Stepped disc cavity pressure adjusting device and gas turbine engine

Abstract

The invention provides a stepped disc cavity pressure adjusting device and a gas turbine engine, and belongs to the technical field of gas turbine engines, the stepped disc cavity pressure adjusting device comprises a gas compressor shaft, a gas compressor final-stage disc, a bearing seat, a bearing and a gas compressor final-stage stator inner ring, and a gas compressor final-stage disc vent hole is formed in the disc spoke low radius position of the gas compressor final-stage disc; the air compressor final-stage disc, the air compressor final-stage stator inner ring, the bearing seat, the bearing and the air compressor shaft form an air compressor final-stage disc rear cavity, the air sealing ring is arranged in the air compressor final-stage disc rear cavity, a multi-echelon labyrinth structure is arranged on the disc face of the rear side of the air compressor final-stage disc, the air sealing ring is provided with a cantilever structure, and the cantilever structure and labyrinth form a stepped throttling structure. The rear cavity of the last-stage disc of the gas compressor is divided into a plurality of sub-cavities; the air sealing ring is provided with an air sealing ring vent hole, and the bearing seat is provided with a bearing seat upper vent hole and a bearing seat lower vent hole. According to the scheme, the axial force balance of the rotor is achieved by adjusting the pressure of the rear cavity of the last-stage disc of the air compressor in an echelon mode, and the bleed air utilization efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of gas turbine engines, and particularly to a stepped cavity pressure regulating device and a gas turbine engine. Background Art

[0002] As one of the most important components in a gas turbine engine, the life and working reliability of the bearings are crucial for the safe operation of the engine and even the aircraft. Axial force is the key load affecting the bearing life and reliability. Exceeding the maximum axial force limit will lead to a reduction in bearing life or strength failure, while being less than the minimum axial force limit will cause rubbing and impact damage to the ball bearings. The axial force of a gas turbine engine mainly includes the axial force of the mainstream gas flow path and the axial force of the air system cavity gas. For the air system cavity, assuming that the pressure and flow velocity in each chamber are evenly distributed, the axial force of the cavity gas is the product of the cavity pressure and the axial area of the cavity.

[0003] The air system of a gas turbine engine draws air from the intermediate stage or the outlet of the compressor mainstream flow path, passes through the compressor cavity, flows into the turbine cavity, and finally is used to achieve functions such as axial force balance, cooling of hot-end components, sealing of inter-stage gas, and sealing of the bearing cavity with lubricating oil. The air in the cavity behind the last stage disk of the compressor is introduced from the gap between the rotor and the stator blade roots at the outlet of the compressor. After passing through the compressor, this air has a very high pressure. Coupled with the large axial area of the cavity behind the last stage disk of the compressor, the high-pressure air in the cavity behind the last stage disk of the compressor will generate a very large rotor axial force. How to balance this axial force to meet the bearing load requirements is an important part of the air system design.

[0004] Regarding the problem of balancing the rotor axial force in the cavity behind the last stage disk of the compressor, in the air system design, it can be adjusted by designing a relief cavity to exhaust to the bypass duct or the atmosphere. As described in the patent "A Device for Adjusting the Axial Force of the High-Pressure Rotor of a Gas Turbine Engine" (CN 115450711 A), by designing a flow path to discharge the high-pressure air behind the last stage disk of the high-pressure compressor to the atmosphere, and setting perforated covers with different exhaust areas on the combustion chamber inlet fairing in the flow path, the flow area of the air discharged from the relief cavity to the atmosphere is adjusted, so as to achieve the purpose of adjusting the pressure behind the last stage disk of the compressor to balance the axial force. However, this method of balancing the axial force discharges the air after the compressor work to the bypass duct or the atmosphere without participating in combustion, ultimately resulting in waste of turbine work and having a greater impact on the engine performance. Summary of the Invention

[0005] In view of this, an embodiment of the present application provides a stepped disk cavity pressure regulating device and a gas turbine engine. By arranging a stepped throttling structure composed of multi-step labyrinth teeth and a gas sealing ring at the rear side of the last-stage disk of the compressor, the cavity behind the last-stage disk of the compressor is radially divided into chambers with different areas, and the pressures of each chamber are adjusted step by step, achieving the purpose of balancing the axial force of the rotor. At the same time, the waste of turbine work is effectively reduced, and the utilization efficiency of the bleed air is improved.

