Drum seal

Patent metadata

Field	Value
Publication number	US-9777576-B2
Application number	US-201314095462-A
Country	US
Kind code	B2
Filing date	Dec 3, 2013
Priority date	Dec 13, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A gas turbine engine comprising at least one drum pack having two or more annular discs 62 a - c . Adjacent discs 62 a - c are connected by drive arms 68 the drum pack is provided with a tubular sealing body 84 positioned radially inwards of the drive arms 68 and extending from a first disc 62 a to a last disc 62 c in the drum pack. The first 62 a and last 62 c discs have the greatest axial separation of all discs 62 a - c in the drum pack. The sealing body 84 engaging the first 62 a and last 62 c discs and the engagement being arranged to limit or prevent the ingress of liquid into a drum cavity 76 defined between the first 62 a and last 62 c discs, the drive arms 68 and the sealing body 84.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
at least one drum pack surrounding a shaft and having two or more annular discs, each of the annular discs comprising a cob, a diaphragm, one or more drive arms, and a rim, wherein
adjacent discs of the two or more annular discs are connected by the drive arms,
the at least one drum pack is provided with a tubular sealing body positioned radially inwards of the drive arms, the tubular sealing body extending from a first disc of the two or more annular discs to a last disc of the two or more annular discs in the drum pack, the first disc and the last disc having the greatest axial separation of all of the annular discs in the drum pack, the sealing body engaging the first disc and the last disc, and the engagement being arranged to limit or prevent ingress of liquid into a drum cavity defined between the first disc and the last disc, the drive arms, and the sealing body,
the sealing body has an upstream end and a downstream end and comprises a radially outward extending rim at the upstream end adjacent the first disc,
the sealing body and the radially outward extending rim are a single piece, and
the radially outward extending rim abuts an upstream face of the cob of the first disc.

2. The gas turbine engine according to claim 1 , wherein the drive arms are not provided with liquid drainage passages.

3. The gas turbine engine according to claim 1 , wherein at points adjacent each of the two or more annular discs, the sealing body extends radially inwards of a minimum radial extent of the respective disc of the two or more annular discs.

4. The gas turbine engine according to claim 1 , wherein the engagement is arranged to direct a flow of liquid away from an interface region between the sealing body and the respective first disc or last disc when the engine is in use.

5. The gas turbine engine according to claim 1 , wherein the rim extends on a side of the adjacent disc opposite the drum cavity.

6. The gas turbine engine according to claim 1 , further comprising one or more fluid passages external to the drum pack configured to allow fluid to pass radially outwards and around the drum pack into a core annulus,
wherein the rim is arranged such that the only access from the one or more fluid passages to the interface region is from a radially inward direction.

7. The gas turbine engine according to claim 4 , wherein the interface region of the first disc and/or the last disc with the sealing body is provided with one or more passages arranged to permit a flow of gas there through.

8. The gas turbine engine according to claim 1 , wherein the sealing body is provided with a sloping gradient in the axial direction.

9. The gas turbine engine according to claim 1 , further comprising one or more fluid passages external to the drum pack to allow fluid to pass radially outwards and around the drum pack into a core flow annulus.

10. The gas turbine engine according to claim 1 , wherein radial gas flow passages are provided at a joint between the drive arms extending from the adjacent discs.

11. The gas turbine engine according to claim 10 , wherein the radial gas flow passages are provided in a seal ring positioned at the joint between the drive arms extending from the adjacent discs.

12. The gas turbine engine according to claim 9 , wherein the one or more fluid passages external to the drum pack supply gas flow to one or more inter-disc stage cavities via one or more blade root gas passages in one or more blade root fixings.

13. A gas turbine engine drum pack for surrounding a shaft in a gas turbine engine, the drum pack comprising:
two or more annular discs, each of the annular discs comprising a cob, a diaphragm, one or more drive arms, and a rim, wherein adjacent discs of the two or more annular discs are connected by the drive arms; and
a tubular sealing body positioned radially inwards of the drive arms, the tubular sealing body extending from a first disc of the two or more annular discs to a last disc of the two or more annular discs in the drum pack, the first disc and the last disc having the greatest axial separation of all of the annular discs in the drum pack, the sealing body engaging the first disc and the last disc, and the engagement being arranged to limit or prevent ingress of liquid into a drum cavity defined between the first disc and the last disc, the drive arms, and the sealing body, wherein
the sealing body has an upstream end and a downstream end and comprises a radially outward extending rim at the upstream end adjacent the first disc,
the sealing body and the radially outward extending rim are a single piece, and
the radially outward extending rim abuts an upstream face of the cob of the first disc.

14. A sealing body for use in a gas turbine engine drum pack that surrounds a shaft in a gas turbine engine, the drum pack having two or more annular discs, each of the annular discs comprising a cob, a diaphragm, one or more drive arms, and a rim, wherein adjacent discs of the two or more annular discs are connected by the drive arms, the sealing body comprising:
a tubular sealing body configured to be positioned radially inwards of the drive arms of the two or more annular discs, the tubular sealing body being configured to extend from a first disc of the two or more annular discs to a last disc of the two or more annular discs in the drum pack, the first disc and the last disc having the greatest axial separation of all of the annular discs in the drum pack, the tubular sealing body engaging the first disc and the last disc, and the engagement being arranged to limit or prevent ingress of liquid into a drum cavity defined between the first disc and the last disc, the drive arms, and the tubular sealing body, wherein
the sealing body has an upstream end and a downstream end and comprises a radially outward extending rim at the upstream end adjacent the first disc,
the sealing body and the radially outward extending rim are a single piece, and
the radially outward extending rim abuts an upstream face of the cob of the first disc.

Assignees

• Rolls Royce Plc

Inventors

• Maguire Alan Robert

Classifications

• F05D2260/609

  Deoiling or demisting · CPC title

• F05D2260/60

  Fluid transfer · CPC title

• F01D5/066 Primary

  Connecting means for joining rotor-discs or rotor-elements together, e.g. by a central bolt, by clamps · CPC title

• F01D5/06 Primary

  Rotors for more than one axial stage, e.g. of drum or multiple disc type; Details thereof, e.g. shafts, shaft connections {(F01D5/022, F01D5/023 take precedence)} · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title