Composite seal structure for a machine and method of manufacturing a composite seal structure

Abstract

The composite seal structure comprises a carrier ring (33) and a sealing element (35) which is accommodated in an annular groove formed between a circumferential outer wall and two side walls of the carrier ring (33). The sealing element has a first region which is in surface-to-surface contact with the annular groove and a second sealing region (35.12) which projects from the annular groove. A fastening arrangement couples the sealing element (35) and the carrier ring (33) to one another. The fastening arrangement comprises a plurality of fastening pins (37) which are arranged circumferentially around an axis of the carrier ring. A method for manufacturing a sealing structure is also disclosed.

Description

Technical Field

[0001] This disclosure relates to a sealing structure for sealing a sealing area between stationary and rotating parts of a machine (particularly a turbine, such as a centrifugal or axial compressor, turbine, turboexpander, etc.). The embodiments disclosed herein specifically relate to labyrinth seals. Background Technology

[0002] Rotating machines (such as turbines) include machine sections with varying fluid pressures. To prevent or limit fluid leakage from a high-pressure area to a low-pressure area within the machine, seals are provided to separate these two pressure-different areas. A typical rotor seal is arranged between a stationary machine component and a rotating shaft, which is typically integrated with the machine housing. The rotating shaft may include a rotating drum, such as a balancing drum in a compressor or pump. The rotating shaft extends through the rotor seal assembly, which is statically mounted on the stationary machine component and includes sealing members that work in conjunction with the rotating shaft to prevent or reduce fluid leakage.

[0003] Typical rotor seals include labyrinth seals, damper or hole pattern seals, honeycomb seals, bagged damper seals, wear-resistant seals, etc.

[0004] Some rotor seals include a carrier ring coupled to the sealing element. The carrier ring is typically made of metal, mounted on a stationary part of the machine, and functions as a retainer for the sealing element, which is designed to be applied to an insert formed in an annular groove in the retainer. The sealing element is typically made of a suitable polymer, such as a thermoplastic polymer. This type of seal is sometimes referred to as a "composite seal."

[0005] The sealing element protrudes radially inward from an annular groove in the carrier ring and includes sealing features such as labyrinth seals (also known as fins or blades), which work in conjunction with the rotating parts of the machine to provide a sealing action. The sealing element makes surface contact with the inner surface of the annular groove of the carrier ring, opposite to the sealing features.

[0006] A key aspect of this sealing structure is the reliability of the connection between the carrier ring and the sealing element. Because a pressure difference exists between the two opposite sides of the seal, high-pressure fluid from the high-pressure side tends to leak through the gap between the carrier ring and the sealing element, and can reach the bottom of the annular groove. When this occurs, the radially inward pressure against the sealing element can cause the sealing element to deform and detach from the carrier ring.

[0007] In composite sealing structures, a more efficient mechanical connection between the load-bearing ring and the sealing element will contribute to better sealing performance and a more reliable sealing structure. Summary of the Invention

[0008] According to one aspect, a sealing structure is disclosed, comprising a carrier ring having a circumferential outer wall, a first side wall, and a second side wall. The first and second side walls project radially inward from the circumferential outer wall of the carrier ring toward a centerline (i.e., axis). The axis or centerline of the carrier ring coincides with the centerline or axis of the sealing structure. The carrier ring further includes an annular groove formed between the circumferential outer wall, the first side wall, and the second side wall. The sealing structure further includes a sealing element having a first region and a second sealing region, the first region being in surface-to-surface contact with the annular groove, and the second sealing region projecting from the annular groove of the carrier ring toward the centerline of the carrier ring. Furthermore, a fastening arrangement formed in the sealing structure is adapted to connect the sealing element and the carrier ring to each other. According to an embodiment disclosed herein, the fastening arrangement includes a plurality of fastening pins circumferentially arranged around the axis of the carrier ring, the plurality of fastening pins extending through at least one of the first and second side walls and each engaging in a corresponding seat formed in the sealing element.

[0009] The pin provides a secure mechanical connection between the bearing ring and the sealing element.

[0010] As understood in this article, a bearing ring is typically a monolithic component of a ring shape, i.e., a component made from a single piece, such as a part machined from a single blank.

[0011] As understood in this article, sealing elements are typically annular, i.e., annular monoliths, such as integral parts machined from tubular blanks.

