A method of manufacturing a flexible gear and a method of manufacturing a flexible gear unit that can achieve a further improvement in productivity and a further reduction in production cost, and a gear that allows a further improvement in productivity and a further reduction in production cost are provided. A method of manufacturing a flexible gear is provided which includes preparing a matrix with a flexible gear shape, and forming, by an electroforming method using the matrix, a flexible gear shape with predetermined thickness and releasing the flexible gear shape from the matrix. A method of manufacturing a flexible gear unit is provided which includes the method of manufacturing the flexible gear according to the present technology, and joining a shaft and/or a hub to the flexible gear. Further, a gear is provided which includes a gear part, a body part, and a diaphragm part, is made from a material suitable for an electroforming method, and has flexibility.

A bending meshing type gear device includes a wave generator, an external gear which is bent and deformed by the wave generator, and an internal gear which meshes with the external gear, in which one gear of the external gear and the internal gear is formed of a resin, the other gear of the external gear and the internal gear is formed of a high thermal conductivity material having a thermal conductivity higher than that of the resin and wear resistance higher than that of the resin, and a tooth thickness of the one gear is larger than a tooth thickness of the other gear in a meshing range between the external gear and the internal gear.

The flat strain wave gearing is provided with an axially arranged rigid gear, flexible gear and wave generator. The flexible gear forms a flat truncated cone shape, has a tooth formation portion connected via a bellows-shaped cross-sectional diaphragm to a rigid boss which is an output shaft linking part. The flat strain wave gearing can ensure axial flexibility of the tooth formation portion, and can enable teeth of the flexible gear to mesh favorably with teeth of the rigid gear in the axial direction in each position in the tooth trace direction. Local bias of the load torque in the meshing portion in the tooth formation portion can also be suppressed.

A wave bearing of a wave generator of a strain wave gearing is provided with steel or stainless steel cylindrical hollow rollers between an inner-race-side raceway surface and an outer-race-side raceway surface, the hollow rollers serving as rolling elements. The ratio Di/Do of the inner diameter Di to the outer diameter Do of the hollow rollers is set to 0.95 or more. The relative radius of curvature of hollow rollers that have been flexed into an ellipsoidal shape increases with respect to the inner-race raceway surface and the outer-race raceway surface with which the hollow rollers are in contact, and the Hertz maximum contact stress is reduced. The hardness of the hollow rollers, the inner-race raceway surface, and the outer-race raceway surface can be reduced.

A cup-shaped strain wave gearing has an externally toothed gear formed with a cylindrical extension portion extending from an end of an external tooth forming portion of the externally toothed gear. A space between the external peripheral surface of the cylindrical extension portion and an end face of an internally toothed gear is sealed by an oil seal. A space between an outer-side lubrication portion on the outer side of the externally toothed gear and an inner-side lubrication portion on the inner side of the externally toothed gear is blocked by a lubricant-mixing-prevention part configured from the cylindrical extension portion and the oil seal. The mixing of different types of lubricants supplied to the outer-side and inner-side lubrication portions can be effectively prevented.

Disclosed is a rotating device including: a first gear part having a first gear; a second gear part coupled to the first gear and having a second gear that rotates relative to the first gear; a third gear part coupled to the second gear and having a third gear that rotates relative to the second gear; and first and second driving units for respectively providing rotational driving forces to first and second input gear parts which are two gear parts of the first to third gear parts to determine a rotational output of an output gear part which is the remaining gear part. At least one of the first and second driving units changes the rotational speed of at least one of the first and second input gear parts to change the rotational speed of the output gear part.

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.

An optimized harmonic drive (“OHD”) includes a wave generator, a flex spline, and a circular rigid spline. The wave generator includes a wave generator contour that minimizes a velocity profile of the wave generator during a high load condition. The flex spline is attached to the wave generator and the circular rigid spline is mechanically engaged to the flex spline. The flex spline includes a plurality of flex spline teeth and the circular rigid spline includes a plurality of rigid spline teeth. The plurality of rigid spline teeth is greater than the plurality of flex spline teeth and the high load condition exists when the rigid spline teeth of the plurality of rigid spline teeth are fully engaged with flex spline teeth of the plurality of flex spline teeth.

A gear device includes an internal gear, an external gear partially meshing with the internal gear, relatively rotating around a rotation axis to the internal gear, and having flexibility, and a wave generator being in contact with an inner circumferential surface of the external gear and moving a meshing position of the internal gear and the external gear in a circumferential direction about the rotation axis, wherein a virtual straight line as an extension of a tooth trace of the internal gear intersects with the rotation axis in a sectional view cut along a plane containing the rotation axis.

The invention relates to a strain wave gear, having an outer ring with an inner toothing, with which a flexible inner ring with an outer toothing engages at two opposing points. The strain wave gear is characterized in that the ratio of the pitch diameter of the outer ring to the rim thickness of the outer ring lies in the region of 13 to 21, especially in the region of 17 to 19, especially at 17.587, wherein the teeth of the toothing of the inner ring have a profile angle in the region of 8 degrees to 15 degrees or in the region of 11 degrees to 12 degrees or one of 11.615 degrees, and/or wherein the teeth of the toothing of the outer ring have a profile angle in the region of 8 degrees to 15 degrees or in the region of 11 degrees to 13 degrees or one of 12.474 degrees.