LIFT AS 2842960 - Caterpillar

Introduction
Illustration 1 g00700330
Swing motor (1) Relief valve (2) Relief valve (3) Motor head (4) Port (5) Swing parking brake solenoid valve (6) Plate (7) Friction plate (8) Plate (9) Body (10) Drive shaft (11) Drain port (12) Check valve (13) Makeup port (14) Passage (15) Check valve (16) Passage (17) Port (18) Port (19) Passage (20) Valve plate (21) Passage (22) Brake spring (23) Brake piston (24) Piston (25) Cylinder barrel (26) Plate (27) ShoeThe swing motor may be divided into the following three groups:
The rotary group consists of drive shaft (10), piston (24), cylinder barrel (25), plate (26) and shoe (27) .
The parking brake group consists of swing parking brake solenoid valve (5), plate (6), friction plate (7), brake spring (22), and brake piston (23) .
The swing relief and makeup valve consists of relief valve (1), relief valve (2), check valve (12) and check valve (15) .Operation
The oil from the lower pump passes through the swing control valve. The swing control valve directs oil to port (17) or (18) .The following paragraphs illustrate swing right operation of the machine. Pump oil enters port (18). Oil flows through passage (19) and into motor head (3). Oil flows into passage (14), valve plate (20) and through passage (21) into cylinder barrel (25) . Pump oil in cylinder barrel (25) acts against piston (24). The piston (24) forces shoe (27) against plate (8). Cylinder barrel (25) rotates. As a result, the piston and the shoe slide along the inclined surface of plate (8).
Illustration 2 g00367472
Motor passages (head side) (A) Bottom center (B) Inlet side (high pressure) (C) Top center (D) Outlet side (low pressure) (14) Passage (16) Passage (17) Port (18) Port (19) Passage (21) Passage (28) Passage (29) Counterclockwise turnShoe (27) and piston (24) apply a force against plate (8). As a result, cylinder barrel (25) rotates counterclockwise. When each piston reaches the bottom dead center position, passage (21) of that piston opens to passage (28) in valve plate (20). Oil now returns to the hydraulic tank. The piston and the shoe continue to move up on the inclined surface of plate (8). Cylinder barrel (25) continues to turn counterclockwise.For a swing left operation, pump oil is supplied to port (17). The supply ports and return ports are reversed. Cylinder barrel (25) and drive shaft (10) turn clockwise.The case drain oil returns through drain port (11) of motor head (3) to the hydraulic tank.