[0012] In the embodiments of the composite seal disclosed herein, the pin provides an efficient connection between the sealing element and the carrier ring, thereby preventing or efficiently reducing radial inward deformation due to pressurized gas leakage.

[0013] According to another aspect, a method for manufacturing a sealing structure is disclosed. The method includes a first step of inserting a sealing element into an annular groove in a carrier ring. The annular groove is formed between a circumferential outer wall, a first side wall, and a second side wall of the carrier ring, the first and second side walls protruding radially inward from the circumferential outer wall toward the centerline of the carrier ring. After inserting the sealing element into the annular groove of the carrier ring, the sealing element is mechanically coupled to the carrier ring such that the sealing element has a first region and a second sealing region, the first region being in surface-to-surface contact with the annular groove, and the second sealing region protruding from the annular groove of the carrier ring toward the centerline of the carrier ring. Subsequently, the inward-facing surface of the second sealing region of the sealing element is machined to create a sealing feature thereon.

[0014] Further features and embodiments of the sealing structure and manufacturing method are described in this invention and are further described in the following description of exemplary embodiments. Attached Figure Description

[0015] A more comprehensive understanding of the embodiments disclosed in the invention and their many accompanying advantages will become readily apparent when considered in conjunction with the accompanying drawings, and will also become better understood by referring to the following detailed description, in which: Figure 1 A schematic cross-sectional view of a centrifugal compressor including multiple rotor seals, which may include corresponding sealing structures according to the present disclosure, is shown. Figure 2 A view of the sealing structure according to the present disclosure, taken in a direction parallel to the axis of the sealing structure; Figure 3 It shows that according to Figure 2 An enlarged cross-sectional view of one embodiment of line III-III in the diagram; Figure 4A , Figure 4B , Figure 4C , Figure 4D , Figure 4E , Figure 4F and Figure 4G The sequence of steps for manufacturing a sealing structure is shown; Figure 5 An embodiment according to another embodiment is shown. Figure 2 Enlarged section view of line III-III in the middle; and Figure 6 A flowchart summarizing the manufacturing method is shown in one embodiment. Detailed Implementation

[0016] This document discloses a novel and useful sealing structure, particularly for rotor seals. The sealing structure includes an annular retainer (referred to herein as a "carrier ring") having an annular groove that receives an annular insert (referred herein as a "sealing element"). The sealing element is mechanically coupled to the carrier ring by a plurality of pins distributed around the axis of the sealing structure and preferably extending parallel to the axis or centerline of the sealing structure. As explained later with reference to a detailed description of the embodiments, the resulting fastening arrangement prevents or limits radial deformation of the sealing element. The specific manner in which the sealing element is fastened to the carrier ring also allows for a novel and useful method of manufacturing the sealing structure, which can save time and cost, resulting in a highly accurate and efficient sealing structure.

[0017] While the following description focuses on labyrinth seals, the novel features of the sealing structures disclosed herein can also be advantageously used in other types of rotor seals, i.e., seals suitable for interaction with rotating components of a machine. For example, features of the sealing structures particularly relating to the mechanical connection between the sealing element and the carrier ring can also be used in wear-resistant seals, honeycomb seals, or other seals as reviewed in the introductory section of this specification. Typically, the features disclosed herein can be used in combined sealing structures comprising a carrier ring and an annular sealing element coupled to and projecting radially inward from the carrier ring, wherein the sealing region is designed to interact with a shaft or drum.

[0018] Now turn to the attached diagram. Figure 1 A schematic cross-sectional view of a centrifugal compressor 1 is shown. The cross-sectional view is taken along a plane containing the axis of rotation AA of the compressor rotor. Figure 1 The cross-section shown is only a portion of the centrifugal compressor sufficient for the purposes of this specification.

[0019] Figure 1 The centrifugal compressor 1 is presented herein as an exemplary embodiment of a turbine, in which the sealing structure of this disclosure can be advantageously applied. However, those skilled in the art of turbine machinery will understand that the sealing structure disclosed herein can also be applied to different types of turbines and different locations within turbines. Typically, the sealing structure is used when a seal is required around a rotating component (such as a rotor, drum, or shaft) between high-pressure and low-pressure regions.

