TURBINE OUTER RING CONNECTION STRUCTURE AND TURBINE ENGINE

Abstract

 A turbine outer ring connection structure comprises a turbine outer ring, a middle-layer casing and a plurality of connection assemblies, wherein each connecting assembly comprises an elastic beam and a connection piece, the bottom of the elastic beam comprises an abutting part, and the abutting part abuts against an outer surface of the middle-layer casing so that a gap exists between other parts of the elastic beam and the middle-layer casing. A column body at one end of the connection piece passes out of the inner side of the middle-layer casing and is fixedly connected to the elastic beam via through holes in the middle-layer casing and the elastic beam, and the other end of the connection piece is connected to the turbine outer ring. The elastic beam provides stable pre-tightening force for the connection piece and the turbine outer ring by means of deformation, and the gap between the elastic beam and the middle-layer casing is used for absorbing the thermal deformation generated by the engine in the radial direction.

Description

Technical Field

[0001] The present invention relates to the field of aircraft engines, and in particular to a turbine outer ring connection structure and a turbine engine.

Background Art

[0002] As main high-temperature components of gas turbine engines, turbine outer rings have to withstand high ambient temperatures in service, and conventional high-temperature alloy materials have become increasingly difficult to meet design requirements. Therefore, ceramic matrix composites (CMC) are increasingly applied to aircraft engines instead of high-temperature alloys to manufacture the turbine outer rings. However, the turbine outer ring of a ceramic matrix composite differs greatly in physical properties from an intermediate casing of a metal material, and in the process of service, obvious mismatch of thermal deformation will occur, which affects the safety and reliability of a connection structure. Some of the existing outer ring connection structures absorb part of the thermal deformation by providing an elastic washer on a fixing surface of a bolt. However, the washer itself will also be affected by temperature. In addition, a temperature alternation is likely to cause repeated expansion and contraction of the washer, which will lead to loosening of the bolt due to decline of a pre-tensioning force for the bolt. Therefore, providing a turbine outer ring connection structure that can effectively absorb thermal deformation is of great significance for improving the reliability of an engine.

Summary of the Invention

[0003] An object of the present invention is to provide a turbine outer ring connection structure that can effectively absorb thermal deformation of a turbine outer ring and an intermediate casing. The present invention further provides a turbine engine.

[0004] According to an aspect of embodiments of the present invention, provided is a turbine outer ring connection structure including a turbine outer ring, an intermediate casing, and a plurality of connecting assemblies, wherein at least one column of mounting through-holes extending through the intermediate casing in a radial direction of an engine are circumferentially provided in the intermediate casing; each of the connecting assemblies includes an elastic beam and a connecting member; at least two mounting holes are provided through a surface of the elastic beam, and the mounting holes are positioned to align with adjacent mounting through-holes in the intermediate casing respectively; an abutting portion is provided between two adjacent mounting holes at the bottom of the elastic beam, and abuts against an outer side of the intermediate casing; the connecting member has one end configured as a cylinder, which passes out from an inner side of the intermediate casing through the mounting through-hole and the mounting hole and is fixedly connected to the elastic beam; the connecting member has the other end configured as a connection structure connected to the turbine outer ring; and the elastic beam provides a stable pre-tensioning force for connection between the connecting member and the turbine outer ring by means of elastic deformation, the elastic beam has a certain clearance with the intermediate casing except for the abutting portion, and the clearance is used for absorbing thermal deformation generated in a radial direction of an engine.

[0005] Since a protrusion is provided at the bottom of the elastic beam, when assembled, the elastic beam is elastically deformed to allow for a certain clearance between an area of the elastic beam where the mounting hole is located and the intermediate casing, and the clearance is used for absorbing thermal deformation in the radial direction of the engine, thereby improving the stability of the connection structure under an operating state of the engine. In addition, the elasticity of the elastic beam can provide a stable pre-tensioning force for a connection mechanism under different temperatures and thermal deformation states, thereby avoiding loosening of a fastener or harmful vibration caused by a temperature alternation. In the connection structure, only by providing a connecting through-hole in an appropriate position, an efficient connection between the turbine outer ring and the intermediate casing can be achieved by means of the connecting assembly, without complex processing of the turbine outer ring.

