Annular spring and robot joint mechanism using the same

Patent metadata

Field	Value
Publication number	US-9656396-B2
Application number	US-201514790839-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Oct 17, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

On an inner peripheral surface of an outer peripheral member 10, a recess 11 is formed to which a pipe spring 30 is fitted. On an outer peripheral surface of an inner peripheral member 20 arranged concentrically with and rotatable relatively to the outer peripheral member 10 on an inner peripheral side of the outer peripheral member 10, a cam surface 21 is formed which abuts against the pipe spring 30. The cam surface 21 protrudes in the radial direction as it is farther away in the circumferential direction of the outer peripheral member 10 from the point of contact with the pipe spring 30 in the state where no load is applied.

First claim

What is claimed is:

1. An annular spring comprising an annular outer peripheral member, an annular inner peripheral member arranged concentrically with the outer peripheral member on an inner peripheral side of the outer peripheral member and rotatable relatively to the outer peripheral member, and an elastic member arranged between the outer peripheral member and the inner peripheral member, wherein
the elastic member is composed of an elastic body having a circular cross section,
one of an inner peripheral surface of the outer peripheral member and an outer peripheral surface of the inner peripheral member has formed thereon a recess to which the elastic member is fitted,
the other of the inner peripheral surface and the outer peripheral surface has formed thereon a cam surface against which the elastic member abuts, and
the cam surface is formed in such a way as to protrude in a radial direction as it is farther away in a circumferential direction of the outer peripheral member or the inner peripheral member from a point of contact with the elastic member in a state where the outer peripheral member and the inner peripheral member are not rotating relatively to each other.

2. The annular spring according to claim 1 , further comprising a rolling element between the outer peripheral surface and the inner peripheral surface.

3. The annular spring according to claim 1 , wherein the elastic member is rotatable inside the recess in which the elastic member is fitted.

4. The annular spring according to claim 1 , wherein the elastic member fitted in the recess has a central axis which becomes farther away from the cam surface as compared to the inner peripheral surface or the outer peripheral surface on which the recess is formed.

5. The annular spring according to claim 1 , wherein the recess has edges chamfered into an arc shape.

6. A robot joint mechanism comprising the annular spring according to claim 1 , a driving source, and a speed reduction mechanism configured to decelerate a driving force from the driving source and transmit the resultant force to the outer peripheral member or the inner peripheral member of the annular spring.

7. The robot joint mechanism according to claim 6 , wherein
the speed reduction mechanism is a wave gear device including a circular spline having teeth formed on an inner peripheral surface and a flex spline having teeth, to be engaged with the teeth of the circular spline, formed on an outer peripheral surface, and
the teeth of the circular spline are arranged on the inner peripheral member of the annular spring.

Assignees

• Honda Motor Co Ltd

Inventors

• Miyazaki Susumu

Classifications

• B25J9/1025

  Harmonic drives (in general: F16H49/001) · CPC title

• F16D3/64

  comprising elastic elements arranged between substantially-radial walls of both coupling parts · CPC title

• F16D3/12

  specially adapted for accumulation of energy to absorb shocks or vibration (by making use of fluid elements F16D3/80) · CPC title

• Y10S901/25

  Gearing · CPC title

• B25J19/0091 Primary

  Shock absorbers (in general F16F) · CPC title