[0020] Centrifugal compressor 1 includes a shaft 3 and one or more impellers 5. Figure 1 Three impellers 5 are shown. Although in Figure 1 In this embodiment, the impeller 5 is mounted on the shaft 3 for rotation with the shaft in a so-called shrink-fit arrangement. However, in other embodiments, the impeller can be configured as a so-called stacked impeller, which is axially stacked and torsionally connected to each other by means of a connecting beam and a corresponding ratchet disc connection or other connecting feature.

[0021] exist Figure 1 In one embodiment, spacer rings 7 are arranged between each pair of adjacent impellers 5. A balancing drum 9 is further keyed to the shaft 3 to rotate with it. The shaft 3, impellers 5, spacer rings 7, and balancing drum 9 together form a rotor 11, which is mounted to rotate about the axis of rotation AA according to arrow F11. The rotor 11 is housed in a housing (not shown) that houses the stationary components of the compressor 1. The stationary components include a diffuser 15 defining the compressor and a diaphragm 13 defining a return passage 17.

[0022] Each impeller includes an impeller eye 5.1. For illustration, an eye labyrinth seal 21 is positioned around each impeller eye 5.1 to reduce gas leakage from the high-pressure side downstream of the impeller to the low-pressure side upstream of the impeller. The terms "upstream" and "downstream" refer to the flow direction of the process gas through the compressor 1, schematically represented by arrow G. Each labyrinth seal 21 is mounted in a housing machined into the corresponding diaphragm of the centrifugal compressor 1.

[0023] The shaft labyrinth seal 23 is further disposed, for example, around the spacer ring 7 between the diaphragm 13 and the shaft 3. The shaft labyrinth seal 23 is mounted in a corresponding housing machined into the diaphragm 13.

[0024] exist Figure 1 In the implementation scheme, the balance drum labyrinth seal 25 is also disposed around the balance drum 9.

[0025] One, some, or all of the labyrinth seals 21, 23, and 25 of the centrifugal compressor 1 may be configured according to this disclosure. Reference is made below. Figure 2 and Figure 3 An embodiment of a universal labyrinth seal is described to illustrate its novel features. Those skilled in sealing technology will be able to design labyrinth seals for different applications and different parts within a centrifugal compressor 1 or another turbine embodying the features described below.

[0026] Figure 2 An exemplary sealing structure 30 is shown, which can be used in eye labyrinth seal 21, shaft labyrinth seal 23, balance drum labyrinth seal 25, or more generally in any different rotor seal within a turbine.

[0027] The labyrinth seal 30 includes a carrier ring 33 and an annular sealing element 35. When the sealing structure is mounted in the turbine around the compressor rotor 11, the axis or centerline of the sealing arrangement is marked AA and coincides with the axis of rotation of the compressor rotor 11.

[0028] The support ring 33 can be made of metal or a metal alloy. The material used to manufacture the support ring 33 can be selected based on the properties of the process gas, the pressure on both sides of the sealing arrangement, the size of the seal, and other design considerations that the process gas will contact the sealing arrangement 30. For example, alloys such as aluminum alloys from the 2000 series, an example of which is AVIONAL, are typically used in normal, sweet, and acidic environments with low acidity. ® 14; or 5000 series aluminum alloys, one example of which is PERALUMAN. ®AVIONAL and PERALUMAN are registered trademarks of Constellium Valais SA of Switzerland; or aluminum alloys of the 6000 series, one example of which is ANTICORODAL. ® ANTICORODAL is a registered trademark of Novelis Switzerland SA; and martensitic stainless steel. Carbon steel and low-alloy steel can be used in normal environments. In acidic environments, austenitic, super austenitic, duplex, and super duplex stainless steels, as well as nickel-based alloys, can be used. As a good design practice, the support ring should be made of the same material as the diaphragm.

[0029] The sealing element 35 can be made primarily of a thermoplastic polymer. For example, the sealing element 35 can be made of a composite polymeric material having a polymer matrix filled with reinforcing fibers or particles (such as carbon fibers, glass fibers, etc.). Polymers such as PEK (polyether ketone), PEEK (polyether ether ketone), PAI (polyamide-imide), PEI (polyethyleneimide), and PFA (perfluoroalkoxyalkane) can be used as options. Depending on the required mechanical properties or available technology, the reinforcing fibers can be long or short (<30µm).

