SWITCH AS-ROTARY 1402930 - Caterpillar

Illustration 1 g02651238
Left side view of the saw pump
(1) Saw pump
(2) Compensator valve
(3) Load sensing valve
(8) Implement pump (Auxiliary pump)
(AA) Case drain hose
(BB) Inlet line from tank
(CC) Supply (discharge) pressure line to test port
(DD) Pressure line to bank valve Port (P2)
Illustration 2 g02651256
Right side view of the saw pump
(2) Compensator valve
(3) Load sensing valve
(8) Implement pump (Auxiliary pump)
(BB) Inlet line from tank
(CC) Supply (discharge) pressure line to test port
(DD) Pressure line to bank valve Port (P2)
( EE) Load sensing line
Illustration 3 g06097727
Schematic of the saw pump
(1) Saw pump
(2) Compensator valve
(3) Load sensing valve
(4) Orifice
(5) Orifice
(6) Actuator piston
(7) Bias piston
(B) Pressure (discharge) port
(L1) Case drain port
(S) Suction line from tank
(X) Load sensing portOil enters the saw pump from the hydraulic oil tank through inlet line (BB). Case drain oil exits the pump through Port (X). The case drain oil cools the pump. The case drain oil lubricates the pump. Also, the case drain oil removes debris from the pump. The case drain oil is filtered by a screen before flowing back to the hydraulic oil tank.Pressure oil flows from the saw pump through line (DD) to the implement control valve (Bank valve) at Port (P2).The signal pressure from the work port with the highest pressure is sensed at signal port (X). Load sensing valve (3) controls the upstroking and destroking of the pump to match the flow demand and required pressure of the hydraulic system.The load sensing valve compares the output pressure from the pump at Port (B) to the signal pressure at port (X). The difference between the two pressures is the margin pressure until you reach a maximum system pressure of 31000 kPa (4500 psi) where the pump will destroke. The signal pressure continues to increase until the pressure reaches maximum system pressure. The difference in the pressure is 2275 kPa (330 psi). The load sensing valve can be adjusted to control the response of the pump to the pressure and flow requirements of the system.When the engine is running and no functions are being used, no signal pressure goes to port (X). A low-pressure standby condition exists. There are no pressure or flow demands on the saw pump.As the pressure in the system increases, load sensing valve (3) moves to the left and oil flows through compensator valve (2) to actuator piston (6). The actuator piston continues to destroke the pump until swashplate (7) is at the minimum angle.When the flow demand increases, the differential pressure from port (X) to port (B) decreases. (The margin pressure decreases.) The force of the spring in load sensing valve (3) plus the oil pressure at port (X) is greater than the force of the oil pressure from port (B). The load sensing valve moves to the right. The oil from actuator piston (6) flows through the compensator valve and orifices (4) and (5) to the case drain. Bias piston (7) moves to the right causing the pump to upstroke.When the flow demand decreases, the differential pressure from port (X) to port (B)