Bearing cavity sealing device and aircraft engine

Abstract

The present invention discloses a bearing cavity sealing device and an aircraft engine. The bearing cavity sealing device includes a mounting seat for mounting a bearing, a rotating shaft fixedly mounted in the bearing, and a dynamic seal and a static seal mounted sequentially in the bearing cavity along the radial direction of the rotating shaft. The dynamic seal includes a sealing track fitted with an interference fit on the rotating shaft and a locking structure for radially locking the sealing track to the rotating shaft. The locking structure is arranged between the sealing track and the bearing and engages with the sealing track to form a retaining ring structure for preventing leaked gas from impacting the bearing. The static seal includes a sealing housing sealingly mounted on the mounting seat and a graphite seal sealingly mounted on the sealing housing. The graphite seal is arranged at the end of the locking structure away from the bearing and has a clearance with the sealing track to form a main sealing interface for sealing the bearing cavity. The present invention has a compact structure and a small radial dimension, effectively reducing linear velocity, and meeting the requirements of long-life and high-performance aircraft engines.

Description

Technical Field

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

[0002] The primary function of an aircraft engine bearing cavity seal is to effectively isolate the rotor system's bearing cavity from the engine's airflow environment, protecting the bearings and lubricating oil from damage in the airflow path and preventing lubricating oil leakage. Conventional aircraft gas turbine propeller engine bearing cavity seals typically utilize grate seals. These non-contact seals have a gap between the rotor and stator, resulting in significant leakage. Furthermore, during acceleration from idle to maximum power, centrifugal force inevitably causes the rotor and stator to rub against each other, leading to wear of the grate tooth tips and coating, resulting in an irreversible, permanent increase in the gap. Consequently, the sealing effectiveness decreases over time.

[0003] As aircraft engines continue to achieve higher thrust, higher pressure, and higher temperature ratios, the linear speed, seal pressure differential, and operating temperature of the main shaft seal continue to increase, leading to increasingly harsh operating conditions. Traditional non-contact grate seals, when used in aircraft engines with high seal pressure differentials, can lead to high bearing cavity temperatures and excessive oil consumption, significantly impacting engine performance. Consequently, grate seals are increasingly being replaced by newer non-contact floating ring seals for bearing cavity sealing. These non-contact floating ring seals typically consist of a housing, graphite rings, wave springs, washers, and retaining rings. The graphite rings and rotating sealing raceways form the primary sealing interface, limiting axial oil leakage. The wave springs force the graphite ring end faces against the inside of the housing, forming a secondary sealing interface. During operation, the sealing raceways of the floating ring seal's stator create radial buoyancy, allowing the graphite rings to float radially to accommodate rotor eccentricity and raceway runout. However, in advanced aircraft engines, the high-pressure turbine is typically supported on the low-pressure turbine, limiting the space available for the bearing cavity seal and necessitating the use of compact inter-shaft sealing devices. Existing floating ring seals, however, occupy a large space, resulting in a large radial dimension and a high linear velocity for the main shaft seal. This high linear velocity intensifies the relative motion between the floating ring seal and the rotor, accelerating wear and increasing leakage, which compromises the sealing effectiveness and increases engine operation risk. Furthermore, non-contact floating ring seals allow a small amount of high-pressure gas to leak into the bearing cavity to prevent oil leakage. However, the clearance of existing floating ring seals is aligned with the bearing. This causes any high-pressure gas leaking from the clearance to directly spray onto the bearing outer ring, the cage end face, or the rolling elements, causing bearing temperatures to rise and compromising engine safety. Summary of the Invention

[0004] The present invention provides a bearing cavity sealing device and an aero-engine, so as to solve the technical problem in the prior art that the radial dimension of the bearing cavity sealing device is large, resulting in high linear speed and affecting the engine performance.

[0005] According to one aspect of the present invention, there is provided a bearing cavity sealing device, comprising a mounting seat for mounting a bearing, a rotating shaft fixedly mounted in the bearing, and a dynamic seal and a static seal sequentially mounted in the bearing cavity along the radial direction of the rotating shaft;

[0006] The dynamic seal includes a sealing track that is interference-fitted on the rotating shaft and a locking structure for radially locking the sealing track to the rotating shaft. The locking structure is arranged between the sealing track and the bearing and engages with the sealing track to form a retaining ring structure for preventing leakage gas from impacting the bearing.

