Inter-shaft sealing device

Abstract

The utility model relates to the technical field of intermediate bearing sealing, in particular to an inter-shaft sealing device. The inter-shaft sealing device comprises a sealing seat, a split type supporting assembly and a sealing floating ring, the sealing seat is of an annular structure, the sealing floating ring is arranged in a ring of the sealing seat, an inner ring of the sealing floating ring is used for installing an inner-layer rotor in a matched mode, and the diameter of the inner ring of the sealing floating ring is larger than that of the inner-layer rotor. The split type supporting assembly is elastically supported between the sealing base and the sealing floating ring, and a plurality of compensation point positions are formed in the circumferential direction of the sealing floating ring, so that after the inner-layer rotor works, compensation is conducted on radial displacement between the sealing floating ring and the inner-layer rotor through the gas dynamic pressure effect. The air dynamic pressure effect between the sealing floating ring and the inner-layer rotor is utilized, the sealing floating ring is pushed to overcome elastic supporting of the split type supporting assembly in the radial direction to generate a small amount of displacement, eccentricity or jumping between the sealing floating ring and the inner-layer rotor is adapted, and contact rub-impact is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of intermediate bearing sealing, particularly to an inter-shaft sealing device. BACKGROUND

[0002] In a dual-rotor aero-engine, the outer rotor and the inner rotor are connected through an intermediate bearing, and the sealing of the intermediate bearing is an inter-shaft sealing. The inter-shaft sealing is usually in the form of gas sealing, which can achieve long service life under the harsh working conditions of the dual-rotor inter-shaft, although a small amount of gas leakage is lost. Due to the harsh working conditions of the narrow space between the two rotors, high interface sliding speed, high boundary pressure difference, and high environmental temperature, combined with the runout of the two rotors in the radial and axial directions, the inter-shaft sealing in the form of a present service grate often produces rubbing damage to the grate teeth due to the radial runout or eccentric operation of the rotor, resulting in reduced performance of the grate sealing, increased leakage, and serious efficiency loss. The rigid grate sealing cannot compensate for the tooth tip wear caused by the radial runout of the rotor, and there is currently no better solution to this problem. SUMMARY

[0003] The technical problem to be solved by the embodiments of the utility model lies in providing an inter-shaft sealing device to solve the problem that the intermediate bearing sealing in the prior art cannot compensate for the radial runout or eccentric operation of the rotor.

[0004] The utility model discloses an inter-shaft sealing device, including seal seat, split type support component and sealing floating ring, the seal seat is annular structure, the sealing floating ring sets up in the ring of seal seat, and with seal seat common central axis, the inner ring of sealing floating ring is used for cooperation installation inner rotor, and the inner ring diameter of sealing floating ring is greater than the diameter of installation inner rotor, split type support component is elastically supported between seal seat and sealing floating ring, and forms a plurality of compensation point positions in the circumferential direction of sealing floating ring, so that after the operation of inner rotor, the sealing floating ring and inner rotor are compensated in the radial displacement under the gas dynamic pressure effect.

[0005] Optionally, the split type support component includes a plurality of metal rubber petals arranged at intervals along the circumferential direction of the sealing floating ring, and the metal rubber petals are porous elastic petal-shaped structures prepared from stainless steel wires.

[0006] Optionally, the metal rubber petals have a first side wall corresponding to and fitted to the outer wall of the sealing floating ring, and a second side wall corresponding to and fitted to the inner wall of the seal seat, and the arc length of the first side wall is less than the arc length of the second side wall.

[0007] Optionally, the inter-shaft sealing device further includes a sealing film, which is an annular structure arranged on one end of the sealing floating ring. The outer edge of the sealing film is connected to the sealing seat, and the inner edge of the sealing film is connected to the sealing floating ring.

[0008] Optionally, the sealing film is a film made of a flexible material, with a continuous "S"-shaped cross-section from the outer edge to the inner edge of the ring, and continuous undulating folds formed on the film surface of the sealing film.

