GEAR-TRANSFER 1232876 - Caterpillar

Illustration 1 g01206856
The implement, steering, pilot and braking pump is mounted on the torque converter case at the flywheel end of the engine.
Illustration 2 g00734018
(1) Housing (2) Pilot and braking pump (3) Steering pump (4) Inlet (5) Implement pump (6) Implement pressure outlet (7) Steering pressure outletThe hydraulic pump consists of a three-section vane type pump. The pumps rotate on a common shaft. The pumps draw oil from the hydraulic tank through inlet (4) .Pilot and braking pump (2) is a straight vane pump. The vanes of a straight vane pump do not have vane inserts. The pilot and braking pump provides the oil that is required to operate the pilot control valves of the implement hydraulic system. The pilot and braking pump provides the oil that is required to operate the pilot control valves of the steering system. The pilot and braking pump provides the oil that is required to operate the braking system.Steering pump (3) is a cartridge type of vane pump. The steering pump provides the oil that is required to operate the steering cylinders.Implement pump (5) is a cartridge type of vane pump. The implement pump provides oil that is required to operate the lift arms and the work tool.Operation of the Implement Vane Pump and the Steering Vane Pump
Illustration 3 g00734204
Implement and steering cartridges (AA) Supply oil (BB) Pressure oil (1) Cam ring (2) Rotor (3) Outlet (4) Vane (5) Inlet (6) Slot (7) Passage (8) Inlet (9) Insert (10) Outlet (A-F) Different vane positionsThe components of the cartridge assembly for a typical vane pump include a plate, an adapter, seal packs, cam ring (1), rotor (2) and vanes (4) .Note: Grooves in the flex plates of the implement and steering cartridges allow pressure oil to flow to slots (6) in rotor (2). Oil from the slots then flows into the area between inserts (9) and vanes (4). The vanes are pushed out against cam ring (1). Both ends of the vanes are connected by passages (7) in the rotor. The oil in these passages will keep the pressure even on both ends of the vanes. This oil also permits the oil behind the vanes to escape as the vanes are pushed in. Refer to Illustration 3.As rotor (2) turns clockwise, the vanes in positions (F) and (E) move outward along the contour of the cam ring. As the chamber area between the vanes increases, the oil pressure drops and a vacuum is created in the chamber. This pressure difference causes oil to flow from the hydraulic tank and through inlet (8). The oil fills the space between positions (E) and (A) .Oil between the vanes at positions (E) and (D) will be trapped when the vanes pass the end of inlet (8). As rotor (2) continues to turn, the vanes are pushed inward by the contour of cam ring (1). The chamber area between the vanes now decreases. The pressure of the oil increases.The pressurized oil that is between the vanes at positions (A) and