ZT150W Slewing Bearing for Excavator Spare Parts Swing Circle Slew Ring

Precision Raceways & Balls: Imagine an oversized, horizontally mounted "bearing." The Big Turntable's inner and outer rings each have a smooth, hardened raceway, like two circular tracks. Countless rigorously selected hardened steel balls (or cylindrical rollers) are precisely arranged between these tracks, carrying loads and allowing relative rotation.

• Gear Drive: Around the turntable's circumference (usually the outer edge) is a precisely machined gear ring. A small drive gear, powered by a high-torque hydraulic motor, meshes tightly with this large gear ring.

• Relative Motion: When hydraulic oil actuates the swing motor, the motor shaft turns the drive gear. Because the drive gear is fixed to the upper structure frame and the large gear ring is fixed to the undercarriage frame (common design), the drive gear rotates around the large gear ring. This action pushes the entire upper structure to rotate relative to the undercarriage. The balls roll smoothly within the raceways, supporting the massive weight and reducing friction.