Yoke for helicopter rotor systems
US5358381A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1993 |
| Grant date | Oct 25, 1994 |
| Priority date | — |
| Expiry date | Mar 19, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/08
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved feathering flexure for a helicopter rotor system yoke includes, in transverse cross section, a relatively thin central web and six relatively thin flanges. Three flanges extend from each of the web's two edges, and the flanges lie in planes which are approximately radial relative to the neutral feathering axis of the feathering flexure. The feathering flexure is constructed of fiberglass material embedded in a polymer matrix. The web's fiberglass material in the web is bias material, that is, material whose glass fibers are oriented at plus or minus 45 degrees relative to the yoke's spanwise axis. In transverse cross section, each of the flanges includes two unidirectional belts disposed on either side of a bias pack. The glass fibers in the unidirectional belts are oriented parallel to the yoke's spanwise axis. The fiberglass material in the bias packs is bias material. Each flange's unidirectional belts taper inwardly toward its bias pack adjacent to web, thereby decreasing the thickness of the flange adjacent to the web. In addition, the portion of each flange adjacent to the web is configured to minimize torsional rigidity and shear stress resulting from twisting th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.