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:
Jan. 25, 2011
Filed:
Aug. 07, 2007
Anthony G Razzell, Derby, GB;
John R Webster, Derby, GB;
Geraint W Jewell, Sheffield, GB;
Rolls-Royce plc, London, GB;
Abstract
Control of blade clearance gaps between rotating turbine blades and an associated casing in a gas turbine engine is important in order to maintain operational efficiency. It is desirable to achieve accurate gap control but previous passive and scheduled thermal gap adjustment systems have been relatively course. By provision of a winding through which a specific electrical current is passed in order to create electro-magnetic force for displacement of an armature associated with a seal forming part of the casing it is possible to adjust the gap between that seal and a tip part of a rotating blade assembly. Normally a blade gap monitoring technique is used in association with specific operational requirements with respect to the gap by the control in order to determine the electrical current presented to the winding. As a fail-safe measure a permanent magnet or bias or some other form can be provided to ensure displacement to a fail-safe position with an adequate blade gap clearance for continued operation should there be power failure or an excess electrical current presented to the winding.