Four Point Contact Ball Slewing Bearing

Four point contact ball slewing bearing is a kind of separation bearing. 

1. The Definition of Four Point Contact Ball Slewing Bearing

When there is no load or pure radial load, the steel ball makes four-point contact with the bearing ring, which is also the origin of the name. When there is only pure axial load, the steel ball makes two-point contact with the bearing ring, which can withstand two-way axial load. The four point contact ball slewing bearing can also bear torque loads and has the functions of single-row angular contact ball bearings and double-row angular contact ball bearings. Four point contact ball slewing bearing can only work properly when forming the two-point contact between steel ball and bearing ring.

2. The Maintenance of Four Point Contact Ball Slewing Bearing

Four point contact ball slewing bearing plays an important role in large construction machinery. In order to prolong the life of four point contact ball slewing bearing, it is necessary to do a good job in the maintenance of four point contact ball slewing bearing. In general, the lubrication interval of four point contact ball slewing bearing is every 250 hours or so, and different operating intensity can be appropriate to adjust the lubrication cycle. a week is the most appropriate. 

In general, ball bearings such as the single row ball slewing bearing need to be refueled every 100 hours, and roller bearings need to be refueled every 50 hours. Under special circumstances, such as tropic and regions with high humidity, high dust and big temperature difference, we should reduce the cycle of lubrication when the bearing has continuous work. Before or after machines stop running for a long time, we must also add new grease, and the raceway must be filled with grease in every lubrication until the grease oozes out from the sealing tape. 

When lubricating grease is injected, we should turn the slewing bearing slowly to make the grease evenly filled. We should also remove debris from the gear surface. We can choose to add grease according to our own situation.  It is forbidden to wash the slewing bearing with water directly to prevent water from entering the raceway and avoid hard objects entering the gear-meshing area. Check the sealing integrity regularly and restore bearings in time if it falls off.