Bearing cavity dynamic sealing device and aero-engine

Abstract

This invention discloses a bearing cavity dynamic sealing device and an aero-engine, belonging to the field of aero-engine bearing cavity sealing technology. It includes a rotor assembly and a stator assembly. The rotor assembly includes a rotor and a sealing runway, with a serrated structure on the sealing runway. The stator assembly includes a floating ring sealing stator and a sealing mounting seat that mates with the floating ring sealing stator. The floating ring sealing stator includes a sealing shell, a retaining ring, a graphite ring assembly, and an elastic element for applying elastic force to the graphite ring assembly. A floating ring sealing structure is formed between the graphite ring assembly and the sealing runway. Cooling channels for introducing gas are provided on the sealing shell and / or the sealing runway. This application can mitigate the influence of the thermal expansion coefficient of the graphite ring and avoid overheating and damage, while reducing additional thermal friction shock caused by eccentricity or vibration, thereby ensuring its service life in high-temperature environments and maintaining good sealing performance.

Description

Technical Field

[0001] This invention relates to the field of bearing cavity sealing technology for aero-engines, specifically to a dynamic sealing device for bearing cavities and an aero-engine. Background Technology

[0002] The bearing cavities of high-speed rotating machinery such as aero engines are typically adjacent to high-temperature, high-pressure airflow channels. To ensure the normal operation of the bearings and lubrication systems in high-temperature, high-speed environments, effective sealing of the bearing cavities is necessary. In recent years, with the continuous improvement of requirements for high thrust-to-weight ratio and high performance, the operating temperature of engines has increased significantly. Traditional mechanical contact seals are prone to severe wear, thermal deformation, and shortened lifespan in high-temperature, high-speed environments, and are therefore gradually being replaced by non-contact floating ring seals, which feature low wear and long lifespan.

[0003] In non-contact floating ring seals, a certain sealing gap is maintained between the graphite ring (stator) and the sealing raceway (rotating component). Sealing is achieved by forming an air film within this gap. Graphite material possesses good self-lubricating properties and high-temperature stability, enabling it to meet sealing requirements under high-temperature and high-speed conditions within a certain range. However, when the rotor temperature further increases or the ambient temperature reaches extreme values, the graphite ring is prone to thermal expansion failure and oxidation weight loss in high-temperature environments.

[0004] To address the above problems, conventional solutions typically include: material improvement, using graphite or synthetic materials with higher temperature resistance and oxidation resistance, but these high-end materials are expensive and have complex manufacturing and processing processes, resulting in high costs; and optimization of elastic support, setting elastic elements (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, but if cooling and elastic force distribution are insufficient, it is still difficult to effectively suppress high-temperature expansion and oxidation reactions.

[0005] Therefore, how to prevent graphite rings from swelling and losing weight due to oxidation in harsh environments with high temperature and high speed, and maintain a long-life, high-performance bearing cavity sealing effect, has become a key technical problem that urgently needs to be solved in the industry. Summary of the Invention

[0006] This invention provides a bearing cavity dynamic sealing device and an aero-engine to solve the technical problem that the graphite rings used in existing bearing cavity seals are prone to thermal expansion and damage in high-temperature environments, resulting in insufficient service life.

[0007] According to one aspect of the present invention, a bearing cavity dynamic sealing device and an aero-engine are provided, including a rotor assembly and a stator assembly; the rotor assembly includes a rotor and a sealing runway, the sealing runway being provided with a grating structure; the stator assembly includes a floating ring sealing stator and a sealing mounting seat cooperating with the floating ring sealing stator, the floating ring sealing stator including a sealing housing, a retaining ring, a graphite ring assembly, and an elastic element for applying elastic force to the graphite ring assembly, the graphite ring assembly and the sealing runway forming a floating ring sealing structure, the retaining ring being provided with a grating mating surface for cooperating with the grating structure to form a grating seal; the sealing housing and / or the sealing runway are provided with a cooling channel for introducing gas, so that the working environment of the floating ring sealing structure is formed by the mixing of gas introduced from the cooling channel with gas leaking from the grating seal.

