Sealing oil return structure in bearing cavity

Abstract

The invention discloses a sealing oil return structure in a bearing cavity, which belongs to the technical field of aero-engine structural design and comprises a bearing assembly and a carbon sealing assembly. The bearing assembly comprises a bearing inner ring, a bearing outer ring and a roller arranged between the bearing outer ring and the bearing inner ring. The bearing inner ring is used for being fixed to the shaft body. The carbon sealing assembly comprises a sealing runway, a sealing shell and a graphite ring assembly arranged in the sealing shell, the sealing runway is used for being fixed to the bearing and rotating synchronously with the shaft body, and a sealing gap is formed between the graphite ring assembly and the sealing runway. The radial distance of the sealing gap relative to the shaft is different from the radial distance of the roller relative to the shaft, so that the sealing gap and the roller are staggered. The bearing cavity structure can solve the technical problems that an existing bearing cavity structure is prone to generating lubricating oil leakage and a bearing oil film is prone to failure.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine structural design, in particular to a sealing oil return structure in a bearing cavity. Background Art

[0002] Existing gas turbine engine bearing support systems typically lubricate and cool the bearings through a lubricating oil supply, while also providing a seal to prevent oil leakage and seal gas from entering the bearing cavity. In practice, the seal and bearing are typically aligned at a certain height, and a certain axial distance is maintained between the bearing and the seal to ensure adequate flow area for the oil return channel. However, during engine operation, this presents the following drawbacks:

[0003] On the one hand, under normal oil supply conditions, due to the centrifugal force under high-speed rotation, lubricating oil can easily splash onto the sealing device through the gap between the bearing and the sealing device, causing oil leakage, increasing oil consumption and possibly contaminating the engine air path, reducing system reliability.

[0004] On the other hand, under abnormal operating conditions such as lubricating oil interruption, the sealing gas can blow directly to the bearing rollers or balls through the sealing gap of the sealing device, destroying the residual oil film in the bearing, significantly increasing the friction and heat accumulation rate of the bearing, causing the bearing surface to heat up rapidly and even the risk of over-temperature failure.

[0005] In order to prevent lubricating oil leakage and maintain the integrity of the bearing lubricating oil film, it is urgent to improve the existing bearing cavity sealing and oil return structure, optimize the lubricating oil flow path, limit the sealing airflow impact, and improve the stability and life of the bearing support system. Summary of the Invention

[0006] The present invention provides a sealing oil return structure in a bearing cavity, so as to solve the technical problems that the existing bearing cavity structure is prone to lubricating oil leakage and the bearing oil film is prone to failure.

[0007] According to one aspect of the present invention, a sealed oil return structure in a bearing cavity is provided, comprising a bearing assembly and a carbon sealing assembly; the bearing assembly comprises a bearing inner ring, a bearing outer ring and a roller arranged between the bearing outer ring and the bearing inner ring, the bearing inner ring being used to be fixed on a shaft; the carbon sealing assembly comprises a sealing runway, a sealing housing and a graphite ring assembly arranged in the sealing housing, the sealing runway being used to be fixed on the bearing and rotate synchronously with the shaft, a sealing gap being formed between the graphite ring assembly and the sealing runway, the sealing gap being different from the radial distance relative to the shaft and the radial distance of the roller relative to the shaft, so that the sealing gap and the roller are misaligned.

[0008] Optionally, an oil return structure is provided between the bearing assembly and the carbon seal assembly, and the oil return structure forms a tortuous oil return channel, with two ends of the oil return channel corresponding to the sealing gap and the roller respectively.

[0009] Optionally, the oil return structure includes a first baffle plate arranged on the sealing housing and a second baffle plate arranged on the outer ring of the bearing, the first baffle plate extends axially toward the bearing assembly, the end of the first baffle plate away from the sealing housing is radially bent to fit the outer ring of the bearing, and the second baffle plate extends axially toward the carbon sealing assembly, so that a first axial channel is formed between the first baffle plate and the sealing runway, a second axial channel is formed between the second baffle plate and the sealing runway, and a first bend is formed at the connecting position between the first axial channel and the second axial channel.