[0007] The static seal includes a sealing shell sealingly mounted on the mounting seat and a graphite seal sealingly mounted on the sealing shell. The graphite seal is arranged at the end of the locking structure away from the bearing and cooperates with the sealing runway gap to form a main sealing interface for sealing the bearing cavity.

[0008] Furthermore, the inner wall of the mounting seat is provided with a limiting ring platform for sealingly installing the sealing housing and a limiting groove for installing the bearing retaining ring in sequence along the axial direction. The bearing retaining ring and the sealing housing are respectively arranged on both sides of the bearing and abut against the end face of the bearing outer ring for axial limitation.

[0009] Furthermore, one end of the sealing housing close to the bearing is bent toward the mounting seat to form a limiting step. The sealing housing is interference fitted on the inner wall of the limiting ring and is axially abutted and sealed with the limiting ring through the limiting step. A limiting boss for axially limiting the graphite seal is radially provided on the inner wall of the sealing housing away from the limiting step.

[0010] Furthermore, the graphite seal comprises a limit ring, an elastic member and a graphite ring assembly which are sequentially arranged along the axial direction of the rotating shaft toward the bearing. The limit ring is radially inserted and fixed in the sealing housing and axially fixed to the elastic member.

[0011] The limiting retaining ring is parallel to the limiting boss, and two sides of the graphite ring assembly are respectively axially abutted against the elastic member and the limiting boss to form an auxiliary sealing interface.

[0012] Furthermore, an anti-rotation ring is provided on the inner wall of the sealed runway in the radial direction. The anti-rotation ring is provided at one end of the sealed runway away from the bearing and is used to be clamped on the end of the rotating shaft for axial limitation.

[0013] There are several anti-rotation grooves radially spaced on the anti-rotation ring, and several protrusions correspondingly arranged along the axial direction of the rotating shaft. The anti-rotation ring is radially limited by the plug-in cooperation between the anti-rotation grooves and the protrusions to prevent relative rotation between the sealed runway and the rotating shaft.

[0014] Furthermore, a plurality of anti-rotation bosses are provided radially on the outer wall of the sealed runway. The anti-rotation bosses are arranged at one end of the sealed runway close to the bearing and are locked with the locking structure.

[0015] The anti-rotation boss is arranged between the main sealing interface and the bearing and is arranged axially corresponding to the anti-rotation groove.

[0016] Furthermore, a drawing groove is provided on one end of the inner wall of the sealed runway away from the bearing, and the drawing groove is arranged on the side of the anti-rotation ring away from the bearing.

[0017] Furthermore, the locking structure includes a locking nut abutting against the inner ring of the bearing and a mounting ring fixed to the locking nut at one end away from the bearing. The inner wall of the mounting ring is provided with a plurality of snap-fit ​​grooves corresponding to the anti-rotation bosses at radial intervals. The anti-rotation bosses are radially inserted into the snap-fit ​​grooves and axially fit and seal with the end face of the locking nut.

[0018] Furthermore, a snap ring groove is radially opened on the inner wall of the mounting ring. The snap ring groove is arranged on the side of the snap groove away from the locking nut and is used to install an air-blocking ring to further prevent the impact of gas leaking into the bearing cavity on the bearing.

[0019] According to another aspect of the present invention, an aircraft engine using the bearing cavity sealing device is also provided.

[0020] The present invention has the following beneficial effects:

[0021] 1. The mounting seat of the present invention can integrate the bearing and static seal, simplifying the structure and the number of parts, reducing the occupied space, making the overall structure compact, and meeting the installation requirements of aircraft engines. The static seal is installed in the mounting seat through a sealing housing, which can reduce the radial dimension of the static seal, thereby reducing the linear velocity and minimizing the impact on engine performance.

