Quiet clutch fan blade
US4930990A · kind A · utility
9Cited by
4References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Sep 15, 2009 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF05D2240/307
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A clutch fan has a new and unique blade design that results in quieter and more efficient operation. The blade design involves the leading edge having inner, intermediate, and outer regions such that the intermediate region is of increasing skew in the direction of rotation and the outer region is of decreasing skew. The pitch ratio increases as a function of increasing blade radius. Along the outer region, the blade increases in pitch on a defined curvature as a function of blade radius and angle to form a tip curl.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.