[0006] Further, the turbine outer ring includes a mounting rib projecting outwardly in a circumferential direction of the engine, and a connecting through-hole in an axial direction of the engine is provided in the mounting rib; the connection structure of the connecting member is configured as a U-shaped fork arm so as to allow insertion of the mounting rib of the turbine outer ring into the U-shaped fork arm; and the U-shaped fork arm includes a first arm provided with a first pin hole, and a second arm provided with a second pin hole coaxial with the first pin hole to allow a connecting pin to sequentially pass through the first pin hole and the connecting through-hole and be inserted into the second pin hole, so as to fix the turbine outer ring and the connecting member together. In the structure, the connection of the turbine outer ring can be effectively realized only by providing the connecting through-hole in the turbine outer ring, without complex structural processing of the turbine outer ring, thereby improving the production efficiency and reducing the processing difficulty.

[0007] Further, a positioning groove is provided on an outer side of the intermediate casing and is arranged between two adjacent mounting through-holes to allow the protrusion of the elastic beam to be engaged in the positioning groove, so as to align the adjacent mounting holes in the elastic beam with the two adjacent mounting through-holes, respectively. The positioning groove facilitates quick positioning of the elastic beam during assembly.

[0008] Further, two mounting holes are provided in the elastic beam, and arranged at two ends of the elastic beam. Arranging the mounting holes at two ends of the elastic beam can make full use of the elasticity of the elastic beam itself and also facilitates mounting.

[0009] Further, two columns of mounting through-holes are provided in the intermediate casing, and the turbine outer ring includes a first mounting rib and a second mounting rib arranged in parallel. The two columns of mounting ribs can provide more stable positioning of the turbine outer ring, thereby avoiding displacement of an axis of the turbine outer ring from an axis of the engine.

[0010] Further, the first mounting rib is engaged in the U-shaped fork arm to form positioning in the axial direction of the engine, and the second mounting rib is configured to be in clearance fit with the connecting member. The first mounting rib provides the turbine outer ring with positioning in the axial direction of the engine, thereby preventing the turbine outer ring from displacing back and forth. The second mounting rib is in clearance fit with the connecting member to absorb thermal deformation in the axial direction of the engine.

[0011] Further, the turbine outer ring includes a plurality of circumferentially arranged outer ring elements, and one mounting rib of each of the outer ring elements includes at least two connecting through-holes, one of the connecting through-holes being configured as a circular hole, and the other of the connecting through-holes being configured as a runway-shaped hole having a major axis in a direction of a connecting line connecting centers of the connecting through-holes. The circular hole provides the turbine outer ring with positioning in the circumferential direction of the engine, and the runway-shaped hole is used for absorbing thermal deformation in the circumferential direction of the engine.

[0012] Further, a positioning structure matching a contour of the connecting member is provided on an inner surface of the intermediate casing so as to allow an axis of the turbine outer ring to be parallel to the axial direction of the engine when the connecting member is engaged in the positioning structure from an inner side. The positioning structure facilitates quick positioning and mounting of the connecting member.

[0013] Further, the first pin hole is configured as a through-hole, and the second pin hole is configured as a blind hole. The second pin hole is configured as a blind hole to prevent the connecting pin from falling off during assembly.

[0014] Further, a vent hole is provided at an end of the second pin hole. The vent hole is used for preventing an air pressure in the blind hole from hindering the insertion of the connecting pin.

[0015] According to another aspect of the embodiments of the present invention, provided is a turbine engine employing the turbine outer ring connection structure of any of the foregoing embodiments.

Brief Description of the Drawings

[0016] 

FIG. 1 is a schematic diagram of a turbine outer ring connection structure according to an embodiment;

FIG. 2a is a partial schematic structural diagram of an intermediate casing according to an embodiment;

FIG. 2b is a partial schematic structural diagram of an intermediate casing according to an embodiment;

FIG. 3 is a schematic structural diagram of an outer ring element according to an embodiment;

FIG. 4 is a schematic structural diagram of an elastic beam according to an embodiment;

FIG. 5a is a schematic structural diagram of a connecting member according to an embodiment;

FIG. 5b is a cross-sectional view of a connecting member according to an embodiment;

FIG. 6 is a cross-sectional view of a turbine outer ring connection structure along a longitudinal section of an engine according to an embodiment; and

FIG. 7 is a cross-sectional view of a turbine outer ring connection structure along a transverse section of an engine according to an embodiment.

