VALVE & MTG GP-MAIN CONTROL 3475103 - Caterpillar

Illustration 1 g01588533
(1) The small section of the vane pump (2) The large section of the vane pumpThe vane pump (elevator) is a two-section vane pump. The pump draws oil from the hydraulic oil tank.Note: The large section and the small section of the pump operate similarly. An explanation of the operation of a typical vane pump follows.
Illustration 2 g01664361
Schematic of the Carriage Assembly for a Typical Vane Pump (3) Rotor (4) Cam ring (5) Outlet (6) Passage (7) Inlet (8) Inlet (9) Outlet (10) Vane (A through G) Locations of the vanes (AA) Pressure oil (BB) Supply oilThe carriage assembly for a typical vane pump is composed of the following components:
A plate
An adapter
Seal packs
Rotor (3)
Cam ring (4)
Vanes (10) Vanes (10) are pushed outward by centrifugal force. The pressure oil in passages (6) keeps the vanes (10) along the contour of cam ring (4). Both ends of the vanes are connected by these passages. The oil in these passages keeps the pressure equal on both ends of the vanes. Also, the oil behind the vanes is allowed to escape as the vanes are pushed inward.As rotor (3) turns clockwise, the vanes in positions (G) and (F) move outward along the contour of cam ring (4). 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 oil tank and through inlet (8). The oil fills the space between positions (F) and (A) .Oil between the vanes at positions (F) and (E) will be trapped when the vanes pass the end of inlet (8). As rotor (3) continues to turn, the vanes are pushed inward by the contour of cam ring (4). The chamber area between the vanes now decreases. The pressure of the oil increases.Pressurized oil between the vanes at positions (A) and (B) is pushed into outlet (5). The oil continues to be pushed through the outlet between positions (B) and (C). When the vane at position (B) passes the end of outlet (5), the cycle is complete.Note: The oil that enters through inlet (7) flows through the cartridge assembly and through outlet (9) similarly.