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| Illustration 1 | g03719380 |
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(1) Charge pump for the winch
(2) Winch pump (3) Flow from pilot control valve for the winch (4) Brake valve (5) Free spool valve (6) Drive away valve (7) Brake (8) Freespool clutch (9) Winch drum (10) Drive away flow restrictor (11) Solenoid valve for the winch pump (12) Crossover relief and makeup valves (13) Charge filter and bypass valve (14) Tank (15) Winch POR (16) Implement Control 2 ECM (17) Winch control lever (18) Winch free spool switch (19) Winch drive away switch | |
Flow from the implement shutoff valve (3) provides flow to the following items:
- Motor displacement control valve for the winch pump (11)
- Brake valve (4)
- Free spool valve (5)
- Drive away valve (6).
The charge pump for the winch (1) provides flow to the following items:
- Charge filter and bypass valve (13)
- Crossover relief and makeup valves (12)
- Drive away flow restrictor (10).
The D6K Track-Type Tractor is available with an optional hydrostatic winch. The winch has four functions: REEL IN, REEL OUT, FREE SPOOL, and BRAKE OFF
The pump for the winch is similar to the pumps for the hydrostatic system. A POR valve is used to limit the maximum winch system pressure instead of a pressure transducer. The F-N-R valve is also controlled by proportional solenoids.
Pilot oil from the implement pilot shutoff valve supplies pilot oil in order to release the winch brake and the winch clutch spool. Pilot oil activates the drive away solenoid valve.
The flow from the implement shutoff valve continues through passage (3) to the winch control valves. Once the oil for the systems has been supplied, any excess oil returns to tank (14) through the open centered solenoid valve for the winch pump (11). The oil from passage (3) flows to brake valve (4). If, the valve is open the oil will overcome the force of the springs. The oil will release brake (7). The oil from passage (3) flows to free spool valve (5). If, the valve is open the oil will overcome the force of the springs. The oil will release free spool valve (8). The oil from passage (3) flows to the drive away valve. When the valve is open, the oil will activate the drive away function.
The charge pump for the winch (1) is a gear pump. The oil for the charge pump for the winch (1) first passes through the charge filter (13). The crossover relief and makeup valves (12) allow charge oil to enter the closed loop circuit. The charge oil accommodates internal leakage in the pump and the motor.
If the winch control lever (17) is moved to the REEL OUT position or the REEL IN position, the pulse width modulated signal to the Implement 2 ECM (16) changes. The ECM detects the change in duty cycle and sends a signal to the servo valve for the winch pump (11) that will shift flow to the right or to the left. The swashplate in winch pump (2) can move over center. The swashplate will move in the requested direction and the pump will produce flow in the appropriate side of the closed loop circuit for the winch. The flow of oil will cause the winch motor to turn.
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| Illustration 2 | g01367998 |
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View of the installed winch motor | |