Hydrostatic Drive System (Neutral)
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| Illustration 1 | g00984891 |
Hydrostatic Drive System (Neutral) (1) Fan Drive Gear Pump (2) Fan Drive Gear Motor (3) Filter (4) Hydrostatic Piston Pump (5) Solenoid Valve (Reverse) (6) Solenoid Valve (Forward) (7) Relief Valve (8) Hydrostatic Piston Motor (9) Oil Cooler (10) Flushing Valve (11) Relief Valve (12) Shuttle Valve (13) Control Valve (Motor Displacement) (14) Multifunction Valve (15) Relief Valve (16) Relief Valve | |
The machine is in the following condition:
- The transmission control is in the NEUTRAL position.
- The machine is stationary.
- The engine is running.
Charging System.
Fan drive gear pump (1) supplies pressurized oil to fan drive gear motor (2). The oil then flows through filter (3) and into hydrostatic piston pump (4). The oil flow is blocked at the solenoid valve (reverse) (5), the solenoid valve (forward) (6) and the multifunction valves (14). Relief valve (7) regulates the pressure of the oil that is in the charging system. The oil from relief valve (7) flows into the case of hydrostatic piston pump (4). The oil then flows through hydrostatic piston motor (8) and the oil cooler (9) before the oil returns to the hydraulic tank.
Relief valve (15) will protect the hydrostatic piston pump, the hydrostatic piston motor and the oil cooler from excessive internal pressures. Relief valve (16) is set at a low pressure in order to promote return oil flow through oil cooler (9) .
Hydrostatic Drive System (Forward with Low Load)
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| Illustration 2 | g00984892 |
Hydrostatic Drive System (Forward with Low Load) (1) Fan Drive Gear Pump (2) Fan Drive Gear Motor (3) Filter (4) Hydrostatic Piston Pump (5) Solenoid Valve (Reverse) (6) Solenoid Valve (Forward) (7) Relief Valve (8) Hydrostatic Piston Motor (9) Oil Cooler (10) Flushing Valve (11) Relief Valve (12) Shuttle Valve (13) Control Valve (Motor Displacement) (14) Multifunction Valve (15) Relief Valve (16) Relief Valve | |
The machine is in the following condition:
- The transmission control is in the FORWARD position.
- The transmission speed control is in the high top speed position.
- The machine is in forward motion.
- The engine is running.
Charging System.
Fan drive gear pump (1) supplies pressurized oil to fan drive gear motor (2). The oil then flows through filter (3) and into hydrostatic piston pump (4). The oil flow is blocked at the solenoid valve (reverse) (5) and the multifunction valves (14). When you select FORWARD, the transmission control will activate the solenoid valve (forward) (6). The oil flows into one side of a servo cylinder in order to upstroke the hydrostatic piston pump. The oil then flows through a check valve to relief valve (7). Relief valve (7) regulates the pressure of the oil that is in the charging system. The oil from relief valve (7) flows into the case of the hydrostatic piston pump. The oil then flows through the hydrostatic piston motor and the oil cooler (9) before the oil returns to the hydraulic tank.
Drive System
Hydrostatic piston pump (4) sends pressurized oil to hydrostatic piston motor (8). Some of the pressurized oil acts on one end of flushing valve (10). This allows some of the reduced pressure oil from the drive loop to pass through relief valve (11). This oil passes through the case for the hydrostatic piston motor and oil cooler (9) before returning to the hydraulic tank.
Pressurized oil from the drive loop also flows through shuttle valve (12) onto the control valve (motor displacement) (13). The control valve (motor displacement) restricts the maximum angle of the swashplate within hydrostatic piston motor (8) when the transmission control is in the high speed position.
Relief valve (15) will protect the hydrostatic piston pump, the hydrostatic piston motor and the oil cooler from excessive internal pressures. Multifunction valves (14) protect the major system components. Refer to System Operation, "Piston Pump (Hydrostatic) ".
Hydrostatic Drive System (Forward with Limited Speed or Forward with a Heavy Load)
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| Illustration 3 | g00984893 |
Hydrostatic Drive System (Forward with Limited Speed or Forward with a Heavy Load) (1) Fan Drive Gear Pump (2) Fan Drive Gear Motor (3) Filter (4) Hydrostatic Piston Pump (5) Solenoid Valve (Reverse) (6) Solenoid Valve (Forward) (7) Relief Valve (8) Hydrostatic Piston Motor (9) Oil Cooler (10) Flushing Valve (11) Relief Valve (12) Shuttle Valve (13) Control Valve (Motor Displacement) (14) Multifunction Valve (14a) High Pressure Relief Valve (Forward) (14b) Pressure Limiter Valve (Forward) (14c) High Pressure Relief Valve (Reverse) (14d) Pressure Limiter Valve (Reverse) (15) Relief Valve (16) Relief Valve | |
The machine is in the following condition:
- The transmission control is in the FORWARD position.
- The transmission speed control is in the limited top speed position or the machine is heavily loaded.