[0006] In a first aspect, an embodiment of the present application provides a stepped disk cavity pressure regulating device. The device includes a compressor shaft, a last-stage disk of the compressor, a bearing housing, a bearing, and an inner ring of the last-stage stator of the compressor. The last-stage disk of the compressor and the bearing are sleeved on the compressor shaft, and the last-stage disk of the compressor is in interference fit with the compressor shaft. An air vent hole of the last-stage disk of the compressor is provided at the low radius of the disk web of the last-stage disk of the compressor. The bearing housing is sleeved on the bearing, and the inner ring of the last-stage stator of the compressor is located at the high radius of the bearing housing. The last-stage disk of the compressor, the inner ring of the last-stage stator of the compressor, the bearing housing, the bearing, and the compressor shaft form a cavity behind the last-stage disk of the compressor. A gas sealing ring is provided at the radial middle position of the cavity behind the last-stage disk of the compressor, and the gas sealing ring is fixedly connected to the bearing housing. A multi-step labyrinth tooth structure formed by a plurality of labyrinth teeth is provided on the rear side disk surface of the last-stage disk of the compressor. A plurality of cantilever structures are arranged along the axial direction of the gas sealing ring, and the cantilever structures are arranged in one-to-one correspondence with the labyrinth teeth to form a stepped throttling structure. The cavity behind the last-stage disk of the compressor is divided into a plurality of sub-chambers through the stepped throttling structure. A plurality of gas sealing ring air vent holes are provided on the connection surface between the gas sealing ring and the bearing housing. An upper air vent hole of the bearing housing and a lower air vent hole of the bearing housing are provided on the bearing housing. The upper air vent hole of the bearing housing corresponds to the gas sealing ring air vent hole one by one, and the lower air vent hole of the bearing housing is located at the low radius of the bearing housing.

[0007] According to a specific implementation manner of an embodiment of the present application, a first labyrinth tooth is provided at the high radius of the last-stage disk of the compressor, and a first coating is provided on the near-axis side of the inner ring of the last-stage stator of the compressor. The first labyrinth tooth and the first coating form a first throttling structure.

[0008] According to a specific implementation manner of an embodiment of the present application, the sub-chambers formed by the cantilever structure on the side of the gas sealing ring close to the compressor shaft, the last-stage disk of the compressor, the compressor shaft, the bearing, and the bearing housing are respectively communicated with the air vent hole of the last-stage disk of the compressor and the lower air vent hole of the bearing housing.

[0009] According to a specific implementation manner of an embodiment of the present application, the gas sealing ring is provided with 3 cantilever structures, and the cavity behind the last-stage disk of the compressor is divided into 4 sub-chambers through the 3 cantilever structures.

[0010] According to a specific implementation manner of an embodiment of the present application, a groove or a step is provided on the inner surface and / or the outer surface of the cantilever structure at the high radius of the gas sealing ring.

[0011] According to a specific implementation manner of an embodiment of the present application, a wear-resistant structure is provided at a position corresponding to each cantilever structure of the air sealing ring and the labyrinth teeth.

[0012] According to a specific implementation manner of an embodiment of the present application, the inner ring of the last-stage stator of the compressor is integrally provided with the bearing housing.

[0013] According to a specific implementation manner of an embodiment of the present application, the radial clearance at the tip of the labyrinth teeth is set to 0.1 - 0.5 mm, the tooth width is set to 0.2 - 0.3 mm, the tooth height is set to 0.5 - 3 mm, the ratio of the tooth pitch to the tooth height is set to 2 - 4, and the fillet radius at the tooth root is set to 0.05 - 0.2 mm.

[0014] According to a specific implementation manner of an embodiment of the present application, the vent holes of the air sealing ring are located on the same circumference with equal radius from the compressor shaft and are evenly arranged circumferentially.

