Patent attributes
A fixed torque preload piece is positioned between two nuts of a ball screw, the preload piece is formed with through hole located in an axial direction of the two nuts for receiving at least two steel balls. Two terminal openings of each of the through holes are defined in the surfaces of the preload piece facing the two opposite nuts. Three radial threaded holes are formed in the outer periphery of the preload piece, and the threaded holes are vertical to and in communication with the through holes. An adjusting member, an elastic member and an adjusting screw are received sequentially in the respective threaded holes. The steel balls in the through holes are pushed against the two nuts by the arc-shaped abutting surface of the adjusting member, the pushing of the steel balls can produce an adjustable preload, and can absorb the sudden increase of the pressure effectively, thus obtaining the objective of the present invention of outputting torque stably.
