This section discusses the features and operation of the hydraulic fan system. The following motor graders are covered in this module:
- 12M Series 3
- 140M Series 3
- 160M Series 3
The hydraulic fan system has the following main components:
- Monitoring system
- Piston pump (brake and hydraulic fan)
- Pump control valve
- Control manifold
- Gear motor (hydraulic fan)
- Oil cooler (brake and hydraulic fan)
The AVSpare Monitoring System consists of an action alarm, action light, and a monitoring panel. The monitoring panel contains individual alert indicators for each machine system and two LCD display screens. The AVSpare Monitoring System provides three warning categories. The first warning category requires only operator awareness. The second warning category needs operator response. The third warning category requires immediate shutdown of the machine systems.
The brake and hydraulic fan pump is a variable displacement axial piston pump. The piston pump also services and gives priority to the brakes. When the engine is operating, the pump will rotate in a counter clockwise direction producing flow to satisfy the following conditions:
- The demand of the brake system
- The demand of the hydraulic fan system
The pump will produce flow until the following conditions are met:
- The pressure setting of the pressure compensator is reached.
- The brakes and the hydraulic fan are not being operated.
The pump control valve is mounted on the piston pump (brake and hydraulic fan). The pump control valve has two functions. The pump control valve controls system pressure. The pump control valve is load sensing. The piston pump (brake and hydraulic fan) will only produce enough oil flow to satisfy the demand of the brake and the hydraulic fan system.
The control manifold directs the oil from the brake and the hydraulic fan pump to the brake circuit and to the fan circuit.
The gear motor (hydraulic fan) is located in the cooling group of the motor grader. The fan is attached to the gear motor. The gear motor converts hydraulic energy into mechanical energy in order to rotate the fan.
The oil cooler (brake and hydraulic fan) is located behind the radiator group. Oil flows from the gear motor (hydraulic fan) through the cooler. The oil flows through the return filter and into the hydraulic tank.