[0030] Continue to refer to Figure 2 , Figure 3 An enlarged cross-section of the bearing ring 33 and the sealing element 35 is shown.

[0031] The bearing ring 33 includes a circumferential outer wall 33.1, a first side wall 33.2, and a second side wall 33.3. The circumferential outer wall 33.1, the first side wall 33.2, and the second side wall 33.3 form an annular groove 33.4 between them, which accommodates the sealing element 35.

[0032] exist Figure 2 and Figure 3 In one embodiment, the circumferential outer wall 33.1 has a widely cylindrical shape. The inner surface of the circumferential outer wall 33.1 forms the bottom of an annular groove 33.4. The outer surface of the circumferential outer wall 33.1 forms a fastening feature 33.5 for connection to an annular seat formed in a stationary component of the turbine, such as a compressor diaphragm, in which a sealing structure 30 is mounted. Figure 2 and Figure 3 In one embodiment, the fastening feature includes an annular protrusion extending from the outer peripheral surface of the circumferential outer wall 33.1. The protrusion has a cross-sectional shape forming an undercut 33.6 for mechanical coupling to an annular seat in the turbine.

[0033] Each of sidewalls 33.2 and 33.3 includes an inner surface, which may be substantially planar and orthogonal to the centerline or axis AA of the sealing structure. The inner surfaces of sidewalls 33.2 and 33.3 extend radially inward from the inner surface of the circumferential outer wall 33.1 and form flanks of the annular groove 33.4. Each sidewall 33.2 and 33.3 further includes a corresponding outer surface, which may be substantially parallel to the corresponding inner surface and may be substantially planar. In some embodiments, anti-vortex devices 33.9 may be provided on one or both outer surfaces of sidewalls 33.2 and 33.3.

[0034] The first sidewall 33.2 is manufactured to have a first set of through holes 33.7 extending from the outer surface of the first sidewall 33.2 to the inner surface. Similarly, the second sidewall 33.3 has a second set of through holes 33.8 extending from the outer surface of the second sidewall 33.3 to the inner surface.

[0035] The sealing element 35 includes a body 35.1 having an outer cylindrical surface 35.2 that is in surface contact with the bottom of the annular groove 33.4. The body 35.1 further includes side surfaces 35.3 and 35.4 that are in surface contact with the inner surfaces of the first sidewall 33.2 and the second sidewall 33.3, respectively. Therefore, the body 35.1 includes a first region of the sealing element that is in surface-to-surface contact with the annular groove 33.4 formed in the support ring 33.

[0036] Furthermore, the main body 35.1 includes a second region, namely a sealing region, which is radially arranged inside the first region and is designated 35.12. The second sealing region 35.12 has multiple sealing features adapted to cooperate with the rotating parts of the rotor. Figure 2 and Figure 3 In one embodiment, the sealing structure 30 has a labyrinth seal, and the sealing features include annular teeth, blades, or lips 35.5 that project radially inward from the support ring 33 toward the centerline or axis AA of the sealing structure 30.

[0037] The fastening arrangement mechanically connects the bearing ring 33 and the sealing element 35 to each other. Figure 3In one embodiment, the fastening arrangement includes a first set of fastening pins 37 and a second set of fastening pins 39. Each fastening pin 37 in the first set extends in a through-hole 33.7 and has an inwardly oriented end protruding in a seat 35.10 formed in a side surface 35.3 of the sealing element 35, which is in surface contact with the sidewall 33.2. Each fastening pin 39 in the second set extends in a through-hole 33.8 that extends across a second sidewall 33.3 and has an inwardly oriented end received in a seat 35.11 formed in a side surface 35.4 of the sealing element 35, which is in surface contact with the sidewall 33.3.

[0038] Seats 35.10 and 35.11 may be in the form of blind holes drilled in sealing element 35.

[0039] In some embodiments, holes 33.7 and 33.8, as well as seats 35.10 and 35.11, are oriented parallel to the axis or centerline AA of the sealing arrangement 30.

[0040] In some implementations, each hole 33.7 and associated seat 35.10 is collinear with the corresponding hole 33.8 and associated seat 35.11, such that the paired fastening pins 37, 39 of the two sets of fastening pins are collinear with each other.

