Axial dip angle type brush type sealing structure between counter rotating shafts and capable of restraining centrifugal effect

Abstract

The axial dip angle type brush type sealing structure between the opposite rotating shafts and capable of restraining the centrifugal effect comprises an inner side rotor, an outer side rotor, a front baffle, a rear baffle and brush wire bundles, the front baffle, the rear baffle and the brush wire bundles are all fixedly installed on the inner side of the outer side rotor, and the free ends of the front baffle, the rear baffle and the brush wire bundles incline towards the high-pressure side. A plurality of drainage grooves are evenly formed in the rear wall face of the front baffle in the circumferential direction of the front baffle, each drainage groove is in a convergent shape and comprises a large end and a small end, and the large ends of the drainage grooves are located in front of the rotating direction of the outer side rotor relative to the small ends of the drainage grooves. The brush type sealing structure between the pair of rotating shafts is reasonable in structure, the front baffle, the rear baffle and the brush wire bundle are obliquely installed between the inner rotor and the outer rotor towards the high-pressure side, the drainage groove is formed in the rear wall face of the front baffle, the centrifugal effect can be effectively restrained, leakage gaps are prevented from being generated between the free ends of the brush wires and the inner rotor, and the overall sealing performance of brush type sealing is improved.

Description

Technical Field

[0001] The invention relates to a brush seal structure between counter-rotating shafts, and in particular provides an axially inclined brush seal structure between counter-rotating shafts capable of suppressing centrifugal effect. Background Art

[0002] Brush seals are typically installed between a rotor and a stator, with the base of the brush filaments attached to the stator and the free end of the brush filaments mating with the rotor. Aircraft engines and other rotating machinery also require sealing between counter-rotating shafts. Due to the high relative speeds between these shafts, differential pressure leaks occur, necessitating high sealing technology requirements. The brush seal filament material is flexible enough to accommodate transient rotor movement without expanding the leak path. It also offers a long service life, making it suitable for the harsh operating conditions between counter-rotating shafts.

[0003] However, there are the following problems when brush seals are applied between counter-rotating shafts: when the brush wires are installed on the outer rotor, the rotor drives the brush wires to rotate at a higher speed. Under the action of centrifugal effect, the brush wires tend to expand radially outward, resulting in a leakage gap between the free end of the brush wire and the inner rotor, which has an adverse effect on the overall sealing performance of the brush seal. As the speed of the outer rotor increases, the leakage gap will further increase, further affecting the overall sealing performance of the brush seal.

[0004] Therefore, how to improve the existing brush seal structure between counter-rotating shafts to suppress the centrifugal effect and improve the sealing performance of the brush seal has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides an axially inclined counter-rotating shaft brush seal structure capable of suppressing the centrifugal effect, so as to solve the problems existing in the prior art.

[0006] The present invention provides an axially inclination type counter-rotating shaft brush sealing structure that can suppress the centrifugal effect, comprising: an inner rotor, an outer rotor, a front baffle, a rear baffle and a brush bundle, wherein the front baffle, the rear baffle and the brush bundle are all fixedly mounted on the inner side of the outer rotor and their free ends are all inclined toward the high-pressure side, and the rear wall surface of the front baffle is evenly provided with a plurality of drainage grooves along its circumference, the drainage grooves are convergent and include a large end and a small end, and the large end of the drainage groove is located in front of the outer rotor in the rotation direction relative to the small end of the drainage groove.

[0007] Preferably, the front baffle, rear baffle and brush bundle have the same inclination angle.

[0008] Further preferably, the brush filament bundle is connected between the front baffle and the rear baffle through a fusion welding area.

[0009] Further preferably, an annular area is formed between the front baffle and the front row of brush filaments of the brush filament bundle, and the annular area is connected to an external air supply device.

[0010] Further preferably, the annular area is connected to the external air supply device via an air inlet, and the air inlets are evenly arranged along the circumference of the front baffle.

[0011] Further preferably, the width and / or depth of the drainage groove gradually decreases from the large end to the small end of the drainage groove.

[0012] More preferably, the depth of the drainage groove is 0.005 to 0.02 mm.

[0013] Further preferably, the radial height of the drainage groove is 3 / 5 of the height of the front baffle.

[0014] The axially inclination type brush seal structure between rotating shafts that can suppress the centrifugal effect provided by the present invention has a reasonable structure. By tilting the front baffle, the rear baffle and the brush bundle toward the high-pressure side and installing them between the inner and outer rotors and providing a drainage groove on the rear wall of the front baffle, the centrifugal effect can be effectively suppressed, and a leakage gap between the free end of the brush and the inner rotor can be avoided, thereby improving the overall sealing performance of the brush seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0016] Figure 1 A cross-sectional view of an axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effects provided by the present invention;

[0017] Figure 2 for Figure 1 Circumferential view of the center front baffle;

[0018] Figure 3 for Figure 2 Enlarged view of area A in the middle;

[0019] Figure 4 Another cross-sectional view of the axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect provided by the present invention;

[0020] Figure 5 for Figure 4 Circumferential view of the center front baffle;

[0021] Figure 6 for Figure 5 Magnified view of area A in the middle. DETAILED DESCRIPTION

[0022] The present invention will be further explained below with reference to specific embodiments.

