High Speed Four Point Contact Ball Slewing Ring Bearing for Tower Crane

Four point contact ball slewing bearing can carry axial loads, tilting moment and radial loads all at the same time. Almost all steel balls will carry load under the combined action of axial load and tilting moment load. Steel balls are in contact with the raceway of outer ring and inner on a single-point, respectively when carrying pure axial load. When radial loads exceed a certain value there would be two points respectively for the contacting balls within the outer and inner raceway. Meanwhile, wear and friction moment would be in large order to overcome the axial force. The tilting moment and radial force loading in any kind of working conditions allow the contact angle to be adjusted accordingly. The four point contact ball slewing bearing in the main consist of a inner ring, outer ring, a single row of steel balls, and a cage (or spacing block). The four point contact ball slewing bearing inner ring, outer ring have integral and split structure. The rigidity of the integral rings is relatively good in holding its rigidity. The split structure is fastened by bolts, this facilitates for a more convenient adjustment process. Normally the four point contact ball slewing bearing have cages (or spacing blocks). The full ball type has a larger load carrying capacity. In some situations this type would be selected for heavy loading applications. However, this design has a high frictional resistance, this could cause nicks on ball surface. This contact ball design slewing bearing is suitable for tilting moment and small frictional resistance applications. The contact mounting surface must have adequate radial rigidity. The mounting needs will suit mounting holes that are designed as straight hole, counter hole, thread blind hole, or thread through hole and etc.