Disclosed is a triple harmonic speed reducer, which enables a flexible inner gear to generate three tooth misalignment motions after a wave generator rotates for one circle, so that the harmonic speed reducer has higher position precision and rotation precision, more stable transmission, and more stable operation. The triple harmonic speed reducer includes a wave generator, a flexspline and a rigid circular spline, wherein the flexspline includes a flexible inner gear and an output part, the wave generator is arranged in an inner installation cavity of the flexible inner gear, the wave generator includes an input shaft end and a cam, wherein a flexible bearing is annularly arranged between an outer ring peripheral surface of the cam and an inner ring peripheral surface of the flexible inner gear, the cam of the wave generator is specifically of a three-convex structure.

Disclosed herein is a wave generator for a reducer of a harmonic drive structure. The reducer of a harmonic drive structure includes: a circular spline of a ring shape; a flex spline mounted inside the circular spline and having teeth engaged with teeth formed at three or more positions of the inner circumferential surface of the circular spline to be rotated; and a wave generator mounted inside the flex spline, and including a cam plate of a circular shape, and three or more protrusions formed at three or more positions of the outer circumferential surface of the circular cam plate so that the protrusions formed on the outer circumferential surface of the cam plate elastically deform the three or more positions inside the flex spline.

Provided is a plate harmonic reducer, and more particularly, a plate harmonic reducer, in which design may be further simplified and a manufacturing cost may be reduced.

Provided is a strain wave gearing apparatus which is able to make the most of the structural advantages of the flat form while achieving ideal mesh-engagement without involving a high degree of dimensional precision or any special adjustment mechanism. A strain wave gearing apparatus is provided with a stationary internal gear, a rotary internal gear disposed side by side with the stationary internal gear, a flexible planetary gear disposed on the inner peripheral side thereof for meshing partially with the internal gears by being deflected in the radial direction, and a wave generator disposed inside the flexible planetary gear for continuously deforming and deflecting the flexible planetary gear by rotation. In the apparatus, backlash during mesh-engagement is eliminated by making the base portions and of the internal gears and elastic.

A disc recliner 18 for a seat assembly includes a fixed plate 22 secured to a seat cushion 12 and a rotatable plate 30 secured to a seat back 14. Each of the fixed and rotatable plates 22,30 has a plurality of teeth 40,48, the number of teeth not being equal. A flex spline 26 has a plurality of teeth 52, the number of teeth being equal to the number of teeth on the fixed plate 22. A wave generator 28 causes a portion of the teeth 52 on the flex spline 26 to meshingly engage with the teeth 40,48 on the fixed and rotatable plates 22,30. Rotation of the wave generator 28 causes the teeth 52 on the flex spline 26 which meshingly engage with the teeth 40,48 on the fixed and rotatable plates 22,30 to change, thereby causing the rotatable plate 30 to rotate relative to the fixed plate 22, which in turn causes the seat back 14 to pivot relative to the seat cushion 12

Disclosed is a triple harmonic speed reducer, which enables a flexible inner gear to generate three tooth misalignment motions after a wave generator rotates for one circle, so that the harmonic speed reducer has higher position precision and rotation precision, more stable transmission, and more stable operation. The triple harmonic speed reducer includes a wave generator, a flexspline and a rigid circular spline, wherein the flexspline includes a flexible inner gear and an output part, the wave generator is arranged in an inner installation cavity of the flexible inner gear, the wave generator includes an input shaft end and a cam, wherein a flexible bearing is annularly arranged between an outer ring peripheral surface of the cam and an inner ring peripheral surface of the flexible inner gear, the cam of the wave generator is specifically of a three-convex structure.

Disclosed herein is a wave generator for a reducer of a harmonic drive structure. The reducer of a harmonic drive structure includes: a circular spline of a ring shape; a flex spline mounted inside the circular spline and having teeth engaged with teeth formed at three or more positions of the inner circumferential surface of the circular spline to be rotated; and a wave generator mounted inside the flex spline, and including a cam plate of a circular shape, and three or more protrusions formed at three or more positions of the outer circumferential surface of the circular cam plate so that the protrusions formed on the outer circumferential surface of the cam plate elastically deform the three or more positions inside the flex spline.

A wave generator of a strain wave gearing is provided with a rigid plug, a wave bearing mounted to the ellipsoidal outer peripheral surface of the rigid plug, and four elastic claws that rotate integrally with the rigid plug. The balls of the wave bearing include balls in a loose state and balls in a tight state. The loose-state balls adjacent to the tight-state balls are applied with braking force by the elastic claws immediately before they transition into a tight state, and the orbital motion thereof is temporarily prevented or suppressed, whereby the gaps between the loose-state balls and the adjacent tight-state balls are secured. It is possible to prevent increase in rotational torque, damage to the balls or other defects due to ball-to-ball contact by the tight-state balls.

A harmonic drive apparatus (also known as a strain wave gear) is constructed with a circular, flexible spline disc having a generally flat configuration or a slightly conical configuration.

A stress-wave actuator is disclosed in which a stressed, elastic member is in frictional contact with a rigid element. A stress altering element moves along the elastic element, temporarily altering stress in a portion of it, moving the stressed element relative to the rigid element. When the rigid element is an open ended enclosure, the elastic member is shaped and sized to be slightly larger in circumference than the open ended enclosure so that the elastic member is compressed and stressed. Movingly reducing the stress in a portion of the elastic member causes it to be displaced relative to the rigid member. Stress alteration may be effected by magnetic, electric or physical means depending of the physical nature of the elastic element. The stress wave actuator may be configured to act as a high torque motor, a high gear ration motion transfer device, and as a clutch.