[0015] In a second aspect, an embodiment of the present application further provides a gas turbine engine, and the gas turbine engine includes the stepped disk cavity pressure regulating device as described in any one of the above first aspects.

[0016] Beneficial effects:

[0017] In the stepped disk cavity pressure regulating device and the gas turbine engine in the embodiments of the present application, by arranging a multi-stage labyrinth tooth structure at different radial positions on the rear side of the last-stage disk of the compressor, and arranging an inverted trapezoidal air sealing ring on the bearing housing, the multi-stage throttling structure formed by the labyrinth teeth and the air sealing ring divides the cavity behind the last-stage disk of the compressor into multiple sub-chambers with different axial areas and different cavity pressures along the radial direction. Without exhausting to the atmosphere or the outer annulus and avoiding waste of turbine work, the utilization efficiency of the bleed air is improved, the pressure in the cavity behind the last-stage disk of the compressor is regulated, and finally the axial force balance of the rotor is achieved. The method of the present application solves the technical problem of the axial force balance of the rotor in the rotating disk cavity behind the last-stage disk of the gas turbine engine compressor, and the proposed disk cavity pressure regulating device can improve the utilization efficiency of the bleed air. Description of the drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description 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.

[0019] Figure 1 It is a structural diagram of a stepped disk cavity pressure regulating device according to an embodiment of the present invention;

[0020] Figure 2 It is a structural diagram of an air sealing ring according to an embodiment of the present invention;

[0021] Figure 3 Structural diagram of the last stage disk of a compressor with multi-stage labyrinth teeth according to an embodiment of the present invention.

[0022] In the figure: 1. Compressor shaft; 2. Last stage disk of the compressor; 21. Vent hole of the last stage disk of the compressor; 22. First labyrinth tooth; 23. Second labyrinth tooth; 24. Third labyrinth tooth; 25. Fourth labyrinth tooth; 3. Gas sealing ring; 31. Vent hole of the gas sealing ring; 32. Second coating; 33. Third coating; 34. Fourth coating; 4. Bearing housing; 41. Vent hole on the bearing housing; 42. Vent hole under the bearing housing; 5. Bearing; 6. First sub-chamber; 7. Second sub-chamber; 8. Third sub-chamber; 9. Fourth sub-chamber; 10. Inner ring of the last stage stator of the compressor; 101. First coating; A. Bleed air from the intermediate stage of the compressor; B. Bleed air behind the last stage disk of the compressor; C. Air after mixing the bleed air from the intermediate stage of the compressor and the bleed air from the last stage of the compressor. Detailed implementation manners

[0023] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0024] The following uses specific specific examples to illustrate the implementation manners of the present application. 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 of protection of the present application.

[0025] 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. In addition, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0026] It should also be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. The components shown in the diagrams are only those 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 proportion of each component in actual implementation can be arbitrarily changed, and the layout type of its components may also be more complex.

[0027] 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.

[0028] In a first aspect, an embodiment of the present application provides a stepped disk cavity pressure regulating device, which will be described in detail below with reference to Figures 1 to 3 for detailed description.

[0029] In one embodiment, the stepped disk cavity pressure regulating device includes a compressor shaft 1, a compressor last-stage disk 2, a bearing housing 4, a bearing 5, and a compressor last-stage stator inner ring 10. The compressor last-stage disk 2 and the bearing 5 are sleeved on the compressor shaft 1. The compressor last-stage disk 2 is in interference fit with the compressor shaft 1. A compressor last-stage disk vent hole 21 is provided at the low radius of the disk web of the compressor last-stage disk 2. The bearing housing 4 is sleeved on the bearing 5. The compressor last-stage stator inner ring 10 is located at the high radius of the bearing housing 4. The compressor last-stage disk 2, the compressor last-stage stator inner ring 10, the bearing housing 4, the bearing 5, and the compressor shaft 1 form a compressor last-stage disk rear cavity. A sealing ring 3 is provided at the radial middle position of the compressor last-stage disk rear cavity. The sealing ring 3 is fixedly connected to the bearing housing 4. The rear disk surface of the compressor last-stage disk 2 is provided with a multi-step labyrinth structure formed by a plurality of labyrinth teeth. The sealing ring 3 is provided with a plurality of cantilever structures in the axial direction. The cantilever structures are arranged in one-to-one correspondence with the labyrinth teeth to form a stepped throttling structure. The compressor last-stage disk rear cavity is divided into a plurality of sub-chambers through the stepped throttling structure. A plurality of sealing ring vent holes 31 are provided on the connection surface between the sealing ring 3 and the bearing housing 4. The bearing housing 4 is provided with a bearing housing upper vent hole 41 and a bearing housing lower vent hole 42. The bearing housing upper vent hole 41 corresponds to the sealing ring vent hole 31 one by one. The bearing housing lower vent hole 42 is located at the low radius of the bearing housing 4. The bearing housing upper vent hole 41 is used for the flow of compressor outlet bleed air. The bearing housing lower vent hole 42 is used for the flow of air C after mixing the compressor intermediate stage bleed air and the compressor last-stage bleed air.

