Bearing cavity dynamic sealing device and aero-engine

Abstract

The invention discloses a bearing cavity dynamic sealing device and an aero-engine, and belongs to the technical field of aero-engine bearing cavity sealing. The rotor assembly comprises a rotor and a sealing runway, and a labyrinth structure is arranged on the sealing runway; the stator assembly comprises a floating ring sealing stator part and a sealing mounting seat matched with the floating ring sealing stator part, the floating ring sealing stator part comprises a sealing shell, a baffle ring, a graphite ring assembly and an elastic element used for applying elastic force to the graphite ring assembly, and a floating ring sealing structure is formed between the graphite ring assembly and the sealing runway; and the sealing shell and / or the sealing runway are / is provided with a cooling channel for introducing gas. The influence of the thermal expansion coefficient of the graphite ring can be reduced, overheating expansion damage is avoided, meanwhile, extra thermal friction impact caused by eccentricity or vibration is reduced, the service life of the graphite ring in a high-temperature scene is guaranteed, and good sealing performance is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine bearing cavity sealing, in particular to a bearing cavity dynamic sealing device and an aero-engine. Background Art

[0002] The bearing cavities of high-speed rotating machinery, such as aircraft engines, are often adjacent to high-temperature, high-pressure airflow channels. To ensure the proper functioning of the bearings and lubrication systems in these high-temperature, high-speed environments, effective sealing of the bearing cavities is essential. In recent years, with the increasing demand for high thrust-to-weight ratios and high performance, engine operating temperatures have risen significantly. Traditional mechanical contact seals are susceptible to severe wear, thermal deformation, and shortened life in these high-temperature, high-speed environments. Consequently, they are being replaced by non-contact floating ring seals, which offer low wear and long life.

[0003] In a non-contact floating ring seal, a certain sealing gap is left between the graphite ring (stator) and the sealing raceway (rotating element). Sealing is achieved by forming an air film within the sealing gap. Graphite material has good self-lubricating properties and high-temperature stability, which can meet the sealing requirements under high-temperature and high-speed operating conditions within a certain range. However, when the rotor temperature increases further or the operating environment temperature reaches extremes, the graphite ring is prone to thermal expansion damage and oxidation weight loss in high-temperature environments: Conventional countermeasures to the above problems usually include: material improvement, using graphite or synthetic materials with higher temperature resistance and high oxidation resistance. However, such high-end materials are expensive and the manufacturing and processing processes are complex, resulting in high costs; elastic support optimization, setting elastic parts (such as wave springs) between the graphite ring and the sealing shell to buffer the local stress caused by the thermal expansion of the graphite ring. However, if the cooling and elastic force distribution are insufficient, it is still difficult to effectively suppress high-temperature expansion and oxidation reactions.

[0004] Therefore, how to avoid expansion and oxidation weight loss of graphite rings by rationally designing their cooling and support structures in harsh environments of high temperature and high speed, and maintain long-life and high-performance bearing cavity sealing effects, has become a key technical issue that needs to be urgently solved in the industry. Summary of the Invention

[0005] The present invention provides a bearing cavity dynamic sealing device and an aero-engine, so as to solve the technical problem that the existing graphite rings used for bearing cavity sealing are prone to thermal expansion damage in a high temperature environment, resulting in insufficient service life.

[0006] According to one aspect of the present invention, a bearing cavity dynamic sealing device and an aircraft engine are provided, comprising a rotor assembly and a stator assembly; the rotor assembly comprising a rotor and a sealing runway, the sealing runway being provided with a grate structure; the stator assembly comprising a floating ring seal stator component and a sealing mounting seat cooperating with the floating ring seal stator component, the floating ring seal stator component comprising a sealing housing, a retaining ring, a graphite ring assembly, and an elastic element for applying elastic force to the graphite ring assembly, a floating ring seal structure being formed between the graphite ring assembly and the sealing runway, the retaining ring being provided with a grate mating surface for cooperating with the grate structure to form a grate seal; a cooling channel for introducing gas is provided on the sealing housing and / or the sealing runway, so that the gas introduced from the cooling channel is mixed with the gas leaked from the grate seal to form a working environment for the floating ring seal structure.