[0009] Optionally, the sealing film is disposed on one end or both opposite ends of the sealing floating ring, and forms a seal on one side or both opposite sides of the metal rubber flap.

[0010] Optionally, the sealing floating ring includes a sealing bushing and a sealing ring with a common central axis sleeved inside the sealing bushing. The sealing bushing is a ring structure made of metal material, and the sealing ring is a ring structure made of non-metallic material with self-lubricating properties. The sealing ring and the sealing bushing are interference-fitted, and the inner ring diameter of the sealing ring is larger than the diameter of the inner rotor.

[0011] Optionally, the outer wall of the sealing bushing is provided with a first embedding groove corresponding to the inner edge of the sealing film ring, and the inner wall of the sealing seat is provided with a second embedding groove corresponding to the outer edge of the sealing film ring.

[0012] Optionally, the inter-shaft sealing device further includes a first clamp disposed in the first embedding groove and a second clamp disposed in the second embedding groove. The first clamp is interference-fitted with the first embedding groove and fixes the inner edge of the sealing film ring, and the second clamp is interference-fitted with the second embedding groove and fixes the outer edge of the sealing film ring.

[0013] Optionally, a flange is provided on one end face of the sealing bushing, and the flange is located on the end side of the sealing ring to form a limiting structure.

[0014] Compared with the prior art, the inter-shaft sealing device provided by this utility model has the following advantages:

[0015] With the sealing seat and sealing floating ring arranged on the common central axis, the sealing seat can be interference-fitted with the outer rotor in a dual-rotor system or the stator in a single-rotor system. The sealing floating ring is coaxially assembled with the inner rotor. By utilizing the fact that the inner ring diameter of the sealing floating ring is larger than the diameter of the inner rotor, a certain radial displacement compensation gap is created between the sealing floating ring and the inner rotor. A segmented support assembly is used to elastically support the sealing seat and the floating sealing ring, forming multiple compensation points in the circumferential direction of the floating sealing ring. Utilizing the principle of gas dynamic pressure lubrication, when the inner rotor operates and causes eccentricity between the floating sealing ring and the inner rotor, a convergent gap is formed in the circumferential direction. Therefore, a gas film force is generated due to the gas dynamic pressure effect. The gas film force pushes the floating sealing ring radially to overcome the elastic support of the segmented support assembly and produce a small displacement, thereby adapting to the eccentricity between the floating sealing ring and the inner rotor and preventing contact and rubbing between them. This compensates for the radial eccentricity or runout of the inner rotor, achieving the design requirement of long service life. It can also compensate for the problem that the existing inter-shaft grate seal cannot compensate for the increased leakage caused by tooth tip wear due to radial runout of the rotor, reducing the frequent disassembly and assembly of the dual-rotor system due to inter-shaft sealing problems. Attached Figure Description

[0016] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0017] Figure 1 A schematic diagram of the overall structure of the inter-shaft sealing device provided in this embodiment of the utility model;

[0018] Figure 2 An exploded view of the structure of the inter-shaft sealing device provided in this embodiment of the utility model;

[0019] Figure 3 A schematic diagram of the cross-sectional structure of the sealing film provided in an embodiment of this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of the sealing floating ring provided in an embodiment of the present utility model;

[0021] Figure 5 This is a schematic diagram of the structure of the sealing bushing provided in an embodiment of the present utility model;

[0022] Figure 6 This is a schematic diagram of the sealing seat provided in an embodiment of the present utility model.

