Sliding contact type wave generator, wave gear device, and wave generating method

摘要

The wave generator (4) of a strain wave gearing (1) is provided with an ellipsoidally contoured wave generator plug (21) and a wave generator bearing (23). The wave generator bearing (23) is provided with an annular body (26) fitted between inner and outer races (24, 25) in a sliding contact state. The annular body (26) is composed of an endless coil spring and has a rigidity that is able to maintain a constant gap between the inner and outer races (24, 25). The annular body also has a specified overall flexibility in the radial direction so that the annular body can be flexed into an ellipsoidal shape by the wave generator plug (11). Since sliding occurs between the annular body (26) and the inner race (24) when the wave generator plug (21) rotates, it is possible to generate a wave motion in an externally toothed gear (3) with a small rotational torque.