IMPELLER 2P5849 - Caterpillar

Illustration 1 g06267478
Charging valve
Illustration 2 g06267503
(1) Inverse shuttle valve
(2) Check valve
(3) Fan solenoid valve
(4) Cut-in/cut-out valve
(5) Priority valve
(6) Flow control valve
(7) Relief valve
(A1) Brake accumulator port (Front service brakes)
(A2) Brake accumulator port (Rear service brakes)
(F) Hydraulic fan port
(FG) Fan output pressure test port
(LS) Load sense port
(P) Pressure port
(PG) Pump pressure test port
(PS1) Pressure sensor port
(PS2) Pressure sensor port
(PSG) Accumulator pressure test 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 12070 345 kPa (1751 50 psi). The system is in the CUT-IN position. When the system is in the CUT-IN position, the brakes are charging.The pump draws oil from the hydraulic tank. The oil is sent to 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 12070 345 kPa (1751 50 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. The fan speed is reduced temporarily because oil is being redirected to charge the brakes.Oil from the pump also flows through 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. Inverse shuttle valve (1) also ensures that the lowest pressure of the two accumulators is communicated to the cut-in/cut-out spool pressure sensor. This communication causes the valve to cut-in and charges the accumulators even if only one accumulator pressure is low. Pressure in the brake system is limited to 15510 345 kPa (2250 50 psi) by cut-in/cut-out valve (4).
Illustration 3 g06267528
(1) Inverse shuttle valve
(2) Check valve
(3) Fan solenoid valve
(4) Cut-in/cut-out valve
(5) Priority valve
(6) Flow control valve
(10) Relief valve
(A1) Brake accumulator port (Front service brakes)
(A2) Brake accumulator port (Rear service brakes)
(F) Hydraulic fan port
(FG) Fan output pressure test port
(LS) Load sense port
(P) Pressure port
(PG) Pump pressure test port
(PS1) Pressure sensor port
(PS2) Pressure sensor port
(PSG) Accumulator pressure test 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 15510 345 kPa (2250 50 psi), accumulator