SHIM 0961017 - Caterpillar

Illustration 1 g01623301
Fan Pump and Control Valve (Maximum Fan Speed)
(1) Pressure Control Solenoid
(2) Output to Fan Motor
(3) Spring
(4) Case Drain Passage
(5) Large Actuator
(6) Swashplate
(7) Drive Shaft
(8) Small Actuator and Bias Spring
(9) Piston and Barrel Assembly
(10) Case Drain
(11) Inlet from Hydraulic Tank
(12) Adjustment Screw
(13) Pressure Control Spool
(14) Pump Control Spool
(15) Orifice
(16) Spring
(17) Signal Passage
(18) Pump Control Valve
(BB) Cutaway Section
(CC) Component Surface
(FF) Activated Components
(GG) Tank Pressure
(JJ) High Pressure The front fan pump is a variable displacement pump. The rear section is a fixed displacement pump. The load sensing control on the rear section is deactivated. The adjustment screw for the margin spool on the rear pump is turned in all the way. This will keep the rear pump working as a fixed pump. This adjustment screw is located farthest from the pump body in the pump control valve. The pressure compensator destrokes the pump if a blocked discharge occurs. The rear pump compensator is set at 19500 kPa (2828 psi).The fan pump adjusts fan speed in order to match the cooling demands of the system. The fan pump adjusts fan speed by adjusting oil flow to the fan motor. Pump flow is adjusted by the pump control valve.The engine ECM controls the pump control valve. Different machines use different sensors in order to gather data for the engine ECM.The engine ECM adjusts pump output by altering current to pressure control solenoid (1).The hydraulic fan pump has the following components:Pressure Control Solenoid (1) - The pressure control solenoid receives electrical input from the engine ECM. When the solenoid is fully energized, the fan rotates at minimum speed. When the solenoid is fully de-energized, the fan rotates at maximum speed. If the pressure control solenoid loses power, the fan will rotate at maximum speed.Spring (3) - The spring reacts against pressure control spool (13) in response to the signal from pressure control solenoid (1).Large Actuator (5) - When oil pressure increases behind the large actuator piston, the piston will overcome the force of the small actuator and bias spring (8). This causes the angle of swashplate (6) to be reduced.Swashplate (6) - The displacement of the pump is controlled by the angle of the swashplate. When the swashplate is at a maximum angle, the pistons move the maximum volume of oil in and out of the rotating barrel.Drive Shaft (7) - The rotation of the pump is clockwise when the pump is viewed from the drive end. The piston and barrel assembly is splined to the drive shaft.Small Actuator and Bias Spring (8) - When oil pressure is behind the small actuator piston, the angle of the swashplate will be increased. If there is no pressure behind the large actuator piston, the bias spring will hold the swashplate at the maximum angle.Piston and Barrel Assembly (9) - The barrel contains nine pistons. The barrel assembly rotates whenever the engine is running. The pistons move oil into the barrel and out of the barrel.Adjustment Screw (12) - The adjustment screw is used in order