash plate (17) remains unchanged, the pump pumps a constant volume
flow.
The following pressures now result on the volume flow controller (772):
Load pressure (signal) + spring force of the compression spring (margin
pressure) (21) on the left side.
·Pump pressure on the right side.
The differential pressure is the margin pressure corresponding to the spring
force of the compression spring (21). The margin pressure is to be 20 bar and
may be adjusted using set screw (22).