SEPARATOR 1362972 - Caterpillar

Gear Pump with a Solenoid Valve
(DJD1-2015)
(WLG1-833)
(RTA1-518)
(WGX1-918)
(DDA1-2277)
(RBB1-1117)
(WMB1-966)
(EWF1-419)
Illustration 1 g00904667
Illustration 2 g00904668
The hydraulic oil flows into pump (6) from the line from tank (7) . The oil flows from the pump through check valve (5) to shuttle valve (3) . The shuttle valve directs the flow of oil to the accumulator with the lowest pressure through the lines to the brake accumulators (2) . The brake system pressure sensor (4) sends a signal to the machine ECM that is proportional to the pressure in the brake accumulators. When the accumulator pressure rises above 16000 345 kPa (2300 50 psi), the machine ECM sends a signal to the solenoid valve for brake charging (8) in order to shift the solenoid valve for brake charging more open.When the solenoid valve for brake charging (8) shifts open, the pressure drop across orifice (10) increases. When the pressure drop across orifice (10) increases, flow control valve (9) for the brakes will shift open. When flow control valve (9) for the brakes shifts open, oil from pump (6) is also directed to the line to the fan motor (1) . Check valve (5) will close in order to prevent the flow of oil in the brake accumulators to the pump.Note: The solenoid valve for brake charging (8) is a proportional valve. The amount of flow that flows through flow control valve (9) for the brakes is proportional to the amount of flow that flows through the solenoid valve for brake charging (8) . The amount of flow that flows through the solenoid valve for brake charging (8) is proportional to the amount of electric current that is sent from the ECM to the solenoid valve for brake charging (8) .After several applications of the brakes, the pressure in the brake accumulators will decrease below 9800 345 kPa (1400 50 psi). Then, the machine ECM will send a signal to the solenoid valve for brake charging (8) in order to close the solenoid valve for brake charging (8) . When the solenoid valve for brake charging closes, the pressure drop across orifice (10) will decrease. When the pressure drop across orifice (10) decreases, flow control valve (9) for the brakes will close in order to direct more oil to the accumulators. This will charge the brake accumulators in order to provide the proper brake system pressure.Gear Pump without a Solenoid Valve
(DJD2016-UP)
(WLG834-UP)
(RTA519-UP)
(WGX919-UP)
(DDA2278-UP)
(RBB1118-UP)
(WMB967-UP)
(EWF420-UP)
Illustration 3 g01083279
Gear pump
Illustration 4 g00424028
The idler gear (3) meshes with the drive gear (1) . The rotation of the two gears creates a partial vacuum. The partial vacuum is created at the pump inlet as the gear teeth separate. This draws the oil from the hydraulic tank. Oil enters the pump into cavity (4) . The turning of the two gears causes the low pressure oil from cavity (4) to move around the inner pump housing to cavity (2) . As the teeth mesh at the outlet port, the oil is forced out of the gear pump.
Illustration 5 g01194725
(5) Shuttle Valves (6) Relief valve (7) Pressure