Harmonic drive and method of assembling

Patent metadata

Field	Value
Publication number	US-2016010738-A1
Application number	US-201414325879-A
Country	US
Kind code	A1
Filing date	Jul 8, 2014
Priority date	Jul 8, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A harmonic drive includes a flexible gear. Also included is a ring gear that meshes with the flexible gear. Further included is a rotor. Yet further included is a wave generator sleeve directly fitted over an outer surface of the rotor, wherein the wave generator sleeve is disposed radially within the flexible gear. Also included is a bearing assembly disposed between the wave generator sleeve and the flexible gear, wherein the wave generator rotates the flexible gear as the wave generator sleeve is rotated by the rotor.

First claim

1 . A harmonic drive comprising:
a flexible gear; a ring gear that meshes with the flexible gear; a rotor; a wave generator sleeve directly fitted over an outer surface of the rotor, wherein the wave generator sleeve is disposed radially within the flexible gear; and a bearing assembly disposed between the wave generator sleeve and the flexible gear, wherein the wave generator rotates the flexible gear as the wave generator sleeve is rotated by the rotor.

2 . The harmonic drive of claim 1 , further comprising:
a stator assembly disposed radially inwardly of the rotor and configured to impose rotation of the rotor.

3 . The harmonic drive of claim 1 , wherein the wave generator sleeve is thermally fitted to the shaft.

4 . The harmonic drive of claim 1 , wherein the wave generator sleeve is directly fitted over the shaft with an adhesive.

5 . The harmonic drive of claim 1 , wherein the wave generator sleeve comprises a hardenable material.

6 . The harmonic drive of claim 5 , wherein the hardenable material comprises steel.

7 . The harmonic drive of claim 5 , wherein the hardenable material comprises stainless steel.

8 . The harmonic drive of claim 1 , wherein the wave generator sleeve comprises a tri-lobed sleeve.

9 . The harmonic drive of claim 5 , wherein the wave generator sleeve comprises a sleeve material and the rotor comprises a rotor material, wherein the sleeve material is different than the rotor material.

10 . A method of assembling a harmonic drive comprising:
positioning a wave generator sleeve radially within a flexible gear and a bearing assembly, the flexible gear comprising radially-outward-extending teeth; positioning a ring gear around a portion of the flexible gear such that radially-inward-extending teeth of the ring gear mesh with the radially-outward-extending teeth of the flexible gear; directly fitting the wave generator sleeve to an outer diameter of a rotor configured to rotate the wave generator and the flexible gear.

11 . The method of claim 10 , wherein the wave generator sleeve is directly fitted to the outer diameter of the rotor with a thermal fitting process.

12 . The method of claim 11 , wherein the wave generator sleeve is directly fitted to the outer diameter of the rotor with an adhesive.

13 . The method of claim 10 , wherein the wave generator sleeve is positioned to be a bearing assembly support.

14 . The method of claim 11 , wherein the thermal fitting process shrinks the wave generator sleeve to provide a fitted configuration.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Balsiger Derick S
• Van De Veire Nicholas R

Classifications

• H02K7/116

  with gears · CPC title

• F16H49/001 Primary

  Wave gearings, e.g. harmonic drive transmissions · CPC title

• F16H2049/003

  Features of the flexsplines therefor · CPC title

• F16H1/32 Primary

  in which the central axis of the gearing lies inside the periphery of an orbital gear · CPC title