PISTON-CLUTCH 9G7442 - Caterpillar

Illustration 1 g06050235
Fan Hydraulic Schematic
(1) To charge filter
(2) Fan solenoid
(3) Fan motor
(4) Makeup valve
(5) Fan pump
(6) From suction strainerWhen the engine is operating, fan pump (5) draws oil through suction strainer (6) inside the hydraulic tank. The fan pump sends flow to fan motor (3). The fan motor consists the following components:
Fan solenoid (2)
Makeup valve (4)Inside fan motor (3) supply oil splits into three branches. One branch flows to the gears of the fan motor. The second branch seats makeup valve (4). The third branch flows to fan solenoid (2).Fan solenoid (2) determines the amount of supply oil flowing through fan motor (3). If the fan solenoid is not energized, the solenoid blocks supply oil. In this case, full supply flow is directed through the fan motor, and the fan operates at the highest speed.Note: During normal operation, fan solenoid (2) is always energized to some degree.When fan solenoid (2) is energized, some pump supply oil flows across the spool of the solenoid. The remaining supply oil flows through fan motor (3). The amount of oil flowing across the solenoid depends on the magnetic field created by the fan solenoid. As the signal strength to the solenoid increases, the magnetic field increases, and the flow across the spool of the solenoid increases.Flow across fan solenoid (2) allows some pump supply oil to bypass fan motor (3). The speed of the fan motor depends on the position of the fan solenoid.After exiting the motor, flow is directed to port "IN" of charge filter (1). This supply flow becomes charge pressure for the propel system.