[0041] If seats 35.10 and 35.11 are collinear, the length of each seat can be less than half the thickness of the sealing element 35, that is, less than half the size of the sealing element 35 in the direction of the centerline (measured between the opposite side surfaces of seats 35.10 and 35.11 of the sealing element 35 where holes are drilled). Figure 3 In this context, such thickness is denoted as "T". In this way, the collinear seats are kept separate from each other by two opposing blind holes.

[0042] Holes 33.7 can be equidistant from each other. Similarly, holes 33.8 can be equidistant from each other. For example, the holes can be arranged according to a constant angular spacing α (see...). Figure 2 In some embodiments, the angular spacing α can be between about 5° and about 45°, preferably between about 10° and about 40°, for example between about 18° and about 36°. Figure 2 In the implementation scheme, the angular spacing α is 20°.

[0043] The fastening pins 37 and 39 can be locked in the holes 33.7 and 33.8 and the seats 35.10 and 35.11 in any suitable manner, such as by gluing, brazing, welding, etc. Gluing may be particularly advantageous because no heat is applied, which could damage the sealing element 35.

[0044] Fastening pins 37 and 39 provide a reliable connection between the bearing ring 33 and the sealing element 35. Fastening pins 37 and 39 provide an effective reaction force opposite to the radially inward pressure, which can be generated by pressurized fluid that penetrates the gap between the bottom of the annular groove 33.4 and the outer cylindrical surface 35.2 of the sealing element 35.

[0045] The sealing structure 30 described above can be conveniently manufactured according to the method described below, with reference to... Figures 4A to 4G sequence.

[0046] The bearing ring 33 can be manufactured using conventional techniques (e.g., by turning, milling, or any other chip removal process), starting from a blank (e.g., in the form of a tube) until its final net shape is obtained, except for through holes 33.7 and 33.8, see [link to documentation]. Figure 4A Through holes 33.7 and 33.8 are manufactured in subsequent steps, as described below.

[0047] The sealing element 35 can be manufactured from blank 35B. Figure 4B The blank 35B is shown in a cross-sectional view. It may have an annular shape, with a simple square or rectangular cross-section. The blank 35B can be manufactured using conventional techniques as well as 3D printing.

[0048] The blank 35B is then partially machined, for example by turning or a similar chip removal process, to produce the outer surfaces 35.2, 35.3, 35.4 of the sealing element 35, namely those surfaces intended to make surface contact with the annular groove 33.4 of the carrier ring 33. See also Figure 4C The inward-facing surface on which the sealing feature 35.5 is located will be machined in a subsequent step, which will be disclosed below.

[0049] Then, the partially machined sealing element 35 is introduced into the annular groove 33.4 of the bearing ring 33, such as... Figure 4D As shown.

[0050] In the next manufacturing step, through holes 33.7 and 33.8 are drilled through sidewalls 33.2 and 33.3. Drilling continues to machine seats 35.10 and 35.11 in the sealing element 35.

[0051] Once holes 33.7, 33.8 and seats 35.10, 35.11 have been drilled, for example by gluing in and locking fastening pins 37, 39, see [link to documentation]. Figure 4F .

[0052] Once the partially machined sealing element 35 has been attached to the carrier ring 33, the second sealing region 35.12 of the sealing element 35 can be machined, for example by turning, to achieve the final shape, including teeth 35.5 or other sealing features, see [link to documentation]. Figure 4G .

[0053] The process described so far allows for very precise machining and reduces the amount of plastic material required. Deformation of the plastic preform during manufacturing is avoided. Annealing or other heat treatments for the sealing element 35 to remove heat-induced stress can be omitted.

[0054] Figure 5 A modified embodiment of the sealing structure 30 is shown. The same reference numerals denote... Figure 2 and Figure 3 The parts shown are the same as or equivalent to those described above. Figure 2 , Figure 3 Implementation plan and Figure 5 The main difference between the implementation schemes involves the fastening arrangement, which mechanically connects the sealing element 35 to the bearing ring 33. Figure 5 A single set of fastening pins 38 is shown. Each pin 38 extends through sidewalls 33.2, 33.3 and seat 35.13, which extends from side surface 35.3 to side surface 35.4 through the entire thickness (i.e., the dimension in the axial direction) of the sealing element 35.