[0030] In specific implementation, the rear cavity of the last-stage compressor disk is a rotating and stationary system cavity jointly formed by the last-stage compressor disk 2, the inner ring 10 of the last-stage compressor stator, the bearing housing 4, the bearing 5, the compressor shaft 1, and the air seal ring 3. The multi-stage labyrinth structure is composed of labyrinths arranged at different radial positions on the rear disk surface of the last-stage compressor disk 2. The air seal ring 3 is provided with a plurality of cantilever structures with different lengths and different radial heights, forming an inverted trapezoidal air seal ring 3. The cantilever structures of the inverted trapezoidal air seal ring 3 are arranged in one-to-one correspondence with the labyrinths of the multi-stage labyrinth structure, forming a stepped throttling structure. Since the cantilever structures are arranged in one-to-one correspondence with the labyrinths, the rear cavity of the last-stage compressor disk is divided into sub-cavities with different areas in the radial direction. The pressures of each sub-cavity can be adjusted in stages through the stepped throttling structure, achieving the purpose of balancing the axial force of the rotor. At the same time, the waste of turbine work can be effectively reduced, and the utilization efficiency of the bleed air can be improved.

[0031] In specific implementation, the labyrinth tooth profile can be straight teeth, helical teeth, stepped teeth, or special-shaped teeth.

[0032] In specific implementation, the material of the air seal ring 3 is similar to or the same as that of the compressor disk, blades, drum, etc. The material has excellent thermal strength performance and hot working processability, can be welded and machined, and has a positive effect on the weight reduction requirement of the engine.

[0033] In specific implementation, the last-stage compressor disk 2 is directly connected to the compressor shaft 1 by interference fit, simplifying other connection structures such as journal and labyrinth disk. During assembly, the assembly is completed by heating the disk and cooling the shaft. It has a positive effect on reducing the weight of the engine and improving the assembly performance.

[0034] In specific implementation, a certain number of ventilation holes 21 of the last-stage compressor disk are circumferentially opened at the low radius of the disk web of the last-stage compressor disk 2 for the flow of bleed air A from the intermediate stage of the compressor. The bleed air A from the intermediate stage of the compressor flows through the ventilation holes 21 of the disk web, which can avoid the temperature rise caused by wind resistance when flowing through the channel between the disk center of the last-stage compressor disk 2 and the compressor shaft 1, so that the bleed air A from the intermediate stage of the compressor meets the temperature requirement when flowing to the periphery of the bearing 5 to seal the lubricating oil.

[0035] In one embodiment, a first labyrinth 22 is provided at the high radius of the last-stage compressor disk 2, and a first coating 101 is provided on the near-axis side of the inner ring 10 of the last-stage compressor stator. The first labyrinth 22 and the first coating 101 form a first throttling structure.

[0036] In one embodiment, the sub-cavities formed by the cantilever structure on the side of the air seal ring 3 close to the compressor shaft 1, the last-stage compressor disk 2, the compressor shaft 1, the bearing 5, and the bearing housing 4 are respectively communicated with the ventilation holes 21 of the last-stage compressor disk and the ventilation holes 42 under the bearing housing.

