Introduction for spacers and cage for slewing bearing

For ball-type slewing bearings, spacers are generally used to eliminate the friction between the balls. a smaller diameter ball can be put into it every now and then . Contact and friction between the ball and the raceway is much lower than full ball type. The support of such a structure does not occur after long-term use. The same principle can also be used for roller bearings. For example, smaller diameter spacers can be used to separate vertical rows of rollers.

Due to the advantage of the ball type rotating conditions, the friction is not as uniform as the slewing bearing of the cage holding slewing bearing, but is significantly smaller and uniform than the full stuffed ball type. The bearings act as oscillating motions, crossed by left and right rotating for excavator & crane application, the friction is very uniform and small. The ball type or roller type with Nylon spacers is characterized by simplicity and economy. The diameter of the ball or roller should be slightly smaller than the Nylon spacer, but the difference should not be distinguishable by the eye watch. The only disadvantage of this type of spacer element is that only half of the ball (roller) can be mounted on the raceway, and the load capacity is half of the full ball (column) support.

In order to remove the product defects, we could choose steel cage, so 80% of full space on raceway could be filled in steel ball which increase 60% loading moment than before. The new structure with metal contact closely which lead to the bigger friction than before.