For Liugong Clg920d Swing Motor Parts 15c0286 Piston Gp 

The slewing motor is a key component of the slewing mechanism. It can convert the oil pressure provided by the main pump into mechanical energy and input it to the gearbox. The quality of its work performance will directly affect the rotation speed, drive torque, rotation parking and parking brake of the whole machine, which is the key to determining the productivity of the whole machine.

Swing motors are divided into two categories: low-speed high-torque motors and high-speed swing motors.

Low-speed and high-torque motors are seldom used in the slewing mechanism of modern excavators due to their large size and heavier weight. High-speed slewing motors are small in size and light in weight, which facilitates the rational layout of the slewing mechanism, and can also meet different rotation speeds and Torque is required, so it is widely used.
The components of the slewing horse include:

Rotating component, composed of cylinder, plunger, sliding shoe, pressure plate and output shaft
The brake assembly consists of a rotary brake control valve, pressure plate, friction plate, brake piston and brake spring
Relief valve and make-up valve are formed, consisting of relief valve and one-way valve
Rotary Damping Valve
Working principle of swing motor

Working principle The direction of the hydraulic oil of the oil pump enters different oil passages and pushes different plungers, sliding shoes, swashplates, etc., and then realizes right rotation and left rotation