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| Illustration 1 | g00474453 |
Fan Motor (1) Output shaft. (2) Case drain port. (3) Adjustment screw. (4) Relief Valve. (5) Check valve. (6) Gears. | |
The fan motor is a fixed displacement gear motor that is mounted behind the hydraulic oil tank. The fan motor drives the radiator fan. The fan motor serves to draw cooling air through the radiator and the hydraulic oil cooler. Hydraulic oil for the fan motor is provided by the gear pump.
The fan motor is equipped with a relief valve (4) and a check valve (5). When the machine is started, the priority valve in the gear pump shifts and the fan motor receives a continuous supply of hydraulic oil. The oil from the gear pump enters the inlet port and flows into the cavity that is formed by gears (6). The pressure of the hydraulic oil forces the gears and the attached output shaft (1) to rotate. The output shaft is mounted to the fan by an adapter and the rotation of the output shaft causes the fan to rotate. As the gears rotate, the hydraulic oil passes through the outlet port and the oil flows out of the motor.
The speed of the fan is controlled by the flow of oil from the priority valve that is in the steering pump and the adjustment of relief valve (4). Adjustment of the relief valve is required in order to change the speed of the fan. Refer to Testing and Adjusting Fan Motor (Radiator Cooling) - Test and Adjust in order to vary the speed of the fan.