[0022] 2. The present invention provides a locking structure on the rotating shaft to radially lock the sealing track to the rotating shaft. By reducing the radial gap between the sealing track and the rotating shaft, the radial dimension of the bearing cavity sealing device is reduced, thereby significantly reducing the linear velocity of the bearing cavity sealing device. This reduces the relative motion between the bearing cavity sealing device and the rotating shaft, thereby reducing wear and leakage, improving the sealing effect, increasing the engine's thrust and efficiency, and reducing fuel consumption. At the same time, it avoids subjecting the bearing cavity sealing device to greater thermal and mechanical stress, reduces the risk of fatigue damage, and increases the engine's service life.

[0023] 3. The locking structure and the sealing track seal lock form a retaining ring structure, which not only prevents relative rotation between the sealing track and the rotating shaft, but also the retaining ring structure is set between the bearing and the main sealing interface, which can block the high-temperature, high-pressure sealing gas leaking from the gap of the main sealing interface, preventing it from directly impacting the bearing outer ring, the cage end face or the rolling element, avoiding the bearing temperature from rising and ensuring the safety of the engine.

[0024] 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

[0025] 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:

[0026] Figure 1 2 is a schematic structural diagram of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0027] Figure 2 2 is a schematic structural diagram of a static seal of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0028] Figure 3 FIG1 is a cross-sectional view of a sealing track of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0029] Figure 4 FIG2 is a cross-sectional view II of the sealing raceway of the bearing cavity sealing device according to a preferred embodiment of the present invention;

[0030] Figure 5 1 is a cross-sectional view of a locking structure of a bearing cavity sealing device according to a preferred embodiment of the present invention;

[0031] Figure 6 FIG2 is a cross-sectional view II of the locking structure of the bearing cavity sealing device according to a preferred embodiment of the present invention.

[0032] Legend:

[0033] 100, bearing; 200, rotating shaft; 300, mounting seat; 301, limiting ring platform; 302, bearing retaining ring; 400, dynamic seal; 401, sealing runway; 4011, anti-rotation ring; 4012, anti-rotation groove; 4013, anti-rotation boss; 4014, drawing groove; 402, locking structure; 4021, locking nut; 4022, mounting ring; 4023, snap-fit ​​groove; 4024, snap-fit ​​ring groove; 500, static seal; 501, sealing housing; 5011, limiting boss; 5012, limiting step; 502, graphite seal; 5021, limiting retaining ring; 5022, elastic member; 5023, graphite ring assembly. DETAILED DESCRIPTION

[0034] 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.

[0035] like Figure 1 and Figure 2 As shown, the bearing cavity sealing device of this embodiment includes a mounting seat 300 for mounting a bearing 100, a rotating shaft 200 fixedly mounted within the bearing 100, and a dynamic seal 400 and a static seal 500 sequentially mounted within the bearing cavity along the radial direction of the rotating shaft 200. The dynamic seal 400 includes a sealing track 401 that is fitted onto the rotating shaft 200 with an interference fit, and a locking structure 402 that is threadedly connected to the rotating shaft 200. The locking structure 402 is disposed between the sealing track 401 and the bearing 100 and engages with the sealing track 401 to form a retaining ring structure, which is used to radially lock the sealing track 401 to the rotating shaft 200 and prevent leaking gas from impacting the bearing 100. The static seal 500 includes a sealing shell 501 sealingly mounted on the mounting seat 300 and a graphite seal 502 sealingly mounted on the sealing shell 501. The graphite seal 502 is arranged at the end of the locking structure 402 away from the bearing 100 and is gap-matched with the sealing runway 401 to form a main sealing interface for sealing the bearing cavity.

[0036] When assembling the bearing cavity sealing device, the dynamic seal 400 is assembled first. Specifically, the rotating shaft 200 is fixedly mounted on the inner ring of the bearing 100, and the mounting seat 300 is sleeved on the outside of the bearing 100, so that a bearing cavity is formed between the mounting seat 300 and the rotating shaft 200. The locking structure 402 is threadedly connected to the rotating shaft 200 in the bearing cavity and abuts and seals with the end face of the inner ring of the bearing 100. The sealing runway 401 is interference-fitted on the side of the locking structure 402 away from the bearing 100 and is clamped and locked with the locking structure 402. The end of the sealing runway 401 away from the locking structure 402 is clamped on the end face of the rotating shaft 200 for axial and radial limiting. At this point, the installation of the dynamic seal 400 is completed. Thus, by providing a locking structure 402 on the rotating shaft 200 to radially lock the sealing runway 401 on the rotating shaft 200, relative rotation between the sealing runway 401 and the rotating shaft 200 can be prevented, and the radial gap between the sealing runway 401 and the rotating shaft 200 can be reduced to reduce the radial size of the bearing cavity sealing device, greatly reduce the linear speed of the bearing cavity sealing device, and reduce the relative movement between the bearing cavity sealing device and the rotating shaft 200 to reduce wear and leakage, improve the sealing effect, improve the thrust and efficiency of the engine, reduce fuel consumption, and at the same time avoid causing the bearing cavity sealing device to be subjected to greater thermal stress and mechanical stress, reduce the risk of fatigue damage, and increase the service life of the engine.

