Counter-rotating shaft brush seal structure with adaptive shroud leakage gap

Abstract

The application discloses a kind of self-adapting brush type sealing structure of sealing leakage gap between counter-rotating shafts, comprising: outer rotor, rotary brush type sealing, buoyancy ring petal, limit ring, tension spring and inner rotor, wherein rotary brush type sealing is fixedly installed in the inside of outer rotor, limit ring is fixedly installed in the outer periphery of inner rotor, limit ring outer periphery is provided with an annular groove, buoyancy ring petal is multiple and cooperatively installed in annular groove, buoyancy ring petal is limited sliding connection with the side wall of annular groove and is connected with the bottom of annular groove by the tension spring corresponding to buoyancy ring petal, the outer periphery of buoyancy ring petal is provided with brush silk runway platform, and the free end of brush silk bundle is interference fit with the brush silk runway platform of buoyancy ring petal.The self-adapting brush type sealing structure of sealing leakage gap between counter-rotating shafts can adaptively seal the leakage gap generated by brush silk and inner rotor due to centrifugal effect, and improve sealing performance.

Description

Technical Field

[0001] This invention relates to a brush seal structure between rotating shafts, and particularly provides a brush seal structure between rotating shafts that adaptively seals leakage gaps. Background Technology

[0002] In a dual-rotor aero-engine, two rotating shafts are located between the high- and low-pressure compressors. To reduce gyroscopic torque and optimize rotor vibration, the two rotors are designed to rotate in opposite directions. This places higher demands on the lifespan and sealing performance of the sealing structure. Brush seals, as a high-performance contact seal structure, have a longer lifespan than graphite seals, offer significantly better sealing performance than labyrinth seals, and possess strong adaptability to rotor radial runout, making them well-suited for the operating conditions between the opposing shafts.

[0003] Currently, brush seal structures installed on the outer rotor between opposing shafts are rarely used. This is because when the brush bristles are installed on the outer rotor, the tips of the brush bristles are generally interference-fitted or in contact with the inner rotor raceway. When the outer rotor speed is low, it has high sealing performance. However, as the outer rotor speed increases, the centrifugal effect on the brush bristles will increase, and the brush bristles will gradually float up. A leakage gap will be generated between the brush bristle tips and the inner rotor raceway, and the leakage gap will increase with the increase of the outer rotor speed. This will generate more leakage and cause the sealing structure to fail.

[0004] Therefore, proposing a novel brush-type sealing structure with brush filaments installed on the outer rotor between the rotating shafts to adaptively seal the leakage gap between the brush filaments and the inner rotor caused by centrifugal effect and improve sealing performance has become an urgent problem to be solved. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide an adaptive sealing leakage gap between opposing shafts brush seals to solve the problem of increased leakage in existing opposing shaft brush seals under high external rotor speeds.

[0006] The technical solution provided by this invention is: an adaptive sealing leakage gap brush seal structure for opposing rotating shafts, comprising: an outer rotor, a rotary brush seal, floating annular petals, a limiting ring, a tension spring, and an inner rotor. The rotary brush seal is fixedly installed on the inner side of the outer rotor and includes a front baffle, a rear baffle, and a brush filament bundle. The limiting ring is fixedly installed on the outer periphery of the inner rotor, and an annular groove is provided on the outer periphery of the limiting ring. Multiple floating annular petals are fitted and installed within the annular groove. Each floating annular petal includes... The sliding connection part and the brush raceway platform connected to the sliding connection part are provided. The sliding connection part is slidably connected to the side wall of the annular groove and connected to the bottom of the annular groove through tension springs corresponding to the floating ring petals. During initial installation, the free end of the brush bundle is interference-fitted with the brush raceway platform of the floating ring petal. During operation, the brush bundle floats up due to centrifugal force and creates a leakage gap with the inner rotor. The floating ring petal slides and floats on the outer periphery of the limiting ring under centrifugal force and seals the leakage gap.

[0007] Preferably, limit posts are provided on both sides of the sliding connection, and the side wall of the annular groove is provided with a limit groove that cooperates with the limit posts, the length of the limit groove being greater than the length of the limit posts.

[0008] Further preferably, the limiting post and the tension spring are both inclined along the circumference of the floating ring and in the same direction.

[0009] Further preferably, the tilting direction of the limiting post and the tension spring is consistent with the tilting direction of the brush filament bundle.

[0010] In a further preferred embodiment, a cavity is provided on the inner side of the sliding connection, a first connecting post is provided in the cavity, a second connecting post is provided at the bottom of the annular groove, and the two ends of the tension spring are respectively connected to the first connecting post and the second connecting post.

[0011] Further preferably, the radial cross-section of the floating ring is T-shaped, and an annular space is formed between the brush runway platform of the floating ring and the limiting ring.

[0012] In a further preferred embodiment, slots and inserts are provided at both ends of the buoyancy ring, and the slots and inserts of adjacent buoyancy rings are connected to each other to drive the buoyancy rings to float up or fall down synchronously.

