End cylindrical surface combined type inter-shaft sealing device
By using a combined end-cylinder-type shaft sealing device, which utilizes a metal-rubber sealing ring and the principle of gas dynamic pressure lubrication, the problem of reduced sealing performance caused by rotor radial runout in a dual-rotor gas turbine is solved. This achieves contactless sealing, extends the service life of the sealing device, and reduces leakage.
Patent Information
- Application Number
- CN202520850192.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-04-30
AI Technical Summary
In dual-rotor gas turbines, conventional grate seal structures suffer from tooth tip wear due to rotor radial runout, resulting in reduced sealing performance, increased leakage, and severe efficiency loss.
The inter-shaft sealing device adopts a combination of end cylindrical surfaces, which uses the elastic deformation of the metal rubber sealing ring to compensate for the radial eccentricity of the rotor. Combined with the principle of gas dynamic pressure lubrication, the sealing ring is prevented from detaching through the dynamic pressure groove and the flange structure, thus achieving contactless sealing.
It effectively compensates for rotor radial eccentricity, protects the integrity of the sealing ring, ensures good shaft seal, extends service life, reduces leakage, and improves efficiency.
Smart Images
Figure CN223938145U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of sealing equipment for dual-rotor gas turbines, specifically to a combined end-cylinder surface type inter-shaft sealing device. Background Technology
[0002] In twin-rotor aero-engines or gas turbines, the outer and inner rotors are connected by an intermediate bearing, which is then sealed—this is called an inter-shaft seal. Due to the unique assembly space requirements and harsh operating conditions involving high interface sliding speeds, high boundary pressure differences, and high ambient temperatures, conventional contact seals are poorly suited for inter-shaft seals. Furthermore, because of the significant relative runout between the outer and inner rotors in both the radial and axial directions, rigid contact seals are prone to component damage, leading to poor sealing performance.
[0003] Currently, in dual-rotor aero-engines or gas turbines, the inter-shaft seal between the outer and inner rotors conventionally uses a grate seal structure. However, in actual use, it has been found that the radial runout or eccentric operation of the rotor can cause wear on the grate teeth, resulting in reduced performance, increased leakage, and severe efficiency loss of the grate seal. Utility Model Content
[0004] To address the problem that the toothed seal used in dual-rotor gas turbines cannot compensate for tooth tip wear caused by rotor radial runout, this invention provides an end-cylinder combined shaft sealing device.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] This utility model proposes an end-cylindrical combined shaft sealing device, including a first sealing ring and a sealing seat. The first sealing ring is sleeved on the outer wall of the inner rotor, and the sealing seat is installed inside the outer rotor.
[0007] The first sealing ring and the sealing seat are fitted together, and the end face of the sealing seat is flush with the end face of the first sealing ring, so that an annular mounting cavity is formed between the first sealing ring and the sealing seat, and a metal rubber sealing ring is installed in the annular mounting cavity.
[0008] Preferably, a flange is provided on the inner wall of the sealing seat near one end face, and when the sealing seat is installed, the flange is located on the low-pressure side between the inner rotor and the outer rotor.
[0009] Preferably, the first sealing ring includes a connecting ring sleeved on the inner rotor, one end of the connecting ring is provided with a first retaining ring, the other end of the connecting ring is provided with a second retaining ring, and the metal rubber sealing ring is installed on the connecting ring between the first retaining ring and the second retaining ring.
[0010] Preferably, the first retaining ring and the second retaining ring are provided with dynamic pressure grooves.
[0011] Preferably, the dynamic pressure groove is one of a spiral groove or a Rayleigh stepped groove.
[0012] Preferably, the depth of the dynamic pressure groove is in the range of 5μm to 8μm.
[0013] Preferably, the inner wall of the connecting ring is provided with helical teeth, which form a gap of 15μm to 25μm between the inner wall of the connecting ring and the outer wall of the inner rotor.
[0014] Preferably, the outer rotor is interference-fitted with the sealing seat.
[0015] Preferably, the outer side of the metal rubber sealing ring is covered with a sealing film.
[0016] Preferably, the metal rubber sealing ring is interference-fitted with both the first sealing ring and the sealing seat.
[0017] Compared with the prior art, the present invention has the following beneficial technical effects:
[0018] This invention proposes an end-cylindrical combined shaft sealing device. This device fully utilizes the principle of gas dynamic pressure lubrication, and integrates a sealing seat, a metal rubber sealing ring, and a first sealing ring between the outer and inner rotor shafts. The elastic deformation of the metal rubber sealing ring allows it to follow the rotor's whirling or radial eccentricity, enabling the first sealing ring to float radially. This compensates for the radial eccentricity between the inner and outer rotors during rotation, preventing contact and friction between the outer wall of the inner rotor and the inner wall of the first sealing ring. This protects the integrity of the first sealing ring, ensures good shaft sealing, and extends the service life of the shaft seal.
[0019] Furthermore, the device has a flange on the inner wall of the sealing seat near one end face. The flange is located on the low-pressure side between the inner rotor and the outer rotor. The flange prevents the metal rubber sealing ring from moving and prevents the metal rubber sealing ring from detaching from the sealing seat.