[0023] The labels for the attached figures are as follows:

[0024] 1. Sealing seat; 11. Second embedded groove; 2. Split-type support assembly; 21. Metal rubber flap; 3. Sealing floating ring; 31. Sealing bushing; 311. First embedded groove; 312. Flanged edge; 32. Sealing ring; 4. Inner rotor; 5. Sealing film; 51. Pleated part; 6. First clamp; 7. Second clamp. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0026] This utility model discloses an inter-shaft sealing device, such as Figure 1 As shown, the device includes a sealing seat 1, a segmented support assembly 2, and a sealing floating ring 3. The sealing seat 1 has an annular structure, and the sealing floating ring 3 is disposed inside the ring of the sealing seat 1 and shares the same central axis with the sealing seat 1. The inner ring of the sealing floating ring 3 is used to fit and install the inner layer rotor 4, and the diameter of the inner ring of the sealing floating ring 3 is larger than the diameter of the inner layer rotor 4. The segmented support assembly 2 is elastically supported between the sealing seat 1 and the sealing floating ring 3, and forms multiple compensation points in the circumferential direction of the sealing floating ring 3, so that after the inner layer rotor 4 is working, the sealing floating ring 3 and the inner layer rotor 4 are compensated for in radial displacement due to the gas dynamic pressure effect.

[0027] Through the implementation of the above-described inter-shaft sealing device embodiment, a sealing seat 1 and a sealing floating ring 3 with a common central axis are provided. The sealing seat 1 can be connected to the outer rotor in a dual-rotor system or the stator in a single-rotor system through a slight interference fit, or it can be directly fixed, so that the central axis of the sealing seat 1 always coincides with the central axis of the outer rotor or stator. This allows the sealing seat 1 to rotate with the outer rotor or stator when it is working. The sealing floating ring 3 is coaxially assembled with the inner rotor 4. The inner ring diameter of the sealing floating ring 3 is larger than the diameter of the inner rotor 4, creating a certain radial displacement compensation gap between the sealing floating ring 3 and the inner rotor 4. A segmented support assembly 2 is elastically supported between the sealing seat 1 and the sealing floating ring 3, forming multiple compensation points in the circumferential direction of the sealing floating ring 3. On one hand, the friction generated by the segmented support assembly 2 contacting the sealing seat 1 and the sealing floating ring 3 respectively allows the sealing seat 1 to rotate with the outer rotor or stator, while simultaneously driving the sealing floating ring 3 to rotate with the outer rotor. In ideal conditions without radial runout or eccentricity, the central axes of the outer rotor or stator, sealing seat 1, sealing floating ring 3, and inner rotor 4 all coincide. On the other hand, utilizing the principle of gas dynamic lubrication, when the inner rotor 4 operates and causes eccentricity between the sealing floating ring 3 and the inner rotor 4, a convergent gap will form between them in the circumferential direction. The inter-shaft seal seals the intermediate bearing. With its special structural arrangement, when the inner rotor 4 operates, the high-pressure side airflow leaks along the axial gap between the sealing floating ring 3 and the inner rotor 4 to the low-pressure side. At this time, the gas relies on the wall surface of the inner rotor 4 to form gas dynamic lubrication, and a fluid dynamic pressure is formed on the inner wall of the sealing floating ring 3, thus generating a gas film force due to the gas dynamic effect. The air film force will push the sealing floating ring 3 to overcome the elastic support of the split support assembly 2 in the radial direction and generate a small displacement, thereby adapting to the eccentricity between the sealing floating ring 3 and the inner rotor 4, so as not to cause contact and friction between the sealing floating ring 3 and the inner rotor 4. This compensates for the radial eccentricity or runout of the inner rotor 4, achieving the design requirement of long service life. It can also make up for the problem that the existing inter-shaft grate seal cannot compensate for the increased leakage after the tooth tip wear caused by the radial runout of the rotor, and reduce the frequent disassembly and assembly of the dual rotor system due to inter-shaft seal problems.

[0028] Furthermore, regardless of whether the outer rotor or the inner rotor 4 experiences whirling or eccentricity, the multiple compensation points formed by the elastic support of the segmented support assembly 2 can accommodate the radial runout of the two rotors, thereby ensuring that there is no contact friction between the sealing floating ring 3 and the inner rotor 4, achieving the requirement of long service life. When the outer rotor speed is 0, it degenerates into a traditional single-rotor dynamic seal, and the shaft sealing device of this embodiment is also fully adapted to the requirements of a single-rotor dynamic seal.

