KNOB AS 3165717 - Caterpillar

Illustration 1 g00513537
(1) Piston and gear pump. (2) Piston pump section. (3) Gear pump section. (4) Shaft. (5) Swashplate. (6) Pistons. (7) Cylinder barrel. (8) Inlet passages in the valve plate. (9) Gear. (10) Piston. (11) Outlet passages in the valve plate. (12) Orifice. (13) Passage. (14) Gear. (P1) Piston pump section port. (P2) Piston pump section port. (P3) Gear pump section port.The piston and gear pump (1) contains three outlet ports. Ports (P1) and (P2) are from the piston pump section (2). Port (P3) is from the gear pump section (3). Ports (P1) and (P2) are connected to the straight travel valve in the bank valve. Port (P3) is connected to the pilot and travel speed manifold. Refer to Systems Operation, "Bank Valve" for more information on the straight travel valve. Refer to Systems Operation, "Pilot and Travel Speed Manifold" for more information on the pilot and travel speed manifold.The piston and gear pump receives oil from the main inlet of the pump group. The main inlet of the pump group is located on the opposite side of the pump group from ports (P1), (P2), and (P3) .Piston Pump Section
Illustration 2 g00606930
(7) Cylinder barrel. (8) Inlet passages. (11) Outlet passages. (15) Valve plate.The shaft (4) is splined to the engine. The shaft turns at engine speed. The cylinder barrel (7) is splined to the shaft. As the cylinder barrel rotates, the pistons (6) inside the cylinder barrel ride along the swashplate (5). The pistons in illustration 1 pull oil into the cylinder as the pistons move to the left. The pistons move to the left because of the angle of the swashplate. The oil is pulled in from the inlet through the passages (8) in the valve plate. The valve plate (15) has two outlet passages (11) and two inlet passages (8). When the pistons are pulling in oil, the pistons alternate between the two suction ports. As the pistons revolve around the swashplate, the pistons will move to the right. By moving to the right, the oil is discharged through ports (P1) and (P2). When the pistons are discharging the oil, the pistons alternate between pushing the oil out of the two outlet passages.
Illustration 3 g00611457
(15) Springs. (16) Screw.The swashplate angle is controlled by a change in the load on the pump and by force balancing. When the pilot valves (joystick) are not moved, the pressure in passage (13) is increased by the orifice (12). This causes the piston (10) to move all the way to the right. If the force on