[0010] Optionally, the oil return structure also includes a runway support seat, which is used to connect the sealing runway and the shaft body and form a radial height difference between the working surface of the sealing runway and the surface of the shaft body. A third axial channel is formed between the second baffle of the runway support seat and the runway support seat, and a second bend is formed at the connecting position between the third axial channel and the second axial channel.

[0011] Optionally, the second baffle is annular, and the inner diameter is consistent with the inner diameter of the bearing outer ring.

[0012] Optionally, the outer diameter of the second baffle is smaller than the outer radius of the bearing ring, so that a step structure is formed at the connection position between the second baffle and the bearing outer ring, and the end of the first baffle away from the sealing shell extends radially to the step structure position.

[0013] Optionally, an axial limit ring is provided in the sealing housing, and a wave spring is provided between the axial limit ring and the graphite ring assembly.

[0014] Optionally, a washer is provided between the wave spring and the graphite ring assembly.

[0015] Optionally, an oil guide groove corresponding to the oil supply hole on the shaft body is provided on the inner wall of the bearing inner ring, and an oil hole connected to the oil guide groove is provided on the bearing inner ring in a radial direction.

[0016] Optionally, one end of the runway support seat is used to abut against the shoulder on the shaft body, and the other end is tightly attached to the inner ring of the bearing. A locking nut for threaded connection with the shaft body is provided on the side of the inner ring of the bearing away from the runway support seat.

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

[0018] This solution prevents the sealing gas from directly impacting the rollers and retaining cage during lubricating oil interruption conditions by designing a radial offset between the sealing gap and the rollers. This effectively protects the integrity of the residual oil film in the bearing, extends the short-term lubrication time of the bearing under abnormal conditions, and reduces the risk of rapid heating and failure of the bearing. At the same time, by providing ribs on the bearing outer ring and the carbon sealing housing, and cooperating to form an S-shaped oil return channel, the lubricating oil flows along a controlled path under the action of centrifugal force, effectively preventing the lubricating oil from being directly thrown toward the sealing device due to centrifugal splashing, significantly reducing the risk of lubricating oil leakage, and improving oil return efficiency. In addition, by providing a runway support seat, the lubricating oil return path is further extended, the stability of the return oil flow is enhanced, and a clockwise stable vortex flow field is formed, which synergistically improves the return oil volume and the continuity of system lubrication. Overall, the solution of the present invention not only improves the operating reliability and durability of the bearing assembly, but also improves the stability and service life of the lubrication system of the gas turbine engine.

[0019] 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

[0020] 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:

[0021] Figure 1 This is a schematic diagram of the sealing oil return structure in the bearing cavity of the present invention;

[0022] Figure 2 This is a schematic structural diagram of the carbon sealing assembly of the present invention;

[0023] Figure 3 This is a structural diagram of a bearing assembly according to the present invention;

[0024] Figure 4 It is a schematic diagram of the flow of lubricating oil and sealing gas in the present invention.

[0025] Legend:

[0026] 1. Shaft; 2. Bearing assembly; 21. Bearing outer ring; 22. Bearing inner ring; 23. Roller; 24. Cage; 3. Carbon seal assembly; 31. Sealing housing; 32. Graphite ring assembly; 33. Wave spring; 34. Retaining ring; 35. Washer; 4. Bearing seat; 5. Bearing deposit nut; 6. Carbon seal runway; 7. First baffle; 8. Second baffle. DETAILED DESCRIPTION

[0027] 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.

[0028] The following is combined with Figure 1-4 This application is described in further detail.

[0029] The embodiment of the present application discloses a sealing oil return structure in a bearing cavity.

[0030] This embodiment provides a sealing oil return structure in the bearing cavity, which aims to solve problems such as lubricating oil splashing and leakage, sealing gas destroying the bearing oil film and low oil return efficiency, thereby improving the working reliability of the bearing assembly 2 and the overall operating performance of the gas turbine engine.