List of reference signs:

[0017] 1 - Outer ring element; 2 - Intermediate casing element; 3 - Connecting assembly; 11 - Outer ring annular wall; 12 - First mounting rib; 13 - Second mounting rib; 14 - Circular hole; 15 - Runway-shaped hole; 21 - Intermediate casing annular wall; 22 - Annular wall flange; 23 - Intermediate casing hook; 24 - Mounting through-hole; 25 - Positioning groove; 26 - Positioning structure; 31 - Elastic beam; 32 - Connecting member; 33 - Connecting pin; 34 - Fixing nut; 311 - Mounting hole; 312 - Protrusion; 321 - Stud; 322 - First arm; 323 - Second arm; 324 - First pin hole; 325 - Second pin hole; 326 - Vent hole.

[0018] The purpose of the accompanying drawings described above is to provide a detailed description of the present invention so as to enable those skilled in the art to understand the technical concepts of the present invention, and is not intended to limit the present invention. For the sake of brevity of expression, in the accompanying drawings described above, only structures related to technical features of the present invention are schematically drawn, and complete parts and full details are not drawn strictly to the actual scale.

Detailed Description of Embodiments

[0019] The present invention is further described below in details through specific embodiments in view of the accompanying drawings.

[0020] The phrase "embodiment" mentioned herein means that the specific features, structures, or characteristics described in conjunction with the embodiment can be encompassed in at least one embodiment herein. The phrase appearing at various places in the specification does not necessarily refer to the same embodiment, nor is it limited to a mutually exclusive independent or alternative embodiment. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without structural conflict.

[0021] In the description herein, unless otherwise specified and defined, the technical terms "mount", "connected" and "connect" should be understood in a broad sense, and for example, may refer to the connection of mechanical structures or the fixation and assembly of physical structures. For those of ordinary skill in the art, the specific meaning of the terms mentioned above in the embodiments of the present application should be construed according to specific circumstances.

[0022] In the description herein, terms indicating orientation or positional relationship, such as "upper", "lower", "left", "right", "transverse", "longitudinal", "height", "length", and "width" are intended to describe an embodiment accurately and simplify the description, and are not intended to limit that a part or a structure involved must have a particular orientation and be mounted or operated in a particular orientation, and therefore will not be construed as limiting the embodiment herein.

[0023] In the description herein, the terms "first", "second" and the like are used merely to distinguish different objects, and should not be construed as indicating relative importance or limiting the number, specific order or primary-secondary relationship of the technical features described. In the description herein, "a plurality of" means at least two.

[0024] According to an embodiment of the present invention, provided is a turbine outer ring connection structure, as shown in FIG. 1, including an intermediate casing and a turbine outer ring connected by means of connecting assemblies 3. The turbine outer ring and the intermediate casing are enclosed by a plurality of outer ring elements and a plurality of intermediate casing elements, respectively. The structure of the intermediate casing element 2 is as shown in FIGS. 2a and 2b, with an intermediate casing annular wall 21 as a boundary, an upper portion of the intermediate casing element 2 forms an outer side of the intermediate casing, and an intermediate casing hook 23 is configured to mount the intermediate casing on an engine; and a lower portion of the intermediate casing element 2 forms an inner side of the intermediate casing, and an annular wall flange 22 matches the corresponding structure of the turbine outer ring. Two pairs of mounting through-holes 24 are respectively provided in an outer surface of the intermediate casing annular wall 21 at a position adjacent to the intermediate casing hook 23. The mounting through-holes 24 penetrate through the intermediate casing annular wall 21 in a radial direction of the intermediate casing or a radial direction of the engine. In the intermediate casing enclosed by the plurality of intermediate casing elements 2, the two pairs of mounting through-holes 24 respectively form two columns of through-holes arranged in parallel in a circumferential direction of the engine. In some embodiments, two or more mounting through-holes 24 may be provided depending on a structural design of a casing, and one or more than two columns of mounting through-holes 24 may be provided. In some embodiments, an abutted portion 25 is provided between two adjacent mounting through-holes 24 in the same column, an embodiment of the abutted portion 25 being a positioning groove. In some embodiments, a positioning structure 26 is further provided on an inner surface of the intermediate casing annular wall 21, and the positioning structure 26 is located in a one-to-one correspondence with the mounting through-hole 24. In view of FIGS. 5a and 5b, the positioning structure 26 matches in contour with a connecting member 32. When the connecting member 32 is fitted in the positioning structure 26, axes of a first pin hole 324 and a second pin hole 325 of the connecting member are parallel to an axial direction of the engine, which in turn makes an axis of the turbine outer ring parallel to the axial direction of the engine.

