Specially Machined Bearings Contact Shaft
The inner race of a rolling ring bearing is machined to form a sort of “ridge” which runs around the entire inner race of the bearing. When mounted on a shaft, the bearing contacts the shaft at a single point on this ridge. The bearing may then be pivoted left or right on the shaft and still maintain point contact with the shaft.
In a rolling ring linear drive, three or four rolling ring bearings are housed inside the nut. When the nut is placed on a smooth shaft, and the shaft is rotated, compression is generated against the bearings’ inner races. This causes the bearings to roll along the length of the shaft. A payload attached to the nut is thereby moved linearly.
Pivoting the bearings changes their angle relative to the shaft. This angle determines the linear pitch and travel direction of the rolling ring drive.
