Self-lubricating contact composite seal device for high temperature parts of gas turbine engines

Abstract

The present invention discloses a self-lubricating contact composite sealing device for a high-temperature part of a gas turbine engine, which solves the technical problem that the sealing structure of the high-temperature part of a gas turbine engine in the existing aerospace industry has a poor effect. The present invention comprises a sealing inner ring arranged at a high-temperature part of a gas turbine engine, a clamping assembly is arranged on the outer periphery of the sealing inner ring, a fingertip sealing ring and a graphite lubricating part are arranged in the clamping assembly, the inner wall of the fingertip sealing ring is slidably matched with the outer wall of the sealing inner ring, and an elastic support member for pressing the graphite lubricating part toward the outer wall of the sealing inner ring is arranged in the clamping assembly. The present invention not only has a simple structure, low cost and long service life, but also has high sealing effectiveness and high sealing efficiency, and overcomes the major difficulty of self-lubrication of contact seals, and has important application value, especially in the sealing direction of the hot end part of aerospace gas turbine engines.

Description

Technical Field

[0001] The invention belongs to the technical field of contact type composite sealing devices, in particular to a self-lubricating contact type composite sealing device for a high temperature part of a gas turbine engine. Background Art

[0002] Contact seal is an advanced and efficient sealing method in mechanical seal. It has developed rapidly and has been widely used in military industry, mold, hydraulic, textile machinery and other industries. This sealing structure is also commonly used in gas turbine engines in the aerospace field. Contact seal achieves the purpose of sealing through dynamic contact between the sealing ring and the bushing. It has the advantages of reducing the leakage area, good sealing effect, strong applicability to materials and sealing part structures, and better sealing effect than non-contact seal.

[0003] The existing contact seals mainly include expansion ring seals, brush seals, fingertip structure seals, etc. The sealing process is as follows: the expansion ring, brush seal assembly or fingertip seal assembly is fixed or limited on the expansion ring seat or support ring by pressing parts, and the inner wall of the expansion ring, the inner wall of the brush seal assembly and the inner wall of the fingertip seal are in contact with the bushing or shaft to be sealed to form a contact seal. In order to improve the wear resistance of the sealing structure, a wear-resistant coating is applied to the bushing or shaft. The air leakage of the sealing structure depends on the leakage area, the pressure difference at both ends of the leakage and the density of the gas.

[0004] However, when the above-mentioned contact seal structure is working, there is friction between the bushing or shaft and the expansion ring, so it is suitable for environments with low relative linear speed or oil, such as the oil seal of the bearing casing. Therefore, there are many shortcomings in the existing contact seals. First, the structure is complex, the cost is high, and the life is limited in the non-lubricated environment; second, many limiting and clamping parts are required, which is prone to seal failure; third, the manufacturing technology is difficult, and it is restricted by manufacturing technology outside the aerospace system, and the scope of use is small, resulting in low technical maturity; fourth, the working conditions and the structure of the parts used are limited, and the requirements for materials and dimensions vary greatly, and cannot be standardized and serialized. Summary of the invention

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a self-lubricating contact composite sealing device for the high-temperature part of a gas turbine engine, which solves the technical problem of poor sealing effect of the high-temperature part of a gas turbine engine in existing aerospace.

