Four basic requirements for precision preload slewing bearings
1. Adjust the axial clearance and radial clearance of the bearing to negative clearance, zero clearance, and narrow clearance, such as (0.03-0.05).
2. Bearing end runout and radial runout: Bearing end runout with a diameter less than 1m is 0.05 and radial runout is 0.08; bearing end runout with a diameter greater than 2m is 0.08 and radial runout is 0.15.
3. Gear grinding, generally grade 7 gears or grade 6 gears.
4. P4 standard, three times stable, rough grinding, fine grinding and final grinding.