Theory of Operation
(3) by hoses connected to the left and right control
The function of pump regulators (34) is to control the
valves and a port in the respective pump regulators.
flow of pilot oil to and from the servo piston large end
The control signal from the front or pump control valve
(4) in response to reduced pilot oil (28) control signals
is sensed by the piston (7) controlling the position of
from the front and rear pump control valves (3) and
the remote control spool (5) against the spring.
supply oil pressure signals from the front and rear
pumps (22 and 20). Pump displacement (flow) is
The pump supply oil (29 and 30) control signals are
changed by sending pilot oil to or releasing pilot oil
from the pump delivery port through a drilled passage
from the servo piston large end.
in pump housing to the pump pressure inlet (12) in the
regulator and through a line from the other pump
Pilot oil from the pilot pump (18) flows to the pilot oil
regulator (17 and 24). The control signal from the front
inlet (8) at each regulator and through drilled passages
and rear pumps is sensed by the load piston (11)
in the pump housing to the small end of servo pistons.
controlling the position of the load spool (10) against
Pilot oil pressure is maintain at the small end of servo
pistons and at the inlet of both regulators.
The reduced pilot oil (28) control signals are
transferred from the front and rear pump control valves