[0008] Optionally, the elastic element is a wave spring.

[0009] Optionally, the retaining ring is provided with an axial end face, which fits against the end face of the sealing housing to achieve axial limiting, and the axial end face fits against the end face of the wave spring to evenly distribute the elastic force of the wave spring.

[0010] Optionally, the graphite ring assembly includes an outer graphite ring and a graphite ring, and the wave spring is used to support the graphite ring so that the graphite ring fits into the sealing housing.

[0011] Optionally, a gasket is provided between the wave spring and the graphite ring.

[0012] Optionally, it also includes a bearing bushing disposed on the rotor, wherein the bearing bushing is provided with an oil guide groove close to the inner side of the rotor, and an oil guide hole is provided radially to connect the oil guide groove and the sealing track.

[0013] Optionally, the sealing mounting base has a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly. A threaded retaining ring is threaded to one end of the sealing mounting base away from the axial support surface. The threaded retaining ring cooperates with the axial support surface to clamp the stator assembly.

[0014] Optionally, the rotor is provided with a first oil passage for supplying oil to the bearing and a second oil passage for supplying oil to the sealed raceway through an oil guide groove.

[0015] Optionally, the rotor is provided with a shoulder, and a rotor locking structure is provided at the end of the rotor away from the shoulder. The sealing raceway, bearing bushing and bearing are arranged in sequence between the shoulder and the rotor locking structure to provide axial positioning through the rotor locking structure.

[0016] According to another aspect of the present invention, an aircraft engine is also provided, which includes the above-described bearing cavity dynamic sealing device.

[0017] In summary, this application includes at least one of the following beneficial technical effects:

[0018] This solution incorporates cooling channels in the sealing housing and / or sealing track. The gas introduced through these channels mixes with the gas leaking from the grate seal, creating a lower-temperature, more uniform-pressure working environment for the floating ring seal, effectively reducing the thermal load on the graphite ring. In this environment, the graphite ring assembly has less contact with the high-temperature gas generated during high-speed rotor rotation, resulting in a smaller temperature gradient. This mitigates the impact of the graphite ring's thermal expansion coefficient and prevents overheating and damage. Simultaneously, the floating ring seal structure allows the graphite ring to float radially, following the rotor's movement, reducing additional thermal friction impacts caused by eccentricity or vibration. This ensures its service life in high-temperature environments and maintains excellent sealing performance.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the bearing cavity dynamic sealing device of the present invention;

[0022] Figure 2 This is a schematic diagram of another embodiment of the bearing cavity dynamic sealing device of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the stator assembly of the present invention, in which the air duct is set in a sealed runway;

[0024] Figure 4 This is a schematic diagram showing the gas and lubricating oil flow directions when the air intake channel of the present invention is installed in a sealed runway.

[0025] Figure 5 This is a schematic diagram of the structure of the stator assembly of the present invention, in which the air duct is disposed in the sealed housing;

[0026] Figure 6 This is a schematic diagram showing the gas and lubricating oil flow direction when the air intake channel of the present invention is set in the sealed shell.

[0027] Legend:

[0028] 1. Rotor; 2. Sealing track; 201. Sealing surface; 202. Grate structure; 203. Air duct; 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. Sealing mounting base; 8. Sealing retaining ring. Detailed Implementation

[0029] The embodiments of the present invention will be 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.

[0030] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0031] In aero-engines, the primary function of bearing cavity 4 is to lubricate and cool the critical bearing 4, and effectively isolate the working area of ​​bearing 4 from external airflow channels, preventing damage from high-temperature gases or impurities. Furthermore, if a large amount of lubricating oil leaks from bearing cavity 4 to the outside, it will not only affect the normal operation of the engine but may also pose safety hazards. Therefore, ensuring reliable sealing and long service life of bearing cavity 4 while meeting high-temperature and high-speed operating conditions has become an important issue in aero-engine design. Existing single-type seals often encounter problems such as thermal expansion and deformation of graphite rings, decreased sealing efficiency, or shortened lifespan under high-temperature and high-pressure environments. To overcome these shortcomings, this invention combines floating ring seals with grate seals and introduces cooling gas into the sealing components, forming a dynamic sealing structure for the bearing cavity that combines high-temperature resistance, low leakage, and long service life, better meeting the requirements of high-performance aero-engines.