[0007] Optionally, the elastic element is a wave spring.

[0008] Optionally, the retaining ring is provided with an axial end face, the axial end face and the end face of the sealing housing are fitted together to achieve axial limitation, and the axial end face and the end face of the wave spring are fitted together to evenly distribute the elastic force of the wave spring.

[0009] Optionally, the graphite ring assembly includes a graphite ring outer ring and a graphite ring, and the wave spring is used to support the graphite ring so that the graphite ring fits the sealing shell.

[0010] Optionally, a gasket is provided between the wave spring and the graphite ring.

[0011] Optionally, it further includes a bearing sleeve arranged on the rotor, wherein the bearing sleeve is provided with an oil guide groove on the inner side of the rotor, and an oil guide hole connecting the oil guide groove and the sealing runway is opened radially.

[0012] Optionally, a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly are formed on the sealing mounting seat, and a threaded retaining ring is threadedly connected to one end of the sealing mounting seat away from the axial support surface, and the threaded retaining ring cooperates with the axial support surface to clamp the stator assembly.

[0013] Optionally, the rotor is provided with a first oil channel for supplying oil to the bearing and a second oil channel for supplying oil to the sealing runway through the oil guide groove.

[0014] Optionally, a shaft shoulder is provided on the rotor, and a rotor locking structure is provided at one end of the rotor away from the shaft shoulder. The sealing runway, bearing sleeve and bearing are sequentially arranged between the shaft shoulder and the rotor locking structure to perform axial limitation through the rotor locking structure.

[0015] According to another aspect of the present invention, an aircraft engine is provided, which includes the above-mentioned bearing cavity dynamic sealing device.

[0016] In summary, this application includes at least one of the following beneficial technical effects: This solution incorporates cooling channels within the seal housing and / or seal runway. The gas introduced through these channels mixes with gas leaking from the grate seals, creating a cooler, more uniform pressure floating ring seal operating environment. This effectively reduces the thermal load on the graphite rings. This environment minimizes contact between the graphite ring assembly and the high-temperature gases generated by the high-speed rotor rotation, minimizing temperature gradients. This mitigates the effects of thermal expansion on the graphite rings and prevents overheating. Furthermore, the floating ring seal structure allows the graphite rings to float radially to follow rotor runout, reducing the additional thermal frictional impact caused by eccentricity or vibration, thereby ensuring service life and maintaining excellent sealing performance in high-temperature environments.

[0017] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 This is a schematic structural diagram of the bearing cavity dynamic sealing device of the present invention; Figure 2 It is a structural schematic diagram of another embodiment of the bearing cavity dynamic sealing device of the present invention; Figure 3 This is a schematic structural diagram of the stator assembly of the present invention in which the air bleed channel is arranged on a sealed runway; Figure 4 A schematic diagram of the flow of gas and lubricating oil when the bleed air channel of the present invention is arranged on a sealed runway; Figure 5 This is a structural schematic diagram of the stator assembly of the present invention in which the air bleed channel is arranged in a sealed housing; Figure 6 This is a schematic diagram of the gas and lubricating oil flow when the air bleed channel of the present invention is arranged in a sealed housing.

[0019] Legend: 1. Rotor; 2. Sealing runway; 201. Sealing surface; 202. Grate structure; 203. Air bleed channel; 3. Bearing bushing; 4. Bearing; 5. Rotor locking structure; 6. Floating ring seal stator; 601. Sealing housing; 602. Retaining ring; 60201. Axial end face; 60202. Grate mating surface; 603. Gasket; 604. Wave spring; 605. Graphite ring assembly; 7. Seal mounting seat; 8. Sealing retaining ring. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0021] The following is combined with Figure 1-5 This application is described in further detail.

