The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 2017
Filed:
Mar. 01, 2013
United Technologies Corporation, Hartford, CT (US);
Robert H. Perkinson, Stonington, CT (US);
United Technologies Corporation, Farmington, CT (US);
Abstract
A wind turbine blade assembly comprises a rotatable hub, a blade secured to the hub, and a pitch system. The pitch system is disposed to rotate the blade with respect to the hub about a pitch axis not extending through an aerodynamic centroid of the blade. The pitch system comprises a hydraulic cylinder pitch actuator and a relief valve. The hydraulic cylinder pitch actuator has first and second pressure chambers. The relief valve is configured to aerodynamically unload the blade by equilibrating the first and second pressure chambers in response to a pressure differential between the first and second pressure chambers exceeding a critical threshold corresponding to a pre-strain blade twist.