[0037] The static seal 500 is then assembled. Specifically, the assembled graphite seal 502 is first sealed and installed in the sealing housing 501. The sealing housing 501 is then interference fit on the mounting seat 300 in the bearing cavity from the side of the inner ring of the bearing 100 away from the sealing runway 401, and is axially limited by the mounting seat 300. The outer ring of the bearing 100 is then installed on the outside of the inner ring of the bearing 100 from the side of the inner ring of the bearing 100 away from the sealing runway 401, and is radially abutted and sealed with the mounting seat 300, so that a main sealing interface with a clearance fit is formed between it and the outer wall of the sealing runway 401. Therefore, the bearing 100 and the static seal 500 can be integratedly installed through the provided mounting seat 300, which can effectively simplify the structure and the number of parts, reduce the occupied space, and make the overall structure compact and highly reliable. The static seal 500 is installed in the mounting seat 300 through the provided sealing shell 501, which can reduce the radial size of the static seal 500 to reduce the linear speed, thereby meeting the long-life and high-performance bearing cavity sealing requirements.

[0038] When the present invention is working, the dynamic seal 400 is interference fitted on the rotating shaft 200 and rotates synchronously with the rotating shaft 200. The static seal 500 is interference fitted on the mounting seat 300 and is gap-matched with the dynamic seal 400 to form a main sealing interface to seal the bearing cavity. A sealing gap is formed between the graphite seal 502 and the sealing runway 401, and the graphite seal 502 can float radially to adapt to the eccentricity of the rotating shaft 200 and follow the jumping of the sealing runway 401. The bearing cavity on the side of the main sealing interface close to the bearing 100 is the low-pressure side, and the side away from the bearing 100 is the high-pressure side, so that the sealing gas on the high-pressure side can enter the low-pressure side through the sealing gap to seal the bearing cavity, thereby preventing the lubricating oil in the bearing cavity from leaking out of the bearing cavity. A locking structure 402 is provided in the bearing cavity between the main sealing interface and the bearing 100, so as to lock it with the sealing runway 401 to form a retaining ring structure. This can prevent the high-temperature, high-pressure sealing gas leaking from the sealing gap from directly aligning with the bearing 100 and impacting the outer ring of the bearing 100, the end face of the retainer or the rolling element, thereby avoiding direct injection causing the temperature of the bearing 100 to rise, ensuring the safety of the engine, and enabling the sealing runway 401 to integrate functions such as sealing, blocking high-temperature gas, and preventing circumferential rotation. The functional integration is high, which greatly improves practicality.

[0039] like Figure 1 and Figure 2 As shown, the inner wall of the mounting seat 300 is provided with a limit ring 301 protruding toward the rotating shaft 200. The limit ring 301 is arranged on the side of the bearing 100 near the static seal 500 and is used to install the sealing housing 501. The sealing housing 501 is sealed against the mounting seat 300 and is engaged with the limit ring 301 for axial positioning. The inner wall of the mounting seat 300 is provided with a limit groove along the radial direction. The limit groove is arranged on the side of the bearing 100 away from the static seal 500 and is used to fix the bearing retaining ring 302. As a result, the bearing retaining ring 302 and the sealing housing 501 are respectively arranged on both sides of the bearing 100 and axially abut against the end face of the outer ring of the bearing 100, thereby achieving axial positioning of the bearing 100.

