Disclosed is a gear system, having: first and second ground gear; a drive shaft disposed along a rotation axis of the gear system and configured to rotate about the rotation axis; and an output gear supported by the first and second ground gear and configured to rotate by engagement between a wave generator portion of a drive shaft, a wave generator bearing, a flex spline, the output gear and the first and second ground gear, the output gear defining: an output gear body; and first and second output arms respectively extending radially outward from opposite sides of the output gear body to respectively define first and second radial inner ends and radial outer ends of the first and second output arms, so that the first and second radial outer ends are disposed on a radial axis that extends through a radial center of the gear system.

A speed reducer comprises a transmission shaft, an eccentric wheel, a first wheel assembly, a rotating wheel and a second wheel assembly. The first wheel assembly comprises a first wheel disc and at least one first roller. The at least one first roller is disposed on the inner wall of first wheel disc. The rotating wheel comprises a main body comprising an outer ring structure and a concave structure. The outer ring structure comprises at least one first tooth. The at least one first tooth is in contact with the corresponding first roller. At least one second roller is disposed within the concave structure. The second wheel assembly comprises a second wheel disc and at least one second tooth. The at least one second tooth is disposed on an outer periphery of the second wheel assembly. The at least one second tooth is in contact with the corresponding second roller.

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.

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.

A unit-type strain wave gearing device provided with a cross roller bearing that supports an internally toothed gear and an externally toothed gear in a state in which both gears can rotate relative to each other, and a meshing section of both gears is lubricated with grease. A gap by which the meshing section and the cross roller bearing raceway groove communicate is formed between the inner ring of the cross roller bearing and the external gear. Due to the pump effect caused by deflection of the external gear, grease is pushed from the meshing section to the gap. Some grease is returned to the inner space of the externally toothed gear via a grease-flowing hole that penetrates the diaphragm of the external gear. Thus, leakage of grease from an oil seal of the cross roller bearing to the unit side can be controlled.

A flexible transmission element is disclosed which can be used, in particular in a harmonic drive and which includes a sleeve-shaped, outer toothed section and a flange connected to this section, the outer toothing of the sleeve-shaped section is sheet metal toothing formed in a die.

An external gear includes a body, external teeth, a diaphragm, and a strain gauge. The diaphragm extends in a direction intersecting with an axial direction on another side in of the body the axial direction. The strain gauge is on at least one of a surface on one side of the diaphragm in the axial direction and a surface on another side of the diaphragm in the axial direction. The strain gauge is only in a region that is about a half or less of a radial length from one end of the diaphragm in the axial direction to the other end of the diaphragm in the axial direction with a radial midpoint between the one end of the diaphragm in the axial direction and the other end of the diaphragm in the axial direction as a center in a section passing through the central axis.

Provided is a bending meshing type gear device including a wave generator, an external gear flexibly deformed by the wave generator, and an internal gear meshing with the external gear. The internal gear includes an internal tooth ring portion including an internal tooth formed on an inner periphery, an external connection portion connected to an external member, an easily deformable portion provided between the internal tooth ring portion and the external connection portion, and configured to be more easily deformable than the internal tooth ring portion, and a distortion measurer provided in the easily deformable portion.

A gear device includes an internal gear, a flexible external gear, and a wave generator. The wave generator includes an elliptical cam and a bearing. Grease is applied to the inner circumferential surface of the external gear. A groove is provided along a rotation axis on at least one of the inner circumferential surface of the external gear and an outer circumferential surface of the bearing.

A gearing includes an internal gear, a flexible external gear partially meshing with the internal gear and relatively rotating about a rotation axis to the internal gear, and a wave generator provided inside of the external gear and moving a mesh position between the internal gear and the external gear in a circumferential direction about the rotation axis, wherein the external gear includes an external tooth having an external tooth surface, the external tooth surface has an external tooth convex pattern including a first convex portion and a second convex portion extending in directions crossing directions of a tooth trace of the external tooth and arranged adjacent to each other in the directions of the tooth trace, and a distance between the first convex portion and the second convex portion is from 80 μm to 520 μm.