Sealing assembly for sealing bearing cavity
By designing a sealing assembly including an inclined brush tow and an adaptive sealing assembly, the problem of insufficient sealing in the case of radial offset of the rotary mechanical bearing cavity is solved, and a higher sealing effect and service life is achieved.
Patent Information
- Application Number
- CN202421555122.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-03
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-07-03
AI Technical Summary
When the existing sealing technology faces the radial offset of the rotating mechanical bearing cavity, the sealing property is insufficient and the sealing member is easily damaged, resulting in an increase in leakage flow and a shortened service life.
A sealing assembly including a first brush seal and a second sealing assembly is designed, the first brush seal consisting of a tilted brush tow, the brush wires are made of a soft polymer material, and the second sealing assembly may be a brush seal or a grate seal to adapt to the radial offset of the rotation shaft.
It effectively prevents oil mist from spreading out from the bearing cavity, improves the service life of the seal, has a simple structure, is practical and powerful, and reduces installation complexity and cost.
Smart Images
Figure CN222687308U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of sealing, and more specifically to a sealing group used for sealing a bearing cavity. Background Art
[0002] Rotating machinery generally includes a rotating part, such as a shaft that can rotate relative to a fixed part (such as a casing). The shaft is usually fixed in a bearing on one or more casings. The oil film bearing used in gas turbines includes a bearing cavity and a layer of oil film. The rotational movement of the shaft in the bearing cavity generates oil mist, which must be prevented from diffusing outside the bearing cavity. Otherwise, the oil mist may be deposited on other parts of the rotating machinery, such as compressor blades, causing damage to the machine. In addition, the oil mist diffused from the bearing cavity may be deposited in the surrounding environment, causing safety hazards and of course affecting the appearance.
[0003] In many rotating machines, a simple tight gap seal (i.e., a stationary component that fits tightly against the rotating component) is sufficient to prevent the oil mist from diffusing out of the bearing cavity. However, in some applications, there may be a large radial offset of the rotor. Therefore, the tightness of the gap seal depends on the radial offset of the rotor. To accommodate this offset, sufficient spacing must be left between the rotating and stationary components at the seal, usually enough clearance to allow the oil mist to diffuse out of the bearing cavity through the gap opening.
[0004] A comb seal is a common seal used as a non-metallic brush seal for gas turbine bearing cavities. It consists of a plurality of axially spaced teeth that extend substantially radially from a stationary component. The teeth may be machined or added to the stationary component as inserts. Since the teeth are relatively small in axial dimension and are generally made of a softer material than the rotating component, the rotating component is less likely to be damaged in the event of radial displacement. It follows that the tortuous path between the rotating component and the teeth of the comb seal provides a sealing effect at least as good as a simple gap seal. However, if a large or significant radial displacement occurs, the teeth of the comb seal will be damaged, and once damaged, the leakage flow rate will be irreversibly increased for the remaining service life of the seal. In addition, in most embodiments of the comb seal, the seal involves a large, complex casting that requires extensive machining to complete. Moreover, the mass of these comb seals can be large, resulting in assembly difficulties. Utility Model Content
[0005] The technical problem to be solved by the utility model is to provide a sealing component for sealing a bearing cavity;
[0006] The solution adopted by the utility model to solve the technical problem is:
[0007] A sealing assembly for sealing a bearing cavity is used in conjunction with a rotating shaft and is located at the end of the rotating shaft. The sealing assembly comprises a bracket which is sleeved on the outside of the rotating shaft and mounted on a bearing seat of the rotating shaft, a first brush seal which is mounted on the bracket and sleeved on the outside of the rotating shaft, and a second sealing assembly which is mounted on the bracket and sleeved on the outside of the rotating shaft; the second sealing assembly is a second brush seal or a comb seal; the first brush seal and the second brush seal are in contact with the rotating shaft, and the comb seal is in clearance with the rotating shaft.
[0008] In some possible implementations, a bearing seat is coaxially sleeved on the outer side of the rotating shaft, and the bracket is connected to the outer ring of the bearing seat and sleeved on the outer side of the rotating shaft.
[0009] In some possible embodiments, the first brush seal includes a first back plate connected to the bracket, a second back plate forming a mounting groove with the first back plate, and multiple groups of brush bundles installed in the mounting grooves and with one end in contact with the outer side of the rotating shaft, the multiple groups of brush bundles are evenly arranged along the circumference of the rotating shaft, and each group of brush bundles is inclined.
