WAVE MOTION GEAR DEVICE

PURPOSE:To realize a small size wave motion generator which increases the displacement of a driving element, and make a displacement amplifying mechanism unnecessary, by composing the driving element with two-directional shape- memory alloy. CONSTITUTION:When a wire 7d which consists of a shape-memory alloy at a random position is heated by feeding a current from a shape-memory alloy driving device 8 through fixed pins 6d and 6j, the wire 7d is contracted, a flake spline 3 is pulled by the wire 7d, the diameter of the flake spline 3 in the direction square to the contracted wire 7d is increased, and the flake spline 3 is engaged with the spline teeth of the inner circular surface of a circular spline 2. Then, the current feeding and the heating of the wire 7d is stopped, and the neighboring wire 7c is heated by feeding the current through fixed pins 6c and 6d. In this case, the deformation of the flake spline 3 is slipped, and the engaging position of the spline teeth is also slipped. By carrying out such an operation continuously, a relative rotation is generated between the splines 2 and 3, and when the flake spline 3 is fixed in this case, a rotation output can be picked up from the output shaft 5 at the end of the circular spline 2.