[0032] Reference Figure 1This embodiment discloses a bearing cavity dynamic sealing device, including a rotor assembly and a stator assembly. The rotor assembly includes a rotor 1 and a sealing raceway 2. The stator assembly includes a floating ring sealing stator 6 and a sealing mounting seat 7 that mates with the floating ring sealing stator 6. The floating ring sealing stator 6 includes 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 sealing structure is formed between the graphite ring assembly 605 and the sealing raceway 2. When the engine is running, the graphite ring adheres tightly to the end face of the sealing housing 601 by spring force, while maintaining a small radial gap with the sealing raceway 2. The high-speed rotation of the rotor 1 induces air film buoyancy within the gap, allowing the graphite ring to adaptively float with the raceway's movement, forming a non-contact floating ring seal. The sealing mounting base 7 securely fixes the stator assembly to the casing, while providing a bearing interface for radial and axial loads. The compressibility of the wave spring 604 ensures that the graphite ring always operates under appropriate preload, thereby achieving a long-life dynamic sealing effect that prevents lubricating oil leakage from the bearing cavity 4 and high-temperature gas intrusion.

[0033] To reduce axial leakage of high-pressure gas, a toothed structure 202 is provided on the sealing runway 2, and a toothed mating surface 60202 is provided on the retaining ring 602 to cooperate with the toothed structure 202 to form a toothed seal. In a specific embodiment, the inner edge of the retaining ring 602 is machined with a multi-stage toothed 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 misaligned in the axial direction to form a series of labyrinth channels. When the engine is running, if the high-temperature and high-pressure gas attempts to rush into the bearing 4 cavity along the axial direction, it must pass through a series of continuous contraction and expansion zones such as "retaining ring 602 tooth tip - runway tooth groove - runway tooth tip - retaining ring 602 tooth groove". Each time it crosses a tooth tip, intense throttling and eddy current energy consumption occur, and the dynamic pressure and static pressure are gradually attenuated, and finally only a very small leakage flow enters the floating ring gap. By reducing the pressure through this toothed seal pair, the burden on the high-pressure side is significantly reduced, and the floating ring seal only needs to withstand a small residual pressure difference to achieve the main sealing function of long service life and low wear.

[0034] Reference Figure 1 and Figure 2The sealing mounting base 7 has a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly. Specifically, the inner hole of the sealing mounting base 7 is machined into a cylindrical precision hole, and its smooth circumferential surface is the radial support surface. After the floating ring sealing stator 6 is fitted in, it can limit its sway under high-speed vibration conditions and achieve concentric guidance. At one end of the hole, the mounting base body directly leaves an annular end face as the axial support surface of the stator assembly, so that the stator can be positioned in place when pushed in. During installation, the floating ring sealing stator 6 is first slid in along the radial support surface until its end face abuts against the axial support surface; then, a threaded retaining ring is screwed into the external thread area at the other end of the mounting base. The inner end face of the retaining ring presses against the outer end face of the stator assembly. The working compression height of the wave spring 604 is finely adjusted by tightening, 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 different casing spaces, this embodiment provides two mirrored arrangements: one places the threaded retaining ring on the left side of the stator assembly and the axial support surface on the right side, facilitating assembly from the high-speed end; the other places the threaded retaining ring on the right side and the axial support surface on the left side, facilitating maintenance from the open end of the housing. The two schemes only change the clamping direction, without affecting the guiding effect of the radial support surface or the reliable locking of the threaded retaining ring to the stator assembly, thus maintaining the axial preload and sealing performance required for the floating ring seal in different engine structures.

[0035] To reduce the operating temperature of the floating ring seal structure and thus extend its service life, a cooling channel is provided for introducing gas. The gas introduced from the cooling channel is mixed with the gas leaking from the grate seal to form the operating environment of the floating ring seal structure.