[0010] In some possible implementations, each group of the brush filament bundles includes multiple groups of brush filaments, and the angle formed by the extension line of each group of brush filaments in the long direction and the radial line of the rotation axis passing through the group of brush filaments and the bracket installation point is A, 10°>A>5°.
[0011] In some possible implementations, the diameter of the brush filament is d, 0.0127 mm<d<0.0254 mm.
[0012] In some possible implementations, the brush filaments are made of polymer material with a hardness a, a<0.27MPa / mm.
[0013] In some possible implementations, the first brush seal and the second brush seal have the same structure and a distance b therebetween is b≥10 mm.
[0014] In some possible implementations, the comb seal includes a comb ring sleeved on the outside of the rotating shaft and connected to the bracket, and a plurality of groups of combs arranged on one side of the comb ring close to the rotating shaft and along the circumference of the rotating shaft.
[0015] In some possible implementations, there is a clearance fit between the comb teeth and the rotating shaft, and the clearance is 1-2 mm.
[0016] In some possible implementations, the bracket includes a connecting plate connected to the outer side of the bearing seat, and a mounting plate connected to a side of the connecting plate away from the bearing seat;
[0017] When the second sealing component is a comb seal, the distance between the connecting plate and the rotating shaft is greater than the distance between the mounting plate and the rotating shaft; the comb seal is mounted on the side of the connecting plate close to the rotating shaft; and the first brush seal is mounted on the side of the mounting plate away from the bearing seat;
[0018] When the second sealing assembly is a second brush seal, the distance between the connecting plate and the rotating shaft is smaller than the distance between the rotating shaft and the mounting plate; the first brush seal and the second brush seal are provided on both inner and outer sides of the mounting plate.
[0019] Compared with the prior art, the utility model has the following beneficial effects:
[0020] The utility model can effectively seal the bearing cavity by being installed on the outside of the bearing seat; when in use, the oil mist will not diffuse outward;
[0021] The utility model tilts the brush wires and supports them with soft polymer materials, so that the brush wires can adapt to the radial deviation of the rotating parts and greatly increase the service life.
[0022] The utility model has the advantages of simple structure and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic diagram of the structure of Example 1 of the present utility model;
[0024] Figure 2 This is a schematic diagram of the structure of Example 2 of the present utility model;
[0025] Figure 3 This is a schematic diagram of the structure of the brush wire, rotating shaft and mounting plate in the utility model;
[0026] Among them: 10, rotating shaft; 20, bearing seat; 1, first brush seal; 11, first back plate; 12, second back plate; 13, brush wire; 2, second sealing assembly; 21, second brush seal; 22, comb seal; 21, comb ring; 22, comb teeth; 3, bracket; 31, connecting plate; 32, mounting plate. DETAILED DESCRIPTION
[0027] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity limit, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can indicate: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.
[0028] The utility model is described in detail below.
[0029] like Figure 1-Figure 3 As shown:
[0030] A sealing assembly for sealing a bearing cavity, used in conjunction with a rotating shaft 10, for sealing the bearing cavity formed by the rotating shaft 10, and located at the end of the rotating shaft 10; it is mainly used to prevent oil mist from diffusing from the bearing cavity, and the sealing environment after sealing is a low-pressure environment;
[0031] It includes a bracket 3 which is sleeved on the outside of the rotating shaft 10 and is installed on the bearing seat 20 of the rotating shaft 10, a first brush seal 1 which is installed on the bracket 3 and sleeved on the outside of the rotating shaft 10, and a second sealing component 2 which is installed on the bracket 3 and sleeved on the outside of the rotating shaft 10; the second sealing component 2 is a second brush seal 21 or a comb seal 22; the first brush seal 1 and the second brush seal 21 are in contact with the rotating shaft 10, and the comb seal 22 is in clearance with the rotating shaft 10.
[0032] When it is applied to a gas turbine, since the rotating shaft 10 of the gas turbine is installed in an oil film bearing, oil mist will be generated during use; the bearing seat 20 installs the first brush seal 1 and the second sealing assembly 2 through the bracket 3 to achieve the fixation of the first brush seal 1 and the second sealing assembly 2, and the first brush seal 1 and the second sealing assembly 2 are effectively sealed through the cooperation of the first brush seal 1 and the second sealing assembly 2, thereby effectively preventing the oil mist in the bearing cavity from diffusing outward.