[0037] Specifically, the fourth sub-chamber 9 communicates with the last-stage compressor disk ventilation hole 21 and the bearing housing lower ventilation hole 42 respectively.

[0038] In one embodiment, the air seal ring 3 is provided with 3 cantilever structures, and the overall shape is a multi-layer inverted trapezoid. The last-stage compressor disk rear chamber is divided into 4 sub-chambers by the 3 cantilever structures.

[0039] Specifically, referring to Figure 2 and Figure 3 , multi-level labyrinth structures are arranged on the rear disk surface of the last-stage compressor disk 2 at different radial positions, including the first labyrinth 22, the second labyrinth 23, the third labyrinth 24, and the fourth labyrinth 25. The second labyrinth 23, the third labyrinth 24, and the fourth labyrinth 25 respectively correspond to the 3 cantilever structures, and sequentially form the second throttling structure, the third throttling structure, and the fourth throttling structure, thus forming a stepped throttling structure. The last-stage compressor disk rear chamber is separated by the air seal ring 3 into the first sub-chamber 6, the second sub-chamber 7, the third sub-chamber 8, and the fourth sub-chamber 9 with different axial areas and chamber pressures. The second sub-chamber 7 communicates with the air seal ring ventilation hole 31 and the bearing housing upper ventilation hole 41, and the fourth sub-chamber 9 communicates with the last-stage compressor disk ventilation hole 21 and the bearing housing lower ventilation hole 42. The rear-stage compressor bleed air B passes through the first throttling structure, the second throttling structure, the third throttling structure, and the fourth throttling structure in sequence. At the same time, a part of the bleed air entering the second chamber 7 through the second throttling structure flows out after passing through the air seal ring ventilation hole 31 and the bearing housing upper ventilation hole 41, and another part passes through the third throttling structure and enters the third sub-chamber 8, and then flows to the fourth sub-chamber 9 through the fourth throttling structure; the bleed air passing through the fourth throttling structure is mixed with the compressor intermediate-stage bleed air A flowing in through the last-stage compressor disk ventilation hole 21 in the fourth sub-chamber 9 (the air C after mixing the compressor intermediate-stage bleed air and the last-stage compressor bleed air) and then flows out through the bearing housing lower ventilation hole 42. Therefore, by regulating the pressures of the respective sub-chambers in the last-stage compressor disk rear chamber in a stepped manner through the throttling structures at different radial positions, the axial force balance of the rotor can be finally achieved.

[0040] Specifically, the bearing housing upper ventilation hole 41 is used to regulate the pressure of the second sub-chamber 7, and the bearing housing lower ventilation hole 42 is used to regulate the pressure of the fourth sub-chamber 9 to achieve the regulation of the pressures of different chambers. At the same time, two independent flow paths can be formed. The flow path through the bearing housing upper ventilation hole 41 realizes the gas sealing in front of the turbine disk and the cooling of the turbine disk, and the flow path through the bearing housing lower ventilation hole 42 realizes the gas sealing behind the turbine disk and the purge cooling of the turbine disk cavity.

[0041] In one embodiment, grooves or steps are provided on the inner surface and / or the outer surface of the cantilever structure at the high radius of the air seal ring 3. By setting the structure of the grooves or steps, the strength problem caused by the resonance of the cantilever structure due to the gas flow excitation force and the like can be avoided.

[0042] In one embodiment, wear-resistant structures are provided at positions corresponding to the labyrinth teeth on each cantilever structure of the air sealing ring 3. For example, coatings, honeycomb structures, metal composite felts, etc.

[0043] During specific implementation, the second coating 32 is sprayed at the position corresponding to the second labyrinth tooth 23 on the cantilever structure of the air sealing ring 3, the third coating 33 is sprayed at the position corresponding to the third labyrinth tooth 24, and the fourth coating 34 is sprayed at the position corresponding to the fourth labyrinth tooth 25. The above coatings can absorb energy when the tips of the labyrinth teeth collide and rub against the air sealing ring 3, so as to protect the air sealing ring 3 from structural damage during hard collision with the labyrinth teeth; during the engine development stage, the radial clearance of the labyrinth seal structure can be controlled by the spraying thicknesses of the second coating 32, the third coating 33, and the fourth coating 34, so as to achieve the purpose of changing the throttling area and regulating the chamber pressure.

