Casing

Patent metadata

Field	Value
Publication number	US-9429039-B2
Application number	US-201313872594-A
Country	US
Kind code	B2
Filing date	Apr 29, 2013
Priority date	May 11, 2012
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

A containment case for a gas turbine including: a cylindrical outer casing extending about an axis and having a radially outer and a radially inner surface; a coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing; and an array of ribs extending radially from the inner skin towards the axis. The case for can have the coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing by a galvanic isolation layer.

First claim

The invention claimed is:

1. A containment case for a gas turbine, the case comprising:
a cylindrical outer casing extending about an axis and having a radially outer surface and a radially inner surface;
a coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing; and
an array of ribs extending radially from the inner skin towards the axis,
wherein each rib has a hollow cavity open to a radially outer surface of the inner skin.

2. A gas turbine engine comprising:
a containment case comprising:
a cylindrical outer casing extending about an axis and having a radially outer surface and a radially inner surface;
a coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing; and
an array of ribs extending radially from the inner skin towards the axis, wherein:

the array of ribs is associated with a row of rotatable aerofoils, each aerofoil having a tip with a tip chord length between a leading edge of the aerofoil and a trailing edge of the aerofoil, and
the ribs are spaced from each other in a circumferential direction at a distance that is up to a ¼ of the tip chord length.

3. A gas turbine engine according to claim 2 , wherein the tip has a stagger angle and the ribs are angled to the direction in which the casing axis extends at 90 degrees to the tip stagger angle.

4. A gas turbine engine according to claim 2 , wherein the rotatable aerofoils are fan blades.

5. A containment case according to claim 1 , wherein the outer casing is aluminium or a composite formed from a plurality of plies of fibres in a resin matrix.

6. A containment case according to claim 1 , wherein the inner skin is formed from steel or a steel alloy.

7. A containment case according to claim 1 , wherein the inner skin is provided by a plurality of skin sections arranged as a circumferential array.

8. A containment case according to claim 1 , wherein the inner skin has dimples for providing stiffness to the inner skin.

9. A containment case according to claim 1 , wherein the inner skin and the outer casing are joined by a layer of polymer or elastomer.

10. A containment case according to claim 2 , wherein each rib is angled to the direction in which the casing axis extends.

11. A containment case according to claim 10 , wherein each rib leans towards a tangent.

12. A containment case according to claim 10 , wherein each rib has a wavy profile in a section taken through the array of ribs.

13. A containment case according to claim 10 , wherein the inner skin has dimples for providing stiffness to the inner skin.

14. A containment case according to claim 7 , wherein each skin section overlaps at its axially extending edge with an adjacent skin section.

15. A containment case according to claim 9 , wherein the polymer or elastomer is selected from a group comprising polyurethane and thermoplastic elastomers.

16. A containment case according to claim 9 , wherein the layer provides galvanic isolation between the material of the inner skin and the material of the outer casing.

Assignees

• Rolls Royce Plc

Inventors

• Finlayson James Alex

Classifications

• F01D25/24 Primary

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F05D2300/603

  Composites; e.g. fibre-reinforced · CPC title

• F01D21/045 Primary

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

• F05D2300/21

  Oxide ceramics · CPC title

• F05D2300/173

  Aluminium alloys, e.g. AlCuMgPb · CPC title