[0022] In an aircraft engine, the main function of the bearing 4 cavity is to lubricate and cool the key bearing 4, and to effectively isolate the working area of the bearing 4 from the external air flow channel to prevent the intrusion of high-temperature gas or impurities and damage to the bearing 4. In addition, if a large amount of lubricating oil in the bearing 4 cavity leaks to the outside, it will not only affect the normal operation of the engine, but may also cause safety hazards. Therefore, how to ensure the reliable sealing and long-life use of the bearing 4 cavity while meeting high-temperature and high-speed working conditions has become an important issue in aircraft engine design. The single-form seal used in the prior art often encounters problems such as thermal expansion and deformation of the graphite ring, decreased sealing efficiency or shortened life under high-temperature and high-pressure environments. In order to overcome these defects, the present invention combines a floating ring seal with a comb seal, and introduces cooling gas on the sealing component to form a set of bearing cavity dynamic sealing structures that are both high-temperature resistant, low-leakage and long-life, which can better meet the use requirements of high-performance aircraft engines.

[0023] Reference Figure 1 This embodiment discloses a bearing cavity dynamic seal device comprising a rotor assembly and a stator assembly. The rotor assembly comprises a rotor 1 and a sealing raceway 2. The stator assembly comprises a floating ring seal stator component 6 and a seal mounting seat 7 for cooperating with the floating ring seal stator component 6. The floating ring seal stator component 6 comprises a sealing housing 601, a retaining ring 602, a graphite ring assembly 605, and an elastic element for applying elastic force to the graphite ring assembly 605. A floating ring seal structure is formed between the graphite ring assembly 605 and the sealing raceway 2. During engine operation, the graphite rings adhere to the end face of the sealing housing 601 due to spring force, while maintaining a slight radial gap with the sealing raceway 2. The high-speed rotation of the rotor 1 induces air film buoyancy within the gap, causing the graphite rings to adaptively float with the raceway's movement, forming a non-contact floating ring seal. The sealing mounting seat 7 firmly fixes the stator assembly on the casing and provides an interface for bearing radial and axial loads. The compressible characteristics of the wave spring 604 ensure that the graphite ring always works under a suitable pre-tightened state, thereby achieving a long-life dynamic sealing effect in which the lubricating oil in the bearing 4 cavity does not leak out and high-temperature gas does not invade.

[0024] To reduce axial leakage of high-pressure gas, a grate structure 202 is provided on the sealing runway 2, and a grate mating surface 60202 is provided on the retaining ring 602 for cooperating with the grate structure 202 to form a grate seal. In a specific embodiment, the inner edge of the retaining ring 602 is machined with a multi-stage tooth groove surface concentric with the rotor 1, and the outer circle of the sealing runway 2 is correspondingly cut with a group of stepped teeth. When the two are assembled, they are axially offset end to end to form a series of maze channels. When the engine is running, if the high-temperature and high-pressure gas attempts to rush into the bearing 4 cavity axially, it must pass through the continuous contraction and expansion zones of "retaining ring 602 tooth tip - runway tooth groove - runway tooth tip - retaining ring 602 tooth groove" in sequence. With each tooth tip, intense throttling and eddy current energy consumption occur, and both dynamic and static pressures are gradually attenuated, ultimately leaving only a very small leakage flow to enter the floating ring gap. Through the throttling weakening of this grate seal pair, the burden on the high-pressure side is greatly shared, and the floating ring seal only needs to withstand a small residual pressure difference to achieve a long-life, low-wear main sealing function.

