PLATE AS 1874586 - Caterpillar

Illustration 1 g03813970
Right Side of Machine
(1) Pump
(2) Forward control solenoid
(3) Port "FE"
(4) Port "A"
(5) Port "B"
(6) Port "T1" Water spray system pump (1) is located in the pump stack under a hinged deck plate on the right side of the cab. The deck plate must be open to access this component.Water spray system pump (1) is splined to the pump for the emulsion spray system. The emulsion pump is splined to the right propel pump. The water spray pump and the pump for the emulsion spray system are functionally identical.Note: On single pump arrangements when no emulsion pump is present, water spray system pump (1) is splined to the right propel pump.Water spray system pump (1) is an axial piston pump with a variable displacement. The pump contains an integral charge pump. The pump and the internal charge pump rotate when the engine is running. The angle of the swashplate in the water spray system pump determines the amount of flow that the pump generates. The charge pump is a positive-displacement pump. The speed of the engine determines the amount of flow that the charge pump generates. Each port on water spray system pump (1) pump housing is identified by a numeric or an alpha-numeric designation. These designations are cast into the housing next to the port. The function of each port is as follows:
Port "FE" (3) is the charge outlet port. Oil is directed out this port to an external charge filter and then returned to the pump.
Port "A" (4) is a system port. Port "A" is connected to the forward port of the water spray motor.
Port "B" (5) is a system port. Port "B" is connected to the reverse port of the water spray motor.
Port "T1" (6) is the main case drain port. Case drain oil from the pump flows to the tank filter through port "T1".Water spray system pump (1) contains a direction control valve and servo piston. The direction control valve is equipped with proportional solenoids. The function of each solenoid is as follows:
Forward control solenoid (2) controls the flow out of port "B" of the pump.Note: The reverse control solenoid present on water spray system pump (1) is not used.
Illustration 2 g03813971
Water Spray Pump Cross Section (ON)
(7) Feedback Linkage
(8) Directional control valve
(9) Port plate
(10) Charge pump
(11) Combination valve
(12) Servo piston
(13) Drive shaft
(14) Swashplate
(15) Slipper pad
(16) Slipper retainer
(17) Piston
(18) Directional control solenoid "B"
(19) Directional control spool
(20) Centering spring
(21) Directional control solenoid "A"
(22) Barrel assembly
(23) Combination valve
(24) Charge relief valve Engine rotation turns drive shaft (13) on the water spray system pump. This action rotates barrel assembly (22). Pistons (17) inside the water spray pump rotate with the barrel assembly. Piston slipper pads (16) allow the pistons to follow the angle of swashplate (14). The pump only generates flow when the swashplate is not at minimum angle.When the water spray system is not operating, both sides of the servo piston (12) are open to the case drain. Centering springs (20) center the servo piston, and swashplate (14)