BUFFER RUBBER 0882593 - Caterpillar

Illustration 1 g03810302
Left Pump Stack
(1) Fan pump Fan pump (1) is located in the left pump stack, under the operator platform. The left pump compartment grate allows access to this component. The cab must be moved to the right to open the grate.Fan pump (1) is the first in a series of pumps that are driven by the engine. The fan pump is driven through a gear system in the flywheel housing.Fan pump (1) is an electronically controlled, axial-piston pump. The pump displacement is variable , and oil flow is reversible. Maximum displacement per revolution of the pump is 56 cc (34 cu in). Two solenoids control the volume and direction of oil flow through the pump.
Illustration 2 g03810305
Fan Pump Cross Section
(2) Direction control solenoid
(3) Speed control solenoid
(4) Port B
(5) Servo piston
(6) Swashplate
(7) Drive shaft
(8) Slipper pad
(9) Piston
(10) Barrel assembly Engine rotation turns pump drive shaft (7), which then rotates the barrel assembly (10). Pistons (9) in the fan pump rotate with the barrel assembly. Piston slipper pads (8) allow the pistons to follow the angle of swashplate (6). When the swashplate is perpendicular to the drive shaft axis, no flow is generated by the pump. As the swashplate angle increases in either direction, oil flow is generated. Flow increases with the angle.Fan pump (1) receives charge oil from the charge pump through port "G1" (21). This charge oil is used to control pump oil flow and to maintain pump fill. The charge oil is directed to the forward makeup and relief valve (22), the reverse makeup and relief valve (20), the valve of speed control solenoid (3), the valve of direction control solenoid (2) and control port (16) of the pressure override relief (POR) valve (13).Each pressure circuit of the fan pump is equipped with makeup and relief valve (20) and (22). The valve function is dependent on direction of oil flow through the pump circuits. The makeup section allows charge oil to flow into the low-pressure circuit in order to replenish the oil lost to internal leakage. The relief section limits the pressure in the high-pressure circuit to 31000 1000 kPa (4496 145 psi).A digital signal is sent to direction control solenoid (2) to control fan pump circuit direction. The direction valve controlled by this solenoid directs charge oil to either side of servo piston (5). This action controls the movement of swashplate (6).When direction control solenoid (2) is not energized, charge oil is directed to the forward chamber of servo piston (5). This oil pressure moves swashplate (6) in the forward direction. In this case, high-pressure oil is directed out port "A" (12) (as shown in the above illustration). When the solenoid is energized, charge oil is directed to the reverse chamber of the servo piston. This oil pressure moves the swashplate in the reverse direction. In this case, high-pressure oil is directed out port "B" (4).The oil pressure in the chamber on the pressurized side of servo piston (5) controls the angle of swashplate