TWI414695B - - Google Patents

Abstract

A transmission shaft device comprises a key shaft, a transmission element sleeved with the key shaft along an axis, and a plurality of rolling key sets. A plurality of first half round slots are formed at an outer surface of the key shaft. A plurality of second half round slots are formed at an inner surface of the transmission element. The rolling keys sets are installed between the first round slots and the second round slots respectively and arranged with at least a round key and a rolling ball parallel to the axis. Thus, with the easy –to-process property of the half-round slot, the easy-to-arrange rolling balls, the linkage operation of column key, maintaining the required transmission torque, and the rolling effect of the rolling balls, the smoothness of sliding can be enhanced , and the goals of simplified processing, less bearing and precision promotion can be further achieved.