GB2287292A

GB2287292A - Seal

Info

Publication number: GB2287292A
Application number: GB9504223A
Authority: GB
Inventors: Wolfgang Krueger; Steffen Grimmler
Original assignee: MTU Motoren und Turbinen Union Muenchen GmbH
Current assignee: MTU Aero Engines AG
Priority date: 1994-03-11
Filing date: 1995-03-02
Publication date: 1995-09-13
Anticipated expiration: 2015-03-02
Also published as: GB9504223D0; DE4408260A1; FR2717244A1; GB2287292B; ITMI950407A1; ITMI950407A0; IT1275854B1

Description

0.

2287292 M&C FOLIO: 230P72018 WANGDOC: 1165k Seal The present invention relates to a seal for a sealing gap formed between two opposed boundary faces movable substantially tangentially relative to each other, a hollow sealing member being urged in a sealing manner against a boundary face by fluid pressure produced therein, wherein a flexurally rigid support structure is secured to the sealing member for positioning and holding thereof.

An object of the invention is to improve the seal, in particular the static seal, of a hot-gas duct in a jetengine nozzle with adjustable components in order to produce different contours of a jet-engine nozzle.

The invention provides a seal as claimed in Claim 1.

The seal according to the invention having a tubular sealing member of metal foils of different thicknesses of material is reinforced with a flexurally rigid support structure. If an internal pressure is increased by a supply of fluid in the sealing member the rear side of the sealing member bulges and is thus pressed against boundary faces, while a front side of 1 2 the sealing member rests over an entire sealing length against a boundary face of a component relatively movable tangentially. The seal according to the invention also rests against ends of a sealing line, so that a sealing gap is closed over the entire length.

A further advantageous embodiment of the seal according to the invention consists in contact faces of the sealing member, which are coated with titanium nitrite in order to reduce wear and are used in jet-engine nozzles with movable contact faces.

According to an advantageous embodiment of the invention, end closure walls of the sealing member have connexion openings, through which fluid can flow out from the sealing members. The fluid which has flowed off is replaced by way of a fluid supply, so that the pressure in the sealing member remains constant.

The seal according to the invention is particularly suitable for sealing the sealing gap between ramps of a jet-engine nozzle which are arranged so as to be movable relative to one another.

The invention will be illustrated below with reference to a model nozzle for hypersonic drives by way of an example of embodiment. In the drawing C 91 1 c.

d ' 3 Fig. 1 is a cross-section through a model nozzle; Fig. 2 is a cutaway portion of the cross-section according to Fig. 1 and a plan view of a seal according to the invention, and Fig. 3 is a further cutaway portion of the cross-section according to Fig. 1 through a seal according to the invention.

Fig. 1 shows a model nozzle 1 for a hypersonic drives which is provided with an inlet 2 through which hot gas is fed into the model nozzle 1 in the direction of the arrow 3. The inlet 2 has bores 4, 5 at which the model nozzle 1 can be fastened and it is covered with an insulating layer 7.

A ramp 6 adjoins the inlet 2 and is rotatably movable about a shaft 8. The ramp 6 is shaped like an ice skate, the runner 9 of which faces an axis 10 of the model nozzle 1. The runner 9 is in three parts. A boundary face 91, which is substantially flat at the rear end 12 thereof and is curved away from the axis 10 at the end 13 facing the inlet 2, is mounted on the runner 9. The runner 9 is provided with profiled reinforcements or ribs 14 on the side remote from the axis 10 of the model nozzle 1. A connecting member 15 d L 4 is welded onto the reinforcement 14 and has a bore 16.

A cooling medium, preferably hydrogen, is conveyed into a duct 23 by way of coolant lines 19, 20 from storage containers which are designated 17, 18, the duct 23 extending parallel to the boundary face 91 and being mounted thereon. The coolant in the duct 23 cools the boundary face 91 and discharges at the rear end 12 into the model nozzle 1.

A ramp 21 adjoins the ramp 6 and is rotatably movable about a shaft 24. The ramp 21 is shaped like an ice skate, the runner 25 of which faces the axis 10 of the model nozzle 1. The runner 25 is in four parts. A boundary face 351, which is flat at the rear end 27 thereof and is curved outwards away from the axis 10 at the end 28 facing the inlet 2, is mounted on the runner 25.

