FIELD: mechanical engineering. SUBSTANCE: device has two balls which are set into free motion and are located along assembly rotation axle and are separated by it. Balls are located at respective ends of axle of assembly are kept in their positions by means of concave (preferably conic or frustum) surface of bearing of rotation assembly and respective concave surface of bearing which is made in stationary rest. One stationary rest is connected to devolving spring for generation of controlled axial preliminary load to assembly. In preferable embodiment, rotation assembly is designed as disk storage drive. EFFECT: decreased number of members, decreased size occupied by bearings, decreased hysteresis and improved shock impact. 10 cl, 8 dwg