[0044] In one embodiment, the inner ring 10 of the last-stage stator of the compressor is integrally provided with the bearing housing 4. This is of positive significance for reducing the weight and cost of the engine.

[0045] In one embodiment, the tip radial clearance of the labyrinth teeth is set to 0.1 - 0.5 mm, the tooth width is set to 0.2 - 0.3 mm, the tooth height is set to 0.5 - 3 mm, the ratio of the tooth pitch to the tooth height is set to 2 - 4, and the root fillet radius of the tooth is set to 0.05 - 0.2 mm.

[0046] According to a specific implementation manner of the embodiment of the present application, the air vent holes 31 of the air sealing ring are located on the same circumference with equal radius from the compressor shaft 1 and are evenly arranged in the circumferential direction.

[0047] Specifically, the bleed air B at the rear of the last-stage disc of the compressor is led out from the gap between the roots of the last-stage rotor and stator of the compressor, and after passing through the first throttling structure composed of the first labyrinth tooth 22 and the first coating 101 for expansion acceleration and dissipation, the air pressure is reduced for the first time and then enters the first sub-chamber 6; similarly, the air flow in the first sub-chamber 6 passes through the second throttling structure composed of the second labyrinth tooth 23 and the second coating 32, and after the air pressure is reduced for the second time, it enters the second sub-chamber 7; a part of the air flow in the second sub-chamber 7 is used for turbine cooling and rim sealing after passing through the air vent holes 31 of the air sealing ring and the air vent holes 41 on the bearing housing, and another part of the air flow passes through the third throttling structure composed of the third labyrinth tooth 24 and the third coating 33, and after the air pressure is reduced for the third time, it enters the third sub-chamber 8; the air flow in the third sub-chamber 8 passes through the fourth throttling structure composed of the fourth labyrinth tooth 25 and the fourth coating 34, and after the air pressure is reduced for the fourth time, it enters the fourth sub-chamber 9 and is mixed with the bleed air A from the intermediate stage of the compressor. The air flow in this chamber creates a sealing environment with appropriate pressure and temperature on the front end face of the bearing 5 to seal the lubricating oil. Finally, the air flow in the fourth sub-chamber 9 is used for turbine cooling, rim sealing, and fulcrum sealing after passing through the air vent holes 42 under the bearing housing.

[0048] When the air flow passes through the gap between the tip of the labyrinth throttle structure and the coating, it expands and accelerates, and part of the pressure energy is converted into kinetic energy. Then, after the air flow accelerates and flows into the tooth cavity, its kinetic energy is dissipated into heat energy due to vortex and wall friction resistance. The high-pressure air of the bleed air B behind the last stage disc of the compressor passes through the throttling effect of four throttle structures, and the pressure drops step by step. That is, the stepped disc cavity pressure regulating device divides the cavity behind the last stage disc of the compressor into the first sub-chamber 6, the second sub-chamber 7, the third sub-chamber 8, and the fourth sub-chamber 9 with different axial areas. At the same time, the air pressure in each chamber is gradually regulated under the action of the throttle structure along the flow direction. And the axial force of the disc cavity gas is the product of the cavity pressure and the axial area of the disc cavity. Therefore, the total axial force generated by the air in the cavity behind the last stage disc of the compressor on the last stage disc 2 of the compressor is regulated.

[0049] In specific implementation, to meet the axial force requirement of the high-pressure rotor, a pressure regulating device needs to be set in the cavity behind the last stage disc of the compressor. The specific design process includes the following steps:

[0050] 1) First, according to the engine aerodynamic and structural scheme, under the condition that there is no pressure regulating device in the cavity behind the last stage disc of the compressor, calculate the axial force of the high-pressure rotor in the full state of the engine (the sum of the axial force of the main flow path and the axial force of the air system disc cavity). Usually, the axial force of the high-pressure rotor at this time does not meet the requirements. Since the axial force of the main flow path has been completed in the engine main flow path design and the adjustment means are limited, it is necessary to carry out the pressure regulation of the air system disc cavity to meet the axial force requirement. In the air system disc cavity of the engine, the area of the cavity behind the compressor disc is large and the pressure is high, which contributes greatly to the axial force regulation. Therefore, the cavity behind the compressor disc is generally selected to carry out the pressure regulation design.

