CYLINDER 5W5696 - Caterpillar

Illustration 1 g01383530
Right Side of Machine (1) Generator pump (2) Pressure compensator spool (3) Flow compensator spoolMachines with a hydraulically driven generator are equipped with generator pump (1). The generator pump is a variable displacement, axial piston pump. The pump is load sensing and pressure compensated. The generator pump is located inside the pump compartment. The generator pump is on the right side of the machine. The ports on the generator pump are labelled for identification. The following describes each port on the generator pump:
Port "S" (pump inlet)
Port "L2" (pump case drain)
Port "X" (load sensing port)
Port "B" (pump outlet)The pump is equipped with a compensator valve. The pump compensator valve maintains the pump's pressure and flow at a level which is adequate to fulfill the system load and flow needs. The compensator valve contains flow compensator spool (3) and pressure compensator spool (2).
Illustration 2 g01383542
Cross Section of the Generator Pump (2) Pressure compensator spool (3) Flow compensator spool (4) Compensator valve (5) Load sensing signal (6) Swashplate (7) Slipper retainer (8) Input shaft (9) Slipper (10) Piston (11) Bias piston (12) Bias spring (13) Line from hydraulic tank (14) Valve plate (15) Pump output (16) Barrel assembly (17) Displacement pistonWhen the input shaft is rotated, the barrel assembly turns. The pistons, which are installed in the barrel assembly, also turn with the barrel assembly. One slipper is attached to each piston. The slippers are held against the swashplate by a slipper retainer.The slippers allow the pistons to follow the angle of the swashplate as the barrel assembly rotates. As the slippers move down the ramp of the swashplate, the pistons which are located on the downhill side of the swashplate are pulled out of the barrel assembly. This action draws oil through the valve plate and into the piston bore in the barrel assembly. When a slipper reaches the bottom of the swashplate ramp, rotation of the input shaft forces the slipper to move up the ramp. At this point, the angled swashplate pushes the piston back into the barrel assembly. This action pushes oil out of the piston bore, through the valve plate, and into the output port.Inside the compensator valve, system pressure acts against one side of the flow compensator spool. The combined force from the flow compensator spring and the load sensing signal acts against the opposite side of the spool. Since the pump does not receive a load sensing signal when the engine is being started, the flow compensator spring provides the only force which acts against the pump supply pressure.The angle of the swashplate determines the amount of oil that is drawn into each piston bore. Therefore, the angle determines the amount of oil that is pumped out of each piston bore per revolution of the input shaft. The greater the swashplate angle, the greater the amount of oil which is pulled into the pump. Also, the greater the angle, the greater the amount of oil which is discharged through the valve plate.Before the engine