[0055] To prevent the fastening pin 38 from being pushed out of the sealing structure 30 (the sealing arrangement 30 is placed between the high-pressure and low-pressure areas) by the pressure difference between the high-pressure and low-pressure areas, the fastening pin 38 may be provided with an annular ridge 38.1 abutting against the side of the sealing structure 30 facing the high-pressure area, or any other feature suitable for holding the fastening pin 38 in place against the force generated by the pressure difference across the sealing structure 30.

[0056] In some embodiments, one of the holes 33.7 and 33.8 may be closed, i.e., limited to only a portion of the thickness of the relevant sidewall, such as not limited to the surface of the bearing ring 33 on the side facing the low-pressure area of ​​the machine on which the sealing structure 30 is mounted. In this way, the fastening pin 38 introduced into the blind hole from the high-pressure side will abut against the bottom of the blind hole and will be held against the forces generated by the pressure differential across the sealing structure 30.

[0057] In all the embodiments disclosed above, the sealing element 35 is formed from a single integral annular member. While this is particularly advantageous in terms of manufacturing precision and ease of assembly, it is not excluded that the sealing element 35 may be formed from separate annular portions that are inserted into the annular groove 33.4 of the carrier ring 33. The annular portions may then be joined together by gluing or any other suitable method.

[0058] Figure 6 The main steps of the manufacturing method according to this disclosure are summarized.

[0059] While the invention has been described with reference to various specific embodiments, those skilled in the art will understand that many modifications, variations, and omissions are possible without departing from the spirit and scope of the claims. Furthermore, unless otherwise specified herein, the order or sequence of any process or method steps may be changed or reordered according to alternative embodiments.

Claims

1. A composite sealing structure suitable for installation in a turbine, the composite sealing structure comprising: A support ring having: a circumferential outer wall having an inner surface and an outer surface, a first side wall and a second side wall, wherein the first side wall and the second side wall protrude radially inward from the circumferential outer wall toward the axis of the support ring; The annular groove is formed between the outer circumferential wall, the first side wall, and the second side wall; A sealing element having a first region and a second sealing region, the first region being in surface-to-surface contact with the annular groove, and the second sealing region protruding from the annular groove of the carrier ring toward the axis of the carrier ring and having a sealing feature; and A fastening arrangement connects the sealing element and the bearing ring to each other, thereby forming the composite sealing structure; The fastening arrangement includes a plurality of fastening pins arranged circumferentially around the axis of the bearing ring; Each of the plurality of fastening pins extends through at least one of the first sidewall and the second sidewall; and each of the plurality of fastening pins engages in a corresponding seat formed in the sealing element.

2. The sealing structure according to claim 1, wherein the fastening pin is parallel to the axis of the bearing ring.

3. The sealing structure according to claim 1 or 2, wherein the second sealing region is a labyrinthine sealing region; and wherein the second sealing region includes a plurality of teeth protruding radially inward from the inner surface of the second sealing region toward the axis of the bearing ring.

4. The sealing structure according to claim 1 or 2, wherein the bearing ring is made of a first material and the sealing element is made of a second material different from the first material; wherein the sealing element is made of a polymer.

5. The sealing structure according to claim 1 or 2, wherein the carrier ring is made of a first material and the sealing element is made of a second material different from the first material; wherein the sealing element is made of a thermoplastic polymer.

6. The sealing structure according to claim 1 or 2, wherein the bearing ring is made of a first material and the sealing element is made of a second material different from the first material; wherein the sealing element is made of a composite polymer material.

7. The sealing structure according to any one of claims 1 to 2, wherein the sealing element is formed from a single annular element.

8. The sealing structure according to any one of claims 1 to 2, wherein the bearing ring is made of a metal and a metal alloy.

9. The sealing structure according to any one of claims 1 to 2, wherein the plurality of fastening pins comprises: The first set of fastening pins extends through a hole across the first sidewall and engages in the first set of seats of the sealing element; A second set of fastening pins extends through a hole across the second sidewall and engages in a second set of seats in the sealing element; and wherein the seats in the sealing element are blind-hole shaped.

10. The sealing structure according to claim 9, wherein each fastening pin in the first group is collinear with a corresponding fastening pin in the second group.