[0013] More preferably, there are three slots at the end of the floating ring, namely slot A, slot B and slot C. Slot A is located in the upper middle part and has an upper opening, while slots B and slot C are symmetrically arranged on both sides of slot A and have lower openings.

[0014] Further optimization involves a total of 30 floating annular petals.

[0015] The adaptive sealing leakage gap brush seal structure between rotating shafts provided by this invention has a reasonable structure and can adapt to the leakage gap generated between the sealing brush filaments and the inner rotor due to centrifugal effect, thereby improving sealing performance. Attached Figure Description

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0017] Figure 1 A schematic diagram of the adaptive sealing leakage gap brush seal structure between rotating shafts provided by the present invention;

[0018] Figure 2 A schematic diagram of a circumferential section of the adaptive sealing leakage gap brush seal structure between rotating shafts provided by the present invention;

[0019] Figure 3 for Figure 2 A cross-sectional view along the direction of the brush bristles' inclination;

[0020] Figure 4 This is a schematic diagram of the structure of the floating annular petals;

[0021] Figure 5 This is a schematic diagram of the limiting ring structure. Detailed Implementation

[0022] The present invention will be further explained below with reference to specific implementation schemes, but this explanation does not limit the scope of the invention.

[0023] like Figures 1 to 5 As shown, this invention provides an adaptive sealing leakage gap inter-shaft brush seal structure, comprising: an outer rotor 1, a rotary brush seal 2, floating annular petals 3, a limiting ring 4, a tension spring 5, and an inner rotor 6. The rotary brush seal 2 is fixedly installed inside the outer rotor 1 and includes a front baffle 21, a rear baffle 22, and a brush filament bundle 23. The limiting ring 4 is fixedly installed on the outer periphery of the inner rotor 6, and an annular groove 41 is provided on the outer periphery of the limiting ring 4. Multiple floating annular petals 3 are fitted within the annular groove 41, and each floating annular petal 3 includes a sliding... The connecting part 31 and the brush track platform 32 connected to the sliding connecting part 31 are connected to the side wall of the annular groove 41 for limiting sliding connection and to the bottom of the annular groove 41 through tension springs 5 ​​corresponding to the floating ring petals 3. During initial installation, the free end of the brush bundle 23 is interference-fitted with the brush track platform 32 of the floating ring petal 3. During operation, the brush bundle 23 floats up due to centrifugal force and creates a leakage gap with the inner rotor 6. The floating ring petal 3 slides and floats on the outer periphery of the limiting ring 4 under centrifugal force and seals the leakage gap.

[0024] This adaptive sealing leakage gap counter-rotating shaft brush seal structure has a rotating brush seal installed on the outer rotor, a limiting ring installed on the inner rotor, and a floating ring lobe sliding and limited in the annular groove on the outer circumference of the limiting ring. Under centrifugal force, it can float outside the limiting ring. When the inner and outer rotors rotate in opposite directions, the brush bundle and the floating ring lobe will float due to the centrifugal effect. The floating ring lobe can achieve the effect of adaptive sealing gap. Among them, the tension spring can overcome the centrifugal force and pull the floating ring lobe to retract quickly when the inner and outer rotors decelerate, avoiding severe wear of the falling brush filaments and brush filament raceway platform due to the slow fall of the brush filament raceway platform.

[0025] As an improvement to the technical solution, limit posts 311 are provided on both sides of the sliding connection part 31 (e.g., Figure 4 As shown), the sidewall of the annular groove 41 is provided with a limiting groove 411 that cooperates with the limiting post 311 (as shown). Figure 5 As shown), the length of the limiting groove 411 is greater than the length of the limiting post 311, so as to realize the limiting sliding connection between the sliding connection part and the limiting ring. The cooperation between the limiting post and the limiting groove can also enhance the stability of the floating ring petals when they are thrown outward by centrifugal effect.

[0026] As an improvement to the technical solution, such as Figure 2 As shown, the limiting post 311 and the tension spring 5 are both inclined along the circumference of the floating ring 3 and the inclination directions are the same.

[0027] As an improvement to the technical solution, such as Figure 2 As shown, the tilting direction of the limiting post 311 and the tension spring 5 is consistent with the tilting direction of the brush filament bundle 23.

[0028] As an improvement to the technical solution, such as Figure 3 As shown, a cavity is provided on the inner side of the sliding connection part 31, a first connecting post 312 is provided in the cavity, a second connecting post 412 is provided at the bottom of the annular groove 41, and the two ends of the tension spring 5 are respectively connected to the first connecting post 312 and the second connecting post 412.

