PIVOT AS 9R4763 - Caterpillar

Illustration 1 g02691720
Control manifold
Illustration 2 g02693657
(1) Inverse shuttle valve (2) Check valve (3) Fan solenoid valve (4) Cut-in/cut-out valve (5) Priority valve (6) Pressure reducing valve (7) Relief valve (A1) Brake accumulator port (Front service brakes) (A2) Brake accumulator port (Rear service brakes) (F) Hydraulic fan port (LS) Load sense port (P) Pump port (PS) Pressure sensor port (T) Tank portIllustration 2 shows the control manifold when the brakes are released and the fan is turning at a reduced speed. Accumulator pressure is below 11720 kPa (1700 psi). The system is in the CUT-IN position.The pump draws oil from the hydraulic tank. The oil is sent to pressure reducing valve (6), priority valve (5), relief valve (10), and fan solenoid valve (3). Oil also flows through check valve (2) to cut-in/cut-out valve (4) and inverse shuttle valve (1) .With the brake accumulator charge pressure below 11720 kPa (1700 psi), cut-in/cut-out valve (4) is moved to the left by spring force. Cut-in/cut-out valve (4) directs oil to the resolver valve and priority valve (5). At the resolver valve, the pressure from cut-in/cut-out valve (4) is higher than pressure from fan solenoid valve (3). The resolver valve allows the pressure from cut-in/cut-out valve (4) to flow to the flow control spool in the pump control valve. The pump upstrokes.Cut-in/cut-out valve (4) also directs oil to the left port on priority valve (5). This oil assists the spring in shifting the priority valve to the right. This shift reduces the oil flow to the fan motor. The fan speed is reduced since the pump oil flowing to the fan flows through an orifice.Oil from the pump also flows through a screen, check valve (2), and the orifice to inverse shuttle valve (1). Oil flowing into inverse shuttle valve (1) continues until both the accumulators are charged. Inverse shuttle valve (1) maintains equal pressure between both brake accumulators. Pressure in the brake system is limited to 17200 kPa (2500 psi) by cut-in/cut-out valve (4).
Illustration 3 g02693199
(1) Inverse shuttle valve (2) Check valve (3) Fan solenoid valve (4) Cut-in/cut-out valve (5) Priority valve (6) Pressure reducing valve (7) Relief valve (A1) Brake accumulator port (Front service brakes) (A2) Brake accumulator port (Rear service brakes) (F) Hydraulic fan port (LS) Load sense port (P) Pump port (PS) Pressure sensor port (T) Tank portIllustration 3 shows the control manifold when the accumulators are charged, brakes are released and the fan is turning at minimum speed.When the accumulators are charged to 17200 kPa (2500 psi), accumulator oil pressure moves cut-in/cut-out valve (4) to the right. Cut-in/cut-out valve (4) opens a passage. The passage allows oil sent to the resolver valve and oil on the left side of priority valve (5) to flow to the tank. The resolver valve shifts and oil from fan solenoid valve (3) is directed to the pump control valve.The amount of oil flowing to the fan motor is determined by fan solenoid valve (3). Fan solenoid valve (3) directs load sensing oil to the resolver