[0006] The technical solution of the present invention is implemented as follows: a self-lubricating contact composite sealing device for a high-temperature part of a gas turbine engine comprises a sealing inner ring arranged at the high-temperature part of the gas turbine engine, and when the high-temperature part of the gas turbine engine rotates or expands, the sealing inner ring moves with it. A pressing assembly is arranged on the outer periphery of the sealing inner ring, and a fingertip sealing ring and a graphite lubricating member are arranged in the pressing assembly, and the inner wall of the fingertip sealing ring and the outer wall of the sealing inner ring are slidably matched to form a contact sealing structure, and an elastic support member for pressing the graphite lubricating member against the outer wall of the sealing inner ring is arranged in the pressing assembly. When the sealing inner ring is installed on the turbine shaft, due to the deformation of the turbine shaft due to heat and recovery due to cooling, the turbine shaft and the sealing inner ring will both produce reciprocating axial deformation, and the sealing inner ring will reciprocate accordingly, that is, the graphite lubricating member will move relative to the outer wall of the sealing inner ring, and under the action of the elastic support member, the graphite lubricating member will produce friction with the outer wall of the sealing inner ring due to the pre-tightening force of the elastic support member, and the graphite lubricating member will fall off graphite powder. Graphite powder is attached to the outer surface of the inner sealing ring. Through the movement or deformation cycle of the inner sealing ring, the graphite powder is transferred to the part where the fingertip sealing ring contacts the inner sealing ring, forming a lubricating layer at this part. The present invention not only effectively solves the self-lubrication problem of brush seals and fingertip seals, but also effectively reduces the leakage area and improves the sealing effect by providing elastic support parts, graphite lubricating parts and fingertip sealing rings. In addition, the sealing contact parts are all elastic structures, which reduces the difficulty of installation; at the same time, the life and reliability of the fingertip seal are improved, and the cost of use is reduced.

[0007] Furthermore, the outer surface of the sealing inner ring is provided with a wear-resistant coating, which further improves the service life.

[0008] Furthermore, the clamping assembly includes a clamping ring surrounding the sealing inner ring, one side of the clamping ring is connected to a sealing outer ring with an L-shaped cross-section, the cross-section of the clamping ring and the sealing outer ring after connection is groove-shaped, and the groove-shaped notch faces the sealing inner ring.

[0009] Furthermore, the fingertip sealing ring and the graphite lubricating part are both arranged in the notch, the inner wall of the fingertip sealing ring extends out of the notch and abuts against the outer wall of the sealing inner ring, and the graphite lubricating part floats with the outer wall of the sealing inner ring under the pressure of the elastic support part.

[0010] Furthermore, two fingertip sealing rings are provided, and the two fingertip sealing rings are arranged at intervals on both sides of the notch, and a fingertip sealing clamping ring and the graphite lubricating part are arranged between the two fingertip sealing rings.

[0011] Furthermore, the elastic support member is arranged between the inner wall of the fingertip sealing compression ring and the outer wall of the graphite lubricating member.

[0012] Furthermore, the graphite lubricating part is annular and is sleeved on the periphery of the sealing inner ring.

[0013] Furthermore, the graphite lubricating part includes several sections of graphite blocks that are interlocked, which not only ensures the reliability of the friction between the graphite lubricating part and the fingertip sealing ring, but also effectively reduces the leakage area and improves the sealing effect. Under the action of the elastic support, the multi-section combined graphite lubricating part automatically sticks to the centripetal part, and the graphite powder falls off by friction. Through the working mode of the sealing inner ring cyclically retracting, the graphite powder is transferred to the fingertip sealing ring, forming a self-lubricating integrated design in the working area of ​​the fingertip sealing ring and the sealing inner ring. It completely realizes the automatic centripetal sticking of the graphite lubricating part, the continuous friction graphite falls off, and the periodic displacement of the sealing inner ring transfers the shed graphite powder to the contact part between the fingertip sealing ring and the sealing inner ring, forming self-lubrication of the part. It has multiple automatic linkage designs, a simple structure, and stable and reliable sealing. The design system is advanced in the field.

[0014] Furthermore, the elastic support member is an elastic ring crimped between the inner wall of the fingertip seal clamping ring and the outer wall of the graphite lubricating member.

[0015] Furthermore, when used in a gas turbine engine with a turbine shaft having an internal air bleed function, an air bleed hole leading to the graphite lubricating part is provided on the side wall of the sealing inner ring, which can form an air seal structure between the graphite lubricating part and the sealing inner ring. This structure is conducive to reducing the leakage area, increasing the friction shedding amount of ultrafine graphite powder, and increasing the transfer amount of graphite powder to the contact position between the fingertip sealing rings at both ends and the sealing inner ring, and can also reduce the interference of the multi-stage graphite lubricating part in a free floating state on the sealing inner ring. When the gas turbine engine is in a stable working state, the sealing system will also form a stable state, which will improve the sealing effect and the life cycle of the entire system.