[0020] Furthermore, the first and second retaining rings in this device are provided with dynamic pressure grooves. The dynamic pressure grooves, in conjunction with the difference in relative rotational speed between the inner and outer rotors, create a dynamic pressure effect, which in turn hinders fluid leakage. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of an end-cylindrical surface combined inter-shaft sealing device proposed in this utility model;
[0022] Figure 2 This is a cross-sectional view of an end-cylindrical combined inter-shaft sealing device proposed in this utility model;
[0023] Figure 3 This is an enlarged schematic diagram of the connection between the sealing seat, the first sealing ring, and the metal-rubber sealing ring in an end-cylinder combined shaft sealing device proposed in this utility model.
[0024] Figure 4 This is an exploded view of an end-cylindrical combined inter-shaft sealing device proposed in this utility model;
[0025] Figure 5 This is a three-dimensional structural diagram of the sealing seat in an end-cylindrical combined inter-shaft sealing device proposed in this utility model.
[0026] Figure 6 This is a side view of the sealing seat in a combined end-cylinder surface type inter-shaft sealing device proposed in this utility model.
[0027] Figure 7 for Figure 5 A schematic diagram of the cross-sectional structure at point AA.
[0028] Figure 8 This is a schematic diagram of the structure of the first sealing ring in an end-cylindrical combined inter-shaft sealing device proposed in this utility model;
[0029] In the attached diagram: 1. Sealing seat; 10. Flanged edge; 2. Metal-rubber sealing ring; 3. First sealing ring; 30. Helical teeth; 31. Dynamic pressure groove; 32. Connecting ring; 33. First retaining ring; 34. Second retaining ring; 4. Inner rotor. Detailed Implementation
[0030] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.
[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0035] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.
[0036] This utility model proposes a combined end-cylinder surface type inter-shaft sealing device, such as... Figures 1-7As shown, this device includes a first sealing ring 3 and a sealing seat 1. The first sealing ring 3 is sleeved on the outer wall of the inner rotor 4, and the first sealing ring 3 and the inner rotor 4 are installed concentrically. At the same time, the inner diameter of the first sealing ring 3 is larger than the outer diameter of the inner rotor 4, so that a gap is formed between the inner wall of the first sealing ring 3 and the outer wall of the inner rotor 4. Gas located on one side of the first sealing ring 3 in the gap leaks from the high-pressure side to the low-pressure side along this gap. The sealing seat 1 is installed in the outer rotor, and the outer rotor and the sealing seat 1 are interference-fitted to ensure a stable connection between the outer rotor and the sealing seat 1. In use, the two can rotate synchronously, and the center of the two does not move during the rotation.
[0037] The first sealing ring 3 and the sealing seat 1 are concentrically fitted together, and the end face of the sealing seat 1 is flush with the end face of the first sealing ring 3, so that an annular mounting cavity is formed between the first sealing ring 3 and the sealing seat 1. A metal rubber sealing ring 2 is installed in the annular mounting cavity, and a sealing film is wrapped around the outside of the metal rubber sealing ring 2. The function of the sealing film is to prevent gas from leaking along the pores of the metal rubber. In this embodiment, the sealing film is one or more of polyimide film, polyethylene naphthalate film, alumina film, fluororubber film, polyetheretherketone film, and polyetherimide film, with polyimide film being preferred. The metal rubber sealing ring 2 is interference-fitted with the first sealing ring 3 and the sealing seat 1, and the mounting centers of the first sealing ring 3, the metal rubber sealing ring 2, the sealing seat 1, and the inner rotor 4 coincide. During the rotation of the inner rotor 4 and the outer rotor, this device moves along with the outer rotor. The outer rotor rotates synchronously. During the rotation of the inner rotor 4 and the outer rotor, radial runout or eccentricity occurs, causing the center of the inner rotor 4 to be out of sync with the center of the sealing seat 1, resulting in an eccentricity. This eccentricity is transmitted between the first sealing ring 3 and the inner rotor 4, forming a convergent gap in the sliding bearing. The gas, driven by the solid wall, forms gas dynamic pressure lubrication, creating fluid dynamic pressure on the inner circumferential cylindrical surface of the first sealing ring 3. Then, driven by the fluid dynamic pressure, the first sealing ring 3 overcomes the elastic support of the metal rubber sealing ring 2, and the first sealing ring 3 also becomes eccentric relative to the sealing seat 1. This compensates for the radial eccentricity during the rotation of the inner rotor 4 and the outer rotor, preventing the outer wall of the inner rotor 4 from contacting the inner wall of the first sealing ring 3 and causing mutual friction. This protects the integrity of the first sealing ring 3 and ensures good inter-shaft sealing.
[0038] like Figures 1-6 As shown, a flange 10 is provided on the inner wall of the sealing seat 1 near one end face. When the sealing seat 1 is installed, the flange 10 is located on the low-pressure side between the inner rotor 4 and the outer rotor. The flange 10 is used to assemble and clamp the metal rubber sealing ring 2, preventing the metal rubber sealing ring 2 from slipping off the sealing seat 1, thus ensuring the stability of the device.
