Grate tooth sealing structure

Abstract

The invention provides a labyrinth sealing structure, and belongs to the technical field of gas turbine and engine sealing, the labyrinth sealing structure specifically comprises a labyrinth disc and a sealing ring, a rotor assembly and the labyrinth disc are coaxial and fixedly connected, a plurality of labyrinth teeth protruding towards a stator assembly are arranged on the peripheral side face of the labyrinth disc, the sealing ring is arranged between any two adjacent labyrinth teeth in a sleeving mode, and the labyrinth teeth are arranged in the labyrinth disc. The sealing ring is of a hollow and internally-closed structure, when the rotating speed of the rotor assembly is smaller than or equal to the first rotating speed, the sealing ring abuts against the labyrinth and the stator assembly, and a gap between the labyrinth and the stator assembly is sealed through the sealing ring; when the rotating speed of the rotor assembly is larger than the first rotating speed, dynamic pressure sealing is formed between the labyrinth and the stator assembly through the pressure difference of the air inlet side and the air outlet side of the labyrinth, the side, facing the stator assembly, of the sealing ring is sunken towards the interior of the sealing ring, and the sealing ring is separated from the stator assembly. According to the treatment scheme, the service life of the labyrinth sealing structure is prolonged.

Description

Technical Field

[0001] This application relates to the fields of gas turbines and engine sealing technologies, and particularly to a labyrinth seal structure. Background Art

[0002] In a conventional labyrinth seal, the main function of the labyrinth seal is to prevent gas or liquid leakage. In the conventional labyrinth seal, the sealing medium is isolated between the contact surfaces of the labyrinth teeth. An elastic O-ring is added between the labyrinth teeth and the stator assembly to provide a sealing effect. However, when the O-ring is used for rotary motion sealing, it is only limited to low-speed rotary sealing devices. When the rotor speed increases, the O-ring is easily worn, resulting in a reduced service life of the seal structure. Summary of the Invention

[0003] In view of this, this application provides a labyrinth seal structure, which solves the problems in the prior art and improves the service life of the labyrinth seal structure.

[0004] A labyrinth seal structure provided by this application adopts the following technical solution:

[0005] A labyrinth seal structure is used for sealing between a stator assembly and a rotor assembly. The stator assembly surrounds the outer periphery of the rotor assembly. The labyrinth seal structure includes a labyrinth disc and a sealing ring. The rotor assembly and the labyrinth disc are coaxial and fixedly connected. A plurality of labyrinth teeth protruding towards the stator assembly are provided on the outer peripheral side surface of the labyrinth disc. The sealing ring is sleeved between any two adjacent labyrinth teeth. The sealing ring is a hollow and internally closed structure. When the rotational speed of the rotor assembly is less than or equal to a first rotational speed, the sealing ring abuts against the labyrinth teeth and the stator assembly, and the gap between the labyrinth teeth and the stator assembly is sealed by the sealing ring. When the rotational speed of the rotor assembly is greater than the first rotational speed, and the side of the sealing ring facing the stator assembly is recessed towards the inside of the sealing ring, the sealing ring is separated from the stator assembly, and the radial pressure difference of the sealing ring forms a hydrodynamic seal between the labyrinth teeth and the stator assembly.

[0006] Optionally, the labyrinth disc is provided with a first labyrinth tooth and a second labyrinth tooth. The distance range between the first labyrinth tooth and the second labyrinth tooth is 5-10 mm, and the sealing ring is pressed against the opposite side walls of the first labyrinth tooth and the second labyrinth tooth.

[0007] Optionally, the sealing ring is an inflated airbag ring, and the airbag ring is made of an elastic material.

[0008] Optionally, the length by which the labyrinth teeth protrude on the labyrinth disc is greater than the radius difference between the inner and outer circles of the airbag ring. When the rotational speed of the rotor assembly is less than or equal to the first rotational speed, there is a gap between the airbag ring and the labyrinth disc. When the rotational speed of the rotor assembly is greater than the first rotational speed, the airbag ring contracts and approaches the labyrinth disc.

[0009] Optionally, the internal pressure of the airbag ring under normal temperature and pressure is 1.3 - 1.5 kPa.

[0010] Optionally, the wall thickness range of the airbag ring is 0.2 - 0.5 mm.

[0011] Optionally, the airbag ring is a toroid.

