TUBE-RADIATOR OUTLET 9Y3715 - Caterpillar

Illustration 1 g00952942
The hydraulic fan pump is a variable displacement piston pump. The movement of piston and barrel assembly in the hydraulic fan pump draws oil from the hydraulic tank. The hydraulic fan pump provides supply oil for the hydraulic fan system. The supply oil flows from the hydraulic fan pump to the hydraulic fan motor. Then, the hydraulic fan motor rotates the fan.Oil to the pump inlet is provided by the hydraulic tank. The oil then flows from the pump inlet through inlet passages in the cylinder plate. When the shaft is rotated, the openings of the barrel assembly move toward the inlet passages of the cylinder plate.Each piston inside the barrel assembly is held against the swashplate by a slipper. As the barrel assembly rotates, the barrel assembly, the piston and the slipper rotate with the shaft. The angle of the swashplate determines the flow of oil that is produced by the piston pump. At a minimum angle, the pistons travel a small distance within the barrel assembly. The pump is at low flow. At the maximum angle, the pistons travel a larger distance. The pump is at maximum flow.The swashplate can be at any angle between the minimum angle and the maximum angle. The swashplate angle is controlled by the actuator piston. The displacement of the actuator piston is controlled by the amount of oil that is directed to the actuator piston by the pressure and flow compensator valve.
Illustration 2 g00952950
When the engine is started, the engine ECM will receive inputs from the four sensors on the machine. The four sensors inform the engine ECM that the temperatures are less than the key target temperatures. The engine ECM sends max current to the solenoid valve. All oil flow above the flow control spool is open to the hydraulic tank back through the solenoid valve. The pump supply oil flows around the cutoff spool and through the hole in the flow control spool. The supply oil will flow behind the lower end of the flow control spool. The flow control spool will override the margin spring and the flow control spool will move up. Supply oil flows around the flow control spool and flows to the actuator piston. The actuator piston moves to the left and pushes on the swashplate. The force on the swashplate overrides the bias spring. The swashplate is moved toward a minimum angle. The hydraulic fan pump supplies minimum oil flow to the fan motor. This will result in minimum fan speed.
Illustration 3 g00952951
When one of the sensors register a temperature that is above the key target temperature, an output is sent to the engine ECM. The engine ECM computes the information. Then, the engine ECM sends a proportional reduction in current to the solenoid valve. The solenoid valve shifts in the downward direction.Oil from the pump output flows through the solenoid valve and to the flow control spool. Oil that is directed to the flow control spool by the solenoid valve is called signal