[0029] Furthermore, combinedFigure 2 As shown, the segmented support assembly 2 includes multiple metal rubber segments 21 spaced along the circumferential direction of the sealing floating ring 3. The metal rubber segments 21 are porous elastic petal structures made of stainless steel wire.

[0030] Through the implementation of the above-described inter-shaft sealing device embodiment, the porous structure of the metal rubber flap 21, woven from stainless steel wire, provides controllable permeability, allowing local gas to infiltrate into the flap body. This balances the transient pressure difference across the metal rubber flap 21, reducing the impact of dynamic load fluctuations on the seal. Simultaneously, the elastic deformation capability of the metal rubber flap 21 allows the sealing floating ring 3 to overcome its supporting force and generate minute radial displacements (typically at the micrometer level), thereby compensating for radial eccentricity or vibration of the inner rotor 4 and preventing wear caused by rigid contact between the sealing floating ring 3 and the inner rotor 4. Furthermore, the stainless steel wire metal rubber flap 21 avoids the aging failure of traditional rubber seals. Moreover, the synergistic effect of multiple metal rubber flaps 21 along the circumference of the sealing floating ring 3 can adapt to the eccentricity or movement of the inner rotor 4 in any direction, preventing overload failure of a single flap, thus achieving uniform load distribution, multi-directional eccentricity compensation, and redundancy tolerance.

[0031] Furthermore, the metal rubber flap 21 has a first sidewall that corresponds to and fits against the outer wall of the sealing floating ring 3, and a second sidewall that corresponds to and fits against the inner wall of the sealing seat 1. The arc length of the first sidewall is smaller than the arc length of the second sidewall.

[0032] Through the implementation of the above-described inter-shaft sealing device embodiment, the shorter arc length of the first sidewall on the metal rubber flap 21 is in contact with the inner sealing floating ring 3. The shorter arc length results in a smaller contact area between the metal rubber flap 21 and the outer ring wall of the sealing floating ring 3, thereby reducing radial stiffness. This allows the sealing floating ring 3 to quickly and finely adjust its displacement when the rotor is eccentric or running, avoiding jamming due to excessive local constraint. Similarly, the longer arc length of the second sidewall on the metal rubber flap 21 is in contact with the outer sealing seat 1. The longer arc length is in contact with a large area of ​​the inner ring wall of the sealing seat 1, providing stable axial and tangential constraints and preventing the sealing floating ring 3 from deflecting or slipping circumferentially.

[0033] Furthermore, combined Figure 2 and Figure 3 As shown, the inter-shaft sealing device also includes a sealing film 5, which is an annular structure arranged on one end of the sealing floating ring 3. The outer edge of the sealing film 5 is connected to the sealing seat 1, and the inner edge of the sealing film 5 is connected to the sealing floating ring 3.

[0034] Furthermore, the sealing film 5 is a film made of flexible material, and its cross-section from the outer edge of the ring to the inner edge of the ring has a continuous "S" shaped structure, and continuous convex and concave wrinkles 51 are formed on the film surface of the sealing film 5.

[0035] Furthermore, the sealing film 5 is disposed on one end or opposite ends of the sealing floating ring 3, and forms a seal on one side or opposite sides of the metal rubber flap 21.

[0036] Through the implementation of the above-described inter-shaft sealing device embodiment, the sealing film 5 seals one side of the metal rubber flap 21 to prevent axial leakage of fluid outside the inter-shaft sealing device along the porous gaps of the metal rubber flap 21 and the space between adjacent metal rubber flaps 21. The sealing film 5 can be set on one or both sides of the metal rubber flap 21, depending on the high and low pressure difference during operation. The sealing film 5 is a high-temperature resistant film material with a certain strength, and polyimide film is preferred. Furthermore, the sealing film 5 should not be stretched too tightly during assembly; a certain amount of allowance should be left in the radial direction. Therefore, the continuous pleats 51 formed on the surface of the sealing film 5 can prevent the sealing floating ring 3 from tearing or breaking the sealing film 5 when it floats radially.

