This disclosure relates to a bearing unit wherein the rolling elements are supplied with at least one of the raceways, and wherein the rolling elements are formed of a magnetically attractable material and that raceway which is furnished with the rolling elements has been treated to have magnetic characteristics wherein the rolling elements are permanently magnetically attracted to the raceway by a force sufficient to overcome gravitational forces normally urging the rolling elements away from the raceway.

A slide mechanism for accurate linear, nonlinear and rotational motion. A first slide located in slidable relation to a second slide wherein the slides are separated by a distance except for small bearing surface. A portion of each of the slides is made of a magnetic material such that the slides are attracted to each other thereby maintaining the first and second slides in slidable relation. Apparatus for adjusting the separation distance between the magnetic materials of said surfaces such as a bearing set screw is disposed in one of the slides thereby providing the adjustment of the distance between the magnetic surfaces of the first and second slides. The bearing of the bearing set screw rest upon the opposite slide and provides a smooth movement of the sliding of the slide mechanism. The slide mechanism provides smooth and accurate movement for several mechanical devices.

A spacer contains a magnetic filler and is disposed between the magnetic conductive balls. The magnetic filler produces an indirect magnetic attractive force on the balls, therefore, when the interval between the two neighboring balls is overlarge, the spacer will not tip over under the effect of gravity or centrifugal force, but will be adsorbed on the balls by the magnetic filler.