[0036] Reference Figure 5 and Figure 6 In one embodiment, a cooling channel is provided on the sealing housing 601. (See reference...) Figure 3 and Figure 4In another embodiment, cooling channels are provided on the sealed runway 2. Alternatively, to further reduce the temperature, cooling channels are provided on both the sealed housing 601 and the sealed runway 2. Specifically, radial holes are pre-drilled in the inner wall of the sealing housing 601 or the sealing runway 2 and connected to the high-pressure bleed air pipeline on the casing. When the engine is running, clean high-pressure gas with a temperature significantly lower than that of the high-temperature compressor outlet gas is injected into the cavity behind the grate seal through the cooling channel. This low-temperature gas first fills the labyrinth groove between the retaining ring 602 and the sealing runway 2, forming a cold air curtain. Then, it mixes thoroughly with the small amount of high-temperature leakage gas remaining after passing through the labyrinth in the gap of the floating ring, quickly reducing the local temperature from 800 degrees Celsius to below 400-500 degrees Celsius, while maintaining sufficient pressure to offset the oil pressure in the bearing 4 cavity. This prevents hot oil leakage and avoids the floating ring from overheating and breaking. To balance cooling efficiency and air supply loss, one or two cooling channels are preferably provided, and a diffuser cone or multi-hole distribution is made at the outlet end to make the jet evenly spread in the tooth root area. This creates a low-temperature, low-differential-pressure and stable airflow working environment for the floating ring seal without significantly increasing the engine extraction loss, thus significantly improving the seal reliability and service life.

[0037] Reference Figure 1 In this embodiment, a metal wave spring 604 is selected as the elastic element. It is radially positioned between the annular step and the retaining ring 602 within the sealing housing 601. The wave crests and troughs are axially alternating, providing both flexible axial preload and, due to the multiple wave contacts, ensuring uniform circumferential distribution of the load applied to the graphite ring assembly 605. The graphite ring assembly 605 consists of an outer ring and an inner graphite ring. The outer ring is made of high-temperature alloy or stainless steel and serves for positioning and load bearing. The inner graphite ring is tightly attached to the inner wall of the outer ring and faces the sealing runway 2 to form a sealing surface 201. During engine operation, the wave spring 604 maintains a constant elastic force within the designed compression range, firmly pushing the outer graphite ring against the end face of the sealing housing 601 to achieve a static seal. Simultaneously, it allows the graphite ring to make slight radial floating within the outer ring, following the eccentricity or thermal deformation of the rotor 1 without generating hard contact. To balance lifespan and stiffness, 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. Through this composite structure composed of the wave spring, the outer ring of the graphite ring, and the graphite ring, the floating ring seal has both compliant self-adaptive capability under high temperature and high speed conditions, and ensures stable contact between the graphite ring and the sealing housing 601 and reliable gap control between the sealing surfaces 201.

[0038] The inner side of the retaining ring 602 is machined with an axial end face 60201 that matches the sealing housing 601. When the floating ring sealing stator 6 is pressed into the sealing housing 601, the two end faces form a full circle of face-to-face contact stop, which first provides a reliable axial positioning reference for the retaining ring 602, ensuring that it will 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 the wide surface of the end ring of the wave spring 604, so that the axial load generated by the wave spring 604 during operation is uniformly transmitted to the retaining ring 602 through a large area of ​​contact, and then evenly distributed from the retaining ring 602 to the graphite ring assembly 605 in a circumferential direction. This fundamentally avoids the retaining ring 602 warping or the graphite ring point stress concentration caused by local peak indentation of the wave spring. To increase the rigidity of the fit and ensure smooth assembly, the end face of the retaining ring 602 is usually machined into a flat or slightly convex surface, and a chamfer is left on the outer edge to facilitate automatic alignment during assembly. The concentricity and surface shape of the end face and the housing surface are controlled during manufacturing so that the retaining ring 602 will naturally align itself after being pushed into place, closely fitting the end face of the wave spring without losing parallelism, thereby maintaining the preset wave spring compression and uniform elastic force distribution throughout the entire service life.