[0025] Reference Figure 1 and Figure 2 , a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly are formed on the sealing mounting seat 7. Specifically, the inner hole of the sealing mounting seat 7 is processed into a cylindrical precision hole, and its smooth circumferential surface is the radial support surface. After the floating ring sealing stator component 6 is inserted, its deflection under high-speed vibration conditions can be limited, and concentric guidance can be achieved; at one end of the hole, the mounting seat body directly leaves an annular end face as the axial support surface of the stator assembly, so that the stator component can be positioned in place when pushed in. During installation, first slide the floating ring sealing stator component 6 along the radial support surface until its end face rests on the axial support surface; then screw the threaded retaining ring into the external thread area at the other end of the mounting seat, and the inner end face of the retaining ring is pressed against the outer end face of the stator assembly. The working compression height of the wave spring 604 is finely adjusted by the tightening amount, and finally a rigid clamp is formed, thereby ensuring the long-term stability of the axial position and preload of the stator assembly. To accommodate varying casing spaces, this embodiment offers two mirrored arrangements: one places the threaded retaining ring on the left side of the stator assembly with the axial support surface on the right, facilitating assembly from the high-speed end; the other places the threaded retaining ring on the right side with the axial support surface on the left, facilitating maintenance from the open end of the casing. Both arrangements only alter the clamping direction, without affecting the guiding effect of the radial support surface or the threaded retaining ring's secure locking of the stator assembly. This ensures that the required axial preload and sealing performance of the floating ring seal are maintained across various engine configurations.

[0026] In order to reduce the working environment temperature of the floating ring seal structure and thus increase its service life, a cooling channel for introducing gas is provided, so that the gas introduced from the cooling channel is mixed with the gas leaked from the grate seal to form the working environment of the floating ring seal structure.

[0027] Reference Figure 3 and Figure 4 In one embodiment, the cooling channel is provided on the sealed housing 601. Figure 5 and Figure 6 In another embodiment, the cooling channel is provided on the sealed runway 2. Alternatively, in order to further reduce the temperature, cooling channels are provided on both the sealed housing 601 and the sealed runway 2. Specifically, radial holes are prefabricated in the inner wall of the seal housing 601 or the seal runway 2 and connected to the high-pressure air bleed line on the casing. When the engine is operating, clean high-pressure air, significantly cooler than the high-temperature compressor outlet gas, is injected into the cavity behind the grate seal through the cooling channel. This low-temperature air first fills the labyrinth groove between the retaining ring 602 and the seal runway 2, forming a cold air curtain. It then fully mixes with the small amount of high-temperature leakage gas remaining after passing through the labyrinth within the floating ring gap, rapidly reducing the local temperature from 800 degrees Celsius to below 400-500 degrees Celsius. At the same time, sufficient pressure is maintained to offset the oil pressure in the bearing chamber 4, preventing hot oil leakage and avoiding the floating ring from overheating and damage. To balance cooling efficiency and air supply losses, one or two cooling channels are preferably provided, and a diffuser cone or multi-hole distribution is formed at the outlet end to ensure that the jet is evenly spread across the tooth root area. This creates a low-temperature, low differential pressure, and stable airflow operating environment for the floating ring seal without significantly increasing engine extraction losses, significantly improving seal reliability and service life.

[0028] Reference Figure 1 In this embodiment, a metal wave spring 604 is used as the elastic element. It is radially positioned between the annular step and the retaining ring 602 within the seal housing 601. The wave peaks and troughs are arranged in an alternating axial pattern, providing a flexible axial preload. The multiple wave contacts also evenly distribute the load applied to the graphite ring assembly 605 along the circumference. The graphite ring assembly 605 consists of an outer ring and an inner graphite ring. The outer ring, made of a high-temperature alloy or stainless steel, provides positioning and load-bearing functions. The inner graphite ring adheres closely to the inner wall of the outer ring and faces the sealing runway 2, forming the sealing surface 201. During engine operation, the wave spring 604 maintains a constant elastic force within its designed compression range, firmly pushing the outer ring against the end face of the seal housing 601 and achieving a static seal. At the same time, the graphite ring is allowed to float slightly radially within the outer ring, following eccentricity or thermal deformation of the rotor 1 without causing hard contact. To balance longevity and rigidity, the wave spring 604 can be made of a high-temperature resistant material. To prevent the spring from shearing the graphite material, a gasket 603 can be added between the spring and the outer ring of the graphite ring. This composite structure of the wave spring, outer ring of the graphite ring, and the graphite ring provides a flexible, adaptive floating ring seal under high-temperature and high-speed operating conditions, while ensuring a stable fit between the graphite ring and the seal housing 601 and reliable clearance control between the sealing surfaces 201.

