TM 5-3805-280-24-1
Theory of Operation
transmitted to the remote control sleeve (6) and load
INCREASING FLOW (DISPLACEMENT)
sleeve (9) by the feedback link (15). The sleeves move
left until the path to return is closed. The oil at the
When a function is actuated, the reduced pilot oil (28)
large end of servo piston is now trapped holding the
control signal from the pump control valve (3) to the
pump at maximum displacement (flow rate) that is
piston (7) increases. The control signal pushes the
proportional to the pressure of the pump control valve
piston and remote control spool (5) to the left against
control signal.
the spring until the spring force and control signal
pressure are equal. Movement of spool opens a path
DECREASING FLOW (DISPLACEMENT)
from the large end of servo piston to return in the
pump housing (14). Pilot oil on the small end of servo
As the function is returned towards neutral, the
piston pushes the piston down increasing pump angle
reduced pilot oil (28) control signal sensed at the
which increases the displacement (flow). The servo
piston (7) also decreases. The spring pushes the
piston movement is transmitted to the remote control
remote control spool and piston to the right. Movement
sleeve (6) and load sleeve (9) by the feedback link
of the spool opens a path for pilot oil (27) to flow to the
(15). The sleeves move left until the path to return is
servo piston large end (4). The pilot oil pressure
closed. The oil at the large end of servo piston is now
applied to the servo piston large end pushes the piston
trapped holding the pump at the displacement (flow
up against the pressure applied to the small end
rate) that is proportional to the pressure of the pump
decreasing pump flow. The piston and remote control
control valve control signal.
spool continues to be pushed to the right until spring
force again equals the reduced pilot oil control
MAXIMUM FLOW (DISPLACEMENT)
pressure or until the spool contacts the piston (7)
cylinder when function is returned to neutral. As the
When the pilot controller lever is actuated to full stroke,
pump displacement decreases, the movement is
the reduced pilot oil (28) control signal from the pump
transmitted to the remote control sleeve (6) and load
control valve (3) to the piston (7) increases to its
sleeve (9) by the feedback link (15). The sleeves move
maximum. The control signal pushes the piston and
right until the path for pilot oil is closed. The oil at the
remote control spool to the left until the spool contacts
9025
large end of servo piston is now trapped holding the
the maximum flow adjusting screw. Movement of spool
05
pump at the displacement (flow rate) that is
opens a path from the large end of servo piston to
23
proportional to the pressure of the pump control valve
return in pump housing (14). Pilot oil on the small end
control signal.
of servo piston pushes the piston down increasing
pump displacement (flow). The servo piston is
TX,05,GG2153
1929MAY982/2
6-22