[0016] The present invention adopts a contact composite seal with a self-lubricating function for the high-temperature parts of aerospace gas turbine engines. There is no need to set up an independent lubrication system. The self-lubricating system has a simple and reliable structure, self-sealing, saves a lot of sealing structures, and effectively avoids seal failure. In addition, the sealing structures are all non-rigid structures, which are convenient for installation during use. The inner ring of the seal can move relatively for a distance, which is more suitable for use in the hot end part, and effectively supports the thermal deformation of the parts at the inner ring installation part. The present invention is not only simple in structure, low in cost, and long in service life, but also has high sealing effectiveness and efficiency, and overcomes the major problem of contact seal self-lubrication. It has important application value in the sealing direction of the hot end part of aerospace gas turbine engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0018] Figure 1 It is a cross-sectional structural schematic diagram of the present invention;

[0019] Figure 2 It is a cross-sectional state diagram of the present invention when the engine is in a cold state;

[0020] Figure 3 It is a cross-sectional state diagram of the present invention when the engine is in a hot state;

[0021] Figure 4 It is a front view of the graphite lubricating part in Example 1;

[0022] Figure 5 It is a front view of the graphite lubricating part in Example 2;

[0023] Figure 6 for Figure 5 Left view of

[0024] Figure 7 is a front view of the elastic support member;

[0025] Figure 8 for Figure 7 Left view of

[0026] In the figure: 1. Sealing inner ring; 2. Wear-resistant coating; 3. Clamping ring; 4. Finger sealing ring; 5. Sealing outer ring; 6. Finger sealing clamping ring; 7. Elastic support; 8. Graphite lubricating part; 9. Air vent. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1, a self-lubricating contact composite sealing device for a high temperature part of a gas turbine engine, such as Figure 1As shown, the sealing inner ring 1 is arranged on the turbine shaft of the gas turbine engine. When the turbine shaft moves, the sealing inner ring 1 will move synchronously with the turbine shaft. Since the turbine shaft is a high-temperature component on the gas turbine engine, the turbine shaft will deform when heated and recover when cooled. The turbine shaft and the sealing inner ring 1 will both undergo reciprocating axial deformation, that is, the sealing inner ring 1 will undergo cyclic expansion and contraction.

[0029] A clamping assembly is provided on the outer periphery of the sealing inner ring 1, and a fingertip sealing ring 4 and an annular graphite lubricating part 8 are provided in the clamping assembly. The inner wall of the fingertip sealing ring 4 slides with the outer wall of the sealing inner ring 1 to form a contact sealing structure, and an elastic supporting part 7 is provided in the clamping assembly to press the graphite lubricating part 8 against the outer wall of the sealing inner ring 1.

[0030] When working, Figure 2 and Figure 3 As shown, due to the deformation of the turbine shaft due to heat and recovery due to cooling, the turbine shaft and the sealing inner ring 1 will produce reciprocating axial deformation, and the sealing inner ring 1 will move back and forth accordingly, that is, the graphite lubricating part 8 will move relative to the outer wall of the sealing inner ring 1, and under the action of the elastic support part 7, the graphite lubricating part 8 will be subjected to the pre-tightening force of the elastic support part 7 and produce friction with the outer wall of the sealing inner ring 1, so the graphite lubricating part 8 will shed graphite powder.

[0031] The graphite powder is attached to the outer surface of the sealing inner ring 1. Through the movement or deformation cycle of the sealing inner ring 1, the graphite powder is transferred to the part where the fingertip sealing ring 4 contacts the sealing inner ring 1, and a lubricating layer is formed at this part. The present invention not only effectively solves the self-lubrication problem of brush seals and fingertip seals, but also effectively reduces the leakage area and improves the sealing effect by providing elastic support parts 7, graphite lubricating parts 8 and fingertip sealing rings 4. In addition, the sealing contact parts are all elastic structures, which reduces the difficulty of installation; at the same time, the life and reliability of the fingertip seal are improved, and the cost of use is reduced.