[0039] Reference Figure 1 In this embodiment, the bearing bush 3 fitted on the rotor 1 has both support and oil guiding functions. Its inner circle is tightly fitted with the rotor 1, and an annular oil guiding groove is machined on the fitting surface. The groove continuously collects the lubricating oil drawn from the second oil passage inside the rotor 1. In order to enable the oil flow to pass over the bushing wall thickness and be evenly sprayed to the back of the sealed runway 2, the bushing is drilled with several through holes radially outward from the oil guiding 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 passage for lubrication and cooling, and then enters the oil guiding groove through the second oil passage and forms a circumferential multi-point oil injection curtain through the radial holes to flush and remove heat from the inner side of the sealed runway 2. The heated oil flows back to the oil tank along the oil return gap between the runway and the rotor 1 to achieve a closed loop. This arrangement not only ensures that bearing 4 obtains a stable oil film, but also provides continuous cooling and cleaning for the sealing track 2—the floating ring sealing area, preventing the track from overheating due to friction or high temperature environment, while avoiding oil and carbon deposits from affecting the sealing performance, thereby improving the overall thermal reliability and service life of the bearing cavity dynamic sealing device.

[0040] To ensure the long-term stability of the bearing 4's support rigidity, the heat dissipation position of the sealing track 2, and the floating ring's sealing performance, the outer diameter of the rotor 1 is first machined with a slightly larger step to form a shoulder. The end face of the shoulder provides a fixed reference for all rotating sealing parts. During assembly, the sealing track 2 is first fitted onto the shoulder, and then the bearing 4 bushing 3 and bearing 4 are installed in sequence on its outer side. The positioning of the three parts relies on the tight contact of the end faces rather than an interference fit, thus ensuring concentricity and facilitating replacement and maintenance. After all parts are in place, the rotor 1 locking structure is screwed on the end of the rotor 1 away from the shoulder. The common form is a threaded locking ring or nut, and it is used with a 603 anti-loosening washer or a safety wire to prevent loosening. After the locking structure is tightened, the shaft shoulder, sealing raceway 2, bearing 4 bushing 3, and bearing 4 are clamped together as a rigid unit. This not only limits their axial position and preload but also ensures that the sealing gap between the sealing raceway 2 and the floating ring will not drift due to high-speed centrifugal force or thermal expansion. At the same time, the locking force is directly transmitted to the rotor 1 body through the shaft shoulder, avoiding additional shear stress during high-speed rotation. By controlling the shaft shoulder width and locking torque, the preload of bearing 4 and the working clearance of sealing raceway 2 can be precisely set, thereby maintaining the support stiffness of bearing 4 and the reliability of the floating ring seal under all operating conditions.

[0041] Before operation, the bearing cavity dynamic sealing device of this invention is installed. The installation process is as follows:

[0042] Installation begins on the rotor 1 side. Holding rotor 1 in a vertical or horizontal support fixture, with the shoulder end face visible, press in the sealing raceway 2, bearing 4, bushing 3, and bearing 4 sequentially along the axial direction. After the three pieces are pressed tightly against the shoulder, tighten the locking ring or nut using the threaded locking structure at the tail end of rotor 1. The end-to-end clamping force securely locks the sealing raceway 2, bushing, and bearing 4 together. Simultaneously, precisely set the preload of bearing 4 and the working clearance of sealing raceway 2, completing the pre-assembly of the entire rotor assembly.

[0043] The stator assembly is then assembled. If the arrangement of "retaining ring 602 in front, threaded retaining ring behind" is adopted, first insert the retaining ring 602 into the inner hole of the sealing mounting base 7 and push it into place; then, arrange the graphite ring assembly 605, thin gasket 603, and wave spring 604 in sequence inside the sealing housing 601, and push them into the mounting base together so that the end face of the sealing housing 601 is completely in contact with the retaining ring 602; finally, screw in the threaded retaining ring, fine-tune until the wave spring 604 reaches the designed compression, and lock it. If the mirror arrangement of "threaded retaining ring in front, retaining ring 602 behind" is adopted, then the graphite ring assembly 605, gasket 603, and wave spring are pre-installed into the sealing housing 601 and placed into the mounting base as a whole; then, press the retaining ring 602 in and place it against the end face of the sealing housing 601; finally, screw in the threaded retaining ring from the opposite side to complete the locking. The two processes are only opposite in direction, both ensuring uniform radial guidance and stable axial preload for the stator components.

