DH55 Excavator Final Drives Swing Gearbox High Precision Reduction Gear Reducer Construction Machinery Parts 

The excavator swing reducer, generally referred to as the swing gearbox, is an essential transmission assembly that links the swing motor with the large slewing gear ring. It is mainly designed for speed reduction and torque boost, enabling the upper carriage to achieve smooth 360-degree rotation.

The hydraulic motor produces high rotational speed with low torque and transmits power to the sun gear. Power is sequentially delivered through the first-stage planetary gear set and planet carrier to the secondary sun gear and second-stage planetary assembly. After two-stage planetary deceleration, power is output from the secondary planet carrier. The pinion runs at low speed and high torque, meshes with the inner gear ring of the slewing bearing, and ultimately drives the upper structure to perform smooth slewing motion.