[0025] The structure of the outer ring element 1 is as shown in FIG. 3, an upper portion of an outer ring annular wall 11 forms an outer side of the turbine outer ring, and a protruding first mounting rib 12 and a protruding second mounting rib 13 are provided on an outer side of the outer ring element 1. The first mounting ribs 12 and the second mounting ribs 13 on the plurality of outer ring elements constituting the turbine outer ring respectively form two rib rings protruding outwardly in the circumferential direction of the engine. Two connecting through-holes in the axial direction of the engine are provided on each of the first mounting rib 12 and the second mounting rib 13, and one of the two connecting through-holes is a circular hole 14 and the other of the two connecting through-holes is a runway-shaped hole 15 having a major axis in a direction of a connecting line connecting centers of the connecting through-holes. When assembled, each connecting through-hole is in a one-to-one correspondence with the mounting through-hole 24 in the intermediate casing. In some embodiments, the outer ring element may also be connected to the connecting assembly 3 by means of a hook structure. In some embodiments, only one mounting rib or a plurality of mounting ribs may be provided on the outer ring element depending on a structural design. In some embodiments, one or more connecting through-holes may be provided in the same mounting rib. In some embodiments, two or more elongated holes may be provided in the same mounting rib.

[0026] In view of FIGS. 4, 5a and 6, the connecting assembly 3 includes an elastic beam 31 and a connecting member 32. The connecting member 32 has one end being a stud 321, and the stud 321 passes through the mounting through-hole 24 from an inner side of the intermediate casing annular wall 21, passes through a mounting hole 311 provided in the elastic beam 31 arranged on an outer side of the intermediate casing annular wall 21, and then is screwed and fixed by a fixing nut 34. The connecting member 32 has the other end being a connection structure configured as a U-shaped fork arm including a first arm 322 and a second arm 323, and the first outer ring rib 12 and the second outer ring rib 13 each are inserted into a corresponding U-shaped fork arm and fixed by a connecting pin 33 passing through the connecting through-hole. In this way, the turbine outer ring and the intermediate casing are connected together. In some embodiments, the connection structure of the connecting member 32 may also be configured as a hook or jaw structure depending on a structural design of the outer ring element, and the stud 321 may also be configured as a rivet or other fixing structure such as a cylindrical elastic jaw with barbs. It will be appreciated that in a specific embodiment, the structure of a part involved in the connection relationship described above may vary depending on the specific structures of the outer ring element 1 and the intermediate casing element 2.

[0027] As shown in FIG. 4, the bottom of the elastic beam 31 can abut against the outer side of the intermediate casing annular wall 21 when mounted. An abutting portion 312 is provided at the bottom of the elastic beam 31, an embodiment of the abutting portion 312 being a protrusion. A mounting hole 311 is provided at each of two ends of the elastic beam, and the two mounting holes 311 are respectively aligned with the mounting through-holes 24 in the intermediate casing unit 21 when the abutting portion 312 is engaged in the abutted portion 25. In some embodiments, a plurality of mounting holes 311 may be provided in the elastic beam 31, and in a mounted state, these mounting holes 311 are respectively aligned with the mounting through-holes 24 in the intermediate casing unit 21, and one abutting portion 312 is arranged between two adjacent mounting holes 311. In all embodiments, the structure of the elastic beam 31 should match a structural design of the intermediate casing.

