Blade with metallic leading edge and angled shear zones

Patent metadata

Field	Value
Publication number	US-10030522-B2
Application number	US-201514954221-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Dec 19, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A turbomachine blade comprising a blade tip and a metallic leading edge having a plurality of shear zones angled to the blade tip, wherein the shear strength of the shear zones is less than the shear strength of the remainder of the leading edge, such that in the event of an impact shear is initially initiated at the shear zones.

First claim

The invention claimed is:

1. A fan blade comprising a blade tip and a metallic leading edge having two wings and a fore portion provided between the two wings and having a plurality of shear zones angled to the blade tip, wherein the shear strength of the shear zones is less than the shear strength of other regions of the leading edge, such that in the event of an impact, shear is initially initiated at the shear zones, wherein
the plurality of shear zones including shear zones located in the wings defining sections of the wings tapered spanwise in a direction defined by a thickness direction and tapered cordwise in a direction defined by the span, the shear zones are angled such that an innermost position of the shear zones is nearer to the blade tip than an outermost position.

2. The blade according to claim 1 , wherein the zones are acutely angled towards a tip of the blade in a direction from the leading edge towards a trailing edge of the blade.

3. The blade according to claim 2 , wherein the zones are angled such that, in use, the angle between the zones and the tip of the blade is equal to or between 30° and 70°.

4. The blade according claim 1 , wherein the metallic leading edge comprises a plurality of sections arranged and adjacently attached in a spanwise direction.

5. The blade according to claim 4 , wherein the shear zones include a bondline between the adjacently attached sections.

6. The blade according to claim 4 , wherein the sections are welded together.

7. The blade according to claim 1 , wherein the leading edge is thinner in a region of the shear zones compared to regions directly adjacent said shear zones.

8. The blade according to claim 1 , wherein the shear zones are each angled in a direction defined by a thickness direction and a spanwise direction.

9. The blade according to claim 1 , wherein the leading edge is formed in two portions, the two portions being connected together in the fore portion.

10. A gas turbine engine comprising a fan case that circumscribes a fan having a plurality of blades according to claim 1 .

11. A fan blade comprising a metallic leading edge, wherein the metallic leading edge comprises a plurality of sections arranged in a spanwise direction, the sections being connected together by a connection having a weaker shear strength than said sections, and the connection between the sections being angled to the leading edge, the metallic leading edge further comprising two wings and a fore portion provided between the two wings, wherein
the connection is located within the region of the wings tapered spanwise in a direction defined by a thickness direction and tapered cordwise in a direction defined by the span, the connection is angled such that an innermost position of the connection is nearer to the blade tip than an outermost position.

Assignees

• Rolls Royce Plc

Inventors

• Benson Christopher

Classifications

• F05D2260/311

  of the frangible or shear type · CPC title

• F01D21/045

  special arrangements in stators or in rotors dealing with breaking-off of part of rotor · CPC title

• F05D2240/303

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

• F01D5/147 Primary

  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