[0032] Specifically, the clamping assembly includes a clamping ring 3 surrounding the sealing inner ring 1, and a sealing outer ring 5 with an L-shaped cross section is connected to one side of the clamping ring 3. The cross section of the clamping ring 3 and the sealing outer ring 3 after being connected is a groove-shaped, and the groove-shaped notch faces the sealing inner ring 1. The fingertip sealing ring 4 and the graphite lubricating member 8 are both arranged in the notch, and the inner wall of the fingertip sealing ring 4 extends out of the notch and is in contact with the outer wall of the sealing inner ring 1. The graphite lubricating member 8 floats with the outer wall of the sealing inner ring 1 under the top pressure of the elastic support member 7.

[0033] There are two fingertip sealing rings 4, which are arranged at intervals on both sides of the notch, and a fingertip sealing clamping ring 6 and the graphite lubricating member 8 are arranged between the two fingertip sealing rings 4. The elastic supporting member 7 is arranged between the inner wall of the fingertip sealing clamping ring 6 and the outer wall of the graphite lubricating member 8.

[0034] Furthermore, the outer surface of the sealing inner ring 1 is provided with a wear-resistant coating 2 to increase the service life.

[0035] Furthermore, if Figure 4 As shown, the graphite lubricating member 8 is annular and is sleeved on the periphery of the sealing inner ring 1, thereby improving the self-lubricating effect.

[0036] Embodiment 2, a self-lubricating contact composite sealing device for a high temperature part of a gas turbine engine, such as Figure 5 and 6 As shown, the graphite lubricating member 8 includes several sections of graphite blocks that are mutually engaged, which not only ensures the reliability of the friction between the graphite lubricating member 8 and the fingertip sealing ring 4, but also effectively reduces the leakage area and improves the sealing effect. Under the action of the elastic support member 7, the multi-section combined graphite lubricating member 8 automatically adheres to the center, and the graphite powder is shed by friction, and the shed graphite powder is transferred to the fingertip sealing ring 4 through the working mode of the cyclic expansion and contraction of the sealing inner ring 1, forming a self-lubricating integrated design in the working area of ​​the fingertip sealing ring 4 and the sealing inner ring 1.

[0037] The present invention completely realizes that the graphite lubricating part 8 automatically adheres to the centripetal surface, forms a contact expansion ring sealing structure, and the friction graphite falls off. Through the periodic displacement of the sealing inner ring 1, the fallen graphite powder is transferred to the contact part between the fingertip sealing ring 4 and the sealing inner ring 1, and the sealing is achieved while forming continuous self-lubrication of the part. The multi-point automatic linkage design has a simple structure, stable and reliable sealing, and the design system is advanced in the field.

[0038] Furthermore, if Figure 7 and 8 As shown, the elastic support member 7 is an elastic ring crimped between the inner wall of the fingertip seal clamping ring 6 and the outer wall of the graphite lubricating member 8. The elastic ring includes two half rings that are interlocked, which is convenient for installation and disassembly. The amount of graphite powder falling off can be controlled by adjusting the preload force of the elastic ring. The elastic ring makes the multi-section graphite lubricating member 8 automatically close to the center, so that the graphite powder continues to fall off, ensuring that the self-lubricating function does not fail. The structure has high controllability and reliability.

[0039] Between the two fingertip sealing rings 4, the graphite lubricating part 8 is in a free suspension state, and the preload force generated by the elastic support part 7 is attached to the outer wall of the sealing inner ring 1. In the axial direction, the center line of the graphite lubricating part 8 coincides with the center line of the sealing inner ring 1. In the working state of the gas turbine engine, when the sealing inner ring 1 deflects or deforms with the turbine shaft and other parts of the gas turbine engine, the graphite lubricating part 8 with a split multi-segment structure has adaptive ability, and deflects or deforms with the sealing inner ring 1 within the allowable deflection or deformation design value range of the sealing inner ring 1, effectively reducing the leakage area and improving the sealing efficiency.

[0040] The other structures of this embodiment are the same as those of Embodiment 1.

