Gas turbine and method for protecting a gas turbine in case of a shaft break

Patent metadata

Field	Value
Publication number	US-10557374-B2
Application number	US-201715646878-A
Country	US
Kind code	B2
Filing date	Jul 11, 2017
Priority date	Jul 14, 2016
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A gas turbine includes a main shaft connecting a turbine to a compressor and an additional shaft extending coaxially to the main shaft. The additional shaft has a first shaft section connected to the compressor and a second shaft section connected to the turbine, the shaft sections separated from each other by a gap. At mutually facing ends, the two shaft sections have mutually corresponding structures. The gap been the two shaft sections is dimensioned such that, upon a break of the main shaft, the mutually corresponding structures of the mutually facing ends of the two shaft sections come into interaction and rotate relative to one another as a result of their differing rotational speeds. The mutually corresponding structures are formed such that the two shaft sections are moved away from one other in the event of twisting of the two shaft sections.

First claim

What is claimed is:

1. A gas turbine, comprising:
a turbine,
a compressor that is arranged upstream of the turbine,
a main shaft extending in an axial direction and connecting the turbine to the compressor, and
a first shaft section and a second shaft section, which are separated from each other by a gap at mutually facing ends thereof and extending coaxially with respect to the main shaft, wherein the first shaft section is connected to the compressor, and the second shaft section is connected to the turbine,
at the mutually facing ends, the first and second shaft sections including mutually corresponding structures,
the gap between the first and second shaft sections being dimensioned in such a manner, that upon a break of the main shaft, the mutually corresponding structures of the mutually facing ends of the first and second shaft sections come into interaction and rotate relative to one another as a result of a difference in rotational speeds of the first and second shaft sections that is then initiated, and
the mutually corresponding structures are embodied in such a manner that the first and second shaft sections are moved away from each other if such relative rotation of the first and second shaft sections occurs.

2. The gas turbine according to claim 1 , wherein the first and second shaft sections are respectively obliquely cut at the mutually facing ends and aligned in such a manner during operation of the main shaft that the mutually facing ends lie in parallel planes.

3. The gas turbine according to claim 2 , wherein an angle (α), which defines the obliquely cut ends of the first and second shaft sections with respect to the axial direction, lies been 10° and 80°.

4. The gas turbine according to claim 2 , wherein when the first and second shaft sections move away from each other, they are displaced with respect to one another by a distance c·cos(α), wherein α is an angle that defines the obliquely cut ends of the first and second shaft sections with respect to the axial direction, and c is a length of the mutually facing ends of the first and second shaft sections.

5. The gas turbine according to claim 1 , wherein the first and second shaft sections are respectively wave-shaped at the mutually facing ends.

6. The gas turbine according to claim 1 , wherein, upon the break of the main shaft, the first shaft section is configured to receive a force counter to the axial direction and to transfer this force to the compressor.

7. The gas turbine according to claim 1 , wherein, upon the break of the main shaft, the second shaft section is configured to receive a force in the axial direction and to transfer this force to the turbine.

8. The gas turbine according to claim 1 , wherein one of the first and second shaft sections includes a pilot pin protruding into the other of the first and second shaft sections.

9. The gas turbine according to claim 1 , wherein the first and second shaft sections are hollow cylinders.

10. The gas turbine according to claim 1 , wherein the turbine is a high-pressure turbine and the compressor is a high-pressure compressor.

11. A turbofan engine comprising the gas turbine of claim 1 .

12. A gas turbine, comprising:
a high-pressure turbine,
a high-pressure compressor that is arranged upstream of the high-pressure turbine,
a main shaft extending in an axial direction and connecting the high-pressure turbine to the high-pressure compressor, and
a hollow first shaft section and a hollow second shaft section, which are separated from each other by a gap at mutually facing ends thereof and extending coaxially with respect to the main shaft, wherein the first shaft section is connected to the compressor, and the second shaft section is connected to the turbine,
at their mutually facing ends, the first and second shaft sections include mutually corresponding structures,
the gap between the first and second shaft sections is dimensioned in such a manner, that upon a break of the main shaft, the mutually corresponding structures of the mutually facing ends of the first and second shaft sections come into interaction and rotate relative to one another as a result of a difference in rotational speeds of the first and second shaft sections that is then initiated, and
the mutually corresponding structures are embodied in such a manner that the first and second shaft sections are moved away from each other if such relative rotation of the first and second shaft sections occurs.

13. A method for protecting a gas turbine in case of a main shaft break, wherein the gas turbine includes a turbine, a compressor arranged upstream of the turbine, and the main shaft extending in an axial direction and connecting the turbine to the compressor, comprising:
providing a first shaft section that is connected to the compressor and a second shaft section that is connected to the turbine, the first shaft section and the second shaft section extending coaxially with respect to the main shaft and being separated from each other by a gap at mutually facing ends thereof, and, at their mutually facing ends, having mutually corresponding structures, and wherein
upon breaking of the main shaft, providing that the mutually corresponding structures of the mutually facing ends of the first and second shaft sections come into interaction with each other as a result of differing rotational speeds of the first and second shaft sections that cause application of a force in the axial direction to the turbine and a force counter to the axial direction to the compressor such that the first and second shaft sections are moved away from each other.

14. The method according to claim 13 , wherein the second shaft section transfers the force in the axial direction to the turbine.

15. The method according to claim 14 , wherein, due to the force transferred by the second shaft section, the turbine is pressed into stators or other non-rotating structures, and is braked in this manner.

16. The method according to claim 13 , wherein the first shaft section transfers the force counter to the axial direction to the compressor.

17. The method according to claim 16 , wherein, due to the force transferred by the first shaft section, the compressor is pressed into stators or other non-rotating structures, and is braked in this manner.

18. The method according to claim 13 , wherein, at their mutually facing ends, the first and second shaft sections are respectively obliquely cut, wherein the first and second shaft sections being moved away from each other occurs at a relative twisting by 180° therebetween.

19. The method according to claim 18 , wherein when the first and second shaft sections move away from each other, they are displaced by a distance c·cos(α) with respect to one another, wherein α is an angle that defines the obliquely cut ends of the first and second shaft section with respect to the axial direction, and c is a length of the mutually facing ends of the first and second shaft sections.

20. The method according to claim 13 , wherein the first and second shaft sections are respectively wave-shaped at their mutually facing ends and wherein the first and second shaft sections being moved away from each other occurs at a relative twisting by a size of one crest of the wave-shape.

Assignees

• Rolls Royce Deutschland Ltd & Co Kg

Inventors

• Panzner Martin
• Sielaff Enrique

Classifications

• F16C3/023

  made of several parts, e.g. by welding · CPC title

• F05D2250/36

  in inner-outer relationship, e.g. shaft-bearing arrangements · CPC title

• F05D2260/902

  using frictional mechanical forces · CPC title

• F05D2240/61

  Hollow · CPC title

• F01D21/006 Primary

  Arrangements of brakes (brakes per se F16D) · CPC title