[0029] As an improvement to the technical solution, such as Figure 3As shown, the radial cross-section of the floating ring 3 is T-shaped. The brush raceway platform 32 of the floating ring 3 and the limiting ring 4 form an annular space. When the outer rotor speed is very high, a leakage gap is formed between the brush tip and the surface of the brush raceway platform. The leakage flow rate of the leakage gap will increase, the leakage air velocity will increase, and the pressure at the leakage gap will drop faster. The pressure below the brush raceway platform remains basically unchanged. Due to the pressure difference, the brush raceway platform will be thrown out faster when the leakage gap is large. After the surface of the brush raceway platform contacts the tip of the brush bundle, the leakage channel is sealed. Since the force generated by the pressure difference disappears, the brush bundle can be prevented from being worn too much on the brush raceway platform, making the floating ring 3 more adaptable to the high speed of the outer rotor.

[0030] As the floating ring segments are thrown outward with the rotation of the inner rotor, the higher the rotational speed of the inner rotor, the greater the centrifugal effect on the floating ring segments, and the greater the distance they are thrown outward. This will cause the gap at the connection interface of the floating ring segments to gradually increase. As an improvement to the technical solution, such as Figure 4 As shown, slots 33 and insert plates 34 are provided at both ends of the floating ring 3. The slots 33 and insert plates 34 of adjacent floating ring 3 are inserted into each other. The matching slots and insert plates can maintain the splicing structure when the floating ring is thrown outward, so that the leakage gap of the floating ring can be well sealed whether it is along the rotor circumference or radial direction.

[0031] As an improvement to the technical solution, such as Figure 4 As shown, there are three slots 33 located at the ends of the buoyancy ring 3, namely slot A, slot B and slot C. Slot A is located in the upper middle part and has an upper opening, while slots B and slot C are symmetrically arranged on both sides of slot A and have lower openings. This structure can ensure the consistency of each buoyancy ring during the outward throwing process (i.e., synchronous floating or falling), and avoid the problem of some buoyancy rings rotating eccentrically.

[0032] The number of floating rings can be determined according to specific needs. As an improvement to the technical solution, the floating ring 3 is a 12-degree ring. The adaptive sealing leakage gap between the rotating shaft brush seal structure includes 30 floating rings.

[0033] The specific embodiments of the present invention are written in a progressive manner, emphasizing the differences between the various implementation schemes, and the similar parts can be referred to each other.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A self-adaptive sealing and leakage gap-sealing brush seal structure between rotating shafts, characterized in that, include: The outer rotor (1), rotary brush seal (2), floating annular petals (3), limiting ring (4), tension spring (5), and inner rotor (6) are provided. The rotary brush seal (2) is fixedly installed on the inner side of the outer rotor (1). The rotary brush seal (2) includes a front baffle (21), a rear baffle (22), and a bristle bundle (23). The limiting ring (4) is fixedly installed on the outer periphery of the inner rotor (6). An annular groove (41) is provided on the outer periphery of the limiting ring (4). Multiple floating annular petals (3) are installed in the annular groove (41). The floating annular petals (3) include a sliding connection part (31) and a bristle runway platform (32) connected to the sliding connection part (31). The sliding connection part (31) is limited by the side wall of the annular groove (41). The sliding connection (31) is connected to the bottom of the annular groove (41) by tension springs (5) corresponding to the floating ring petals (3). During initial installation, the free end of the brush bristle bundle (23) is press-fitted with the brush bristle track platform (32) of the floating ring petal (3). During operation, the brush bristle bundle (23) floats up due to centrifugal force and creates a leakage gap with the inner rotor (6). The floating ring petal (3) slides and floats on the outer periphery of the limiting ring (4) under centrifugal force and seals the leakage gap. Limiting posts (311) are provided on both sides of the sliding connection (31). The side wall of the annular groove (41) is provided with a limiting groove (411) that cooperates with the limiting post (311). The length of the limiting groove (411) is greater than the length of the limiting post (311).

2. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: The limiting post (311) and the tension spring (5) are both inclined along the circumference of the floating ring (3) and in the same direction.

3. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: The tilting direction of the limiting post (311) and the tension spring (5) is consistent with the tilting direction of the brush filament bundle (23).

4. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: A cavity is provided inside the sliding connection part (31), a first connecting post (312) is provided in the cavity, a second connecting post (412) is provided at the bottom of the annular groove (41), and the two ends of the tension spring (5) are respectively connected to the first connecting post (312) and the second connecting post (412).

5. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: The radial section of the floating ring (3) is T-shaped, and an annular space is formed between the brush runway platform (32) of the floating ring (3) and the limiting ring (4).

6. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: The two ends of the floating ring (3) are provided with slots (33) and inserts (34), and the slots (33) and inserts (34) of adjacent floating rings (3) are connected to each other to drive the floating rings (3) to float up or fall down synchronously.

7. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 6, characterized in that: There are three slots (33) located at the end of the floating ring (3), namely slot A, slot B and slot C. Slot A is located in the upper middle part and has an upper opening, while slots B and slot C are symmetrically arranged on both sides of slot A and have lower openings.

8. The adaptive sealing leakage gap brush seal structure between rotating shafts according to claim 1, characterized in that: There are a total of 30 floating ring petals (3).

Images