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:
Apr. 09, 2013
Filed:
Feb. 12, 2009
Norman Mark Wereley, Potomac, MD (US);
Wei HU, Rockville, MD (US);
Curt Steven Kothera, Crofton, MD (US);
Peter Che-hung Chen, Clarksville, MD (US);
Grum Tamrat Ngatu, Alexandria, VA (US);
Norman Mark Wereley, Potomac, MD (US);
Wei Hu, Rockville, MD (US);
Curt Steven Kothera, Crofton, MD (US);
Peter Che-Hung Chen, Clarksville, MD (US);
Grum Tamrat Ngatu, Alexandria, VA (US);
Techno-Sciences, Inc., Calverton, MD (US);
The University of Maryland at College Park, College Park, MD (US);
Abstract
A MagnetoRheological Fluid Elastic (MRFE) lag damper system for adaptive lead-lag damping of helicopter main rotors. Embodiments include snubber dampers especially for hingeless helicopter rotors, and concentric bearing dampers. The snubber lag dampers include a flexible snubber body defining a cavity, a flexible or rigid interior (e.g., center) wall subdividing the cavity, and a flow valve in the interior wall or external to the cavity. The flexible snubber body may comprise elastomeric materials and metal rings stacked together to create a sealed MR fluid cavity. The shear deformation of the snubber body induces MR fluid flow through the valve, controlled by a magnetic field in the valve. An MRFE concentric bearing damper is also disclosed, comprising a pair of concentric tubes with elastomeric material injected and cured in an annular gap between the two tubes, and an MR fluid reservoir with piston-mounted MR valve housed inside the innermost tube.