SCREEN 8X3508 - Caterpillar

Illustration 2 g06077770
(12) Pressure and flow compensator valve
(13) Margin spool adjustment
(14) Margin spring
(15) Load sensing signal port
(16) Margin spool
(17) Spool control orifice
(18) Cutoff valve adjustment screw
(19) Cutoff spring
(20) Plug orifice
(21) Case drain passage
(22) Orifice valve
(23) Signal passage to the actuator piston
(24) Spool control orifice
(25) Cutoff spool
(26) Pump pressure passagePressure and flow compensator valve (12) is mounted to the pump. Pressure and flow compensator valve (12) contains two spools. Margin spool (16) regulates the pump output flow in response to load sensing signal port (15).Pressure and flow compensator valve (12) maintains the correct pressure and correct oil flow. The flow and pressure of the pump are maintained by sending pump oil to actuator piston (3) or draining pump oil from actuator piston (3).Actuator piston (3) and bias spring (1) work together to adjust the angle of swashplate (7). Pressure and flow compensator valve (12) prevents overloading of the pump.Pump Destroke
Illustration 3 g06077774
Piston pump in destroke
(1) Bias spring
(3) Actuator piston
(5) Pump outlet port
(7) Swashplate
(12) Pressure and flow compensator valve
(14) Margin spring
(15) Load sensing signal port
(16) Margin spool
(17) Spool control orifice
(21) Case drain passage
(22) Orifice valve
(23) Signal passage to the actuator piston
(25) Cutoff spoolWhen the hydraulic system requires a reduction in flow, a signal is constantly sent to load sensing signal port (15). The signal will reduce pump flow in the hydraulic system.High-pressure oil flows to margin spool (16) through pump pressure passage (5). The high-pressure oil flows through spool control orifice (17). When the pressure overcomes the force of both load sense signal (15) and margin spring (14).The oil will flow around the cutoff spool (25). The oil flows