LOCK-WRIST PIN 5A9148 - Caterpillar

Construction
Illustration 1 g03385784
(1) Port A
(2) Swing motor
(3) Shock reducing valve
(4) Make-up port
(5) Port B
(6) Shock reducing valve
(7) Check valve
(8) Motor rotary group
(9) Check valve
(10) Passage
(11) Passage Swing motor (2) is piston type motor. Oil flow from the main pump is supplied to the swing motor. When a swing operation is performed, the swing motor rotates planetary gear sets inside the swing drive assembly. The Swing drive contains two sets of planetary gear sets to provide a gear reduction at the drive gear . The gear reduction decreases the speed of the swing motor to allow better control of the swing operations. The drive gear rotates and causes the upper structure to rotate.
Illustration 2 g03386090
Motor rotary group (typical example)
(12) Output shaft
(13) Piston
(14) Shoe
(15) Swashplate
(16) Barrel
(17) Valve plate
Illustration 3 g03386122
Motor passages
(1) Port A
(5) Port B
(10) Passage
(11) Passage The internal construction of the swing motor is divided into the following two groups:
The Head group consists of shock reducing valve (3), shock reducing valve (6), check valve (7) and check valve (9).
Motor rotary group (8) consists of output shaft (12), barrel (16), pistons (13), shoes (14) and valve plate (17). Operation
Supply oil from the main pump is delivered to either port A (1) or to port B (5) depending on the swing operation. During a SWING RIGHT operation, the oil delivery enters the swing motor through port A (1). The supply oil flows through passage (11) and then through valve plate (17). Supply oil then passes into cylinder barrel (16). This oil pressurizes piston (13) in the swing motor.Shoe (14) is pressed against the upper surface of swashplate (15) by the force of piston (13). Shoe (14) and piston (13) slide along the slope of swashplate (15) in a counterclockwise direction. This sliding force causes cylinder barrel (16) to rotate in a counterclockwise direction. As each piston reaches the bottom center position (A), oil flows through valve plate (17). This oil then flows through passage (10) of the swing motor and into the hydraulic tank. As cylinder barrel (16) continues to rotate counterclockwise, the piston and the shoe continue to move up the inclined surface of swashplate (15). Since cylinder barrel (16) is splined to output shaft (12), the output shaft rotates in the same direction as the cylinder barrel.For a SWING LEFT operation, main pump supply oil is delivered to port B (2). The supply ports and the return ports are reversed. Cylinder barrel (16) rotates in the clockwise direction.The case drain oil from the swing motors returns through makeup port (4) of the swing motor and into the hydraulic tank.Shock Reducing Valve
Illustration 4 g03386176
Shock reducing valve operation at the stop of a SWING RIGHT operation
(1) Port A
(2) Port B
(3) Shock reducing valve
(6) Shock reducing valve
(10) Passage
(11) Passage Shock reducing valves (3) and (6) are mounted in the head of the swing motor. The valves are used to reduce the shock load on the swing motor when the swing function starts and when the swing function stops. This action prevents jerky movement of the upper