[0031] Reference Figure 1 The sealed oil return structure within the bearing cavity primarily comprises a bearing assembly 2 and a carbon seal assembly 3. The bearing assembly 2 is mounted on a bearing seat 4 and includes a bearing inner ring 22, a bearing outer ring 21, and a roller 23 disposed between the outer and inner rings 21 and 22. The inner ring 22 is secured to the shaft 1. The carbon seal assembly 3 comprises a sealing raceway, a sealing housing 31, and a graphite ring assembly 32 disposed within the sealing housing 31. The sealing raceway is secured to the bearing and rotates synchronously with the shaft 1, forming a sealing gap between the graphite ring assembly 32 and the sealing raceway. In this embodiment, the sealing gap and the roller 23 have different radial distances relative to the shaft, resulting in a radially offset arrangement. This offset arrangement effectively prevents sealing gas from directly passing through the sealing gap toward the roller 23 and retainer 24. This prevents oil film damage during lubrication interruptions or abnormal operating conditions, reduces friction and temperature rise on the bearing surface, and prevents bearing overheating and failure. At the same time, under normal oil supply conditions, the centrifugal force can be blocked to prevent the oil from being thrown directly to the carbon sealing device, thereby reducing oil leakage and improving the lubrication efficiency of the system.

[0032] Specifically, rollers 23 can be rods or balls, positioned between the inner bearing ring 22 and the outer bearing ring 21, and maintained in spacing by a retainer 24. They are used to carry the radial and axial loads of the bearing assembly 2. The sealing raceway is an annular rotating surface located outside the bearing assembly 2 and rotating synchronously with the shaft 1. It provides sliding contact for the graphite ring assembly 32, creating a seal. The graphite ring assembly 32 is a floating seal element located within the sealing housing 31. A predetermined sealing gap is maintained between its outer circumference and the sealing raceway, ensuring both gas sealing and oil leakage isolation. The sealing gap is the small, pre-set space between the graphite ring assembly 32 and the sealing raceway. This gap ensures that the graphite ring assembly 32 effectively seals the gas during rotational engagement and prevents contact wear under high-speed rotational conditions.

[0033] Reference Figure 2In this embodiment, the interior of the seal housing 31 is provided with an axially arranged axial retaining ring 34, a wave spring 33, a washer 35, and a graphite ring assembly 32. The axial retaining ring 34 is fixedly mounted within the seal housing 31, providing rigid support at the first end to prevent the internal floating element from dislodging or losing its position in the axial direction. The wave spring 33 is positioned between the axial retaining ring 34 and the graphite ring assembly 32, applying a continuous elastic preload to the graphite ring assembly 32 to ensure that the graphite ring assembly 32 maintains proper contact with the sealing track under all operating conditions, thereby achieving a stable sealing effect. To prevent the wave spring 33 from directly acting on the graphite surface during force application, causing localized stress concentration or material damage, a washer 35 is positioned between the wave spring 33 and the graphite ring assembly 32. The washer 35 is preferably made of a high-temperature and wear-resistant metal material. This not only evenly distributes the elastic load of the wave spring 33 but also improves the durability and stability of the device over long-term operation. Through the above-mentioned structural arrangement, a sealing component layout with both flexible compensation capability and rigid limiting characteristics is formed inside the sealing shell 31, which can effectively adapt to the vibration, temperature rise and thermal expansion changes caused by the rotation of the shaft 1, ensuring that the carbon sealing system can continue to work stably in a high-speed and high-temperature environment, and improving the sealing reliability and life of the gas turbine engine bearing support system.

[0034] To ensure the stability and durability of the sealed housing 31 in high-temperature, high-speed environments, it is preferably manufactured from a high-strength, high-temperature-resistant alloy, such as a nickel- or cobalt-based heat-resistant alloy. Ribs or localized thickening may be incorporated into the interior of the housing to enhance its overall rigidity and fatigue resistance, preventing cracking and deformation caused by thermal fatigue or vibration during long-term operation. Furthermore, the surface of the sealed housing 31 may be treated with a corrosion-resistant coating as needed to enhance its durability in complex oil and gas environments.