The runner 25 is provided with profiled reinforcements or ribs 28 on the side remote from the axis 10 of the model nozzle 1. The connecting member 15 is attached to the shaft 24 in an articulated manner.

Valves 29, 30 are connected to a coolant, preferably hydrogen. The coolant lines 31, 32 open into a duct 49 which extends parallel to the boundary face 0 351 and is mounted thereon. The coolant in the duct 49 cools the boundary face 351 and discharges at the rear end 27 into the model nozzle 1.

Fig. 2 shows a sealing member 36 of metal foils which is mounted between the boundary face 91 and a flexurally rigid support structure 37 at the inlet 2. The metal foils have different thicknesses of material ranging from 0.1 to 0.4 mm, the metal foils of greater material thickness being arranged on a front side 35 of the sealing member 36 and the metal foils of smaller material thickness on a rear side 40 of the sealing member 36. A flexurally rigid support structure 39 of metal, which is joined to the flexurally rigid support structure 37 by welding or soldering, is secured to the front side 35 of the sealing member 36. The sealing member 36 rests tightly and firmly with contact faces 33 on the rear side 40 against a boundary face 241 of the flexurally rigid support structure 37 and with contact faces 34 on the front side against the boundary face 91 of the flexurally rigid support structure 39 of the ramp 6 along an entire sealing line (not shown).

Fig. 3 shows a sealing member 38 of metal foils which is mounted between the boundary face 351 and a boundary face 401 mounted on the reinforcements 14 of the ramp 6. The metal foils have different thicknesses 6 of material ranging from 0.1 to 0.4 mm, the metal foils of greater thickness being arranged on the front side 35 of the seal 38 and the metal foils of smaller thickness on the rear side 40 of the sealing member 38. A flexurally rigid seal-carrier component 44 with the boundary face 401 is mounted on the reinforcements 14, the sealing member 38 resting tightly and firmly with contact faces 33a on the rear side 40 against the boundary face 401. The contact surfaces 34a on the front side 35 of the sealing member 38 rest against the boundary face 351 of the ramp 21 along an entire sealing line (not shown). A flexurally rigid support structure 39 of metal is joined to the front side 35 and the seal- carrier component 44 by welding or soldering. The seal-carrier component 44 is provided with a recess 43 and a fluid-connexion opening 42 which opens into the rear side 40 of the sealing member 38.

The sealing members 36, 38 are provided with respective connexion openings for the supply and removal of the fluid.

The sealing members 36, 38 are provided with end closure walls 47 which ensure closed sealing lines over the entire length to be sealed. The end closure walls 47 are constructed as lateral covers for the sealing members 36, 38, and can be welded to the sealing members i, Z 7 36, 38. The bores 48 are provided in the end closure walls 47. Fluid, for example hot air, can escape from the sealing members 36, 38 through the bores 48 and is supplemented by fluid, for example following cold air, which can reach the sealing members 38 through the connexion opening 42 for example.

The contact faces 33, 34, 33a, 34a of the sealing members 36, 38 can be coated with titanium nitrite on the surfaces thereof.

The seal according to the invention with the sealing members 36, 38 can be used in particular between ramps 6, 21 of a jet-engine nozzle which are arranged so as to be movable relative to one another.

8

Claims

Claims:

1. A seal for a sealing gap formed between two opposed boundary faces movable substantially tangentially relative to each other, a hollow sealing member being urged in a sealing manner against a boundary face by fluid pressure produced therein, wherein a flexurally rigid support structure is secured to the sealing member for positioning and holding thereof, characterized in that the sealing member is a tube formed by a metal foil extending over the width of the boundary faces so as to form a sealing line, and the support structure is a strap extending along the sealing line in the longitudinal direction of the tube and extending laterally beyond the cross-section of the tube.

2. A seal according to Claim 1, wherein the tubular sealing member is coated on the contact faces thereof with titanium nitrite.

3. A seal according to Claim 1 or 2, wherein connexion openings for the respective supply and removal of fluid are provided in front closure walls of the sealing member.

4. A seal substantially as herein described with i, p 9 reference to the accompanying drawing.

Use of a seal as claimed in any one of the preceding claims for sealing the gap between ramps of a jet-engine nozzle arranged so as to be movable relative to one another.