[0037] Furthermore, combined Figure 1 and Figure 4 As shown, the sealing floating ring 3 includes a sealing bushing 31 and a sealing ring 32 with a common central axis sleeved inside the sealing bushing 31. The sealing bushing 31 is a ring structure made of metal material, and the sealing ring 32 is a ring structure made of non-metallic material with self-lubricating properties. The sealing ring 32 and the sealing bushing 31 are interference-fitted, and the inner ring diameter of the sealing ring 32 is larger than the diameter of the inner rotor 4.

[0038] Through the implementation of the above-described inter-shaft sealing device embodiment, since the inter-shaft seal seals the intermediate bearing, under its special structural arrangement, the sealing floating ring 3 is usually close to the bearing raceway. However, in this embodiment of the present invention, in order to compensate for the eccentricity or runout of the inner rotor 4 during operation, there is an axial gap between the sealing floating ring 3 and the inner rotor 4 to form a non-contact structure. In order to ensure the rigidity and sealing performance of the inter-shaft sealing device, the sealing floating ring 3 needs to be made of metal material to provide structural support. However, since the sealing floating ring 3 may come into contact with the inner rotor 4 during the displacement compensation process, the metal material sealing floating ring 3 is prone to generating metal abrasive particles after collision and friction with the inner rotor 4. Once the metal abrasive particles are entrained into the bearing raceway by the airflow, they can easily cause damage to the bearing raceway. Therefore, in this embodiment of the present invention, the sealing floating ring 3 is divided into an interference fit sealing bushing 31 and a sealing ring 32. The outer sealing bushing 31 is a ring structure made of metal material, and the inner sealing ring 32 is a ring structure made of a non-metallic material with self-lubricating properties, such as graphite. The metal sealing bushing 31 provides sufficient rigidity for the entire sealing floating ring 3 to accommodate displacement compensation during the inner rotor 4's runout or eccentric operation. The self-lubricating sealing ring 32 ensures that even if abrasive particles generated from the collision and friction between the sealing floating ring 3 and the inner rotor 4 are drawn into the bearing raceway, their self-lubricating properties effectively prevent damage to the bearing raceway, thus extending its service life.

[0039] Furthermore, combined Figure 2 , Figure 5 and Figure 6 As shown, the outer wall of the sealing bushing 31 is provided with a first embedding groove 311 that corresponds to and is connected to the inner edge of the sealing film 5 ring, and the inner wall of the sealing seat 1 is provided with a second embedding groove 11 that corresponds to and is connected to the outer edge of the sealing film 5 ring.

[0040] Furthermore, the inter-shaft sealing device also includes a first clamp 6 disposed in the first embedding groove 311 and a second clamp 7 disposed in the second embedding groove 11. The first clamp 6 is interference-fitted with the first embedding groove 311 and fixes the inner edge of the sealing film 5 ring. The second clamp 7 is interference-fitted with the second embedding groove 11 and fixes the outer edge of the sealing film 5 ring.

[0041] Through the implementation of the above-described inter-shaft sealing device embodiment, the first embedding groove 311 on the sealing bushing 31 and the second embedding groove 11 on the sealing seat 1 are used to limit and fix the sealing film 5. This restricts the axial and circumferential displacement of the sealing film 5 by wrapping its edge with the groove wall, preventing it from coming off under high pressure or vibration conditions. Preferably, the inner edge of the sealing film 5 is fixed in the first embedding groove 311 with high-temperature sealant, and the outer edge of the sealing film 5 is fixed in the second embedding groove 11 with high-temperature sealant.

[0042] Furthermore, a flange 312 is provided on one end face of the sealing bushing 31, and the flange 312 is located on the end side of the sealing ring 32 to form a limiting structure.