[0028] As shown in FIGS. 5a and 5b, a first pin hole 324 is provided through the first arm 322 of the connecting member 32; a second pin hole 325, which is a blind hole, is provided in the second arm 323; and a vent hole 326 is provided at a blind end of the second pin hole 325. In view of FIG. 6, during insertion of the connecting pin 33, the blind end of the second pin hole 325 can prevent the connecting pin from slipping out, thereby improving the assembly efficiency. The vent hole 326 can prevent an air pressure in the blind hole from hindering the insertion of the connecting pin 33. In some embodiments, the second pin hole 325 may also be provided as a through-hole. In some other embodiments, for example, in the case where an air guide groove is provided on the connecting pin 33, no vent hole 326 may be provided at the end of the second pin hole 325 as the blind hole.

[0029] In the mounted state, as shown in FIG. 7, since the abutting portion 312 is arranged at the bottom of the elastic beam 31, there will be a certain clearance between other areas of a bottom surface of the elastic beam 31 and the outer surface of the intermediate casing annular wall 21, and when the fixing nut 34 is screwed, the elastic beam 31 will be elastically deformed with an abutting position as a fulcrum, thereby providing a pre-tensioning force for the fixing nut 34. At different temperatures, a part is thermally expanded, and the clearance between the elastic beam 31 and the intermediate casing annular wall 21 is capable of absorbing a strain in the radial direction of the engine caused by the thermal expansion. The elastic beam 31 remains the pre-tensioning force of the fixing nut 34 relatively constant by means of its own elasticity to prevent loosening of the fixing nut 34. The positioning pin 33 is inserted into the circular hole 14 provided in the first mounting rib 12 of the outer ring element 1 to provide positioning of the outer ring element 1 in the circumferential direction of the engine. When the positioning pin 33 is inserted into the runway-shaped hole 15, there is a clearance in the direction of the major axis of the runway-shaped hole 15, and this clearance can absorb deformation of a part in the circumferential direction of the engine when the part is thermally expanded. As shown in FIG. 6, the first mounting rib 12 is tightly engaged in the U-shaped fork arm of the connecting assembly 3 so as to provide positioning of the outer ring element 1 in the axial direction of the engine. However, the second mounting rib 13 is in clearance fit with the U-shaped fork arm of the connecting 3, and the clearance can absorb deformation of a part in the axial direction of the engine when the part is thermally expanded. The clearance fit can be achieved by configuring the second mounting rib 13 to have a smaller thickness or by configuring the corresponding U-shaped fork arm to have a larger width. In some embodiments, the outer ring element 1 has only one mounting rib, and the mounting rib is then in interference fit with the connecting assembly 3. In some other embodiments, the outer ring element 1 has a plurality of mounting ribs, one of the mounting ribs is tightly engaged in the connecting assembly 3 so as to provide axial positioning, and the remaining mounting ribs are in clearance fit with the connecting assembly.

[0030] In the embodiment shown in FIGS. 1 to 7, an assembly process of the turbine outer ring connection structure is as follows. First, each of the first mounting rib 12 and the second mounting rib 13 of the outer ring element 1 is engaged in the U-shaped fork arm of the connecting member 32 at a corresponding position, and the connecting pin 33 passes through the first pin hole 324 and the connecting through-hole in the mounting rib and then is inserted into the second pin hole 325 to complete fixing. Next, the stud 321 of the connecting member 32 passes out of the mounting through-hole 24 from the inner side of the intermediate casing element 2, and at the same time, the contour of the connecting member 32 fits into the positioning structure 26 on the inner side of the intermediate casing element 2. At the outer side of the intermediate casing element 2, the abutting portion 312 of the elastic beam 31 is engaged in the abutted portion 25, the stud 321 passes out of the mounting hole 311 of the elastic beam 31, the fixing nut 34 is screwed onto the stud 321, the fixing nuts 34 at two ends of the elastic beam 31 are adjusted to prevent the elastic beam 31 from tilting to one side, and then the fixing is completed. Thereby, the connection and fixation between the turbine outer ring and the intermediate casing of the engine are achieved, the connection structure is able to effectively absorb the radial, circumferential and axial thermal deformation of the engine, thereby improving the reliability of the engine. It should be understood that the specific step of the process described above and the connection relationship between the parts may vary in different embodiments depending on the structure of the relevant part.

[0031] According to another embodiment of the present invention, provided is a turbine engine employing the turbine outer ring connection structure of any of the above embodiments.