[0051] 2) Second, according to the spatial dimensions of the cavity behind the last stage disc of the compressor, such as the axial distance, the radial distance, etc., design the labyrinth structure and the corresponding air sealing ring 3 structure at different radial positions on the rear side of the compressor disc. Generally, the initial labyrinth structure tooth profile is a simple straight tooth; generally, the initial air sealing ring 3 structure is a simple cantilever structure, and the part corresponding to the labyrinth to form a seal is a coating, and the coating thickness can be adjusted according to the labyrinth gap requirement in the later stage.

[0052] 3) Third, under the condition that there is a pressure regulating device in the cavity behind the last stage disc of the compressor, calculate the axial force of the high-pressure rotor in the full state of the engine. Usually, the axial force meets the requirements in most engine states at this time. For a few engine states, it is necessary to carry out the structural optimization of the pressure regulating device.

[0053] 4) Next, based on the axial force calculation results in step 3), carry out the structural optimization of the pressure regulating device. For the labyrinth seal structure, the general parameters of different tooth profiles usually have about 2 - 5 teeth, the radial clearance at the tooth tip is generally about 0.1 - 0.5 mm, the tooth width is generally about 0.2 - 0.3 mm, the tooth height is generally about 0.5 - 3 mm, the ratio of the tooth pitch to the tooth height is generally 2 - 4, and the fillet radius at the tooth root is generally about 0.05 - 0.2 mm. The tooth profile of the labyrinth seal structure can be optimized into helical teeth, stepped teeth, and special-shaped teeth. Among them, the inclination angle of the helical teeth can be selected around 50° - 70°; the stepped teeth and special-shaped teeth are generally combined structures of simple tooth profiles such as straight teeth and helical teeth, which are greatly restricted by space, and the parameter design can refer to the general parameters of the labyrinth seal structure. For the air sealing ring 3 structure, the coating thickness is optimized according to the requirements of the labyrinth seal clearance. If particularly high sealing effect is required, the honeycomb structure can be considered; the air sealing ring 3 structure is generally installed with the stator bearing housing 4 through bolts. To meet the functional requirements of the air system flow path, corresponding ventilation holes can be designed on the installation surface between the air sealing ring 3 structure and the bearing housing 4.

[0054] Finally, based on the structural optimization results of the pressure regulating device in step 4), carry out the axial force calculation of the high-pressure rotor under all engine operating conditions to obtain the final design results that meet the axial force requirements.

[0055] In a second aspect, the embodiments of the present application further provide a gas turbine engine, which includes the stepped disk cavity pressure regulating device as described in any one of the embodiments of the first aspect above.

[0056] In the embodiments provided by the present invention, by arranging multi-stage labyrinth seal structures at different radial positions on the rear side of the last-stage compressor disk 2, and arranging an inverted trapezoidal air sealing ring 3 on the bearing housing 4, the multi-stage throttling structure composed of the labyrinth seal and the air sealing ring 3 divides the rear cavity of the last-stage compressor disk into multiple sub-chambers with different axial areas and different chamber pressures along the radial direction. Without exhausting to the atmosphere or the outer annulus and avoiding waste of turbine work, the utilization efficiency of the bleed air is improved, the pressure in the rear cavity of the last-stage compressor disk is regulated, and finally the axial force balance of the rotor is achieved. The method of the present application solves the technical problem of the axial force balance of the rotating disk cavity rotor behind the last-stage compressor disk of the gas turbine engine, and the proposed disk cavity pressure regulating device can improve the utilization efficiency of the bleed air.