[0033] Embodiment 1:
[0034] like Figure 1 As shown, in this embodiment, the second sealing assembly 2 is a second brush seal 21 having the same structure as the first brush seal 1; the first brush seal 1 and the second brush seal 21 cooperate to seal the bearing cavity and prevent the oil mist from diffusing outwards;
[0035] In some possible implementations, in order to effectively implement the installation of the bracket 3;
[0036] A bearing seat 20 is coaxially sleeved on the outer end of the rotating shaft 10 , and the bracket 3 is connected to the bearing seat 20 and sleeved on the outer side of the rotating shaft 10 .
[0037] In some possible embodiments, the first brush seal 1 includes a first back plate 11 connected to the bracket 3, a second back plate 12 forming a mounting groove with the first back plate 11, and multiple groups of brush filaments 13 bundles installed in the mounting groove and with one end in contact with the outer side of the rotating shaft 10, the multiple groups of brush filaments 13 bundles are evenly arranged along the circumference of the rotating shaft 10, and each group of brush filaments 13 bundles are arranged at an angle.
[0038] A mounting groove is formed between the first back plate 11 and the second back plate 12, and one end of the brush filament 13 bundle is welded to the bottom of the mounting groove; it is arranged in an inclined manner; the inclined arrangement is used to adapt to the radial deviation of the rotating shaft 10 during use;
[0039] In some possible implementations, each group of brush filaments 13 bundles includes multiple groups of brush filaments 13, such as Figure 3 As shown, the angle formed by the extension line of the long direction of each group of brush filaments 13 and the radial line of the rotating shaft 10 passing through the installation point of the group of brush filaments 13 and the bracket 3 is A, 10°>A>5°; the diameter of the brush filament 13 is d, 0.0127mm<d<0.0254mm; the brush filaments 13 in each group of brush filaments 13 are closely arranged; the brush filaments 13 are made of polymer material, and their hardness is a, a<0.27MPa / mm, that is, the brush filaments 13 are made of soft polymer material, and are matched with their inclined setting to adapt to the radial deviation of the rotating shaft 10.
[0040] Specifically, the hardness of the brush filament 13 is 0.054 MPa / mm, and the diameter is 0.014 mm; compared with the prior art, the diameter of the brush filament 13 in the utility model is smaller than that in the prior art, so that there are more brush filaments 13 in each group of brush filaments 13 and the density is higher.
[0041] In some possible embodiments, in order to facilitate the installation of the first brush seal 1 and the second brush seal 21, the distance between the first brush seal 1 and the second brush seal 21 is b, b≥10mm; after stable operation, the end of the brush 13 close to the rotating shaft 10 will be in linear contact with the outer side surface of the rotating shaft 10.
[0042] Embodiment 2:
[0043] like Figure 2 As shown, in this embodiment, the first brush seal 1 has the same structure as the first brush seal 1 in Embodiment 1, and the second sealing assembly 2 is a comb seal 22; the first brush seal 1 cooperates with the comb seal 22 to seal the bearing cavity and prevent the oil mist from diffusing outward;
[0044] In some possible implementations, the comb seal 22 includes a comb ring 221 that is sleeved on the outside of the rotating shaft 10 and connected to the bracket 3 , and multiple groups of comb teeth 222 that are arranged on one side of the comb ring 221 close to the rotating shaft 10 and along the circumference of the rotating shaft 10 .
[0045] In some possible implementations, there is a clearance fit between the comb teeth 222 and the rotating shaft 10, and the clearance is 1-2 mm.
[0046] Embodiment 3:
[0047] like Figure 1 , Figure 2 As shown, in order to effectively install the first brush seal 1 and the second sealing assembly 2 through the bracket 3, the bracket 3 is installed on the outer side of the bearing seat 20 and fixedly connected to the bearing seat 20; the bracket 3 is made of metal plate;
[0048] The bracket 3 includes a connecting plate 31 connected to the outer side of the bearing seat 20, and a mounting plate 32 connected to the connecting plate 31 and located on a side of the connecting plate 31 away from the bearing seat 20;
[0049] like Figure 1 As shown, when the second sealing assembly 2 is the second brush seal 21, the distance between the mounting plate 32 and the rotating shaft 10 is smaller than the distance between the connecting plate 31 and the rotating shaft 10; the first brush seal 1 and the second brush seal 21 are arranged on the inner and outer sides of the mounting plate 32 and are symmetrically arranged; the inner and outer sides refer to the side close to the bearing seat 20 and the side away from the bearing seat 20; wherein the first back plate 11 is connected to the mounting plate 32.