[0032] The purpose of the embodiments described above is to provide a detailed description of the implementation of he present invention in view of the accompanying drawings so as to enable those skilled in the art to understand the technical concepts of the present invention, and is not intended to limit the present invention. Within the scope of claims of the present invention, optimization or equivalent replacement of the structure of the part involved, as well as combinations of implementation methods in different embodiments without any conflict of structures and principles, all fall within the protection scope of the present invention.

Claims

1. A turbine outer ring connection structure, which comprises a turbine outer ring, an intermediate casing, and a plurality of connecting assemblies, characterized in that

at least one column of mounting through-holes extending radially through the intermediate casing are circumferentially provided in the intermediate casing; and

each of the connecting assemblies comprises:

an elastic beam, at least two mounting holes being provided through a surface of the elastic beam, the mounting holes being positioned to align with adjacent mounting through-holes in the intermediate casing respectively, and an abutting portion being provided between two adjacent mounting holes at the bottom of the elastic beam, and abutting against an outer side of the intermediate casing; and

a connecting member having one end configured as a cylinder, which passes out from an inner side of the intermediate casing through the mounting through-hole and the mounting hole and is fixedly connected to the elastic beam, and the connecting member having the other end configured as a connection structure connected to the turbine outer ring;

wherein the elastic beam provides a stable pre-tensioning force for connection between the connecting member and the turbine outer ring by means of elastic deformation, the elastic beam has a clearance with the intermediate casing except for the abutting portion, and the clearance is used for absorbing thermal deformation generated in a radial direction of an engine.

2. The turbine outer ring connection structure according to claim 1, characterized in that the turbine outer ring comprises a mounting rib projecting outwardly in a circumferential direction of the engine, and a connecting through-hole in an axial direction of the engine is provided in the mounting rib; the connection structure of the connecting member is configured as a U-shaped fork arm so as to allow insertion of the mounting rib of the turbine outer ring into the U-shaped fork arm; and the U-shaped fork arm comprises a first arm provided with a first pin hole, and a second arm provided with a second pin hole coaxial with the first pin hole to allow a connecting pin to sequentially pass through the first pin hole and the connecting through-hole and be inserted into the second pin hole, so as to fix the turbine outer ring and the connecting member together.

3. The turbine outer ring connection structure according to claim 1 or 2, characterized in that the abutting portion of the elastic beam is a protrusion, a positioning groove is provided on an outer side of the intermediate casing and is arranged between two adjacent mounting through-holes to allow the protrusion of the elastic beam to be engaged in the positioning groove, so as to align the adjacent mounting holes in the elastic beam with the two adjacent mounting through-holes, respectively.

4. The turbine outer ring connection structure according to claim 1 or 2, characterized in that two mounting holes are provided in the elastic beam, and arranged at two ends of the elastic beam.

5. The turbine outer ring connection structure according to claim 2, characterized in that two columns of mounting through-holes are provided in the intermediate casing, and the turbine outer ring comprises a first mounting rib and a second mounting rib arranged in parallel.

6. The turbine outer ring connection structure according to claim 5, characterized in that the first mounting rib is engaged in the U-shaped fork arm to form a positioning connecting member in the axial direction of the engine, and the second mounting rib is configured to be in clearance fit with the connecting member.

7. The turbine outer ring connection structure according to claim 2, characterized in that the turbine outer ring comprises a plurality of circumferentially arranged outer ring elements, and one mounting rib of each of the outer ring elements comprises at least two connecting through-holes, one of the connecting through-holes being configured as a circular hole, and the other of the connecting through-holes being configured as a runway-shaped hole having a major axis in a direction of a connecting line connecting centers of the connecting through-holes.

8. The turbine outer ring connection structure according to claim 1 or 2, characterized in that a positioning structure matching a contour of the connecting member is provided on an inner surface of the intermediate casing so as to allow an axis of the turbine outer ring to be parallel to the axial direction of the engine when the connecting member is engaged in the positioning structure from an inner side.

9. The turbine outer ring connection structure according to claim 2, characterized in that the first pin hole is configured as a through-hole, and the second pin hole is configured as a blind hole.

10. The turbine outer ring connection structure according to claim 9, characterized in that a vent hole is provided at an end of the second pin hole.

11. A turbine engine employing a turbine outer ring connection structure of any one of claims 1 to 10.

Drawing