SHAFT AS 7K5770 - Caterpillar

Illustration 2 g01332901
Pressure and Flow Compensator Valve
(11) Pump pressure passage
(12) Pump control valve
(13) Cutoff valve adjustment screw
(14) Cutoff spring
(15) Cutoff spool
(16) Margin spool adjustment
(17) Margin spring
(18) Load sensing port
(19) Margin spool
(20) Case drain passage
(21) Signal passage to the actuator piston Pump control valve (12) is mounted to the brake and the hydraulic fan pump. Pump control valve (12) contains two spools. Margin spool (19) regulates the pump output flow in response to load sensing port (18). Cutoff spool (15) protects the pump for high pressures.Pump control valve (12) maintains the correct pressure and correct oil flow. The pump is controlled by either sending pump oil to actuator piston (9) or by draining the pump oil from actuator piston (9).Actuator piston (9) and bias spring (7) work together in order to adjust the angle of swashplate (2). Pump control valve (12) prevents overloading of the pump. Pump Destroke
Illustration 3 g01332919
Piston Pump in Destroke
(2) Swashplate
(7) Bias spring
(9) Actuator piston
(11) Pump pressure passage
(15) Cutoff spool
(17) Margin spring
(18) Load sensing port
(19) Margin spool
(20) Case drain passage
(21) Signal passage to the actuator piston When the hydraulic system requires a reduction in flow, a reduced signal is sent to load sensing port (18). High-pressure oil flows to margin spool (19) through pump pressure passage (11). When the pressure against spool (19) overcomes the force of both signal (18) and