An actuator system including a harmonic drive operable to drive a variable vane system of a gas turbine engine.

A gear device includes an internal gear, an external gear having flexibility, a wave generator, a cross roller bearing, and a first seal and a second seal. The external gear includes a cylindrical body section including a first end portion, with which the wave generator is in contact, and a second end portion on the opposite side of the first end portion, external teeth provided on the outer circumferential surface of the first end portion, an annular diaphragm section provided on the outer side of the second end portion, and a boss section provided on the outer side of the diaphragm section. The first seal is sandwiched between the boss section and an outer ring of the cross roller bearing. The second seal includes a proximal end fixed to the outer ring and a distal end in contact with the outer circumferential surface of an inner ring.

The addendum tooth profile of the inner teeth and outer teeth of a strain wave gearing is stipulated by a first and second similar curve obtained from the curve segment from an inflection point to a low point in a movement trajectory when the meshing of both teeth is approximated by rack meshing. The addendum tooth profile of the inner teeth is stipulated by a curve generated at the inner teeth in the process of the addendum profile of the outer teeth moving from the inflection point to the apex of the movement trajectory. The addendum tooth profile of the outer teeth is stipulated by a curve generated at the outer teeth when the addendum profile of the inner teeth moves from the inflection point to the apex. The addendum profile of the outer teeth makes double contact with the addendum profile and dedendum profile of the inner teeth.

Devices convert non-uniform rotational motion into uniform rotational motion and vice versa. A motion conversion mechanism includes a housing, a common shaft, a symmetrical differential reduction gear, rings for differential power flows, cams having an inner working surface, cams having an outer working surface, and sliders with fingers. The inner working surface cam profile is described by the polar radius as a function of the polar angle and is an equidistant curve distanced outwardly from a first-order derivative of a basic closed curve by the size of the finger's radius. The outer working surface cam profile is described by the polar radius as a function of the polar angle and is an equidistant curve distanced outwardly from a second-order derivative of a basic closed curve by the size of the finger's radius. In a single revolution of the shaft, each ring performs two half revolutions back and forth.

A servo control device for controlling a motor based on a position command when an operation target is connected to the motor via a wave gear reduction mechanism may include a position control system configured to detect a shaft angular position of the motor to perform a closed-loop control based on the shaft angular position; an inverse control element having an inverse characteristic of dynamics of the position control system; and a compensation amount generation unit configured to generate a compensation amount for compensating for an angular transmission error of the wave gear reduction mechanism. The inverse control element is configured to apply compensation amount to the position control system.

An elastic transmission element is used in a strain wave gear. Such strain wave gears are also referred to as Harmonic Drives. The elastic transmission element is also referred to as a flexspline. Outer toothing is formed on the elastic transmission element. Furthermore, at least one strain gauge for measuring a mechanical strain of the elastic transmission element is arranged on the elastic transmission element. The at least one strain gauge is formed as a coating directly on a metallic surface of the elastic transmission element.

The structure for detecting tooth-skipping of the speed reducer of the rotary driver is reduced in weight and size. In the rotary driver the occurrence of tooth-skipping is detected based on the difference in outputs from the encoders located at the input side (the side of the motor) and at the output side (the side of the load), which is opposite the input side in relation to the speed reducer. The rotary driver comprises a motor, a speed reducer located between the motor and a load to reduce the rotary speed of a rotary shaft at the side of the motor, to thereby transmit the reduced rotary speed to a rotary shaft at the side of the load, a first encoder for detecting a rotation of the rotary shaft at the side of the motor, a second encoder for detecting a rotation of the rotary shaft at the side of the load, a section for detecting any difference between a first detected value that is obtained by dividing an output of the first encoder by a rate for reducing the speed by the speed reducer and a second detected value that is obtained from an output of the second encoder, and a section for detecting tooth-skipping that detects tooth-skipping of the speed reducer based on the difference.

Described herein is an example a strain wave gear that includes: gear elements, where the gear elements include a circular element with an internally toothed gear and where the gear elements include a flex element with a flexible externally toothed gear arranged in the circular element; a wave generator rotatably arranged in the flex element and configured to flex the externally toothed gear in a radial direction to partly mesh the internally toothed gear and the externally toothed gear; support elements including a bearing input support element and a bearing output support element rotatably coupled to the bearing input support element, where elements of the support elements are fixed to elements of the gear elements; and an encoder arrangement including an encoder track and an encoder reader, where a part of the encoder arrangement is fastened between an element of the support elements and an element of the gear elements.

In the cup-shaped externally toothed gear, the outside end face profile of the diaphragm is defined by a first concave circular arc having a first radius, a second concave circular arc that has a second radius and is smoothly connected to the first concave circular arc, an inclined straight line that is smoothly connected to the second concave circular arc and is inclined toward an inside straight line with respect to the center axis line, the inside straight line defining the outside profile of the diaphragm. The second radius is larger than the first radius, and the thickness of the diaphragm is gradually decreased from the side of the boss to the side of the cylindrical body. The stress concentration in the boss-side joint portion of the diaphragm can be relieved, whereby enhancing fatigue strength of the flexible externally toothed gear.

A magnetic coupling device includes a driving magnet array having multiple annular sector-shaped, circumferentially arranged first permanent magnets, and a driven magnet array having multiple circular sector-shaped, circumferentially arranged second permanent magnets with pole surfaces facing pole surfaces of the first permanent magnets. The driven magnet array is rotated by the driving magnet array being rotated. A repulsion zone where a repulsive force acts is designed to have an area that is 5% to 15% of that of an attraction zone where an attractive force acts between a specific first permanent magnet and a specific second permanent magnet, with a radial first centerline of the specific first permanent magnet overlapping a radial second centerline of the specific second permanent magnet so that opposite poles face each other, including between first and second permanent magnets respectively adjacent the specific first and second permanent magnets with overlapping the centerlines.