The harmonic gear device includes a rigid internal gear, a flexible external gear and a wave generator. The rigid internal gear is an annular component having internal teeth. The flexible external gear is an annular component having external teeth and configured on an inner side of the rigid internal gear. The wave generator is configured on an inner side of the flexible external gear and flexes the flexible external gear. The harmonic gear device is configured to deform the flexible external gear along with the rotation of the wave generator with the rotation shaft as a center, so that some of the external teeth mesh with some of the internal teeth. The flexible external gear thus rotates relative to the rigid internal gear according to the difference in the number of teeth between the flexible external gear and the rigid internal gear.

This strain wave gear unit includes: a bottomed cylindrical first internal gear having internal teeth formed on a cylindrical part and a teeth-non-formed part protruding farther inward than the tooth bottom of the internal teeth in a corner area where a bottom wall part is integrally connected to the cylindrical part; a flexible cylindrical external gear having external teeth meshing with the internal teeth of the first internal gear, an opposed part opposed to the teeth-non-formed part with a gap therebetween, and an end part opposed to the bottom wall part to make contact therewith; a second internal gear arranged adjacent to the first internal gear and having internal teeth meshing with the external teeth; and a rotation member that causes the external gear to deform in an oval shape and causes the meshing position to move while partially meshing with the first internal gear and the second internal gear.

The tooth profile contours of a rigid internally toothed gear and a flexible externally toothed gear in this strain wave gearing are stipulated by: meshing portions which each mesh with the opposing gear; tooth-crest-side convex surface portions which, respectively, are smoothly connected to the addendum-side ends of the meshing portions and extend from said ends to the apices of the tooth crests; and tooth-bottom-side concave surface portions which, respectively, are smoothly connected to the dedendum-side ends of the meshing portions and extend from said ends to the deepest parts of the tooth bottoms. The meshing portions and tooth-crest-side convex surface portions are machined portions that are simultaneously machined by topping gear cutting, and there are no edges on the teeth of either gear on the tooth-crest side.

A gear device includes an internal gear, an external gear having flexibility configured to partially mesh with the internal gear and rotate around a rotation axis relatively to the internal gear, and a wave generator configured to come into contact with an inner circumferential surface of the external gear and move a meshing position of the internal gear and the external gear in a circumferential direction around the rotation axis. The external gear includes a cylindrical section including a first end portion with which the wave generator is in contact and a second end portion adjacent to the first end portion along the rotation axis. An inner circumferential surface of the first end portion includes a polished surface. An inner circumferential surface of the second end portion includes a lathe-cut surface.

A strain wave gear speed reducer unit includes: a casing extending in the axial direction; an internal gear disposed to be rotatable relative to the casing and having internal teeth on the inner circumference; a flexible external gear disposed to the inside of the internal gear in the radial direction, an end of which is fixed to the casing on one side in the axial direction, and which has external teeth on the outer circumference for meshing with the internal teeth; a cam disposed to the inside of the external gear in the radial direction and deforming the external gear in the radial direction by rotating together with a rotating shaft of a motor unit; a connecting part formed integrally with the cam and connected to the rotating shaft on the inside of the external gear; and a support connected to the casing and rotatably supporting the connecting part.

A strain wave gearing, comprising an elastic gear retained by a housing component, wherein a connection between the elastic gear and the housing component has a first play in a circumferential direction and a second play in an axial and radial direction with respect to a center axis of rotation of the elastic gear, wherein the first play is an amount less than the second play.

A variable-speed gear arrangement for a vehicle includes a harmonic drive device, a driven wheel and an optional stop disk. The stop disk can be arranged between the driven wheel and a shaft, with a fastener for connecting the shaft to the stop disk and the driven wheel. The fastener presses the shaft, the stop disk and the driven wheel together in an axial direction. The driven wheel and/or the shaft and/or the stop disk includes a deformation section, and the deformation section includes a contact surface and a deformation surface. In a first state of assembly, the deformation section brings a member of the clamping connection into contact with the contact surface, simultaneously forming a free deformation region. In a second state of assembly, the contact surface and the deformation surface are applied to the member of the clamping connection in a flat manner.

A harmonic ring gear system can include at least one inner gear with external toothing, the at least one inner gear defining an axis of rotation; at least one outer gear with internal toothing arranged concentrically to the at least one inner gear about the axis of rotation, the internal toothing spaced apart from the external toothing; a pin ring positioned between the at least one inner gear and the at least one outer gear, the pin ring comprising a multiplicity of pins; and a rotary transmitter configured to lift a portion of the pins of the multiplicity of pins off the external toothing and press the portion of the pins into the internal toothing.

Provided is a method for producing a gear including an intermediate product forming process of solidifying a fluid material to form a gear intermediate product, and a tooth forming process of cutting the gear intermediate product to form teeth.

A strain wave gear system (10) includes first and second sets of ball bearings (80, 82) located intermediate a flange (84) and a retainer plate (88) rotatable with an output (54) and a radially oriented flat disc (74) of the input including strain relief (76). Strain relief (76) is a helical slot in a coupling (70) located radially within the wave generator (94) and the ring gear (22). The ring gear (22) is sealed by a sealing system including sealant (42) forced by a protrusion (34) of the cap (24) entering into a cavity (36) through a channel (40) into a relief volume (38) of the housing (12). The bearing (48) rotatably mounting the housing (12) to the output (54) is lubricated by a lubricating system including plungers (110) threadably received in axial bores (102) intersecting with radial bores (104) in communication with radial holes (47) of the bearing (48).