摘要 |
A harmonic drive apparatus comprises a circular spline which has internal spline teeth and which is rotatable around a rotational axis, a flexible cylindrical flexspline which is concentrically disposed within the circular spline and which has external spline teeth, the number of flexspline external teeth being less than the number of internal teeth of the circular spline, a wave generator disposed within the flexspline for flexing the flexspline in the radial direction thereof so as to locally engage the flexspline external teeth with the internal teeth of the circular spline, and a multi-row ball bearing flexible in the radial direction thereof which has balls equally spaced along the circumferential direction of the wave generator and which is disposed between the wave generator and the flexspline, the balls being disposed in a plurality of circumferential lines which are separated from one another along the axial direction of the wave generator, the balls in each circumferential line being disposed between the balls in the other circumferential lines with respect to the circumferential direction of the wave generator. |