Harmonic Drive Systems Inc.

Sotaro Miyake

Hiroaki Kimura

Jun Handa

Yoshihide Kiyosawa

Hideo Yasue

In a rotation transmission mechanism that transmits the rotational driving force of a motor to a load-side member via a speed reducer, a strain wave gearing is used as the speed reducer, and the allowable load torque of members in the powertrain other than the strain wave gearing is greater than a predetermined upper-limit load torque. The allowable load torque of the strain wave gearing is dictated by the ratcheting torque, which is set so as not to exceed the upper-limit load torque. In an overload state, ratcheting is generated in the strain wave gearing, so that the strain wave gearing functions as a mechanical fuse. Other power transmission members can be protected from an overload state without adding a separate member such as a torque limiter.

Rotation transmission mechanism provided with strain wave gearing

A restraint mechanism for limiting the movement of the flexible external gear of a flat strain wave gearing in the axial direction has a first restraining member installed in a floating state in a first recess and a second restraining member installed in a floating state in a second recess. The restraining member is able to limit the movement of the flexible external gear in the axial direction to a range in which there are no difficulties during actual use. Moreover, compared with when movement of the flexible external gear is limited using members that are disposed at fixed positions, it is possible to reduce the sliding abrasion that occurs between the flexible external gear and the first and second restraining members.

Flat strain wave gearing

A wave generator for a strain wave gearing makes a flexible externally toothed gear to flex into an elliptical shape and mesh with rigid internally toothed gears, and makes meshing positions of the flexible externally toothed gear with the both gears to move in a circumferential direction. On the inner side of a rigid plug of the wave generator, a plug support ring is secured and integrated. The rigid plug is formed from an iron-based material, and the plug support ring is formed from a high-rigidity material that is more rigid than the iron-based material. Since deformation of the rigid plug is suppressed, the wave generator provided with a large hollow part can be obtained.

Wave generator for strain wave gearing

A wave generator of a flat-type strain wave gearing has an insertion member disposed between two wave bearings. The insertion member is pressed into an elliptical outer peripheral surface of a plug and is fixed thereto by an adhesive. An inner ring contact part of the insertion member is in contact with inner rings of the wave bearings from the direction of a center axis. When the flat-type strain wave gearing is in an operating state, the wave bearings can be prevented from moving relative to the plug in the direction of the center axis by means of thrust force acting on the wave bearings.

Strain wave gearing and wave generator

A press plate is tacked to a boss of a cup-shaped flexible externally toothed gear of a wave gear device unit. A second arm as a driven member is attached by a fastening bolt to an end surface on an outer side of an output flange of the wave gear device unit. The fastening bolt is screwed into and secured in a tap hole of the press plate from each bolt insertion hole of the second arm, via a flange-side bolt insertion hole and a boss-side bolt insertion hole. A fastening structure can be achieved in which a driven member is fastened to a wave gear device unit in which holes are easily machined into the output flange, and only a few fastening bolts are needed to fasten the boss, the output flange, and the driven member.

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Azumino, Japan

Sotaro Miyake