The slewing bearing allows the welding torch assembly of the robot to rotate smoothly and precisely through a wide range of angles.

It is typically a single-row four point contact ball bearing mounted in the robot arm. Diameters range from 6 inches to 12 inches.

The inner race of the bearing connects to the torch mount, while the outer race attaches to the robot arm structure.

The bearing allows high rotational accuracy and repeatability for consistent welding quality. It has preload to minimize backlash.

Stainless steel bearing rings resist welding spatter and fumes. Seals keep contaminants out of the lubricant.

Grease lubrication is common, though some may use oil. Lubrication is vital to prevent overheating at high robot speeds.

Rigid mounting, proper installation and tight tolerances are necessary to minimize vibration and deflection during rapid movement.

Periodic relubrication and inspection for wear, noise and backlash is required. Bearings are replaced if damaged.

Newer bearing designs utilize ceramic balls for higher precision, speed and temperature resistance in demanding applications.