[0050] like Figure 2As shown, when the second sealing component 2 is a comb seal 22, the distance between the connecting plate 31 and the rotating shaft 10 is smaller than the distance between the mounting plate 32 and the rotating shaft 10, and the comb seal 22 is installed on the side of the connecting plate 31 close to the rotating shaft 10; the first brush seal 1 is installed on the side of the mounting plate 32 away from the connecting plate 31, wherein the comb ring 221 is connected to the side of the connecting plate 31 close to the rotating shaft 10.
[0051] The seal of the utility model can be used for all forms of rotating machinery, including gas turbines, steam turbines, compressors, motors and other equipment that need to seal the oil film bearing cavity, does not require a lot of mechanical processing, simplifies installation and reduces costs.
[0052] The present invention is not limited to the above-mentioned specific implementation modes, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.
Claims
1. A sealing assembly for sealing a bearing cavity, used in conjunction with a rotating shaft, characterized in that: Located at the end of the rotating shaft, it includes a bracket, a first brush seal installed on the bracket and sleeved on the outside of the rotating shaft, and a second sealing component installed on the bracket and sleeved on the outside of the rotating shaft; the second sealing component is a second brush seal or a comb seal; the first brush seal and the second brush seal are in contact with the rotating shaft, and the comb seal and the rotating shaft are in clearance fit.
2. A sealing assembly for sealing a bearing cavity according to claim 1, characterized in that: A bearing seat is coaxially sleeved on the outer side of the rotating shaft, and the bracket is connected to the outer ring of the bearing seat and sleeved on the outer side of the rotating shaft.
3. A sealing assembly for sealing a bearing cavity according to claim 1, characterized in that: The first brush seal includes a first back plate connected to the bracket, a second back plate forming a mounting groove with the first back plate, and multiple groups of brush bundles installed in the mounting groove and with one end in contact with the outer side of the rotating shaft. The multiple groups of brush bundles are evenly arranged along the circumference of the rotating shaft, and each group of brush bundles is arranged at an angle.
4. A sealing assembly for sealing a bearing cavity according to claim 3, characterized in that: Each group of the brush filament bundles includes multiple groups of brush filaments. The angle formed by the extension line of each group of brush filaments in the long direction and the radial line of the rotation axis passing through the group of brush filaments and the bracket installation point is A, 10°>A>5°.
5. A sealing assembly for sealing a bearing cavity according to claim 3, characterized in that: The diameter of the brush filament is d, 0.0127mm<d<0.0254mm.
6. A sealing assembly for sealing a bearing cavity according to claim 3, characterized in that: The brush filaments are made of polymer material with a hardness a, a<0.27MPa / mm.
7. A sealing assembly for sealing a bearing cavity according to claim 1, characterized in that: The first brush seal and the second brush seal have the same structure and a distance b therebetween is b≥10 mm.
8. A sealing assembly for sealing a bearing cavity according to claim 1, characterized in that: The comb teeth seal comprises a comb teeth ring which is sleeved on the outside of the rotating shaft and connected to the bracket, and a plurality of groups of comb teeth which are arranged on one side of the comb teeth ring close to the rotating shaft and along the circumference of the rotating shaft.
9. A sealing assembly for sealing a bearing cavity according to claim 8, characterized in that: There is a clearance fit between the comb teeth and the rotating shaft, and the clearance is 1-2 mm.
10. A sealing assembly for sealing a bearing cavity according to claim 2, characterized in that: The bracket includes a connecting plate connected to the outer side of the bearing seat, and a mounting plate connected to a side of the connecting plate away from the bearing seat; When the second sealing component is a comb seal, the distance between the connecting plate and the rotating shaft is greater than the distance between the mounting plate and the rotating shaft; the comb seal is mounted on the side of the connecting plate close to the rotating shaft; and the first brush seal is mounted on the side of the mounting plate away from the bearing seat; When the second sealing assembly is a second brush seal, the distance between the connecting plate and the rotating shaft is smaller than the distance between the rotating shaft and the mounting plate; the first brush seal and the second brush seal are provided on both inner and outer sides of the mounting plate.