Harmonic Drive Systems Inc.

Toyota Jidosha Kabushiki Kaisha

Masashi Horiuchi

Ivan Godler

Hirokazu Ohta

Morihiko Ohkura

Toshihiro Hirabayashi

Minoru Hashimoto

Naoki Kanayama

Naomi Shirasawa

Akihiro Yokoyama

Kaneo Mohri

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 multi-joint finger unit () has first and second joint sections () constructed by using bevel gears. In each joint section (), the section where a driving bevel gear () and a driven bevel gear () mesh with each other and also a bearing section of a joint shaft () are assembled in a tubular housing () whose forward end is closed. Rear end openings (A,) of the tubular housings () are closed by a tubular housing () at a finger root and a tubular housing () at a finger body section. The section where the gears of the joint sections () mesh and the bearing section are substantially sealed, so that a foreign matter is prevented from entering from the outside to these sections and lubricant does not leaks from these sections. The multi-joint finger unit is suitable for use in place where thick powder dust is present and in a clean room.

Finger unit for robot hand and method of assembling the same

A sealed worm gear type finger joint unit for a robot hand has a circular opening in a gear box case of the unit, and the opening is closed by a rubber bush. When the rubber bush is removed, a shaft end face of a worm shaft section is exposed from the circular opening, and this makes a tool engagement section formed on the shaft end face is accessible from the outside. A tool for turning the worm shaft section is fitted in the tool engagement section, and the worm shaft section can be easily turned by the tool. Turning the worm shaft section turns a worm, turning a worm wheel meshing with the worm, and this turns the joint shaft. As a result, a swing arm connected to shaft end sections of the joint shaft can be moved to a predetermined position. In the finger joint unit, the joint shaft can be easily manually turned.

Sealed worm gear type finger joint unit

A driving mechanism includes a motor and a wave gear device. Three sets of torque sensors are attached at intervals of 120&#xb0; on a diaphragm of a flexible external gear of the wave gear device. In the rotational angle detecting part of the signal processing circuit, signal components that are included in the outputs of the torque sensors, that vary in the form of two cycles of a sine wave per rotation of the wave generator and are synchronous with a rotational angle of the wave generator are extracted and a coordinate transformation is carried out for the obtained three-phase sinusoidal signals to calculate two-phase sinusoidal signals that are 90&#xb0; out of phase, with the rotational angle of the wave generator being calculated based on these signals. Without providing a rotational angle detector separately, it is possible to detect the rotational angle of the wave generator using the outputs of the torque sensors.

Rotational angle detecting device for a wave gear device

The torque detection device for a wave gearing comprises a strain gauge unit having a strain gauge pattern. The strain gauge pattern includes circular-arc shaped detection segments A and B, and three terminal portions for external wiring with one being formed between the detection segments and the others at opposite ends thereof. The strain gauge unit having the strain gauge pattern can be mounted on the diaphragm of a flexible external gear by a simple operation of positioning the strain gauge unit on the diaphragm and connecting the three terminal portions to the external wirings. Compared to the case where a large number of perpendicular biaxial strain gauges are positioned and wired to form a bridge circuit, the wiring operation can be simplified, the mounting space can be reduced, and errors in detected signals due to the positioning errors of the strain gauges can also be reduced.

Torque detection device for wave gearing

A wave gear device torque detection method in which the gain of the output of each of a plurality of strain gauge sets affixed to the diaphragm of a flexible external gear is amplified and the outputs are then combined to form a detection signal. Adjusting the gain of each of the strain gauge outputs makes it possible to compensate for rotational ripple included in the output. Compensation of up to n order ripple components is possible by using at least (2n+1) strain gauges.

Wave gear device torque detection method

A method of compensating periodic error signals in sensor output is provided. The method comprises obtaining a sum signal from sensing outputs of M sensor elements (where M is a positive integer), obtaining the amplitude and phase of N frequency components included in the sum signal, and calculating a sensing output gain adjustment coefficient for each sensor output. To ensure that a sum signal level obtained by summing a pre-adjustment output of each sensor element multiplied by the gain adjustment coefficient equals a sum signal level obtained by summing the unmodified outputs of the sensors, a gain adjustment coefficient is obtained for each sensor output by using a calculated scaling coefficient to perform pre-adjustment scaling of each gain adjustment coefficient. The adjustment gains thus obtained are used to adjust the gain of each sensor output.

Method of compensating periodic signals in sensor output

A cup-shaped flexible external gear,of a flexed meshing type gear drive,is flexed into an elliptical shape by a wave generator,A first torque detection device,is disposed on a portion of the external gear,for example, on a diaphragm,thereof which has a pair of torque detection elements arranged at an angular interval of 90&deg; around a center axis,Likewise, a second torque detection device,is also disposed, which has a pair of torque detection elements arranged at an angular interval of 90&deg;. The first and second torque detection devices,are arranged at an angular interval of (k&times;45&deg;) around the center axis,with each other. A torque detection mechanism of this invention synthesizes outputs of the two torque detection devices,thereby realizing a high accurate torque detection with quite few effect of rotational ripple and with high linearity.

Growing community of inventors

Nagano-ken, Japan

Masashi Horiuchi