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:
Oct. 16, 2001
Filed:
Aug. 20, 1999
Applicant:
Inventor:
John M. Hawkins, Greenwood, IN (US);
Assignee:
Rolls-Royce Corporation, Indianapolis, IN (US);
Primary Examiner:
Int. Cl.
CPC ...
B64C 2/712 ;
U.S. Cl.
CPC ...
B64C 2/712 ;
Abstract
A twin turbine engine helicopter has a two-stage main reduction gearbox, the input stage having a speed reduction ratio exceeding 5.5:1, into an epicyclic gear train second stage ratio about 6:1 for approximately 30:1 or higher overall ratio output to the main rotor. In various embodiments, the first stage uses face gears, or bevel gears, with a reduction greater than 5.5:1 and a second stage epicyclic gear train using single or double row helical or spur gears. The first stage gears are straddle mounted in the housing.