[0044] After completing the two main sub-assemblies, rotor 1 and stator, keep rotor 1 fixed and smoothly push 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 forming the designed clearance. The outer circle of the stator has an interference or clearance fit with the mounting seat hole wall, and can be gently tapped to final positioning. After assembly, rotor 1 should be manually rotated to confirm that the graphite ring floats freely and the grates do not rub against each other, and that the wave spring 604 is at its normal compression height. The entire bearing cavity dynamic sealing device can then proceed to the overall machine assembly or bench testing stage.

[0045] After the installation of the bearing cavity dynamic seal device is completed, the bearing cavity dynamic seal device will start working. The working principle is as follows:

[0046] After the engine starts, the under-ring lubrication system first diverts the pressurized lubricating oil. One part goes directly into the bearing 4 to establish a stable oil film for the rolling elements and cage, while the other part flows through the internal oil passages of the rotor 1 into the oil guide groove of the bushing 3 of the bearing 4. Then, it is sprayed onto the inner side of the sealing raceway 2 through the radial guide holes of the bushing, forming a continuous oil film flushing and evaporative cooling. This promptly removes the heat accumulated in the raceway and the grate labyrinth due to rotational friction and high-temperature radiation, significantly reducing the overall temperature gradient of the floating ring sealing area. At the same time, the casing extraction system introduces two low-temperature high-pressure gases with a temperature significantly lower than that of the high-pressure gas source into the preset cooling channels of the sealing raceway 2 or the sealing housing 601. The cold air curtain first fills the bottom of the grate labyrinth groove, and then quickly mixes with the small amount of high-temperature leaked gas seeping into the labyrinth gaps, reducing its temperature and suppressing the remaining dynamic pressure. This creates a working environment with a lower temperature and a gentler pressure difference on the high-pressure side of the floating ring seal. Relying on this temperature control and differential pressure cooperation mechanism, a designed micro-gap is maintained between the floating ring seal stator 6 and the sealing raceway 2. When the rotor 1 rotates at high speed, the radial buoyancy induced within the gap slightly lifts the graphite ring, allowing it to float in real time with the slight jumps of the raceway, with almost no solid contact. The contact between the outer ring of the graphite ring and the end face of the sealing housing 601 remains reliable under the uniform preload of the wave spring 604. With the continuous injection of sealing airflow, an outward micro-positive pressure gradient is formed, effectively preventing the hot oil in the bearing cavity 4 from escaping. This not only cuts off the erosion path of high-temperature and high-pressure gas to the bearing cavity 4, but also maintains good heat dissipation and lubrication of the floating ring seal surface with low-volume, low-temperature cooling gas and oil mist, achieving a long-life, low-leakage dynamic seal for the bearing cavity under high-temperature and high-speed operating conditions.

[0047] This invention addresses the high-temperature, high-speed, and long-life requirements of the four cavities in aero-engine bearings, and establishes the following key improvements. Through the synergistic effect of these improvements, the reliability, ease of maintenance, and service life of the dynamic seals are significantly enhanced:

[0048] Modular long-life dynamic seal assembly: With the sealing mounting base 7 as the main body, the floating ring seal stator 6, sealing retaining ring 8, bearing 4 bushing 3, sealing raceway 2, bearing 4 and rotor 1 locking structure are integrated into an integral module, which not only facilitates integrated assembly, disassembly and maintenance, but also ensures that each functional component maintains long-term stability of coaxiality and axial preload under thermal cycling and vibration conditions, thus laying the structural foundation for a highly reliable seal.

