Seal and seal arrangement for confining leakage flows between adjacent components of turbo-machines and gas turbines

1. A seal for stemming leakage flows between adjacent components of turbomachines, the seal comprising:

an elongated, thin-walled sealing element which is elastically deformable in at least one transverse direction and in cross section has the shape of a bent band;

an elongated, thin-walled cover element having a U-shaped cross section, the U-shape having legs and a base, the legs and the base delimiting a recess in which the sealing element is positioned, wherein:

the sealing element has a relaxed state in which a portion of the sealing element is outside said recess;

the sealing element has a cross sectional shape of a repeatedly bent band which has a plurality of consecutive bends with alternating bend directions; and

each bend is the cross-sectional shape of an associated bent wall section of the sealing element;

the sealing element includes a plurality of transversely extending wall sections;

the sealing element has two adjacent rows of consecutive bent wall sections, two consecutive bent wall sections of each row are connected by one transversely extending wall section, and in each row all the transversely extending wall sections intersect a common center plane;

the two adjacent rows each define a center plane, the center planes being parallel to each other; and

the seal further comprises a thin-walled cover strip which has a band-like cross section and extends between two of said wall sections, both rows of the bent wall sections being connected by the cover strip, and the cover strip has at least one convex surface region oriented away from the recess configured and arranged to at least partially bear against a sealing surface of the other component.

2. The seal as claimed in claim 1 , wherein the cover element base has an outer side which faces away from the recess has and a strip-like, raised surface section on the base outer side configured and arranged to bear against a sealing surface of one of the components.

3. The seal as claimed in claim 2 , wherein:

the outer side of the cover element base has a strip-like region which extends at a lateral distance from the strip-like, raised surface section, the strip-like region including a plurality of spaced-apart, raised surface sections positioned to bear against the sealing surface of one component;

the strip-like region comprises a plurality of raised surface sections; and

a flow passage for low-pressure fluid is delimited at least by the sealing surface of the one component and the cover element, the flow passage being located between at least two adjacent, raised surface sections of the strip-like region.

4. The seal as claimed in claim 1 , wherein:

each two consecutive bent wall sections of the sealing element are connected by one of the transversely wall sections; and

all the transversely extending wall sections intersect a common center plane.

5. The seal as claimed in claim 1 , wherein:

the cover element base includes an inner side oriented toward the recess; and

each row of bent wall sections includes a last bent wall section, and an end section adjoining the last bent wall section having a free end, the end section has a band-like cross section, and the end section at least partially bears tightly against the cover element base inner side.

6. The seal as claimed in claim 5 , further comprising:

a wall section connecting the cover strip to a first bent wall section of a row of bent wall sections, said wall section including at least one opening for the passage of high-pressure fluid.

7. The seal as claimed in claim 1 , wherein at least one of the sealing element and the cover element is formed of metal.

8. The seal as claimed in claim 7 , wherein at least one of the sealing element and the cover element is resistant to high temperatures.

9. The seal as claimed in claim 1 , wherein the sealing element and the cover element are formed of different metals.

10. The seal as claimed in claim 1 , wherein the sealing element and the cover element are interconnected in a fixed and gastight manner by welding or soldering.

11. The seal as claimed in claim 1 , wherein:

the cover element legs each include a free end; and at least one of the cover element legs includes at least one slot which extends from a leg free end towards the cover element base.

12. A sealing arrangement for stemming leakage flows between adjacent components of turbomachines, the sealing arrangement comprising:

first and second adjacent components of a turbomachine each having a wall, the walls together delimiting a space, each of said walls defining one of two oppositely disposed sealing surfaces;

wherein a first component of said two adjacent components comprises two oppositely disposed walls, said oppositely disposed walls forming a U-shaped groove with the wall of the second component;

a seal having an elongated, thin-walled sealing element which is elastically deformable in at least one transverse direction and having a cross sectional shape of a bent band;

wherein the seal is arranged in the space in a pretensioned manner in the at least one transverse direction in such a way that the at least one transverse direction extends perpendicularly to the two oppositely disposed sealing surfaces;

an elongated, thin-walled cover element, the cover element being U-shaped in cross section, the U-shape comprising two legs, a base, and a recess between the legs and the base in which the sealing element is positioned;

wherein, in a relaxed state of the sealing element, a portion of the sealing element is outside of the recess; wherein the two legs are arranged between the two oppositely disposed walls of the first component, the two legs being movable relative to the two oppositely disposed walls,

wherein the space delimited by the walls of the two components is part of a gap which extends between the two components and comprises at least two spaced-apart outlets between which the seal is positioned,

wherein one of the gap outlets is in communication with a region which contains high-pressure fluid and the other gap outlet is in communication with a region which contains low-pressure fluid; at least one portion of the outer surface of the cover element base is exposed to low-pressure fluid and at least one portion of the inner surface of the cover element base is exposed to high-pressure fluid, and

wherein the difference in pressure between the low-pressure fluid and the high-pressure fluid creating a force which acts upon the cover element to press the cover element against the sealing surface of the second component.

13. The sealing arrangement as claimed in claim 12 , wherein the two legs of the cover element are arranged with a lateral clearance between the two oppositely disposed walls of the first component.

14. The sealing arrangement as claimed in claim 12 , wherein at least a portion an outer surface of the cover element base bears against the sealing surface of the second component.

15. The sealing arrangement as claimed in claim 12 , wherein:

the turbomachine is a gas turbine having a combustor; and

the components are parts of the combustor.

16. The sealing arrangement as claimed in claim 12 , wherein the high-pressure fluid is a gas of relatively low temperature and the low-pressure fluid is a gas of relatively high temperature.

17. A turbomachine comprising:

two adjacent components, each having a wall, the walls together delimiting a space; and

a sealing arrangement according to claim 1 positioned in the space between the two components.