JP2545317Y2 - Torque detection device for wave gear transmission - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque detecting device for detecting a torque generated in a wave gear transmission.

[0002]

2. Description of the Related Art In order to mechanically detect a torque generated in a wave gear transmission, for example, a wave gear reducer, a torque sensor formed of an existing rotating body is used. In this case, a torque sensor is mounted on a tip portion of an output shaft connected to an output element of the wave gear drive. Generally, a flexible external gear member constituting a wave gear drive is used as an output element, and a torque sensor is mounted on an output shaft connected thereto.

[0003]

However, arranging the torque sensor in this way increases the axial and radial dimensions of the entire device accordingly. For this reason, it may be difficult or impossible to attach the torque sensor due to the installation space or the like.

[0004] In view of this point, an object of the present invention is to realize a mechanism capable of detecting a generated torque of a wave gear transmission without mounting a separate torque sensor as in the related art.

[0005]

According to the present invention, in a wave gear transmission such as a wave gear reducer, a plurality of strain gauges or the like are disposed at predetermined intervals in a circumferential direction with respect to an annular rigid member. A configuration is adopted in which a detection piece is attached and the generated torque is detected based on the amount of distortion obtained from these distortion detection pieces.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIGS. 1 and 2 show an annular rigid internal gear member constituting a wave gear drive. As shown in these figures, four strain gauges 21, 22, 23, 24 are attached to the outer peripheral surface 1a of the internal gear member 1 at equal intervals in the circumferential direction, in this example, at 90 ° intervals. It is attached. These strain gauges are arranged so that circumferential strain can be detected.

As shown in FIG. 3, in this embodiment, a bridge circuit is formed using these strain gauges. In this figure, R1, R2, R3 and R4 are resistors corresponding to the strain gauges 21, 22, 23 and 24, respectively. Resistance R
A constant voltage is applied between 1 and R2 and between the resistors R3 and R4 to obtain an output voltage between the resistors R1 and R4 and between the resistors R2 and R3. When no distortion occurs, the circuit equilibrium condition is satisfied, and these potentials are set to be equal. Therefore, when a strain occurs in the internal gear member and the resistance value of each strain gauge fluctuates, the equilibrium condition is broken and the potential between them is different. Here, the causes of the distortion are caused by the torque and by the pressing force from the side of the elliptical wave generator at both ends of the long axis. The potential fluctuation caused by only the former is taken out through an amplifier circuit (not shown), and the torque generated in the internal gear member is calculated based on the taken out value.

[0009]

As described above, the torque detecting device according to the present invention detects the strain caused by the torque generated in the annular rigid member of the wave gear transmission by using the strain detecting piece such as a strain gauge attached thereto. Then, the generated torque is calculated based on the detected value. Therefore, according to the present invention, it is possible to perform torque detection without increasing the size of the device.

[Brief description of the drawings]

FIG. 1 is a plan view showing a rigid internal gear member to which a strain gauge is attached in a wave gear drive.

FIG. 2 is a side view of the rigid internal gear member of FIG. 1;

FIG. 3 is a circuit diagram showing a connection example of the strain gauge of FIG. 1;

[Explanation of symbols]

 1 ... Rigid internal gear member 21, 22, 23, 24 ... Strain gauge

Claims (1)

(57) [Scope of request for utility model registration] 1. An annular rigid member, an annular flexible member having an inner peripheral surface or an outer peripheral surface engageable with an outer peripheral surface or an inner peripheral surface of the rigid member, and a radius of the flexible member. A wave generator for bending in a direction to partially engage the rigid member at a plurality of points and moving the engaged points in a circumferential direction. A plurality of strain detecting pieces attached at predetermined intervals along the circumferential direction of the above, and the generated torque is detected based on the amount of strain obtained from these strain detecting pieces.