[0039] like Figure 1 , Figure 2 , Figure 3 and Figure 7 As shown, the first sealing ring 3 includes a connecting ring 32 sleeved on the outer wall of the inner rotor 4. A first retaining ring 33 is provided at one end of the connecting ring 32. The outer diameter of the first retaining ring 33 is smaller than the inner diameter of the sealing seat 1. The inner diameter of the first retaining ring 33 is the same as the inner diameter of the connecting ring 32. A second retaining ring 34 is provided at the other end of the connecting ring 32. The inner diameter of the second retaining ring 34 is the same as the inner diameter of the connecting ring 32. The outer diameter of the second retaining ring 34 is smaller than the outer diameter of the first retaining ring 33. The outer diameter of the second retaining ring 34 is smaller than the inner diameter of the flange 10. A metal rubber sealing ring 2 is installed on the connecting ring 32 between the first retaining ring 33 and the second retaining ring 34.
[0040] Dynamic pressure grooves 31 are provided on the end faces of the first retaining ring 33 and the second retaining ring 34 away from the connecting ring 32. The depth of the dynamic pressure grooves 31 ranges from 5μm to 8μm. When the inner rotor 4 and the outer rotor rotate, the dynamic pressure grooves 31, in conjunction with the difference in relative rotational speed between the inner rotor 4 and the outer rotor, form a dynamic pressure effect. This dynamic pressure effect hinders fluid leakage. The dynamic pressure grooves 31 are either spiral grooves or Rayleigh stepped grooves. When the inner rotor 4 and the outer rotor rotate in the same direction, the opening directions of the dynamic pressure grooves 31 on the first retaining ring 33 and the second retaining ring 34 are different. When the inner rotor 4 and the outer rotor rotate in different directions, the opening directions of the first retaining ring 33 and the second retaining ring 34 are the same and consistent with the rotation direction of the outer rotor.
[0041] like Figure 7 As shown, a spiral tooth 30 is provided on the inner wall of the connecting ring 32. The spiral tooth 30 forms a gap of 15μm~25μm between the inner wall of the connecting ring 32 and the outer wall of the inner rotor 4. When the inner rotor 4 and the outer rotor rotate, the spiral tooth 30 also rotates at high speed, further suppressing the leakage of fluid from the high-pressure side to the low-pressure side.
[0042] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications made to the technical solutions based on the technical concept proposed by this utility model shall fall within the scope of protection of the claims of this utility model.
Claims
1. A combined end-cylindrical-face shaft sealing device, characterized in that, It includes a first sealing ring (3) and a sealing seat (1), wherein the first sealing ring (3) is sleeved on the outer wall of the inner rotor (4), and the sealing seat (1) is installed inside the outer rotor; The first sealing ring (3) and the sealing seat (1) are fitted together, and the end face of the sealing seat (1) is flush with the end face of the first sealing ring (3) so that an annular mounting cavity is formed between the first sealing ring (3) and the sealing seat (1), and a metal rubber sealing ring (2) is installed in the annular mounting cavity.
2. The end-cylindrical combined shaft sealing device according to claim 1, characterized in that, A flange (10) is provided on the inner wall of the sealing seat (1) near one end face. When the sealing seat (1) is installed, the flange (10) is located on the low-pressure side of the pressure between the inner rotor (4) and the outer rotor.
3. The end-cylindrical combined inter-shaft sealing device according to claim 1, characterized in that, The first sealing ring (3) includes a connecting ring (32) sleeved on the inner rotor (4). One end of the connecting ring (32) is provided with a first retaining ring (33), and the other end of the connecting ring (32) is provided with a second retaining ring (34). The metal rubber sealing ring (2) is installed on the connecting ring (32) between the first retaining ring (33) and the second retaining ring (34).
4. The end-cylindrical combined shaft sealing device according to claim 3, characterized in that, The second retaining ring (34) and the first retaining ring (33) are provided with dynamic pressure grooves (31).
5. The end-cylindrical combined inter-shaft sealing device according to claim 4, characterized in that, The dynamic pressure groove (31) is one of a spiral groove or a Rayleigh stepped groove.
6. The end-cylindrical combined inter-shaft sealing device according to claim 5, characterized in that, The depth range of the dynamic pressure groove (31) is 5μm~8μm.
7. The end-cylindrical combined inter-shaft sealing device according to claim 3, characterized in that, The inner wall of the connecting ring (32) is provided with helical teeth (30), and the helical teeth (30) form a gap of 15μm~25μm between the inner wall of the connecting ring (32) and the outer wall of the inner rotor (4).
8. The end-cylindrical combined shaft sealing device according to claim 1, characterized in that, The outer rotor is interference-fitted with the sealing seat (1).
9. The end-cylindrical combined shaft sealing device according to claim 1, characterized in that, The outer side of the metal rubber sealing ring (2) is covered with a sealing film.
10. The end-cylindrical combined shaft sealing device according to claim 1, characterized in that, The metal rubber sealing ring (2) is interference-fitted with the first sealing ring (3) and the sealing seat (1) respectively.