Fan casing liner support

• US 6,382,905 B1
• Filed: 04/28/2000
• Issued: 05/07/2002
• Est. Priority Date: 04/28/2000
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Ruehr, William Carl, Czachor, Robert Paul
• Primary Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US09/560,460
• Time in Patent Office: 739 Days
• Field of Search: 415/9, 415/126, 415/128, 415/136, 415/173.1, 415/173.2, 415/173.3, 415/173.4, 415/173.5, 415/135
• US Class Current: 415/9
• CPC Class Codes: F01D 11/122 with erodable or abradable material blades having cutting or grinding tips F01D5/20
• CPC Class Codes: F01D 11/14 Adjusting or regulating tip-clearance, i.e. distance between rotor-blade tips and stator casing rotors with blades adjustable in operation F01D7/00
• CPC Class Codes: F01D 25/246 Fastening of diaphragms or stator-rings
• CPC Class Codes: F04D 29/164 of an axial flow wheel
• CPC Class Codes: F04D 29/526 Details of the casing section radially opposing blade tips ducts F04D29/545
• CPC Class Codes: F05B 2230/606 using maintaining alignment while permitting differential dilatation
• CPC Class Codes: F05D 2230/642 using maintaining alignment while permitting differential dilatation
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A casing for the fan section of an aircraft gas turbine engine of the turbofan type. The casing includes an inner filler material and is defined by an outer shell and an inner liner that is spaced radially inwardly from the outer shell. The inner liner is held in position relative to the outer shell by a plurality of radially-inwardly-extending support pins. The pins are carried by the outer shell and are slidably received in and extend at least partially into the inner liner. The support pins retain the inner liner against axial and rotational movement relative to the outer shell, while allowing relative radial movement therebetween in response to thermal expansion and contraction, as well as in response to aircraft maneuver loads imposed on the engine.

Claims

1. A casing for surrounding a rotatable turbomachine member that includes a rotor and a plurality of substantially radially-extending, circumferentially spaced rotor blades, said casing comprising:

a. an annular outer shell formed from a material having a first coefficient of thermal expansion;

b. an annular inner liner carried within and spaced radially inwardly of the outer shell and substantially coaxial therewith, the annular inner liner formed from a material having a second coefficient of thermal expansion that is lower than the first coefficient of thermal expansion and capable of radially expanding and radially contracting relative to the outer shell as a result of changes in inner liner temperature, the annular liner surrounding and spaced radially outwardly from outer tips of the rotor blades by a predetermined distance to limit gas flow between the rotor blade tips and the inner liner;

c. a plurality of substantially radially inwardly extending support members fixedly carried by the outer shell and extending at least partially into substantially radial openings carried by the inner liner to support the inner liner against axial and rotational movement relative to the outer shell, and to allow relative radial sliding movement between the outer shell and the inner liner along the support members and without relative rotation between the support members and the inner liner.

2. A casing in accordance with claim 1, wherein the outer shell is a metallic structure that has sufficient rigidity to contain separated fragments of the rotatable member.

3. A casing in accordance with claim 1, wherein the outer shell includes an impact-energy-absorbing annular intermediate layer positioned between the outer shell and the inner liner.

4. A casing in accordance with claim 3, wherein the intermediate layer includes a metallic honeycomb material.

5. A casing in accordance with claim 3, wherein the intermediate layer is secured to the outer shell and is spaced from the inner liner.

6. A casing in accordance with claim 5, wherein the intermediate layer is adhesively bonded to the outer shell.

7. A casing in accordance with claim 1, wherein the outer shell includes a radially-inwardly-extending step for retaining separated fragments of the rotatable member.

8. A casing in accordance with claim 1, wherein the coefficient of thermal expansion of the inner liner is substantially the same as that of the rotor blades.

9. A casing in accordance with claim 1, wherein the inner liner includes a composite material.

10. A casing in accordance with claim 9, wherein the composite material is the same material as the rotor blade material.

11. A casing in accordance with claim 1, wherein the inner liner includes a metallic honeycomb material.

12. A casing in accordance with claim 1, wherein the inner liner includes a radially-inwardly-facing surface formed by a layer of abradable material.

13. A casing in accordance with claim 1, wherein the support members include support pins that are slidably received in the inner liner.

14. A casing in accordance with claim 13, wherein the support pins are threadedly carried by the outer shell.

15. A casing in accordance with claim 14, wherein the inner liner includes a plurality of radially-inwardly-extending tubular sleeves that slidably receive respective support pins.

16. A casing in accordance with claim 14, wherein the support pins are provided in a single row of circumferentially-spaced support pins.

17. A casing in accordance with claim 14, wherein the support pins are provided in plural, axially-spaced rows of circumferentially-spaced support pins.

18. A casing in accordance with claim 1, wherein the support members are formed from a composite material.

19. A fan casing for surrounding a rotatable fan having a plurality of substantially radially-outwardly-extending blades, said casing comprising:

a. an annular outer shell;

b. an annular inner liner freely carried within and spaced radially inwardly of the outer shell and substantially coaxial therewith, wherein the inner liner is formed from a composite material having a coefficient of thermal expansion that is lower than the coefficient of thermal expansion of the outer shell, and capable of radially expanding and radially contracting relative to the outer shell as a result of changes in inner liner temperature, the annular liner surrounding and spaced radially outwardly from outer tips of the rotor blades by a predetermined distance to limit gas flow between tips of the rotor blade and the inner liner; and

c. a plurality of substantially radially inwardly extending support pins fixedly carried by the outer shell and extending at least partially into a plurality of radially-inwardly-extending openings carried by the inner liner to support the inner liner against axial and rotational movement relative to the outer shell, and to allow relative radial movement between the outer shell and the inner liner along the support pins and without relative rotation between the support pins and the inner liner.