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| Illustration 1 | g00905199 |
The hydraulic fan motor (1) is a gear-type motor. The motor is located behind the radiator. The hydraulic fan motor drives the radiator fan. The fan draws cooling air through the radiator and the hydraulic oil cooler. Hydraulic oil for the hydraulic fan motor is provided by the gear pump. The fan motor can be a standard fan motor (1) or the fan motor can be a reversing fan motor (13) .
Standard Fan Motor
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| Illustration 2 | g00905203 |
When the machine is started, oil flows into the hydraulic fan motor (7) from the line from pump (2) . The hydraulic oil flows into a cavity that is formed by gears. The pressure of the hydraulic oil forces the gears and the output shaft to rotate.
The fan is attached to the output shaft by an adapter. The rotation of the output shaft causes the fan to rotate. As the gears rotate, the hydraulic oil passes through the outlet port (5) and the oil flows out of the motor.
The hydraulic fan motor is equipped with a demand fan solenoid valve (6) , a flow control valve (9) and a makeup valve (3) . The demand fan solenoid valve is controlled by the machine ECM. The machine ECM sends a signal to the demand fan solenoid valve in order to control the speed of the fan. When the machine ECM sends a maximum signal to the demand fan solenoid valve, the pressure drop across orifice (8) will increase and flow control valve (9) will open. The fan speed will be at the minimum because the flow control valve is diverting oil flow from the pump around the motor. When the machine ECM sends a minimum signal to the demand fan solenoid valve, the pressure drop across orifice (8) will decrease and flow control valve (9) will close. The fan speed will be at the maximum because the flow control valve is no longer diverting oil flow around the motor.
The machine ECM will send the required signal to the demand fan solenoid valve in order to provide the proper fan speed for the cooling system. The machine ECM will monitor the following parameters in order to provide the proper fan speed:
- Coolant temperature
- Hydraulic oil temperature
- Transmission oil temperature
- Air inlet temperature
The makeup valve (3) prevents cavitation in the hydraulic fan motor. During a quick deceleration, the flow of oil to fan motor can stop. The makeup valve will open. This allows oil to flow from the outlet side of the hydraulic fan motor to the inlet side of the fan motor.
The case drain (4) drains oil from the motor to the tank.
Reversing Fan Motor
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| Illustration 3 | g01538333 |
The reversing fan motor (15) is also a gear-type motor.
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| Illustration 4 | g00905205 |
When the machine is started, oil flows into the reversing fan motor from the line from pump (2) . The hydraulic oil flows through fan reversing solenoid (10) . The oil then flows into a cavity that is formed by gears in the motor (15) . The pressure of the hydraulic oil forces the gears and the output shaft to rotate.
The fan is attached to the output shaft by an adapter. The rotation of the output shaft causes the fan to rotate. As the gears rotate, the hydraulic oil flows from the gears toward the fan reversing solenoid (11) . The oil then flows to the outlet port (5) .
The reversing fan motor is equipped with a demand fan solenoid valve (6) , a flow control valve (9) , a fan reversing solenoid (11) and a crossover relief valve (10) . The demand fan solenoid valve is controlled by the machine ECM. The machine ECM sends a signal to the demand fan solenoid valve in order to control the speed of the fan. When the machine ECM sends a maximum signal to the demand fan solenoid valve, the pressure drop across orifice (8) will increase and flow control valve (9) will open. The fan speed will be at the minimum because the flow control valve is diverting oil flow from the pump around the motor. When the machine ECM sends a minimum signal to the demand fan solenoid valve, the pressure drop across orifice (8) will decrease and flow control valve (9) will close. The fan speed will be at the maximum because the flow control valve is no longer diverting oil flow around the motor.
The machine ECM will send the required signal to the demand fan solenoid valve in order to provide the proper fan speed for the cooling system. The machine ECM will monitor the following parameters in order to provide the proper fan speed:
- Coolant temperature
- Hydraulic oil temperature
- Transmission oil temperature
- Air inlet temperature
The crossover relief valve (10) prevents cavitation in the fan motor (15) . During a quick deceleration, the flow of oil to the fan motor can be interrupted. The relief valve will open. This allows oil to flow from the outlet side of the fan motor to the inlet side of the fan motor.
The case drain (4) drains oil from the motor to the tank and the case drain (4) drains oil from the crossover relief valve (10) to the tank.
Fan Reversing Solenoid
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| Illustration 5 | g00996954 |
The reversing fan switch sends a signal to the machine ECM. The fan reversing solenoid (11) is controlled by the machine ECM. When the fan reversing solenoid is shifted, pump oil will be directed in the opposite direction through the fan motor. This will cause the fan to turn in the opposite direction.
When the top of the reversing fan switch (12) is depressed, the fan reversing solenoid (11) is energized in order to reverse the fan for 15 seconds. The fan will be reversed after a delay of approximately 5 seconds. The fan motor will slow down when the direction of the fan is reversed in order to prevent mechanical damage to the fan motor.
When the bottom of the reversing fan switch (14) is depressed, the fan reversing solenoid (11) is energized in order to reverse the fan for 15 seconds. The fan will be reversed after a delay of approximately 5 seconds. This will repeat every 30 minutes until the reversing fan switch is returned to the center position (13) . The fan motor will slow down when the direction of the fan is reversed in order to prevent mechanical damage to the fan motor.