[0035] To achieve orderly oil return and prevent oil leakage, an oil return structure is installed between the bearing assembly 2 and the carbon seal assembly 3. The oil return structure guides the ejected oil and sealing airflow back to the bearing oil cavity along a specific path, forming a controlled oil return flow field.

[0036] Specifically, the oil return structure consists of a first baffle 7 and a second baffle 8. The first baffle 7 is arranged on the sealing housing 31 and extends axially toward the bearing assembly 2. Its free end is radially bent and close to the surface of the bearing outer ring 21. The second baffle 8 is arranged on the bearing outer ring 21 and extends axially toward the carbon seal assembly 3. A first axial channel is formed between the first baffle 7 and the sealing runway, and a second axial channel is formed between the second baffle 8 and the sealing runway. The two form a first bend at the connecting position. Through the cooperation of the first baffle 7 and the second baffle 8, a tortuous oil return path is constructed, which effectively reduces the radial momentum of the lubricating oil and airflow during the flow process and improves the lubricating oil return efficiency.

[0037] If the first baffle 7 and the second baffle 8 are not respectively provided on the sealing housing 31 and the bearing outer ring 21, the lubricating oil can easily splash radially directly onto the carbon seal assembly 3 and its surrounding structures under the action of centrifugal force during normal operation of the bearing assembly 2, causing the lubricating oil to leak rapidly to the outside under uncontrolled conditions. Furthermore, in the absence of the zigzag channel and the first bend structure formed by the first baffle 7 and the second baffle 8, the lubricating oil flow path is too direct, failing to effectively reduce the radial momentum of the lubricating oil. This not only results in low oil return efficiency but also easily causes localized lubricating oil accumulation, increasing the risk of localized pressure fluctuations within the bearing oil cavity. Furthermore, in the event of lubricating oil interruption, the sealing gas may also flow directly along the axial channel to the rollers 23 and retainer 24, directly destroying the residual oil film in the bearing and exacerbating the risk of friction heating and over-temperature failure of the bearing under abnormal operating conditions.

[0038] In this embodiment, the first baffle 7 is provided on the sealing shell 31 and can be fixed by integral molding or subsequent welding, screw connection, etc. Preferably, the first baffle 7 and the sealing shell 31 adopt an integral molding structure to reduce the number of parts and connection interfaces, and improve the structural strength and sealing reliability. Specifically, the first baffle 7 can be directly formed during the casting or machining process of the sealing shell 31, or it can be connected to the shell by welding or screw connection after the shell is processed. The second baffle 8 is provided on the bearing outer ring 21 and can also be integrally molded or welded. Preferably, the second baffle 8 and the bearing outer ring 21 are integrally machined to ensure the coaxiality and dimensional accuracy of the baffle and the bearing outer ring 21, reduce assembly errors, and improve the consistency of the lubricating oil flow guided by the baffle.