[0029] An axial end face 60201 matching the sealing housing 601 is machined on the inner side of the retaining ring 602. When the floating ring seal stator 6 is pressed into the sealing housing 601, the two end faces form a full circle of face-to-face stoppers, which first provide a reliable axial positioning reference for the retaining ring 602 to ensure that it does not move back and forth under high-frequency vibration and thermal cycling conditions; the end face is also designed to fit with the end line or end ring wide surface of the wave spring 604, so that the axial load generated by the wave spring 604 during operation is evenly transmitted to the retaining ring 602 through large-area contact, and then evenly distributed circumferentially by the retaining ring 602 to the graphite ring assembly 605, fundamentally avoiding the local peak indentation of the wave spring that causes warping of the retaining ring 602 or point-like stress concentration in the graphite ring. To increase the fit rigidity while ensuring smooth assembly, the end face of the retaining ring 602 is usually ground into a flat or slightly convex surface, with a chamfered edge to facilitate automatic alignment during assembly. The concentricity and surface shape of the end face and the shell surface are controlled during manufacturing, so that the retaining ring 602 is naturally aligned after being pushed into place, closely fitting with the end face of the wave spring without losing parallelism, thereby maintaining the preset wave spring compression and uniform elastic force distribution throughout its service life.

[0030] Reference Figure 1 In this embodiment, the bearing 4 bushing 3 mounted on the rotor 1 has both supporting and oil guiding functions. Its inner circle fits tightly with the rotor 1, and an annular oil guide groove is processed on the fitting surface. The groove continuously collects the lubricating oil led from the second oil channel inside the rotor 1; in order to allow the oil flow to pass through the bushing wall thickness and be evenly sprayed to the back of the sealed runway 2, the bushing is drilled with a number of through holes radially outward from the oil guide groove. When the engine is running, the oil pump first sends the low-temperature lubricating oil directly to the rolling elements of the bearing 4 through the first oil channel for lubrication and cooling, and then enters the oil guide groove through the second oil channel and forms a circumferential multi-point oil filling curtain through the radial holes, which flushes the inner side of the sealed runway 2 and removes heat; the heated oil flows back to the oil tank along the oil return gap between the runway and the rotor 1, realizing a closed circulation. This arrangement not only ensures that bearing 4 obtains a stable oil film, but also provides continuous cooling and cleaning for the sealing runway 2 - floating ring sealing area, preventing the runway from overheating due to friction or high temperature environment, while avoiding oil and carbon deposits that affect the sealing performance, thereby improving the thermal reliability and service life of the bearing cavity dynamic sealing device as a whole.

