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Bulletin 948675A
8
Bulletin 948675A
CONTROL SERVICE MANUAL
PRINCIPLE OF OPERATION
Operation for a typical pump is described. Section
diagrams are a representation of typical pumps
with “P-1NN” control.
Functionally, the swashblock (and resultant
displacement) is positioned by two opposite acting
control pistons (unloading control piston and bias
control piston).
See control parts drawing for actual configuration
and location of par t assemblies, orifices,
connections and ports.
STARTING
The bias spring
(329)
positions the control pistons
and connected pump swashblock so that the pump
is at maximum displacement to raise pressure in
the system.