[0039] In terms of shape, the first baffle 7 and the second baffle 8 can be designed as a full-ring structure, i.e., forming a continuous closed ring along the circumference, or as multiple curved plates evenly distributed along the circumference. Specifically, the full-ring baffle is circumferentially continuous and gapless, forming a completely closed oil return channel. This facilitates the continuity of lubricating oil flow and vortex stability, while minimizing the passage of sealing gas directly into the bearing cavity, improving sealing effectiveness and oil return efficiency. This makes it suitable for applications with extremely high requirements for airtightness and lubricating oil return. The multiple curved baffles are evenly spaced along the circumference, typically consisting of three, four, or more segments. This form facilitates manufacturing and assembly, maintaining a certain level of oil return guidance while reducing processing complexity and manufacturing costs. Furthermore, it exhibits a certain degree of adaptability under extreme operating conditions and can tolerate local thermal deformation or assembly errors. This design is suitable for applications requiring cost control or ease of maintenance. Depending on specific usage requirements, a full-ring structure can be selected for superior oil return and sealing performance, or a multi-segment structure can be selected to balance manufacturing convenience and cost control. In this embodiment, the second baffle 8 of the bearing outer ring 21 is provided as a continuous, full circle, while the first baffle 7 of the sealing housing 31 comprises three circumferentially evenly spaced curved plates. The ribs of the bearing outer ring 21, through their continuous annular structure, guide oil splashes, while the ribs of the carbon sealing housing 31, through their locally arranged curved plates, effectively limit the radial momentum of the oil. While maintaining controllable changes in the bearing oil cavity area, this promotes the formation of a stable clockwise vortex flow under the action of centrifugal force, thereby optimizing the oil return path and flow field environment.

[0040] To further optimize oil flow characteristics, the radial bend of the first baffle 7 is arranged opposite the direction of the centrifugal oil splash generated by bearing rotation, while the extension of the second baffle 8 conforms to the oil return flow trend. This relative configuration ensures that during high-speed rotation, the oil is first effectively intercepted by the first baffle 7 and axially guided to the second baffle 8. It is then further guided into the oil return path by the second baffle 8, thereby minimizing the loss of oil kinetic energy and reducing turbulence in the return path. This oil guidance design not only improves oil recovery efficiency but also stabilizes the gas-liquid flow field within the bearing cavity, further enhancing the system's lubrication reliability and airtightness barrier under high-load, long-term operating conditions.

[0041] Reference Figure 1In order to enhance the flow stability and structural rigidity of the oil return path, a runway support seat is provided between the sealing runway and the shaft body 1. One end of the runway support seat abuts against the shoulder on the shaft body 1, and the other end is connected to the sealing runway, so that a radial height difference is formed between the working surface of the sealing runway and the surface of the shaft body 1. A third axial channel is formed between the runway support seat and the second baffle 8, and the third channel is connected to the second axial channel, forming a second bend at the connection point, further extending the lubricating oil return path. In this embodiment, the runway support seat is preferably an annular structure, extending circumferentially around the shaft body 1, and its cross-section can be a stepped or arc transition structure to reduce the flow resistance of the lubricating oil while ensuring rigidity. One end of the runway support seat is fixed to the shoulder of the shaft body 1 by interference fit or threaded connection, and the other end is connected to the bottom of the sealing runway by interference fit or welding, ensuring the positioning accuracy and structural rigidity of the sealing runway in the radial and axial directions. The runway support seat creates a radial height difference between the working surface of the sealed runway and the surface of the shaft body 1. This height difference not only limits the space for the oil return path but also, through the guidance of the potential energy difference, encourages the oil to return axially under the combined effects of centrifugal force and gravity, thereby improving oil return efficiency. Furthermore, the third axial channel formed between the runway support seat and the second baffle 8 has a moderate axial width and radial spacing, ensuring oil flow continuity while suppressing flow separation caused by sudden local changes in flow velocity.

[0042] In this embodiment, the runway support seat not only supports and positions the sealed runway, but also assists in heat exchange within the lubricating oil return path. Because the runway support seat is constructed from a highly thermally conductive metal material and is tightly connected to the shaft 1, it can rapidly transfer a portion of the heat removed by the lubricating oil during the lubricating oil return process to the shaft 1 and surrounding structures, thus assisting in heat dissipation. This structure helps slow the local temperature rise around the bearing, particularly during lubricating oil interruptions or high-load conditions, further ensuring the stability of the lubricating oil viscosity and the persistence of the bearing lubricating oil film, thereby enhancing the operational safety and reliability of the entire bearing support system in high-temperature environments.

