Blade

Patent metadata

Field	Value
Publication number	US-2016177779-A1
Application number	US-201514954087-A
Country	US
Kind code	A1
Filing date	Nov 30, 2015
Priority date	Dec 19, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A turbomachine blade comprising a metallic leading edge having a weakened region extending in a spanwise direction; and a crack initiator for selectively initiating cracking of the metallic leading edge along the weakened region.

First claim

1 . A turbomachine blade comprising
a metallic leading edge having a weakened region extending in a spanwise direction; and a crack initiator for selectively initiating cracking of the metallic leading edge along the weakened region.

2 . The blade according to claim 1 , wherein the crack initiator is provided at the tip of the blade.

3 . The blade according to claim 1 , wherein the crack initiator comprises a leading edge cap positioned at the blade tip.

4 . The blade according to claim 3 , wherein the cap is a wedge shaped insert having a reduced width in a direction from the blade tip towards the blade root, width being measured in a direction from a pressure side to a suction side of the blade.

5 . The blade according to claim 4 , wherein the wedge shaped insert comprises planar sides angled to reduce the width of the insert.

6 . The blade according to claim 4 , wherein insert is shaped to converge towards the weakened region.

7 . The blade according to claim 3 , wherein the cap is bonded to the leading edge.

8 . The blade according to claim 4 , wherein the cap includes shoulders that are arranged such that in a non-failure condition the shoulders rest on a region of the metallic leading edge, and configured so as to shear from the remainder of the cap when a predetermined impact force is applied to the cap.

9 . The blade according to claim 1 , wherein the metallic leading edge is formed of at least two parts and the weakened region is a bondline between said two parts of the metallic leading edge.

10 . The blade according to claim 1 , wherein the crack initiator is entirely contained within a region defined by the metallic leading edge.

11 . The blade according to claim 1 , wherein the leading edge includes two wings and a fore portion positioned between said two wings.

12 . The blade according to claim 1 , wherein the blade comprises a composite core to which the leading edge is attached.

13 . The blade according to claim 1 , wherein the blade is a fan blade for a gas turbine engine.

14 . A gas turbine engine comprising the blade according to claim 1 .

Assignees

• Rolls Royce Plc

Inventors

• Benson Christopher

Classifications

• F01D5/282

  Selecting composite materials, e.g. blades with reinforcing filaments · CPC title

• F01D5/147

  Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18) · CPC title

• F02C7/05

  having provisions for obviating the penetration of damaging objects or particles · CPC title

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title

• F05D2260/311

  of the frangible or shear type · CPC title