[0040] like Figure 1 and Figure 2As shown, one end of the sealing housing 501 close to the bearing 100 is bent toward the mounting seat 300 to form a limiting step 5012, and a limiting boss 5011 is radially provided on the inner wall of the sealing housing 501 away from the limiting step 5012. The graphite seal 502 is arranged on the side of the limiting boss 5011 away from the bearing cavity so that the graphite seal 502 can be axially limited and installed through the limiting boss 5011. When installing the seal housing 501, it is axially inserted from one end of the retaining groove on the mounting seat 300 toward one end of the retaining ring 301. This creates an interference fit between the outer wall of the seal housing 501 and the inner wall of the retaining ring 301 to ensure a seal between the seal housing 501 and the mounting seat 300. Simultaneously, the retaining step 5012 of the seal housing 501 is axially engaged with the retaining ring 301 of the mounting seat 300 to limit the axial position. Furthermore, the outer wall of the retaining step 5012 fits tightly against the mounting seat 300, and the end of the retaining step 5012 abuts against the outer ring of the bearing 100, further ensuring a seal between the seal housing 501 and the mounting seat 300. By integrating the seal housing 501 with the mounting seat 300 and cooperating with the bearing retaining ring 302 to axially limit the bearing 100, the number of parts can be significantly reduced, the structure is simplified, and the occupied space is reduced, thus meeting the installation requirements of aircraft engines.

[0041] like Figure 1 and Figure 2 As shown, the graphite seal 502 is arranged on the side of the limiting boss 5011 away from the bearing cavity, and includes a limiting retaining ring 5021, an elastic member 5022 and a graphite ring assembly 5023 which are arranged in sequence along the axial direction of the rotating shaft 200 toward the bearing 100. The limiting retaining ring 5021 is radially inserted and fixed in the sealing shell 501 and is axially fixed to the elastic member 5022. The limiting retaining ring 5021 is arranged parallel to the limiting boss 5011, so that a space for installing the elastic member 5022 and the graphite ring is formed between the limiting boss 5011 and the limiting retaining ring 5021. The two sides of the graphite ring assembly 5023 are axially abutted against the elastic member 5022 and the limiting boss 5011 to form an auxiliary sealing interface.

[0042] Specifically, the elastic member 5022 includes a spring arranged axially and a gasket arranged at both ends of the spring and fixedly connected to the spring. The gasket on the side away from the graphite ring assembly 5023 is fixed on the limiting ring 5021. Under the elastic action of the spring, the gasket close to the graphite ring assembly 5023 generates an extrusion force toward the graphite ring assembly 5023, so as to press the graphite ring assembly 5023 axially onto the limiting boss 5011, so that the two ends of the graphite ring assembly 5023 axially abut against the gasket and the limiting boss 5011 respectively to form an auxiliary sealing interface, which can effectively reduce the impact caused by axial movement of the rotating shaft 200 and further enhance the sealing effect. At the same time, the inner wall of the graphite ring assembly 5023 and the outer wall of the sealing runway 401 are gap-matched to form the main sealing interface. Therefore, there is a sealing gap between it and the sealing runway 401, so that it can float radially to adapt to the eccentricity of the rotating shaft 200 and follow the jumping of the sealing runway 401 to form a non-contact floating ring seal. This method can effectively reduce wear and improve engine performance.

[0043] like Figure 1 、 Figure 3 and Figure 4 As shown, the inner wall of the sealing runway 401 close to the bearing 100 is set as an interference surface that is interference fit with the rotating shaft 200. By interference sleeve-fitting the sealing runway 401 on the rotating shaft 200 so that it rotates synchronously with the rotating shaft 200, a dynamic seal is formed to prevent the leakage of lubricating oil between the sealing runway 401 and the rotating shaft 200, thereby ensuring the sealing effect. The inner wall of the sealing runway 401 away from the bearing 100 is radially provided with an anti-rotation ring 4011. The anti-rotation ring 4011 is axially clamped on the end of the rotating shaft 200 for limiting the position and fitting tightly with the end face of the rotating shaft 200. A plurality of anti-rotation grooves 4012 are radially spaced apart on the anti-rotation ring 4011, and a plurality of protrusions are correspondingly provided axially on the rotating shaft 200. The anti-rotation ring 4011 circumferentially limits the sealing runway 401 through the plug-in cooperation between the anti-rotation grooves 4012 and the protrusions. On the one hand, relative rotation between the sealing runway 401 and the rotating shaft 200 can be prevented, so that the installation of the sealing runway 401 on the rotating shaft 200 is stable and reliable, ensuring that the sealing runway 401 is not affected by the radial runout and axial movement of the rotating shaft 200, and rotates synchronously with the rotating shaft 200. On the other hand, it can further prevent the leakage of lubricating oil between the sealing runway 401 and the rotating shaft 200.