[0049] Integrated cooling bushing for the ring under lubrication track: An oil guide groove is constructed in the bushing 3 of bearing 4 and a radial guide hole is set to guide the diverted lubricating oil to directly flush and heat the sealing track 2, so as to realize the synchronous cooling of bearing 4 and track; this cooling path effectively reduces the heat load of the floating ring sealing area, avoids graphite ring from cracking or oxidizing due to high temperature, and improves the thermal reliability of the sealing structure.

[0050] Adjustable threaded retaining ring axial clamping mechanism: an external thread is provided at the end of the sealing mounting seat 7, and the threaded retaining ring is pressed against the end face of the floating ring sealing stator 6; the threaded feed can precisely control the working compression height of the wave spring 604, ensuring that the designed micro gap is maintained between the graphite ring tracks and the floating ring buoyancy is stable; at the same time, the threaded retaining ring is detachable, which is conducive to in-situ maintenance without disassembling the rotor 1.

[0051] Integrated retaining ring 602 grating labyrinth sealing structure: The inner edge of the retaining ring 602 directly forms a multi-stage toothed groove, which, together with the opposing tooth tips of the outer circle of the sealing track 2, forms a labyrinth throttling channel, and also has the functions of uniform force distribution and end face limiting of graphite ring and wave spring 604; it eliminates the traditional straight-edge retaining ring, avoids the risk of local deformation or detachment of the retaining ring, simplifies the number of parts and assembly steps, and at the same time significantly reduces the axial leakage kinetic energy of high-pressure gas.

[0052] Cold air mixing heat management channel: An air intake channel 203 is installed on the sealed runway 2 or the sealed housing 601 to directly introduce clean high-pressure gas with a temperature lower than that of the high-temperature and high-pressure side airflow into the root of the labyrinth. It is then rapidly mixed with a very small amount of leaked high-temperature gas before entering the high-pressure side of the floating ring seal. This design reduces the temperature and residual pressure difference of the high-pressure side of the floating ring seal on the one hand, and establishes an appropriate positive pressure in the floating ring gap on the other hand, preventing the lubricating oil in the bearing 4 cavity from escaping, which significantly improves the overall stability and service life of the sealing system.

[0053] This embodiment also discloses an aero-engine, including the aforementioned bearing cavity dynamic sealing device.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A bearing cavity dynamic sealing device, characterized in that: Including rotor assembly and stator assembly; The rotor assembly includes a rotor (1) and a sealed raceway (2), on which a grate structure (202) is provided; The stator assembly includes a floating ring seal stator (6) and a sealing mount (7) that mates with the floating ring seal stator (6). The floating ring sealing stator (6) includes 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). The graphite ring assembly (605) and the sealing raceway (2) form a floating ring sealing structure. The retaining ring (602) is provided with a tooth mating surface (60202) for mating with the tooth structure (202) to form a tooth seal. The sealing housing (601) and / or the sealing runway (2) are provided with cooling channels for introducing gas, so as to form a working environment for the floating ring sealing structure by mixing the gas introduced from the cooling channels with the gas leaking from the grate seal.

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), which is in contact with the end face of the sealing housing (601) to achieve axial limiting. The axial end face (60201) is in contact with the end face of the wave spring (604) 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 against 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) disposed on the rotor (1). The bearing (4) bushing (3) is provided with an oil guide groove close to the inner side of the rotor (1) and has an oil guide hole in the radial direction connecting the oil guide groove and the sealing runway (2).

7. The bearing cavity dynamic sealing device according to claim 6, characterized in that: The sealing mounting base (7) has a radial support surface for radially supporting the stator assembly and an axial support surface for axially supporting the stator assembly. A threaded retaining ring is threaded to one end of the sealing mounting base (7) away from the axial support surface. 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 sealed runway (2) through the oil guide groove.

9. The bearing cavity dynamic sealing device according to claim 6, characterized in that: The rotor (1) is provided with a shoulder, and a rotor (1) locking structure is provided at the end of the rotor (1) away from the shoulder. The sealing track (2), bearing (4) bushing (3) and bearing (4) are arranged in sequence between the shoulder and the rotor (1) locking structure to be axially limited by the rotor (1) locking structure.

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

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