[0041] Embodiment 3, a self-lubricating contact composite seal device for a high temperature part of a gas turbine engine, when used for a gas turbine engine having a turbine shaft with an internal air bleed function, Figure 1 As shown, the side wall of the sealing inner ring 1 is provided with an air inlet 9 leading to the graphite lubricating member 8, which can form an air seal structure between the graphite lubricating member 8 and the sealing inner ring 1. This structure is conducive to reducing the leakage area, increasing the friction shedding amount of ultrafine graphite powder, and increasing the transfer amount of graphite powder to the contact position between the fingertip sealing rings 4 at both ends and the sealing inner ring 1, and can also reduce the interference of the multi-stage combined graphite lubricating member 8 in a free floating state on the sealing inner ring 1. When the gas turbine engine is in a stable working state, the sealing system will also form a stable state, which will improve the sealing effect and the life cycle of the entire system.

[0042] The other structures of this embodiment are the same as those of Embodiment 1 or 2.

[0043] The details not described in detail in the present invention are all conventional technical means known to those skilled in the art.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-lubricating contact composite sealing device for a high temperature part of a gas turbine engine, comprising a sealing inner ring (1) arranged at the high temperature part of the gas turbine engine, characterized in that: The outer periphery of the sealing inner ring (1) is provided with a clamping assembly, a fingertip sealing ring (4) and a graphite lubricating member (8) are provided in the clamping assembly, the inner wall of the fingertip sealing ring (4) is slidably matched with the outer wall of the sealing inner ring (1), and an elastic supporting member (7) is provided in the clamping assembly for pressing the graphite lubricating member (8) toward the outer wall of the sealing inner ring (1); The elastic support member (7) is an elastic ring crimped between the inner wall of the fingertip seal clamping ring (6) and the outer wall of the graphite lubricating member (8); An air inlet hole (9) leading to the graphite lubricating part (8) is provided on the side wall of the sealing inner ring (1).

2. The self-lubricating contact composite sealing device for high temperature parts of a gas turbine engine according to claim 1, characterized in that: The outer surface of the sealing inner ring (1) is provided with a wear-resistant coating (2).

3. The self-lubricating contact composite sealing device for high temperature parts of a gas turbine engine according to claim 1 or 2, characterized in that: The clamping assembly comprises a clamping ring (3) surrounding the sealing inner ring (1), and one side of the clamping ring (3) is connected to a cut-off The sealing outer ring (5) has an L-shaped surface, and the cross section of the clamping ring (3) and the sealing outer ring (3) after being connected is in a groove shape, with the notch of the groove facing the sealing inner ring (1).

4. The self-lubricating contact composite sealing device for high temperature parts of a gas turbine engine according to claim 3, characterized in that: The fingertip sealing ring (4) and the graphite lubricating member (8) are both arranged in the notch, and the inner portion of the fingertip sealing ring (4) The wall extends out of the slot and contacts the outer wall of the sealing inner ring (1); the graphite lubricating member (8) is in floating cooperation with the outer wall of the sealing inner ring (1) under the pressure of the elastic supporting member (7).

5. The self-lubricating contact composite sealing device for high temperature parts of a gas turbine engine according to claim 4, characterized in that: Two fingertip sealing rings (4) are provided, and the two fingertip sealing rings (4) are arranged at intervals on both sides of the notch, and a fingertip sealing clamping ring (6) and the graphite lubricating part (8) are arranged between the two fingertip sealing rings (4).

6. The self-lubricating contact composite sealing device for the high temperature part of the gas turbine engine according to claim 5, characterized in that: The elastic support member (7) is arranged between the inner wall of the fingertip seal clamping ring (6) and the graphite lubricating member (8). Between the outer walls.

7. The self-lubricating contact composite sealing device for high temperature parts of a gas turbine engine according to any one of claims 1-2 and 4-6, characterized in that: The graphite lubricating element (8) is annular and is sleeved on the periphery of the sealing inner ring (1).

8. The self-lubricating contact composite sealing device for the high temperature part of the gas turbine engine according to claim 7, characterized in that: The graphite lubricating element (8) comprises a plurality of graphite blocks which are clamped together.

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