TRANSMISSION 0R4845 - Caterpillar

Illustration 1 g03705036
(1) Machine ECM (2) Motor for rotation (3) Line relief valves (4) Auxiliary control valve (5) Main relief valve (6) Extend solenoid valve "A3" (7) Retract solenoid valve "A3" (8) Main control valve (9) Pilot manifold (10) Solenoid valve for hydraulic lock (11) Pilot pump (12) Idler pump (13) Drive pump (14) Auxiliary pump (15) Hydraulic tankAuxiliary pump (14) is mounted on machines that are equipped with medium pressure with a load sense valve in order to supply hydraulic oil for rotation of the work tool. A typical example is a grapple.The medium pressure circuit for the work tool can be operated by joysticks with modulation switches, joysticks with three buttons, and a foot pedal. Refer to Systems Operation, "Switches" for the Tool Control System for more information on the device for activation.The default parameter values for medium pressure with a load sense valve are shown in Testing and Adjusting, "Medium Pressure: Default Value of Work Tool Parameters (Load Sense Valve)" for the Tool Control System.Use the display monitor or ET in order to set the hydraulic flow to the work tool. Refer to Testing and Adjusting, "Work Tool Setup" section for the Tool Control System for more information.Note: The auxiliary control valve (4) does not influence the proportional solenoid valve for negative flow control.Clockwise Rotation
Illustration 2 g01454096
Operation
Pilot pump (11) supplies oil to pilot manifold (9) . When the hydraulic activation lever is moved to the UNLOCK position, pilot oil flows from pilot manifold (9) to solenoid valves: (6) and (7) .When the device for activation is pressed, the machine ECM sends a signal to retract solenoid (7) for the auxiliary control valve (4) . Pilot oil flows to the top of the auxiliary control valve (4) . The pilot oil will shift the control valve spool to the DOWNWARD position. This allows oil from auxiliary pump (14) to flow through auxiliary control valve (4) to motor (2) for clockwise rotation. Return oil flows back through auxiliary control valve (4) and back to hydraulic tank (15) . The working pressure for rotation is limited by main relief valve (5) .Counterclockwise Rotation
Illustration 3 g01454099
Operation
Pilot pump (11) supplies oil to pilot manifold (9) . When the hydraulic activation lever is moved to the UNLOCK position, pilot oil flows from pilot manifold (9) to solenoid valves: (6) and (7) .When the device for activation is pressed for the opposite direction of flow, the machine ECM sends a signal to extend solenoid (6) for the auxiliary control valve (4) . Pilot oil flows to the top of the auxiliary control valve (4) . The pilot oil will shift the control valve spool to the UPWARD position. This allows oil from auxiliary pump (14) to flow through auxiliary control valve (4) to motor (2) for counterclockwise rotation. Return oil flows back through auxiliary control valve (4) and back to hydraulic tank (15) . The working pressure for rotation is limited by main relief valve (5) .