When the working parts of the machine tool move, the steel ball circulates in the groove of the slider, spreading the load of the slider to each steel ball, thus extending the service life of the linear guide. In order to eliminate the gap between the sliding block and the guide rail, preloading can improve the stability of the guide rail system. The preloading is achieved by installing oversized steel balls between the guide rail and the sliding block.
The diameter tolerance of steel balls is ± 20 microns. The steel balls are selected and classified in increments of 0.5 microns. They are respectively installed on the guide rails. The size of the preload depends on the force acting on the steel balls.
