METHOD OF MAKING AN INTERNAL WAVE GENERATOR FOR STRAIN WAVE GEARING

A method of making an elliptoidal internal journal type wave generator for use with a flexspline (10), the latter having internal spline teeth (12), an outer diameter (O.D.) designated two times the radius (R), and a radial deflection (d) for spline meshing at minor axis localities with diametrically opposed spline teeth of at least one rigid circular spline, the method comprising:a. providing a circular wave generator ring (16) with a radially inner wall diameter (I.D.) equal to twice R plus three times d, and a ring thickness 1.3 to 1.4 times the inner wall LD.;b. opening the ring (16) by forming only one gap (18) at least eight times d in circumferential dimension;c. radially reducing (22) the ring portion (20) diametrically opposite to the gap (18) to enhance radial flexibility of the ring (16) while still enabling it to maintain its I.D. dimension;d. compressing the ring (16) along an axis perpendicular to a median through the gap '18) and the reduced portion to circumferentially decrease the gap (18) until permanent deformation occurs establishing a minor axis dimension in the ring corresponding to loose meshing of the spline teeth; ande. further closing the gap (18) to selectively decrease the minor axis dimension to enable the ring to preload the spline teeth.