[0031] In order to ensure the long-term stability of the bearing 4 support stiffness, the heat dissipation position of the sealing runway 2 and the sealing performance of the floating ring, the outer circle of the rotor 1 is first turned out with a step difference with a slightly larger outer diameter to form a shaft shoulder. The end face of the shaft shoulder provides a fixed reference for all rotating sealing parts. During assembly, the sealing runway 2 is first placed on the shaft shoulder, and the bearing 4, bushing 3 and bearing 4 are then installed on its outside in turn, so that the positioning between the three parts relies on the close contact of the end faces rather than an interference fit, thereby ensuring concentricity and facilitating replacement and maintenance. After all the parts are in place, the rotor 1 locking structure is screwed onto the end of the rotor 1 away from the shaft shoulder. The common form is a threaded locking ring or nut, and it is used with a retaining washer 603 or a safety wire to prevent loosening. Once tightened, the locking mechanism secures the shaft shoulder, sealing track 2, bearing 4, bushing 3, and bearing 4 into a rigid, integrated unit. This not only defines their axial position and preload, but also ensures that the seal gap between sealing track 2 and the floating ring does not drift due to high-speed centrifugal forces or thermal expansion. Furthermore, the locking force is directly transmitted to the rotor 1 body via the shaft shoulder, preventing additional shear stress during high-speed rotation. By controlling the shaft shoulder width and tightening torque, the preload on bearing 4 and the operating clearance on sealing track 2 can be precisely set, maintaining bearing 4 support stiffness and floating ring seal reliability under all operating conditions.

[0032] Before the present invention works, the bearing cavity dynamic sealing device is installed. The installation process is as follows: Installation begins on the rotor 1 side. Holding rotor 1 in a vertical or horizontal support fixture with the shaft shoulder end face visible, the seal track 2, bearing 4, bushing 3, and bearing 4 are then pressed axially in sequence. Once the three-piece assembly is against the shaft shoulder, a locking ring or nut is tightened using the threaded locking mechanism at the rear end of rotor 1. The end-to-end clamping force securely locks the seal track 2, bushing, and bearing 4. Simultaneously, the bearing 4 preload and the operating clearance of the seal track 2 are precisely set, completing the pre-installation of the entire rotor assembly.

[0033] Then assemble the stator assembly. If the "retaining ring 602 in front, threaded retaining ring in back" arrangement is adopted, first insert the retaining ring 602 into the inner hole of the sealing mounting seat 7 and push it into place; then, stack the graphite ring assembly 605, thin gasket 603 and wave spring 604 in the sealing housing 601 in order and push them into the mounting seat together so that the end face of the sealing housing 601 and the retaining ring 602 are completely in contact; finally, screw in the threaded retaining ring, fine-tune until the wave spring 604 reaches the designed compression amount and lock it. If the "threaded retaining ring in front, retaining ring 602 in back" mirror scheme is adopted, then pre-install the graphite ring assembly 605, gasket 603 and wave spring into the sealing housing 601 and place them as a whole into the mounting seat, then press the retaining ring 602 into and against the end face of the sealing housing 601, and finally screw in the threaded retaining ring from the opposite side to complete the locking. The two processes are only in opposite directions, and both ensure that the stator components are uniformly radially guided and stably axially preloaded.

[0034] After completing the rotor 1 and stator subassemblies, maintain rotor 1 in place while steadily advancing the stator assembly from the outside along the radial support surface, aligning the floating ring seal stator 6 and the sealing raceway 2 coaxially and creating the designed clearance. The stator's outer diameter and the mounting seat wall form an interference or clearance fit and can be tapped into final alignment. After assembly, manually rotate rotor 1 to confirm that the graphite ring floats freely, the grate teeth are not gnawing, and that the wave spring 604 is at its normal compression height. The entire bearing cavity dynamic seal assembly can then proceed to the complete machine assembly or bench testing phase.