[0044] The number, shape, and size of the anti-rotation grooves 4012 of the sealing track 401 match the protrusions at the end of the rotating shaft 200 to prevent imbalance of the rotating shaft 200. Preferably, the protrusions at the end of the rotating shaft 200 are evenly spaced along the circumference, typically numbering 6-12. The number of anti-rotation grooves 4012 and the number of protrusions are the same to facilitate installation. Preferably, the size of the anti-rotation grooves 4012 is slightly larger than the size of the protrusions to ensure smooth insertion of the protrusions into the anti-rotation grooves 4012. Thus, by snapping the protrusions into the anti-rotation grooves 4012, the sealing track 401 is circumferentially limited, preventing relative rotation between the sealing track 401 and the rotating shaft 200.

[0045] like Figure 3 and Figure 4 As shown, a drawing groove 4014 is provided on the inner wall of the sealing runway 401 at the end away from the bearing 100. The drawing groove 4014 is arranged on the side of the anti-rotation ring 4011 away from the bearing 100. The provision of the drawing groove 4014 provides a fulcrum for the operator. By grasping the drawing groove 4014, force is applied to the sealing runway 401 to install or remove the sealing runway 401 from the rotating shaft 200, saving time and effort and improving assembly and disassembly efficiency. The outer wall of the sealing runway 401 at the end away from the bearing 100 is also provided with a chamfer to guide the installation of the graphite ring and prevent the graphite ring assembly 5023 from being scratched or damaged by the sharp edge of the sealing runway 401 during assembly to the outer wall of the sealing runway 401, thereby avoiding affecting the sealing effect of the graphite ring assembly 5023.

[0046] like Figure 1 、 Figure 3 and Figure 4 As shown, the outer wall of the sealing track 401 is a mating surface for clearance fit with the graphite ring assembly 5023. The outer wall of the sealing track 401, close to the end of the bearing 100, extends radially toward the bearing cavity to form an anti-rotation boss 4013. Several anti-rotation bosses 4013 are arranged at radial intervals along the sealing track 401. The anti-rotation bosses 4013 are arranged in the bearing cavity between the main sealing interface and the bearing 100 and are tightly fitted and locked with the locking structure 402, so that the anti-rotation bosses 4013 are arranged in a On the one hand, it can block the high-temperature, high-pressure sealing gas leaking from the main sealing interface to the bearing cavity, prevent it from directly impacting the bearing 100, avoid impacting the outer ring of the bearing 100, the end face of the retainer or the rolling element, causing the temperature of the bearing 100 to rise, and improve the safety performance of the engine. On the other hand, the circumferential limitation of the sealing runway 401 can be achieved through the snap-fit ​​cooperation between the anti-rotation boss 4013 and the locking structure 402, preventing relative rotation between it and the rotating shaft 200, and ensuring the stable and reliable installation of the sealing runway 401.