[0057] The above are only the specific embodiments 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 by 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 stepped cavity pressure regulating device, characterized in that The device includes a compressor shaft (1), a last-stage compressor disk (2), a bearing housing (4), a bearing (5), and an inner ring of the last-stage compressor stator (10). The last-stage compressor disk (2) and the bearing (5) are sleeved on the compressor shaft (1). The last-stage compressor disk (2) is in interference fit with the compressor shaft (1). An air vent hole (21) of the last-stage compressor disk is provided at a low radius of the disk web of the last-stage compressor disk (2). The bearing housing (4) is sleeved on the bearing (5). The inner ring of the last-stage compressor stator (10) is located at a high radius of the bearing housing (4). The last-stage compressor disk (2), the inner ring of the last-stage compressor stator (10), the bearing housing (4), the bearing (5), and the compressor shaft (1) form a rear cavity of the last-stage compressor disk. An air sealing ring (3) is provided at a radial middle position of the rear cavity of the last-stage compressor disk. The air sealing ring (3) is fixedly connected to the bearing housing (4). A multi-step labyrinth structure formed by multiple labyrinth teeth is provided on the rear disk surface of the last-stage compressor disk (2). The air sealing ring (3) is provided with multiple cantilever structures in the axial direction. The cantilever structures are arranged in one-to-one correspondence with the labyrinth teeth to form a stepped throttling structure. The rear cavity of the last-stage compressor disk is divided into multiple sub-chambers through the stepped throttling structure. Multiple air vent holes (31) of the air sealing ring are provided on the connection surface between the air sealing ring (3) and the bearing housing (4). The bearing housing (4) is provided with an upper air vent hole (41) and a lower air vent hole (42) of the bearing housing. The upper air vent hole (41) of the bearing housing corresponds to the air vent hole (31) of the air sealing ring one by one. The lower air vent hole (42) of the bearing housing is located at a low radius of the bearing housing (4).

2. The stepped cavity pressure regulating device according to claim 1, wherein A first labyrinth tooth (22) is provided at a high radius of the last-stage compressor disk (2). A first coating (101) is provided on the near-axis side of the inner ring of the last-stage compressor stator (10). The first labyrinth tooth (22) and the first coating (101) form a first throttling structure.

3. The stepped disk cavity pressure regulating device according to claim 1, characterized in that, The sub-chambers formed by the cantilever structure on the side of the air sealing ring (3) close to the compressor shaft (1), the last-stage compressor disk (2), the compressor shaft (1), the bearing (5), and the bearing housing (4) communicate with the air vent hole (21) of the last-stage compressor disk and the lower air vent hole (42) of the bearing housing respectively.

4. The stepped disk cavity pressure regulating device according to claim 1, wherein, The air sealing ring (3) is provided with 3 cantilever structures. The rear cavity of the last-stage compressor disk is divided into 4 sub-chambers through the 3 cantilever structures.

5. The stepped cavity pressure regulating device according to claim 1, characterized in that, Grooves or steps are provided on the inner surface and / or outer surface of the cantilever structure at the high radius of the air sealing ring (3).

6. The stepped disk cavity pressure regulating device according to claim 1, wherein A wearable structure is provided at the position of each cantilever structure of the air sealing ring (3) corresponding to the labyrinth tooth.

7. The stepped disk cavity pressure regulating device according to claim 1, characterized in that, The inner ring of the last-stage compressor stator (10) and the bearing housing (4) are integrally provided.

8. The stepped disk cavity pressure regulating device according to claim 1, characterized in that, The radial tip clearance of the labyrinth tooth is set to 0.1 - 0.5 mm, the tooth width is set to 0.2 - 0.3 mm, the tooth height is set to 0.5 - 3 mm, the ratio of the tooth pitch to the tooth height is set to 2 - 4, and the fillet radius of the tooth root is set to 0.05 - 0.2 mm.

9. The stepped disk cavity pressure regulating device according to any one of claims 1-8, characterized in that, The air vent holes (31) of the air sealing ring are located on the same circumference with the same radius from the compressor shaft (1) and are evenly arranged in the circumferential direction.

10. A gas turbine engine, characterized in that, The gas turbine engine includes a stepped disk cavity pressure regulating device as described in any one of claims 1 - 9.

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