[0035] After the installation of the bearing cavity dynamic seal device is completed, the bearing cavity dynamic seal device starts working. The working principle is as follows: After the engine starts, the under-ring lubrication system first diverts the pressurized oil. A portion flows directly into bearing 4, establishing a stable oil film for the rolling elements and retainer. The remaining portion flows through the internal oil passages of rotor 1 and into the oil guide grooves of bushing 3 of bearing 4. The remaining portion is then sprayed onto the inside of the sealing runway 2 through radial guide holes in the bushing, creating a continuous oil film flushing and evaporative cooling process. This promptly removes heat accumulated between the runway and the grate labyrinth due to rotational friction and high-temperature radiation, significantly reducing the overall temperature gradient in the floating ring seal area. Simultaneously, the casing exhaust system introduces a second stream of low-temperature, high-pressure air, significantly lower in temperature than the high-pressure air source, into the pre-set cooling channels of sealing runway 2 or seal housing 601. This cold air curtain first fills the bottom of the grate labyrinth grooves and then rapidly mixes with the small amount of high-temperature leaked air that seeps through the labyrinth teeth, lowering its temperature and suppressing residual dynamic pressure. This creates a lower temperature and more moderate pressure differential operating environment on the high-pressure side of the floating ring seal. Relying on this collaborative mechanism of temperature control and pressure differential, the floating ring seal maintains a designed micro-gap between the stator component 6 and the sealing track 2. The radial buoyancy induced within the gap by the high-speed rotation of the rotor 1 slightly lifts the graphite ring, allowing it to float in real time with the track's minute movements with virtually no solid contact. The uniform preload of the wave spring 604 ensures a secure fit between the outer ring of the graphite ring and the end face of the sealing housing 601. This, coupled with the continuous injection of sealing airflow, creates a slightly positive outward pressure gradient, effectively preventing the escape of hot oil from the bearing cavity 4. This not only cuts off the path for high-temperature, high-pressure gas to corrode the bearing cavity 4, but also ensures excellent heat dissipation and lubrication of the floating ring seal surface through the low-volume, low-temperature cooling air and oil mist, achieving a long-life, low-leakage dynamic seal for the bearing cavity under high-temperature and high-speed operating conditions.

[0036] This invention addresses the high temperature, high speed, and long life requirements of the four-cavity bearing of an aircraft engine, and develops the following key improvements. Through the synergistic effect of these improvements, the reliability, maintenance convenience, and service life of the dynamic seal are significantly improved: Modular long-life dynamic seal combination: With the seal mounting seat 7 as the main body, the floating ring seal stator 6, sealing retaining ring 8, bearing 4 bushing 3, sealing runway 2, bearing 4 and rotor 1 locking structure are integrated into an overall module, which not only facilitates integrated assembly and disassembly maintenance, but also ensures that the coaxiality and axial preload of each functional component remain stable over the long term under thermal cycle and vibration conditions, thus laying the structural foundation for highly reliable sealing.

[0037] Integrated bushing with under-ring lubrication and runway cooling: An oil guide groove and radial guide holes are constructed within the bushing 3 of the bearing 4 to direct the diverted lubricating oil to directly flush and heat the sealing runway 2, achieving synchronous cooling of the bearing 4 and the runway. This cooling path effectively reduces the thermal load in the floating ring sealing area, prevents the graphite ring from cracking or oxidation failure due to high temperature, and improves the thermal reliability of the sealing structure.

[0038] Adjustable threaded retaining ring axial clamping mechanism: an external thread is provided at the end of the seal mounting seat 7, and the threaded retaining ring is tightened against the end face of the floating ring seal stator component 6; the thread feed rate can accurately control the working compression height of the wave spring 604, ensuring that the designed micro-gap is maintained between the graphite ring runways and stabilizing the buoyancy of the floating ring; at the same time, the threaded retaining ring is removable, which facilitates in-situ maintenance without disassembling the rotor 1.

[0039] Integrated retaining ring 602 grate labyrinth seal structure: Multi-level tooth grooves are directly formed on the inner edge of the retaining ring 602, which are combined with the opposite tooth tips on the outer circle of the sealing runway 2 to form a labyrinth throttling channel, and have the force distribution and end face limiting functions of the graphite ring and wave spring 604; the traditional straight-edge clamping ring is eliminated, avoiding the risk of local deformation or falling off of the clamping ring, simplifying the number of parts and assembly steps, and at the same time greatly reducing the axial leakage kinetic energy of the high-pressure gas.

