An externally toothed gear of a cup-type strain wave gearing has external teeth, the tooth profile of which gradually changes in the tooth-trace direction. The external teeth are formed with an external teeth portion capable of meshing with internal teeth of an internally toothed gear, a first external teeth extension portion and a second external teeth extension portion, in which the first and second external teeth extension portions do not mesh with the internal teeth. The second external teeth extension portion has a narrowing tapered tooth profile so that the second external teeth extension portion serves as a guide when the external teeth is inserted into the internal teeth. The work of assembling the externally toothed gear in the internally toothed gear is made easier.

In some examples, a brake assembly includes an actuator assembly configured to cause the translation of a piston to compress a disc stack. The actuator assembly is configured to generate a first torque around a motor axis using a motor and generate a second torque from the first torque using a harmonic drive. The actuator assembly may include a gear set configured to cause a linear actuator to translate the piston using the second torque. In some examples, the actuator is configured to translate the piston along a compression axis different from the motor axis.

A speed reducer according to one embodiment of the disclosure includes: a casing; a carrier disposed rotatably relative to the casing; a speed reduction mechanism that is disposed in the casing and reduces rotation inputted from a motor and outputs reduced rotation; and a bolt protruding from the carrier toward the outside of the casing. The bolt has a male threaded portion that is configured to engage with a female threaded portion provided in a second arm.

There is provided a technique capable of increasing support rigidity of a bearing when a support member expands due to moisture absorption. A power transmission device includes: a rotary shaft; a support member disposed outside the rotary shaft in a radial direction; a bearing disposed between the rotary shaft and the support member; and a fitting member fitted to an outer peripheral portion of the support member. The fitting member is made of a material having lower hygroscopicity than hygroscopicity of a material of the support member.

A driving device includes a motor, a wave gear device including a wave generator having first thickness, a flex spline, and a circular spline having thickness larger than the first thickness, a housing functioning as a housing of the motor and including a flange, and an oil seal fixed to the inner side of the flange and extending along the outer circumference of the shaft. The wave generator is set closer to the opposite direction of the flange to configure an internal space with the members. When the internal space is filled with grease, a distance between the oil seal and the wave generator is set smaller than distances among the other members.

An elastic gear wheel for a harmonic drive has a cylinder portion with tooth, and a flange which is integrally designed with the cylinder portion. The flange has recesses for fastening, and through-apertures for fastening.

The present disclosure relates to a frictional wave reducer mainly used for industrial robot joints and having an operating principle modified from that of a conventional strain wave gearing, which includes a wave generator having a conic pressurizing face on the outermost side, a toothless flex spline having a conic friction tube in which the wave generator is accommodated with the conic pressurizing face inscribed in the conic friction tube, and a toothless circular spline accommodating the toothless flex spline and having an internal conic friction face in which the conic friction tube is inscribed at a plurality of axially symmetrical points to form an internal friction wheel with the toothless flex spline. Accordingly, disadvantages of the conventional strain wave gearing are overcome to provide a reducer having high productivity and high rotation accuracy without generation of vibration and noise.

A joint apparatus for a robot includes a housing, a bearing including an inner ring and an outer ring contacting the housing, a rotating member contacting the inner ring of the bearing, and a driving apparatus configured to rotate the rotating member, where the first housing includes a first support region configured to support a front surface of the outer ring and a first fastening region extending rearward from the first support region and on which a first thread is formed, the sounding housing includes a second support region configured to support a rear surface of the outer ring and a second fastening region extending forward from the second support region and on which a second thread is formed, and the second thread is configured to engage the first thread.

An annular body includes a base, a first resistance wire, a second resistance wire, a first terminal, and a second terminal. The base surrounds a central axis and expands in a direction intersecting the central axis. Resistance values of the first and second resistance wires change according to strain of the base. The first terminal is electrically connected to the end of the first resistance wire. The second terminal is electrically connected to an end of the second resistance wire. The first terminal is at a first position in the circumferential direction. The second terminal is at a second position in the circumferential direction. When viewed in the axial direction, the central angle defined by the first position, the central axis, and the second position is equal to or greater than about 90°.

This gear wheel mechanism includes a rotator, a first gear wheel, a second gear wheel, and a reinforcement member. The rotator is configured to be rotatable about a rotation shaft and has an elliptical shape as viewed in an axis direction of the rotation shaft. The first gear wheel includes a first base portion including a first outer circumferential surface and a first inner circumferential surface and having a hollow cylindrical shape configured to be deformable by the rotator being inserted in the axis direction of the rotation shaft and external teeth formed in the outer circumferential surface. The second gear wheel includes a second base portion including a second outer circumferential surface and a second inner circumferential surface and having a hollow cylindrical shape disposed to cover the external teeth and internal teeth which are formed at positions facing the external teeth of the second inner circumferential surface, with which the external teeth are partially engaged in accordance with deformation of the first base portion by rotation of the rotator. The reinforcement member is disposed in contact with a region of the second outer circumferential surface corresponding to a region in which the internal teeth of the second inner circumferential surface are formed.