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:
Nov. 14, 2000
Filed:
May. 28, 1999
Ronald E Munson, Round Rock, TX (US);
Shane Joseph Findlan, Harrisburg, NC (US);
David W Gandy, Concord, NC (US);
Ramaswamy Viswanathan, Saratoga, CA (US);
Electric Power Research Institute, Inc., Palo Alto, CA (US);
Abstract
A method for repairing a shrink-fitted turbine disc without removing the disc from the shaft. The method is composed of two basic steps: (1) depositing one or more weld layers in a vicinity of a defective region of the disc using a temperbead welding process and (2) heat treating the disc using an induction heating process. In a first embodiment of the method, the heat treating step includes heating a heat-affected zone of the disc in a vicinity of the one or more weld layers to a temperature T.sub.h, heating a rim region of the disc to a temperature T.sub.r and heating a bore region of the disc to a temperature T.sub.b, where T.sub.h, T.sub.r >T.sub.b. In a second embodiment of the method, the heat treating step includes heating a region of the disc in a vicinity of the one or more weld layers using the induction heating process and concurrently cooling a bore region of the disc. In a third embodiment of the method, the heat treating step includes heating at least a portion of the disc using the induction heating process and concurrently heating the shaft to maintain a predetermined temperature differential between the bore region of the disc and the shaft. In a fourth embodiment of the method, the heat treating step includes heating at least a portion of the disc using the induction heating process and concurrently heating the shaft to maintain a uniform temperature between the bore region of the disc and the shaft.