Patent attributes
An automatic tool changer in which the load produced when a turret is rotation-driven is reduced, and abrasion in the balls and the like of a speed reducer, and mal-distribution of an axial pressing force are prevented. The speed reducer that drives the turret in the automatic tool changer is constructed by superposing a driving plate, a holder, and a driven plate in the order named. In the driven plate fitted with tools, there is formed a ball groove in a concave-convex shape having the number of cycles corresponding to the number of the tools. In the driving plate, there is provided a ball groove obtained by enlarging the ball groove of the driven plate in the angular direction and copying two cycles. The holder is provided with a plurality of guide holes in the radial direction, which hold their respective balls. The driving plate is rotated by spindle rotation, and the driven plate is driven at a reduced speed of (the number of tools/2) through the balls. It is possible to reduce the load by setting the ball groove of the driven plate at the optimum pressure angle. The balls are dispersed, so that the axial pressure is even, to thereby reduce the abrasion of the balls and ball grooves, and the like.