[0012] In summary, the present application includes the following beneficial technical effects:

[0013] When the compressor starts to rotate or is in a low operating condition, the sealing ring abuts against the inner wall of the labyrinth teeth and the stator assembly. At this time, the gap between the labyrinth teeth and the stator assembly is sealed by the sealing ring. As the rotational speed of the compressor increases and the compressor is in a high operating condition, due to the centrifugal force effect, the gas or liquid between the labyrinth teeth will be pressed against the outer edge of the rotor assembly. The pressure at the outer edge of the labyrinth teeth is greater than the pressure at the root of the labyrinth teeth. The pressure on the side of the sealing ring facing the stator assembly is greater than the pressure on the side of the sealing ring facing away from the stator assembly. The radial pressure difference of the sealing ring in the present application forms a hydrodynamic seal between the labyrinth teeth and the stator assembly. Specifically, the radial pressure difference of the sealing ring causes a negative pressure region to form between the labyrinth teeth and the shaft. When the pressure difference between the outer ring and the inner ring of the sealing ring exceeds the yield strength of the sealing ring material, the sealing ring contracts, and the pressure on the outer ring side of the sealing ring causes the side of the sealing ring facing the stator assembly to sink inward into the sealing ring, and the sealing ring separates from the stator assembly. The high-speed airflow forms an air film between the sealing ring and the stator assembly, and the leakage is suppressed through viscous shear resistance to form a non-contact seal. At this time, the sealing ring and the stator assembly do not contact, reducing the wear of the stator assembly on the sealing ring and improving the service life of the sealing ring. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of the sealing structure under low operating conditions in the embodiment of the present application;

[0016] Figure 2 It is a schematic structural diagram of the sealing structure under high operating conditions in the embodiment of the present application.

[0017] Description of the reference numerals: 1. Stator assembly; 2. Rotor assembly; 3. Labyrinth disc; 4. Labyrinth teeth; 5. Sealing ring. Detailed Embodiments

[0018] The embodiments of the present application will be described in detail below with reference to the drawings.

[0019] The following describes the implementation manners of the present application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope protected by the present application.

[0020] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. Additionally, this device and / or this method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0021] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. The drawings only show the components related to the present application, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in its actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0022] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0023] An embodiment of the present application provides a labyrinth seal structure.

[0024] Such as Figure 1 and Figure 2As shown, a labyrinth seal structure is used for sealing between the stator assembly 1 and the rotor assembly 2 of a gas turbine or a turbine engine. The stator assembly 1 surrounds the outer periphery of the rotor assembly 2. In the embodiments of the present application, the compressor is taken as an example for detailed description. The stator assembly 1 of the compressor is the non-rotating part in the compressor, including a casing and a stator blade assembly; the rotor assembly 2 of the compressor refers to the rotating body supported by bearings, and the rotor assembly 2 is mostly the main rotating component in power machinery and working machinery.

[0025] The labyrinth seal structure includes a labyrinth disc 3 and a sealing ring 5. The rotor assembly 2 and the labyrinth disc 3 are coaxial and fixedly connected. A plurality of labyrinth teeth 4 protruding towards the stator assembly 1 are provided on the outer peripheral side surface of the labyrinth disc 3. Each labyrinth tooth 4 is annular, and a plurality of labyrinth teeth 4 are arranged in sequence along the axial direction of the rotor assembly 2. The sealing ring 5 is sleeved between any two adjacent labyrinth teeth 4, and the sealing ring 5 has a hollow and internally closed structure.

[0026] When the compressor starts to rotate or is in a low operating condition, the rotational speed of the rotor assembly 2 is less than or equal to the first rotational speed. The sealing ring 5 radially expands under the action of its own mechanical pre-tightening force. The sealing ring 5 abuts against the labyrinth teeth 4 and the inner wall of the stator assembly 1. At this time, the sealing ring 5 is in contact with the sealing surface and the sealing ring 5 is compressed to play a sealing role. The gap between the labyrinth teeth 4 and the stator assembly 1 is sealed by the sealing ring 5.

[0027] When the compressor is operating at a high condition with an increasing rotational speed, the rotational speed of the rotor assembly 2 is greater than the first rotational speed. A pressure difference is formed between the labyrinth teeth 4, and the pressure on the exhaust side of the labyrinth teeth 4 is greater than that on the intake side. Moreover, in high-speed rotating components, due to the centrifugal force effect, the gas or liquid between the labyrinth teeth 4 will be pressed towards the outer edge of the rotor assembly 2. The pressure at the outer edge of the labyrinth teeth 4 is greater than that at the root of the labyrinth teeth 4. The pressure on the side of the sealing ring 5 facing the stator assembly 1 is greater than the pressure on the side of the sealing ring 5 facing away from the stator assembly 1. The radial pressure difference of the sealing ring 5 in this application forms a hydrodynamic seal between the labyrinth teeth 4 and the stator assembly 1. Specifically, the radial pressure difference of the sealing ring 5 causes a negative pressure region to be formed between the labyrinth teeth 4 and the shaft. When the pressure difference between the outer and inner rings of the sealing ring 5 exceeds the yield strength of the sealing ring 5 material, the sealing ring 5 shrinks, and the pressure on one side of the outer ring of the sealing ring 5 causes the side of the sealing ring 5 facing the stator assembly 1 to sink inward into the sealing ring 5, and the sealing ring 5 separates from the stator assembly 1. At this time, a high-speed viscous gas film is generated in the controllable gap between the sealing ring 5 and the stator assembly 1, and non-contact sealing is achieved through the hydrodynamic effect. At this time, the sealing ring 5 and the stator assembly 1 do not contact, reducing the wear of the stator assembly 1 on the sealing ring 5 and improving the service life of the sealing ring 5. In one embodiment, the first rotational speed is 12,000 rpm. The labyrinth disc 3 is provided with a first labyrinth tooth and a second labyrinth tooth, and the distance range between the first labyrinth tooth and the second labyrinth tooth is 5 - 10 mm. The sealing ring 5 is pressed against the opposite side walls of the first labyrinth tooth and the second labyrinth tooth. The appropriate thickness design of the sealing ring 5 in the axial direction enables the sealing ring 5 to play a good sealing role under low conditions and has good deformation ability, ensuring the separation state between the sealing ring 5 and the stator assembly 1 under high conditions.