[0023] The traditional brush seal structure between counter-rotating shafts has a tendency for the brush wires to expand outwards under the centrifugal effect of high speed, which will cause a leakage gap to form between the free end of the brush wire and the inner rotor, which has a great impact on the overall sealing performance of the brush seal. In view of this, Figures 1 to 6 As shown, the present invention provides an axially inclination type counter-rotating shaft brush sealing structure that can suppress the centrifugal effect, comprising: an inner rotor 1, an outer rotor 2, a front baffle 3, a rear baffle 4 and a brush bundle 5, wherein the front baffle 3, the rear baffle 4 and the brush bundle 5 are all fixedly installed on the inner side of the outer rotor 2 and the free ends are all inclined toward the high-pressure side, thereby forming an axial inclination angle with the radial section of the rotor. Preferably, the initial size of the inclination angle is 30°, and the rear wall surface of the front baffle 3 is evenly provided with a plurality of drainage grooves 31 along its circumference, and the drainage groove 31 is convergent (the cross-sectional area gradually becomes smaller) and includes a large end and a small end, and the large end of the drainage groove 31 is located in front of the rotation direction of the outer rotor 2 relative to the small end of the drainage groove 31. This arrangement can enable the drainage groove to guide the fluid therein to flow from a large space to a small space during rotation.

[0024] This axially tilted counter-rotating shaft brush seal structure, which can suppress centrifugal effects, effectively suppresses the centrifugal effect of the brushes and improves the sealing performance of the brush seal by tilting the front baffle, rear baffle, and brush bundle toward the high-pressure side between the inner and outer rotors and providing a drainage groove on the rear wall of the front baffle. The specific working principle is as follows: During operation, the leakage airflow flows from the high-pressure side to the low-pressure side, forming a pressure gradient. The airflow force can force the tilted brush bundle to adhere to the inner rotor surface; when the outer rotor rotates, the drainage groove guides the fluid between the front baffle and the brush bundle to flow along the path in the groove (large end to small end), forming a velocity gradient between the groove and the non-groove area, which can increase viscous shear stress and generate local dynamic pressure. This forms an inclined stable air film between the front baffle and the brush bundle, blocking the outward expansion of the brush due to centrifugal force, preventing the free end of the brush from lifting upward and creating a leakage gap, and improving the sealing performance of the brush seal.

[0025] As an improvement of the technical solution, Figure 1 、 Figure 4 As shown, the front baffle 3, the rear baffle 4 and the brush bundle 5 have the same inclination angle.

[0026] As an improvement of the technical solution, Figure 1 、 Figure 4 As shown, the brush bundle 5 is connected between the front baffle 3 and the rear baffle 4 through a fusion welding area 6 .

[0027] As an improvement of the technical solution, Figure 4As shown, an annular area 7 is formed between the front baffle 3 and the front row of brush wires of the brush wire bundle 5. The annular area 7 is connected to an external air supply device. By introducing gas into the annular area, the gas flow rate flowing through the drainage groove can be increased, the fluid dynamic pressure effect can be made more obvious, the role of the air film in suppressing the centrifugal effect of the brush wire bundle can be increased, and the sealing performance can be improved.

[0028] As an improvement of the technical solution, Figures 4 to 6 As shown, the annular area 7 is connected to the external air supply device through the air inlet 8, and the air inlet 8 is evenly arranged along the circumference of the front baffle 3. Preferably, the air inlet and the drainage groove are arranged in a one-to-one correspondence.

[0029] There are many ways in which the drainage groove 31 is convergent. As an improvement to the technical solution, the width and / or depth of the drainage groove 31 gradually decreases from the large end to the small end of the drainage groove 31. Figure 1 、 Figure 4 As shown, the depth of the drainage groove 31 gradually decreases from the large end to the small end of the drainage groove 31. Figure 2 、 Figure 3 、 Figure 5 、 Figure 6 As shown, the width of the drainage groove gradually decreases from the large end to the small end of the drainage groove 31.

[0030] As an improvement of the technical solution, the number of the drainage grooves 31 is 20-30, and the depth of the drainage grooves 31 is 0.005-0.02 mm.

[0031] As an improvement to the technical solution, the radial height of the drainage groove 31 is 3 / 5 of the height of the front baffle 3 .

[0032] The detailed description of the present invention is written in a progressive manner, emphasizing the differences between the various implementation schemes, and similar parts thereof can be referenced to each other.

[0033] 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. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. An axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect, characterized in that: include: An inner rotor (1), an outer rotor (2), a front baffle (3), a rear baffle (4) and a brush bundle (5); the front baffle (3), the rear baffle (4) and the brush bundle (5) are all fixedly mounted on the inner side of the outer rotor (2) and their free ends are all inclined toward the high-pressure side; a rear wall surface of the front baffle (3) is uniformly provided with a plurality of drainage grooves (31) along its circumference; the drainage grooves (31) are convergent and include a large end and a small end; the large end of the drainage groove (31) is located in front of the outer rotor (2) in the rotation direction relative to the small end of the drainage groove (31).

2. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: The front baffle (3), the rear baffle (4) and the brush bundle (5) have the same inclination angle.

3. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: The brush bundle (5) is connected between the front baffle (3) and the rear baffle (4) via a fusion welding area (6).

4. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: An annular area (7) is formed between the front baffle (3) and the front row of brush filaments of the brush filament bundle (5), and the annular area (7) is connected to an external air supply device.

5. The brush seal structure capable of suppressing hysteresis effect based on fluid dynamic pressure effect according to claim 4, characterized in that: The annular area (7) is connected to the external air supply device via an air inlet (8), and the air inlet (8) is evenly arranged along the circumference of the front baffle (3).

6. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: The width and / or depth of the drainage groove (31) gradually decreases from the large end to the small end of the drainage groove (31).

7. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: The depth of the drainage groove (31) is 0.005-0.02 mm.

8. The axially inclined counter-rotating shaft brush seal structure capable of suppressing centrifugal effect according to claim 1, characterized in that: The radial height of the drainage groove (31) is 3 / 5 of the height of the front baffle (3).

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