11. The sealing structure according to any one of claims 1 to 2, wherein the inner surface forms the bottom of the annular groove, and wherein the sealing element includes a body having an outer cylindrical surface in surface contact with the bottom of the annular groove.

12. The sealing structure according to any one of claims 1 to 2, wherein the fastening pins are spaced apart at an angular distance between 18° and 36°.

13. The sealing structure according to any one of claims 1 to 2, wherein the circumferential outer wall of the carrying ring includes a fastening feature adapted to fasten the sealing structure in an annular seat of the machine.

14. The sealing structure according to claim 13, wherein the machine is a turbine.

15. The sealing structure of claim 13, wherein the fastening feature includes an annular protrusion extending from the outer peripheral surface of the circumferential outer wall.

16. The sealing structure of claim 15, wherein the annular protrusion has a cross-sectional shape forming an undercut for mechanical coupling to the annular seat of the machine.

17. The sealing structure according to any one of claims 1 to 2, wherein at least one of the first sidewall and the second sidewall includes an anti-vortex device formed on its outer surface.

18. A machine, said machine comprising: Housing; shaft arranged for rotation within the housing; According to at least one sealing structure of any one of claims 1 to 17, the at least one sealing structure is adapted to provide a sealing effect on the shaft arranged for rotation in the housing.

19. The machine according to claim 18, wherein, The machine in question is a turbine.

20. A method for manufacturing a sealing structure, the method comprising the steps of: A sealing element is inserted into an annular groove of a support ring, the annular groove being formed between the outer circumferential wall, a first side wall, and a second side wall of the support ring, the first side wall and the second side wall protruding radially inward from the outer circumferential wall toward the axis of the support ring; The sealing element is mechanically coupled to the carrier ring such that the sealing element has a first region and a second sealing region, the first region being in surface-to-surface contact with the annular groove, and the second sealing region protruding from the annular groove of the carrier ring toward the axis of the carrier ring; The inward-facing surface of the second sealing region of the sealing element is machined to create a sealing feature thereon.

21. The method of claim 20, wherein the step of mechanically coupling the sealing element to the carrier ring comprises the following steps: Multiple fastening pins are introduced by extending through corresponding holes through at least one of the first and second sidewalls, and each fastening pin is engaged in a corresponding seat formed in the sealing element.

22. The method of claim 21, wherein the step of introducing the plurality of fastening pins through the corresponding plurality of holes and engaging each fastening pin in the corresponding seat comprises the following steps: A first set of fastening pins is introduced by extending through a first set of holes through the first sidewall and the fastening pins in the first set are engaged into a first set of seats formed on the first side of the sealing element; A second set of fastening pins is introduced by extending a second set of holes through the second sidewall and engaging the fastening pins in the second set into a second set of seats formed on the second side of the sealing element.

23. The method of claim 22, wherein the step of mechanically coupling the sealing element to the carrier ring further comprises the following steps after the sealing element has been inserted into the annular groove of the carrier ring: The first set of holes is machined through the first sidewall and extended to each hole in the first set of holes to form the first set of seats, each seat being collinear with the corresponding hole in the first set of holes; The second set of holes is machined through the second sidewall and extended to each hole in the second set of holes to form the second set of seats, each seat being collinear with the corresponding hole in the second set of holes.

24. The method according to any one of claims 20 to 23, wherein the step of machining the inward-facing surface of the second sealing region of the sealing element includes the step of generating a plurality of sealing teeth forming a labyrinth seal.

25. The method according to any one of claims 20 to 23, the method further comprising the following steps: A ring-shaped blank is machined to create the annular groove between the outer circumferential wall, the first side wall, and the second side wall in the ring-shaped blank. And a plurality of through holes are further machined in at least one of the first sidewall and the second sidewall.

26. The method of claim 25, wherein the step of machining the annular blank further comprises the step of forming a fastening feature that projects radially outward from the outer surface of the outer wall of the circumference.

27. The method according to any one of claims 20 to 23, wherein the carrier ring is made of metal or a metal alloy, and the sealing element is made of polymer.

28. The method according to any one of claims 20 to 23, wherein the carrier ring is made of metal or a metal alloy, and the sealing element is made of a thermoplastic polymer.

29. The method according to any one of claims 20 to 23, wherein the carrier ring is made of metal or a metal alloy, and the sealing element is made of a composite polymer material.

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