BUCKET AS-GENERAL PURPOSE 4330362 - Caterpillar

Illustration 1 g06292027
Swing motor
(1) Swing motor
(2) Spring
(3) Parking brake
(4) Piston
(5) Rotary group
(6) Relief valve
(7) Relief valve
(8) Port (B)
(9) Check valve
(10) Port (T)
(11) Check valve
(12) Port (A)
(13) Drain port (DR)
(14) Port (PP)Introduction
Swing motor (1) may be divided into the following three groups:
Rotary group (5) consists of the following components: cylinder barrel, pistons, shoes, and retainer plate.
Parking brake (3) consists of the following components: springs (2), piston (4), plate, and friction plate.
The relief valve and the makeup valve consist of the following components: relief valve (6), relief valve (7), check valve (9), and check valve (11).Operation
Illustration 2 g06292046
Cylinder barrel
(A) Bottom center position
(B) Outlet side (low pressure)
(C) Inlet side (high pressure)
(D) Top center position
(8) Port (B)
(12) Port (A)
(15) Passage
(16) Passage
(17) Counterclockwise turn
(18) Passage (valve plate)
(19) Passage (cylinder barrel)
(20) Passage (cylinder barrel)
(21) Passage (valve plate)Main pump oil passes through the swing control valve and the oil is directed to port (8) and port (12).For a SWING RIGHT operation, pump oil enters port (8). The oil then goes through passage (15) and passage (18). Oil then goes through passage (20) inside the cylinder barrel.Pump oil in the cylinder barrel acts against a piston inside rotary group (5). This forces the piston out of the cylinder barrel. This action causes rotary group (5) to rotate.For a SWING LEFT operation, main pump oil is supplied to port (12). The supply ports and the return ports are reversed. The cylinder barrel turns clockwise.The case drain oil from the swing motor returns through drain port (13) and flows to the hydraulic tank.Reference: For more information concerning the swing relief valves , refer to Systems Operation, "Relief Valve (Swing)".