A bending meshing type gear device includes a wave generator; an external gear that is disposed on an outer periphery of the wave generator, and is bendably deformed as the wave generator rotates; a first internal gear meshing with the external gear; a second internal gear that is disposed on one side in an axial direction of the first internal gear to mesh with the external gear; and a wave generator bearing that is disposed between the external gear and the wave generator in a state where movement in the axial direction of the wave generator bearing is restricted. The external gear includes a protrusion on an inner periphery of the external gear. The protrusion engages with the wave generator bearing to restrict movement in the axial direction of the external gear.

A wave gear apparatus comprises a spline having top, bottom, exterior, and interior surfaces. A plurality of spline teeth extend from the interior surface toward a center axis. A wave generator is rotatably disposed in the spline. A belt assembly extends about the wave generator and includes a plurality of belt teeth extending radially outwardly, whereby a total number of the belt teeth is less than a total number of the spline teeth. An output member defines a recess receiving the wave generator and the belt whereby, in response to a rotational movement from the wave generator, the output member rotates in a direction same or opposite of the wave generator. A bearing assembly is disposed between the wave generator and the belt assembly and includes a plurality of needles each extending parallel to the center axis. A vehicle lifting system including the wave gear apparatus is also disclosed herein.

A speed reducer includes a reduction mechanism, which includes an internal gear and an external gear meshing with the internal gear, and a first member, and transmits rotating motion decelerated by the reduction mechanism to a driven member. The speed reducer includes a protection member disposed between the first member and the driven member. The first member is formed of a material having specific gravity lower than at least one of the internal gear and the external gear and hardness lower than the driven member. The protection member is formed of a material having hardness higher than the first member.

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 speed reducer includes an input shaft, an input gear, a fixing gear and an output gear. The input shaft includes an eccentric structure. The input gear is disposed on the eccentric structure and includes first teeth of which each with a first contact portion and a second contact portion. The fixing gear and the output gear are disposed corresponding to the input gear, wherein the fixing gear includes second teeth, and the second teeth are in contact with the first contact portions, wherein the output gear includes third teeth, and the third teeth are in contact with the second contact portions. A first tooth number difference between the first teeth and the second teeth is different from a second tooth number difference between the first teeth and the third teeth.

A harmonic speed reducer is provided. The harmonic speed reducer includes a wave generator, a flexible gear, a first rigid gear, and a second rigid gear. The wave generator can be driven to rotate relative to a central axis. The flexible gear has a plurality of first outer gear structures, a division groove, and a plurality of second outer gear structures. The first rigid gear has a plurality of first inner gear structures configured to be engaged with the first outer gear structures. The second rigid gear has a plurality of second inner gear structures configured to be engaged with the second outer gear structures. A first intersection line is defined between each of the first inner gear structures and a sectional surface. An angle between the first intersection line and a first horizontal line is within a range from 0.1 degrees to 5 degrees.

A strain wave gearing unit has a unit housing, a strain wave gearing, and a bearing device. Balls of a bearing part of the bearing device are positioned on the diametrically outer side with respect to a cylindrical barrel part of an externally toothed gear. The diameter S of the balls is 0.05 to 0.15 times the pitch diameter D of the externally toothed gear. The centers of the balls are positioned between a point at a distance of 1.2 times the diameter S toward the cylindrical-barrel-part side from an inner-side end surface of a diaphragm along a center axis and a point at a distance of 1 times the diameter S toward a side opposite the cylindrical barrel part from the inner-side end surface. The bearing device can be configured to be used in common for strain wave gearing units having different axial lengths.

The present application discloses a double-flexspline harmonic reducer, comprising a strong flexspline (3) , a weak flexspline (2), a wave generator (1), and a deformation stopper (4) of the strong flexspline; the strong flexspline and the weak flexspline are coaxially fixed axially and radially, the strong flexspline and the weak flexspline are respectively provided with teeth that can engage with each other; the number of teeth of the strong flexspline and the weak flexspline are different; the wave generator is used to make the weak flexspline to undergo non-circular elastic deformation and partially engage with the strong flexspline; the contact part of the strong flexspline and the weak flexspline is subjected to the radial pressure of the weak flexspline to generate a non-circular elastic deformation, a flexible tubular wall of the strong flexspline has a toothless surface, and a limiting contact surface is processed on the toothless surface.

Provided is a sensor device that detects a predetermined state quantity, including: a correction unit that performs first detection and second detection having a smaller generated state quantity than the first detection, and that corrects a detection value of the first detection, based on a detection value of the second detection.

In a wave generator for a strain wave gearing, a plug outer peripheral surface of a rigid wave plug has a non-circular profile and is fixed to an inner-race inner peripheral surface of a wave bearing by press-fitting and using an adhesive. The plug outer peripheral surface is a groove formation surface in which microgrooves are formed as adhesive-retaining grooves that can retain the adhesive. When the wave plug is press-fitted into the wave bearing, the amount of adhesive that is scraped out from therebetween is reduced and the bonding strength therebetween can be increased while also preventing unevenness of the bonding strength.