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 gear device includes an external gear, and an internal gear that meshes with the external gear. The external gear is formed of metal. The internal gear is formed of a carbon fiber reinforced resin.

Methods for the fabrication of metal strain wave gear flexsplines using a specialized metal additive manufacturing technique are provided. The method allows the entire flexspline to be metal printed, including all the components: the output surface with mating features, the thin wall of the cup, and the teeth integral to the flexspline. The flexspline may be used directly upon removal from the building tray.

Provided is a double-flexspline harmonic reducer, comprising a strong flexspline (3), a weak flexspline (2) and a wave generator (1). The strong flexspline (3) and the weak flexspline (2) are coaxially fixed in an axial direction and a radial direction, and teeth which can be engaged with each other and are different in the number thereof are provided on the strong flexspline (3) and the weak flexspline (2) respectively. The wave generator (1) causes the weak flexspline (2) to undergo non-circular elastic deformation and then to partially engage with the strong flexspline (3), and a contact portion of the strong flexspline (3) and the weak flexspline (2) undergoes non-circular elastic deformation under a radial pressure from the weak flexspline (2). A wall thickness of the strong flexspline (3) is greater than or equal to 2 times and less than 5 times that of the weak flexspline (2).

A gear device includes a first gear, and a second gear meshing with the first gear. At least the first gear is made of a resin. The gear device further includes a connection member connected to an external member, a path member disposed in a path leading to the first gear and the connection member, and other members that are members other than the first gear, the second gear, the connection member, and the path member, and are made of a resin. The first gear, the connection member, and the path member are made of a resin having a higher thermal conductivity than a thermal conductivity of the other members.

A variable stiffness actuator comprises a flexure plate which comprises a first cantilevered beam that extends inwards from an outer periphery of the flexure plate. A housing and the flexure plate rotatable about a common joint axis. A first contactor is pivotably secured at a revolute joint to the housing. The first contactor rotates about the revolute joint at a first rotation axis. The first rotation axis offset on the housing from the joint axis. The first contactor engages the first cantilevered beam at a variable angle about the rotation axis to adjust a stiffness of a mechanical connection between the flexure plate and the housing.

An actuator assembly is disclosed herein. The assembly includes a motor shaft; support; harmonic drive connected to the motor shaft that includes an output connected to a drive shaft defining a first sun gear; drive mechanism; and actuator arm. The drive mechanism includes a first gear set and a second gear set. The first gear set has a first carrier including a second sun gear. The first carrier supports a first plurality of planetary gears that engage both the first sun gear and a first ring gear rotationally fixed to the support. The second gear set has a second carrier fixed to the support. The second carrier supports a second plurality of planetary gears that engage both the second sun gear and a second ring gear. The actuator arm is connected to the second ring gear such that the actuator arm is rotationally driven by the motor shaft.

An outer-ring lubrication groove pattern formed in an outer-race raceway surface and an inner-race lubrication groove pattern formed in an inner-race raceway surface of a wave generator bearing of a strain wave gearing device are patterns in which linear lubrication grooves having very small widths and depths of several micrometers or less are arranged at fine pitches of several micrometers or less. The inner-race lubrication groove pattern includes a second groove pattern formed in long-axis-side inner-race raceway surface portions to hold the lubricant, and a first groove pattern formed in short-axis-side inner-race raceway surface portions to hold the lubricant and guide the lubricant to the second groove pattern. This configuration improves the contact state between balls and the inner-race and outer-race raceway surfaces of the wave generator bearing, thus reducing the coefficient of friction therebetween.

A shaft retention mechanism of the present invention includes: a casing forming a housing space containing a lubricant; an input shaft penetrating a through-hole formed in the casing, the input shaft extending through the casing; a sealing ring encircling the input shaft in the through-hole, the sealing ring sealing between the input shaft and the casing; and a bearing disposed on an opposite side of the sealing ring to the housing space, the bearing rotatably supporting the input shaft in the through-hole.

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.