[0047] like Figure 1 、 Figure 5 and Figure 6 As shown, the locking structure 402 is disposed within the bearing cavity and includes a locking nut 4021 that abuts against the inner ring of the bearing 100, and a mounting ring 4022 fixed to the end of the locking nut 4021 away from the bearing 100. Specifically, the locking nut 4021 is disposed between the sealing track 401 and the bearing 100 and is threadedly connected to the sealing track 401. The two ends of the locking nut 4021 abut against the anti-rotation boss 4013 and the inner ring of the bearing 100, respectively, to form a seal. The mounting ring 4022 is disposed on the outer periphery of the locking nut 4021 and is radially spaced from the sealing housing 501 to ensure relative rotation between the dynamic seal 400 and the static seal 500, thereby preventing radial collision between the two during relative rotation and ensuring safety. The inner wall of the mounting ring 4022 is provided with a plurality of snap-fit ​​grooves 4023 at intervals along the radial direction. The snap-fit ​​grooves 4023 are correspondingly arranged to the anti-rotation boss 4013 for the anti-rotation boss 4013 of the sealing runway 401 to be inserted and snap-fitted to form a retaining ring structure, and the anti-rotation boss 4013 is tightly sealed with the end face of the locking nut 4021, so that the retaining ring structure can not only circumferentially limit the sealing runway 401, further prevent it from relative rotation with the rotating shaft 200, and ensure the sealing effect between the sealing runway 401 and the rotating shaft 200, but also the retaining ring structure is arranged in the bearing cavity between the main sealing interface and the bearing 100, which can protect the bearing 100 and prevent the high-temperature and high-pressure sealing gas leaking from the sealing gap of the main sealing interface from entering the bearing cavity and directly impacting the outer ring of the bearing 100, the end face of the retaining frame or the rolling element, thereby avoiding direct injection causing the temperature of the bearing 100 to rise, thereby improving the safety and service life of the engine. The inner wall of the mounting ring 4022 is further radially provided with a snap ring groove 4024 , which is arranged on the side of the snap groove 4023 away from the locking nut 4021 and is used to install an air-blocking ring to further prevent the gas leaking into the bearing cavity from impacting the bearing 100 .

[0048] The number, shape and size of the anti-rotation bosses 4013 should match the snap-fit ​​grooves 4023 in the mounting ring 4022 to prevent the generation of an imbalance in the rotating shaft 200. Preferably, the snap-fit ​​grooves 4023 are evenly spaced along the circumference of the mounting ring 4022, and the number thereof is generally 6, 8, 10 or 12. The positions of the anti-rotation bosses 4013 on the sealing runway 401 correspond to the snap-fit ​​grooves 4023 for easy snap-fit ​​installation, and the number of the anti-rotation bosses 4013 can be adaptively adjusted according to the number of snap-fit ​​grooves 4023, but should be less than or equal to the number of snap-fit ​​grooves 4023. Preferably, the size of the anti-rotation bosses 4013 is slightly smaller than the size of the snap-fit ​​grooves 4023 so that the anti-rotation bosses 4013 can be smoothly inserted. In the clamping groove 4023, by inserting the anti-rotation boss 4013 into the clamping groove 4023, not only can the circumferential limitation of the sealing runway 401 be achieved to prevent relative rotation between the sealing runway 401 and the rotating shaft 200, but the sealing runway 401 can also be radially locked on the rotating shaft 200 to reduce the radial distance between the sealing runway 401 and the rotating shaft 200, thereby reducing the overall radial size of the bearing cavity sealing device and greatly reducing its linear speed, thereby ensuring the sealing effect while meeting the long life and high performance requirements of the aircraft engine.

[0049] Preferably, in this embodiment, Figure 4 As shown, the anti-rotation boss 4013 of the sealing runway 401 is axially corresponding to the anti-rotation groove 4012. It is only necessary to adjust the position of the locking groove 4023 of the locking structure 402 to correspond to the anti-rotation boss 4013 of the sealing runway 401, so that the position of the anti-rotation groove 4012 of the sealing runway 401 can be synchronized with the position of the protrusion on the end face of the rotating shaft 200, saving adjustment time and greatly improving assembly efficiency.

[0050] According to another aspect of the present invention, the present invention further provides an aircraft engine having a bearing cavity sealing device as described above.

