Harmonic Drive Systems Inc.

Akihiro Yokoyama

Toshiki Maruyama

Kiyoto Kobayashi

Naomi Shirasawa

Masashi Horiuchi

A concentric double axis actuator has a two-stage cross roller bearing, and a preceding-stage actuator and a subsequent-stage actuator which are linked in tandem. The front end of a subsequent stage rotary output shaft of the subsequent actuator, said subsequent stage rotary output shaft passing through a hollow section of the preceding-stage actuator and projecting forward, is linked and fixed to an inner ring of the two-stage cross roller bearing, and the inner ring functions as a subsequent-stage rotary output member. The output rotary side of the preceding-stage actuator is linked to an middle ring of the two-stage cross roller bearing, which functions as a preceding-stage rotary output member. The rotary output element of each stage is supported by the two-stage cross roller bearing, and surface oscillations of the rotary output member of each stage can be minimized, and the moment stiffness of the members can be increased.

Concentric multi-axis actuator

A unit type wave gear device () has a unit housing (), one end of which is defined by a two-stage cross roller bearing (). The two-stage cross roller bearing () has: an inner cross roller bearing formed by an inner ring (), an intermediate ring (), and inner rollers () inserted into an inner track (); and has an outer cross roller bearing formed by an outer ring (), the intermediate ring (), and outer rollers () inserted into an outer track (). A flexible externally-toothed gear () affixed to the intermediate ring () is rotatably supported by the unit housing () via the outer cross roller bearing. An input shaft () affixed to the inner ring () and a wave generator () affixed to the input shaft () are rotatably supported by the intermediate ring () via the inner cross roller bearing. A unit type wave gear device can be realized in which the number of components are reduced and a large moment load is applied.

Unit type wave gear device

A ball screw/nut type linear actuator () where a ball nut () moves in forward-backward directions by rotation of a ball screw shaft () connected to a motor (), wherein the ball screw shaft () is connected and fixed, in a small diameter hollow section () of the motor shaft (), to the motor shaft so that a part of the locus of the movement of the ball nut () also enters into a large diameter hollow section () of the motor shaft (). The construction eliminates the need of a coupling for connecting the motor shaft () and the ball screw shaft () and enables the ball screw shaft () to be supported together with the motor shaft () by bearings () of the motor. As a result, a support bearing for supporting the ball screw shaft can be eliminated. Thus, a short and light linear actuator is realized.

Ball screw/nut type linear actuator

A flat, hollow brushless servomotor () has a motor housing (), housing through holes () formed in a center of both end plate portions (), a rotor shaft () of which a portion of both ends is exposed from the through holes, a tool-mounting hole () that extends through a center thereof, and workpiece insertion recesses () formed in an external surface of both end plate portions () of the motor housing () by reducing the thickness thereof. A workpiece with a shape that has facing portions facing each other across a narrow space can be introduced from an outside to a center of the motor () along the workpiece insertion recesses, and the facing portions of the workpiece can be machined by a tool mounted in the center of the motor.

Growing community of inventors

Nagano, Japan

Akihiro Yokoyama