Transmission apparatus with reduced frictional force
US4715247A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 25, 1986 |
| Grant date | Dec 29, 1987 |
| Priority date | — |
| Expiry date | Sep 25, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
This invention relates to reduction in frictional torque of a harmonic drive type transmission apparatus having a circular spline, a flexspline, and a wave generator. A wave generator bearing of the wave generator has a retainer for holding a number of balls which roll between the inner and outer races to be in contact with an inner race and an outer race and to be separated from each other in the circumferential direction. The ball retainer has a number of radial pockets for storing the balls. Each pocket is formed into a shape forming a narrow (in the circumferential direction) opening portion at the inner race side and a wide (in the circumferential direction) opening portion at the outer race side. The balls are in contact with the opening portion at the inner race side in the pockets at the minor axis positions of a drive cam, and the balls are in contact with substantially the central portion of the pocket inner surface at the major axis positions of the cam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.