WAVE GENERATOR OF STRAIN WAVE GEARING

摘要

A wave generator of a hollow strain wave gearing has a rigid plug and a needle roller bearing. The needle roller bearing has an inner ring trajectory surface formed in the plug external peripheral surface, a flexible outer ring, an outer ring trajectory surface formed in an inner peripheral surface of the outer ring, and needle rollers. An inner ring trajectory groove is formed in the plug external peripheral surface, and the inner ring trajectory surface is formed in a groove bottom surface of the inner ring trajectory groove. Inner-ring-side restricting surfaces for restricting the needle rollers from moving in the center axis direction are formed in groove side surfaces on both sides of the inner ring trajectory groove. A wave generator can be obtained, which is suitable for increasing the hollow diameter of a strain wave gearing.

主权项

1. A wave generator of a strain wave gearing for flexing a flexible externally toothed gear into an ellipsoidal shape to partially mesh with a rigid internally toothed gear, and for moving meshing positions of the two gears in a circumferential direction; the wave generator comprising:
a rigid plug having an ellipsoidal shape and a needle roller bearing mounted on an ellipsoidal plug external peripheral surface of the rigid plug, wherein the needle roller bearing has an ellipsoidal inner ring trajectory surface formed in the plug external peripheral surface, an outer ring capable of flexing in a radial direction, an outer ring trajectory surface formed in an inner peripheral surface of the outer ring, and a plurality of needle rollers mounted in a rollable state between the inner ring trajectory surface and the outer ring trajectory surface; an inner ring trajectory groove is formed in the plug external peripheral surface and extends in a circumferential direction of the plug external peripheral surface; the inner ring trajectory surface is formed in a groove bottom surface of the inner ring trajectory groove; and an inner-ring-side restricting surface for restricting the needle rollers from moving in an axis direction thereof is formed in groove side surfaces on both sides of the inner ring trajectory groove.