- The machine is in forward motion.
- The engine is running.
Charging System.
The charging system is in the same position that is described with illustration 2.
Drive System
The drive system is in the same condition that is described for illustration 2 except for the condition of the control valve (motor displacement) (13). The control valve (motor displacement) (13) will move to the left in order to destroke the motor when the transmission speed control is in the limited top speed position. An increase in loop pressure will move the control valve (motor displacement) (13) to the left in order to destroke the motor when the machine is heavily loaded and the transmission speed control for the machine is in the high speed position. An excessive increase in loop pressure will open pressure limiter valve (14b). This will allow high pressure oil from the loop to destroke the hydrostatic piston pump. The system is protected against pressure spikes by high pressure relief valve (14a). When the high pressure relief valve (14a) is open, high pressure oil from the loop flows through relief valve (7) to the hydraulic tank.
Hydrostatic Drive System (Reverse with Low Load)
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| Illustration 4 | g00984894 |
Hydrostatic Drive System (Reverse with Low Load) (1) Fan Drive Gear Pump (2) Fan Drive Gear Motor (3) Filter (4) Hydrostatic Piston Pump (5) Solenoid Valve (Reverse) (6) Solenoid Valve (Forward) (7) Relief Valve (8) Hydrostatic Piston Motor (9) Oil Cooler (10) Flushing Valve (11) Relief Valve (12) Shuttle Valve (13) Control Valve (Motor Displacement) (14) Multifunction Valve (15) Relief Valve (16) Relief Valve | |
The machine is in the following condition:
- The transmission control is in the REVERSE position.
- The transmission speed control is in the high top speed position.
- The machine is in reverse motion.
- The engine is running.
Charging System.
Fan drive gear pump (1) supplies pressurized oil to fan drive gear motor (2). The oil then flows through filter (3) and into hydrostatic piston pump (4). The oil flow is blocked at the solenoid valve (forward) (6) and the multifunction valves (14). The transmission control will activate the solenoid valve (reverse) (5). The oil flows into one side of a servo cylinder in order to upstroke the hydrostatic piston pump. The oil then flows through a check valve to relief valve (7). Relief valve (7) regulates the pressure of the oil that is in the charging system. The oil from relief valve (7) flows into the case of the hydrostatic piston pump. The oil then flows through the hydrostatic piston motor and the oil cooler (9) before the oil returns to the hydraulic tank.
Drive System
Hydrostatic piston pump (4) sends pressurized oil to hydrostatic piston motor (8). Some of the pressurized oil acts on one end of flushing valve (10). This allows some of the reduced pressure oil from the drive loop to pass through relief valve (11). This oil passes through the case for the hydrostatic piston pump and oil cooler (9) before returning to the hydraulic tank.
Pressurized oil from the drive loop also flows through shuttle valve (12) to the control valve (motor displacement) (13). The control valve (motor displacement) limits the maximum angle of the swashplate within hydrostatic piston motor (8) when the transmission speed control is in the high speed position.
Relief valve (15) will protect the hydrostatic piston pump, the hydrostatic piston motor and the oil cooler from excessive internal pressures. Multifunction valves (14) protect the major system components. Refer to System Operation, "Piston Pump (Hydrostatic)".
Hydrostatic Drive System (Reverse with Limited Speed or Reverse with Heavy Load)
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| Illustration 5 | g00984895 |
Hydrostatic Drive System (Reverse with Limited Speed or Reverse with Heavy load) (1) Fan Drive Gear Pump (2) Fan Drive Gear Motor (3) Filter (4) Hydrostatic Piston Pump (5) Solenoid Valve (Reverse) (6) Solenoid Valve (Forward) (7) Relief Valve (8) Hydrostatic Piston Motor (9) Oil Cooler (10) Flushing Valve (11) Relief Valve (12) Shuttle Valve (13) Control Valve (Motor Displacement) (14) Multifunction Valve (14a) High Pressure Relief Valve (Forward) (14b) Pressure Limiter Valve (Forward) (14c) High Pressure Relief Valve (Reverse) (14d) Pressure Limiter Valve (Reverse) (15) Relief Valve (16) Relief Valve | |
- The transmission control is in the REVERSE position.
- The transmission speed control is in the high top speed position.
- The machine is in reverse motion.
- The engine is running.
Charging System.
The charging system is in the same condition that is described for illustration 4.
Drive System
The drive system is in the same condition that is described for illustration 4 except for the condition of solenoid valve (13). The solenoid will move solenoid valve (13) to the left in order to destroke the motor when the transmission speed control is in the limited top speed position. An increase in loop pressure will move solenoid valve (13) to the left in order to destroke the motor when the machine is heavily loaded. An excessive increase in loop pressure will open pressure limiter valve (14d). This will allow high pressure oil from the loop to destroke the hydrostatic piston pump. The system is protected against pressure spikes by high pressure relief valve (14c). When the high pressure relief valve (14c) is open, high pressure oil from the loop flows through relief valve (7) to the hydraulic tank.