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. 20, 2004
Filed:
Aug. 23, 2002
Christopher Freeman, Nottingham, GB;
Adam M Bagnall, Derby, GB;
Rolls-Royce plc, London, GB;
Abstract
A fan ( ) for a turbofan gas turbine engine ( ) comprises a fan rotor ( ) carrying a first set of circumferentially spaced radially extending fan blades ( ) and a second set of circumferentially spaced radially extending fan blades ( ). The second set of fan blades ( ) is arranged downstream of the first set of fan blades ( ). The hub to tip ratio (R /R ) of the first set of fan blades ( ) is substantially the same as the hub to tip ratio (R /R ) of the second set of fan blades ( ) and the radius (R ) of the radially outer ends of the first set of fan blades ( ) is less than the radius (R ) of the radially outer ends of the second set of fan blades ( ). This increases the flow area of the fan ( ) by about 7% compared to a conventional fan of the same radius and thus increases the mass flow by about 7% and/or increases the pressure ratio.