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:
Dec. 17, 2013
Filed:
Jun. 22, 2010
Neil William Harvey, Derby, GB;
Stephane Michel Marcel Baralon, Derby, GB;
Neil William Harvey, Derby, GB;
Stephane Michel Marcel Baralon, Derby, GB;
Rolls-Royce PLC, , GB;
Abstract
A shroudless blade for use in a compressor or fan of an axial flow gas turbine engine includes a treatment to the tips of the blades to improve the surge margin of the compressor. A series of cross bleed holes are formed at the tip of the blade, which may be a stator or rotor component, extending between the pressure and suction sides of the blades. Notches are provided at the tip of the blades to provide initiation sites for any fatigue cracks such that the cracks propagate from the base of these slots or notches and radially inwards into the body of the blades. The present invention provides an arrangement, which by provision of the cross bleed holes the propagation of the cracks is arrested. A preferred placement and orientation for the holes for best mechanical and aerodynamic performance is described.