[0051] 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. A bearing cavity sealing device, characterized in that: It comprises a mounting seat (300) for mounting a bearing (100), a rotating shaft (200) fixedly mounted in the bearing (100), and a dynamic seal (400) and a static seal (500) sequentially mounted in the bearing cavity along the radial direction of the rotating shaft (200); The dynamic seal (400) comprises a sealing track (401) which is interference-fitted on the rotating shaft (200) and a locking structure (402) for radially locking the sealing track (401) on the rotating shaft (200); the locking structure (402) is arranged between the sealing track (401) and the bearing (100) and is engaged with the sealing track (401) to form a retaining ring structure for preventing leaked gas from impacting the bearing (100); The static seal (500) comprises a sealing housing (501) sealingly mounted on the mounting seat (300) and a graphite seal (502) sealingly mounted on the sealing housing (501); the graphite seal (502) is arranged at one end of the locking structure (402) away from the bearing (100) and is clearance-matched with the sealing runway (401) to form a main sealing interface for sealing the bearing cavity; The outer wall of the sealing runway (401) is provided with a plurality of anti-rotation bosses (4013) along the radial direction. The anti-rotation bosses (4013) are arranged at one end of the sealing runway (401) close to the bearing (100) and are locked with the locking structure (402). The locking structure (402) includes a locking nut (4021) abutting against the inner ring of the bearing (100) and a mounting ring (4022) fixed to the end of the locking nut (4021) away from the bearing (100), and the inner wall of the mounting ring (4022) is provided with a plurality of snap-fit ​​grooves (4023) corresponding to the anti-rotation boss (4013) at intervals along the radial direction, and the anti-rotation boss (4013) is radially inserted into the snap-fit ​​grooves (4023) and axially fits and seals with the end face of the locking nut (4021).

2. The bearing cavity sealing device according to claim 1, characterized in that: The inner wall of the mounting seat (300) is provided with a limiting ring platform (301) for sealingly mounting the sealing housing (501) and a limiting groove for mounting a bearing retaining ring (302) in sequence along the axial direction. The bearing retaining ring (302) and the sealing housing (501) are respectively arranged on both sides of the bearing (100) and abut against the end face of the outer ring of the bearing (100) for axial limitation.

3. The bearing cavity sealing device according to claim 2, characterized in that: One end of the sealing housing (501) close to the bearing (100) is bent toward the mounting seat (300) to form a limiting step (5012). The sealing housing (501) is interference-mounted on the inner wall of the limiting ring (301) and is axially abutted and sealed with the limiting ring (301) through the limiting step (5012). A limiting boss (5011) for axially limiting the graphite seal (502) is radially provided on the inner wall of the sealing housing (501) away from the limiting step (5012).

4. The bearing cavity sealing device according to claim 3, characterized in that: The graphite seal (502) comprises a limit ring (5021), an elastic member (5022), and a graphite ring assembly (5023) which are sequentially arranged along the axial direction of the rotating shaft (200) toward the bearing (100); the limit ring (5021) is radially inserted and fixed in the sealing housing (501) and axially fixed to the elastic member (5022); The limiting retaining ring (5021) is parallel to the limiting boss (5011), and the two sides of the graphite ring assembly (5023) are axially abutted against the elastic member (5022) and the limiting boss (5011) to form an auxiliary sealing interface.

5. The bearing cavity sealing device according to claim 1, characterized in that: An anti-rotation ring (4011) is radially provided on the inner wall of the sealed runway (401), and the anti-rotation ring (4011) is provided at an end of the sealed runway (401) away from the bearing, and is used to be clamped on the end of the rotating shaft (200) for axial limitation; The anti-rotation ring (4011) is provided with a plurality of anti-rotation grooves (4012) spaced apart in the radial direction, and the rotating shaft (200) is provided with a plurality of protrusions correspondingly in the axial direction. The anti-rotation ring (4011) is radially limited by plugging and fitting the anti-rotation grooves (4012) with the protrusions, so as to prevent relative rotation between the sealed runway (401) and the rotating shaft (200).

6. The bearing cavity sealing device according to claim 5, characterized in that: The anti-rotation boss (4013) is arranged between the main sealing interface and the bearing (100) and is axially corresponding to the anti-rotation groove (4012).

7. The bearing cavity sealing device according to claim 5, characterized in that: A drawing groove (4014) is further provided on one end of the inner wall of the sealing runway (401) away from the bearing (100), and the drawing groove (4014) is arranged on the side of the anti-rotation ring (4011) away from the bearing (100).

8. The bearing cavity sealing device according to claim 1, characterized in that: The inner wall of the mounting ring (4022) is further provided with a snap ring groove (4024) in the radial direction. The snap ring groove (4024) is arranged on the side of the snap groove (4023) away from the locking nut (4021) and is used for installing an air-blocking ring to further prevent the impact of gas leaking into the bearing cavity on the bearing.

9. An aircraft engine, characterized in that: The bearing cavity sealing device comprises the bearing cavity sealing device according to any one of claims 1 to 8.

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