[0028] The sealing ring 5 is an inflated airbag ring. The airbag ring is made of an elastic material and can be made of rubber. Under normal temperature and pressure, the internal pressure of the airbag ring is 1.3 - 1.5 kPa, and the airbag ring is filled with an inert gas such as nitrogen.

[0029] The wall thickness range of the airbag ring is 0.2 - 0.5 mm. The designed thickness of the airbag ring in this application enables the airbag ring to withstand wear under low conditions, and at the same time ensures that the side of the airbag ring facing the stator assembly 1 can stably sink inward under high conditions, separating the airbag ring from the stator assembly 1.

[0030] The airbag ring is a toroid. That is, the cross-section of the airbag ring is circular. The circular design of the airbag ring can provide a stable sealing effect while reducing the contact area between the airbag ring and the stator assembly 1, reducing the wear of the airbag ring under low conditions and improving the service life of the sealing structure.

[0031] The protruding length of the labyrinth teeth 4 on the labyrinth disc 3 is greater than the radius difference between the inner and outer circles of the airbag ring. When the rotational speed of the rotor assembly 2 of the compressor is less than or equal to the first rotational speed, there is a gap between the airbag ring and the labyrinth disc 3; when the rotational speed of the rotor assembly 2 of the compressor is greater than the first rotational speed, the pressure difference between the outer and inner circles of the airbag ring causes the airbag ring to contract and approach the labyrinth disc 3, and the separation state of the airbag ring and the stator assembly 1 improves the service life of the sealing structure.

[0032] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A labyrinth seal structure for sealing between a stator assembly (1) and a rotor assembly (2), wherein the stator assembly (1) surrounds the outer periphery of the rotor assembly (2), and is characterized in that, The labyrinth seal structure includes a labyrinth disc (3) and a sealing ring (5). The rotor assembly (2) and the labyrinth disc (3) are coaxial and fixedly connected. A plurality of labyrinth teeth (4) protruding towards the stator assembly (1) are provided on the outer peripheral side of the labyrinth disc (3). The sealing ring (5) is sleeved between any two adjacent labyrinth teeth (4). The sealing ring (5) has a hollow and internally closed structure. When the rotational speed of the rotor assembly (2) is less than or equal to the first rotational speed, the sealing ring (5) abuts against the labyrinth teeth (4) and the stator assembly (1), and the gap between the labyrinth teeth (4) and the stator assembly (1) is sealed by the sealing ring (5). When the rotational speed of the rotor assembly (2) is greater than the first rotational speed, and the side of the sealing ring (5) facing the stator assembly (1) is recessed towards the inside of the sealing ring (5), the sealing ring (5) is separated from the stator assembly (1), and the radial pressure difference of the sealing ring (5) forms a hydrodynamic seal between the labyrinth teeth (4) and the stator assembly (1).

2. The labyrinth seal structure according to claim 1, wherein The labyrinth disc (3) is provided with a first labyrinth tooth and a second labyrinth tooth, and the distance range between the first labyrinth tooth and the second labyrinth tooth is 5 - 10 mm. The sealing ring (5) is pressed against the opposite side walls of the first labyrinth tooth and the second labyrinth tooth.

3. The labyrinth seal structure according to claim 1, characterized in that The sealing ring (5) is an inflated airbag ring, and the airbag ring is made of an elastic material.

4. The labyrinth seal structure according to claim 3, characterized in that, The length by which the labyrinth teeth (4) protrude on the labyrinth disc (3) is greater than the radius difference between the inner circle and the outer circle of the airbag ring. When the rotational speed of the rotor assembly (2) is less than or equal to the first rotational speed, there is a gap between the airbag ring and the labyrinth disc (3). When the rotational speed of the rotor assembly (2) is greater than the first rotational speed, the airbag ring contracts and approaches the labyrinth disc (3).

5. The labyrinth seal structure according to claim 3, characterized in that, At normal temperature and pressure, the internal pressure of the airbag ring is 1.3 - 1.5 kPa.

6. The labyrinth seal structure according to claim 1, wherein The wall thickness range of the airbag ring is 0.2 - 0.5 mm.

7. The labyrinth seal structure according to claim 1, wherein, The airbag ring is an annular body.

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