Method for manufacturing a flexible external gear, flexible external gear, harmonic drive gear, and robot joint device.

Abstract

To provide a method of manufacturing a flexible external gear that can realize a wave gear device less likely to lower reliability, a flexible external gear, a wave gear device, and a joint device for a robot.SOLUTION: A method of manufacturing a flexible external gear 3 for a wave gear device including a rigid internal gear, the flexible external gear 3, and a wave generator, includes a stress generation step and a shot-peening step. The wave gear device deforms the flexible external gear with rotation of a cam, makes a part of external teeth 31 engage with a part of internal teeth, and rotates the flexible external gear 3 relatively to the rigid internal gear in accordance with a difference in tooth number with respect to the rigid internal gear. In the stress generation step, the flexible external gear 3 is elastically deformed to generate a stress on the flexible external gear 3. In the shot-peening step, shot-peening is applied to at least a part of a surface of the flexible external gear 3 on which the stress is generated.SELECTED DRAWING: Figure 8

Claims

1. An annular rigid internal gear having internal teeth, A flexible external gear having external teeth and positioned inside the rigid internal gear, with a cup-shaped or top-hat-shaped design, The device comprises a non-circular cam that is rotationally driven around a rotation axis, and a wave generator having a bearing mounted on the outside of the cam, positioned inside the flexible external gear, and causing deflection in the flexible external gear, A method for manufacturing a flexible external gear of a harmonic drive gear, wherein the flexible external gear is deformed as the cam rotates, a portion of the external teeth meshing with a portion of the internal teeth, and the flexible external gear rotates relative to the rigid internal gear in accordance with the difference in the number of teeth between the flexible external gear and the rigid internal gear, A stress generation step is performed by elastically deforming the flexible external gear to generate stress in the flexible external gear, The process includes a shot peening step of applying shot peening to at least a portion of the surface of the flexible external gear where the aforementioned stress occurs, In the stress generation step, the flexible external gear is elastically deformed by combining a jig having at least the same outer circumferential shape as the wave generator with the flexible external gear. A method for manufacturing a flexible external gear.

2. In the stress generation step, the flexible external gear is elastically deformed so that its diameter expands uniformly over the entire circumference in the circumferential direction. A method for manufacturing a flexible external gear according to claim 1.

3. In the shot peening process, the area to be treated on the surface of the flexible external gear is moved in the circumferential direction of the flexible external gear while shot peening is performed on the area to be treated. A method for manufacturing a flexible external gear according to claim 1 or 2.

4. In the stress generation process, the flexible external gear is elastically deformed using a jig. In the shot peening process, the portion of the surface of the flexible external gear that is not to be shot peened is masked with the jig. A method for manufacturing a flexible external gear according to claim 1 or 2.

5. An annular rigid internal gear having internal teeth, A flexible external gear having external teeth and positioned inside the rigid internal gear, with a cup-shaped or top-hat-shaped design, The device comprises a non-circular cam that is rotationally driven around a rotation axis, and a wave generator having a bearing mounted on the outside of the cam, positioned inside the flexible external gear, and causing deflection in the flexible external gear, The flexible external gear of a harmonic drive gear device, wherein the flexible external gear is deformed as the cam rotates, a portion of the external teeth meshing with a portion of the internal teeth, and the flexible external gear rotates relative to the rigid internal gear in accordance with the difference in the number of teeth between the flexible external gear and the rigid internal gear, An elastically deformed portion is formed by combining a jig, whose outer circumferential shape is at least the same as that of the wave generator, with the flexible external gear, The system comprises a shot peening portion formed on at least a part of the elastically deformable portion, Flexible external gear.

6. A flexible external gear according to Claim 5, The rigid internal gear and, The wave generator comprises, Harsh drive gear system.

7. The wave drive gear device according to Claim 6, A first member fixed to the rigid internal gear, The system comprises a second member fixed to the aforementioned flexible external gear, Joint device for robots.

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