[0043] Through the implementation of the above-described inter-shaft sealing device embodiment, since the inter-shaft seal is used to seal the intermediate bearing, during operation, the airflow on the high-pressure side will leak to the low-pressure side along the axial gap between the sealing floating ring 3 and the inner rotor 4. However, since the sealing bushing 31 and the sealing ring 32 in this embodiment of the present invention are interference-fitted, the airflow on the high-pressure side often pushes the sealing ring 32 to move axially along the inner rotor 4. Therefore, in this embodiment of the present invention, the flange 312 provided on the sealing bushing 31 forms a limiting structure on the low-pressure side of the sealing ring 32, which can prevent the sealing ring 32 from sliding axially with the sealing bushing due to pressure difference.

[0044] It should be understood that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of this utility model.

Claims

1. An inter-shaft sealing device, characterized in that: The inter-shaft sealing device includes a sealing seat, a segmented support assembly, and a sealing floating ring. The sealing seat has an annular structure, and the sealing floating ring is disposed inside the ring of the sealing seat and shares a central axis with the sealing seat. The inner ring of the sealing floating ring is used to fit and install the inner layer rotor, and the diameter of the inner ring of the sealing floating ring is larger than the diameter of the inner layer rotor. The segmented support assembly is elastically supported between the sealing seat and the sealing floating ring, and forms multiple compensation points in the circumferential direction of the sealing floating ring, so that after the inner layer rotor is working, the sealing floating ring and the inner layer rotor are compensated for radial displacement due to gas dynamic pressure effect.

2. The inter-shaft sealing device according to claim 1, characterized in that: The segmented support assembly includes multiple metal rubber segments spaced apart along the circumferential direction of the sealed floating ring. The metal rubber segments are porous elastic petal-shaped structures made of stainless steel wire.

3. The inter-shaft sealing device according to claim 2, characterized in that: The metal rubber flap has a first sidewall that corresponds to and fits against the outer wall of the sealing floating ring, and a second sidewall that corresponds to and fits against the inner wall of the sealing seat ring. The arc length of the first sidewall is smaller than the arc length of the second sidewall.

4. The inter-shaft sealing device according to claim 2, characterized in that: The inter-shaft sealing device further includes a sealing film, which is an annular structure arranged on one end of the sealing floating ring. The outer edge of the sealing film is connected to the sealing seat, and the inner edge of the sealing film is connected to the sealing floating ring.

5. The inter-shaft sealing device according to claim 4, characterized in that: The sealing film is a film made of flexible material, and its cross-section from the outer edge of the ring to the inner edge of the ring has a continuous "S" shape structure, and continuous convex and concave wrinkles are formed on the film surface of the sealing film.

6. The inter-shaft sealing device according to claim 4, characterized in that: The sealing film is disposed on one end or both opposite ends of the sealing floating ring, and forms a seal on one side or both opposite sides of the metal rubber flap.

7. The inter-shaft sealing device according to any one of claims 4-6, characterized in that: The sealing floating ring includes a sealing bushing and a sealing ring with a common central axis sleeved inside the sealing bushing. The sealing bushing is a ring structure made of metal material, and the sealing ring is a ring structure made of non-metallic material with self-lubricating properties. The sealing ring and the sealing bushing are interference-fitted, and the inner ring diameter of the sealing ring is larger than the diameter of the inner rotor.

8. The inter-shaft sealing device according to claim 7, characterized in that: The outer wall of the sealing bushing is provided with a first embedding groove that corresponds to and is connected to the inner edge of the sealing film ring, and the inner wall of the sealing seat is provided with a second embedding groove that corresponds to and is connected to the outer edge of the sealing film ring.

9. The inter-shaft sealing device according to claim 8, characterized in that: The inter-shaft sealing device further includes a first clamp disposed in the first embedding groove and a second clamp disposed in the second embedding groove. The first clamp is interference-fitted with the first embedding groove and fixes the inner edge of the sealing film ring. The second clamp is interference-fitted with the second embedding groove and fixes the outer edge of the sealing film ring.

10. The inter-shaft sealing device according to claim 9, characterized in that: A flange is provided on one end face of the sealing bushing, and the flange is located on the end side of the sealing ring to form a limiting structure.

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