Excavator Parts Swing Motor Inside Parts Planet Carrier Planetary Gear J221-21A-100000

Excavator Parts Swing Motor Inside Parts Planet Carrier Planetary Gear

The planetary carrier and planetary gears in an excavator's swing motor are core transmission components. They offer high load-bearing capacity, multiple gears share the load, a compact structure, and high torque density. The helical gear design reduces vibration and noise for smooth transmission, but inadequate machining can easily lead to pitting or tooth breakage. The planetary carrier is the rotating frame that supports the planetary gears. It utilizes a monolithic frame structure consisting of double annular side plates and evenly spaced support struts, ensuring even load distribution and high rigidity. The blanks, manufactured using welding or casting processes, are stress-relieved to prevent deformation. Cantilever or modular designs facilitate assembly and are suitable for compact spaces. In the swing motor, they are directly connected to the planetary gear shafts, transmitting the reduced torque to the output shaft. The planetary gears simultaneously rotate on their own axes and orbit with the planetary carrier around the sun gear axis, creating a compound motion. They mesh with the sun gear (center gear) and the internal ring gear, achieving a large reduction ratio through the combination of tooth numbers.