[0040] Cold air mixing thermal management channel: An air bleed channel 203 is arranged on the sealed runway 2 or the sealed shell 601 to directly introduce clean high-pressure air with a temperature lower than the high-temperature and high-pressure side airflow into the root of the maze. It is quickly mixed with a very small amount of leaked high-temperature gas before entering the high-pressure side of the floating ring seal. This design not only reduces the temperature and residual pressure difference on the high-pressure side of the floating ring seal, but also establishes an appropriate positive pressure in the floating ring gap, preventing the lubricating oil in the bearing chamber 4 from escaping, significantly improving the overall stability and service life of the sealing system.

[0041] This embodiment also discloses an aero-engine, comprising the above-mentioned bearing cavity dynamic sealing device.

[0042] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. Bearing cavity dynamic sealing device, characterized by: including a rotor assembly and a stator assembly; A rotor assembly comprises a rotor (1) and a sealed runway (2), wherein the sealed runway (2) is provided with a grate structure (202); The stator assembly comprises a floating ring seal stator component (6) and a seal mounting seat (7) matched with the floating ring seal stator component (6). The floating ring seal stator component (6) comprises a sealing housing (601), a retaining ring (602), a graphite ring assembly (605), and an elastic element for applying elastic force to the graphite ring assembly (605); a floating ring seal structure is formed between the graphite ring assembly (605) and the sealing runway (2); and a grate matching surface (60202) for matching with the grate structure (202) to form a grate seal is provided on the retaining ring (602); The sealing housing (601) and / or the sealing runway (2) are provided with a cooling channel for introducing gas, so that the gas introduced from the cooling channel is mixed with the gas leaked from the grate seal to form a working environment of the floating ring sealing structure.

2. The bearing cavity dynamic sealing device according to claim 1, characterized in that: The elastic element is a wave spring (604).

3. The bearing cavity dynamic sealing device according to claim 2, characterized in that: The retaining ring (602) is provided with an axial end face (60201), the axial end face (60201) and the end face of the sealing housing (601) are fitted together to achieve axial limitation, and the axial end face (60201) and the end face of the wave spring (604) are fitted together to evenly distribute the elastic force of the wave spring (604).

4. The bearing cavity dynamic sealing device according to claim 3, characterized in that: The graphite ring assembly (605) includes a graphite ring outer ring and a graphite ring, and the wave spring (604) is used to support the graphite ring so that the graphite ring fits with the sealing housing (601).

5. The bearing cavity dynamic sealing device according to claim 4, characterized in that: A gasket (603) is provided between the wave spring (604) and the graphite ring.

6. The bearing cavity dynamic sealing device according to claim 1, characterized in that: It also includes a bearing (4) bushing (3) arranged on the rotor (1), wherein the bearing (4) bushing (3) is provided with an oil guide groove on the inner side of the rotor (1) and an oil guide hole connecting the oil guide groove and the sealing runway (2) is opened in the radial direction.

7. The bearing cavity dynamic sealing device according to claim 6, characterized in that: The sealing mounting seat (7) is formed with a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly. One end of the sealing mounting seat (7) away from the axial support surface is threadedly connected to a threaded retaining ring, and the threaded retaining ring cooperates with the axial support surface to clamp the stator assembly.

8. The bearing cavity dynamic sealing device according to claim 7, characterized in that: The rotor (1) is provided with a first oil passage for supplying oil to the bearing (4) and a second oil passage for supplying oil to the sealing runway (2) through an oil guide groove.

9. The bearing cavity dynamic sealing device according to claim 6, characterized in that: The rotor (1) is provided with a shaft shoulder, and a rotor (1) locking structure is provided at one end of the rotor (1) away from the shaft shoulder. The sealing runway (2), the bearing (4) bushing (3), and the bearing (4) are sequentially arranged between the shaft shoulder and the rotor (1) locking structure to perform axial limitation through the rotor (1) locking structure.

10. An aircraft engine, characterized in that The invention comprises the bearing cavity dynamic sealing device according to any one of claims 1 to 9.

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