GUIDE 8K9615 - Caterpillar

Illustration 1 g03380661
Swing motor
(1) Relief valve
(2) Relief valve
(3) Motor head
(4) Solenoid valve for swing parking brake
(5) Port (pilot system oil)
(7) Plate
(8) Friction plate
(9) Body
(10) Shoe
(11) Retainer plate
(12) Drain port
(13) Check valve
(14) Makeup port
(15) Passage (supply oil or return oil)
(16) Check valve
(17) Passage (supply oil or return oil)
(18) Port (supply oil or return oil)
(19) Passage (supply oil or return oil)
(20) Port (supply oil or return oil)
(22) Valve plate
(23) Passage (supply oil or return oil)
(24) Brake spring
(25) Brake piston
(26) Piston
(27) Cylinder barrel
(28) Plate
(29) Drive shaft Operation
The swing motor may be divided into the following three groups:
The rotary group consists of the following components cylinder barrel (27), pistons (26), shoes (10), retainer plate (11) and drive shaft (29).
The parking brake consists of the following components: brake spring (24), brake piston (25), solenoid valve for swing parking brake (4), plate (7) and friction plate (8).
The relief valves and the makeup valves consist of the following components: relief valve (1), relief valve (2), check valve (13) and check valve (16).Rear pump supply oil is delivered to port (18) or port (20). During a SWING RIGHT operation, the oil delivery enters port (20) and flows through passage (19). The oil then flows through passage (15) in valve plate (22) and passes through passage (23) in cylinder barrel (27). This oil pressurizes piston (26) in motor head (3).
Illustration 2 g02160973
Motor passages
(A) Bottom center position
(B) Inlet side (high pressure)
(C) Top center position
(D) Outlet side (low pressure)
(15) Passage (valve plate)
(17) Return passage
(18) Port
(19) Supply passage
(20) Port
(23) Passage (cylinder barrel)
(30) Passage (valve plate)
(31) Direction of motor rotation (counterclockwise rotation) Shoe (10) is pressed against the upper surface of plate (28) by the force of piston (26). The shoe and the piston slide along the slope of plate (28) in a counterclockwise direction. This sliding force causes cylinder barrel (27) to rotate in a counterclockwise direction (31). As each piston reaches the bottom center position (A), oil flows through passage (23) of piston (26) and through passage (30) in valve plate (22). This oil then flows through passage (17) and port (18) of motor head (3) to the hydraulic tank. As cylinder barrel (27) continues to rotate counterclockwise, the piston and the shoe continue to move up the inclined surface of plate (28).For a SWING LEFT operation, rear pump supply oil is delivered to port (18). The supply ports and the return ports are reversed. Cylinder barrel (27) turns clockwise.The case drain oil from the swing motors returns through drain port (12) of motor head (3). The oil flows to the case drain filters and to the hydraulic tank.Reference: For more information concerning the swing parking brake, refer to Systems Operation, "Pilot Valve (Swing Parking Brake)".Reference: For more information concerning the swing relief valves, refer to Systems Operation, "Relief Valve (Swing)".