Event: Drum (Up)

1. See “Pump (Running)” for first sequence of this event.

2. See “Drum Brake (Released)” for second sequence of this event.

3. The operator shifts the drum control joystick to the “UP” position and a proportional electrical signal is routed through the pump controller and supplies a signal to the control valve of Drum Drive Pump (1) linear to the movement of the joystick.

4. Charge pressure fluid flows through the control valve and brings the pump on stroke supplying pressure fluid flow through the pump “A” port to Drum Drive Motor (4).

5. Pressure fluid rotates the large drum in the up direction and returning fluid flows through the “B” work port of Drum Drive Pump (1).

6. Drum Drive Motor (4) is variable displacement and will remain at full stroke, full torque until the operator shifts the control joystick.

7. Charge fluid pressure above the setting of the internal charge pressure relief valve will vent to Drum Drive Pump (1) case drain.

8. High fluid pressure above the spring setting of the work port internal relief valve will vent to the low pressure side of the closed loop.

9. Drum drive Pump (1) control fluid pressure above the spring setting of the internal pressure override relief valve will vent to the pump case drain and prevent Drum Drive Pump (1) from exceeding preset conditions.