[0043] Precision-machined end face positioning chamfers or guide fillets are preferably provided at the shaft shoulder abutment end of the track support seat and the sealing track connection end to guide the mating alignment during assembly and reduce local stress concentration or coaxial deviation caused by assembly offset. Especially under high-speed rotation, optimizing the machining quality of the track support seat end can effectively improve the radial runout control level between the sealing track and the shaft body 1, thereby further enhancing the stability of the lubricating oil return flow field and the smooth operation of the overall sealing system.

[0044] Reference Figure 4In the S-shaped channel formed by the sequential connection of the first axial channel, the second axial channel and the third axial channel, the lubricating oil forms a clockwise flow vortex under the action of centrifugal force, which reduces its radial outward momentum toward the bearing oil chamber while preventing the lubricating oil from splashing, thereby increasing the oil return efficiency and the amount of oil returned. In order to further optimize the lubricating oil return performance, in the S-shaped oil return channel formed by the sequential connection of the first axial channel, the second axial channel and the third axial channel, the cross-sectional area and the channel turning radius of each channel are reasonably designed. Preferably, a smooth transition fillet is provided at the first bend and the second bend to reduce the flow separation and pressure loss of the fluid at the turning point, thereby causing the lubricating oil to form a continuous and stable clockwise vortex flow field in the channel. Through this flow field control design, not only the oil return efficiency of the lubricating oil is improved, but also the risk of the sealing gas flowing back into the bearing chamber is effectively reduced, thereby further ensuring the stability of the bearing lubrication environment and the sealing reliability.

[0045] Second baffle 8 is sized so that its inner diameter matches that of bearing outer ring 21, while its outer diameter is smaller than that of bearing outer ring 21. This creates a stepped structure between bearing outer ring 21 and second baffle 8. This stepped structure, combined with the radially extending end of first baffle 7, provides effective positioning support, ensuring the axial and radial stability of first baffle 7 in the oil return passage, further guaranteeing the stability of the oil return passage and the continuity of lubricating oil flow.

[0046] To further optimize the positioning accuracy of the first baffle 7 and the structural stability of the oil return channel, the stepped structure is preferably a radially formed right-angled step or a rounded transition step. The step height and radial dimensions are determined based on the thickness of the end of the first baffle 7 and the positioning requirements, ensuring a precisely matched stop surface between the bearing outer ring 21 and the second baffle 8. The radially extending end of the first baffle 7 can be designed with a slight clearance fit within the stepped structure. This design allows for a small amount of assembly clearance in the cold state to accommodate dimensional changes caused by material expansion under high-temperature conditions, ensuring the continued effectiveness of the positioning function under varying operating conditions. This stepped positioning effectively mitigates the risk of displacement of the first baffle 7 caused by high-speed oil erosion, axial vibration, and rotational inertia, preventing the oil return channel from shifting or deforming during operation. Furthermore, the stepped structure provides a clear assembly reference surface for the installation of the first baffle 7, reducing assembly errors and improving system consistency and reliability. This further ensures the flow continuity and stability of the oil within the oil return channel, enhancing the overall performance of the oil return system.

[0047] Reference Figure 3In terms of the oil supply path, the inner wall of the bearing inner ring 22 is provided with an oil guide groove, which is connected to the oil supply hole on the shaft body 1; at the same time, the bearing inner ring 22 is also provided with oil holes in the radial direction, which are used to radially spray the lubricating oil in the oil supply hole, thereby lubricating the roller 23 and the raceway, effectively taking away the heat from the bearing operation, and ensuring the long-term and stable operation of the bearing assembly 2.

[0048] In this embodiment, one end of the runway support seat is tightly abutted against the shoulder on the shaft body 1 through the end face, forming a first positioning surface for providing thrust support in the axial direction. The other end of the runway support seat is fitted with the bearing inner ring 22 through the end face, forming a second positioning surface for accurately positioning the bearing inner ring 22 on the outer surface of the shaft body 1. A clamping nut is provided on the side of the bearing inner ring 22 away from the runway support seat. The clamping nut is threadedly connected to the shaft body 1 and, when tightened, presses and fixes the bearing inner ring 22 and the runway support seat together on the shaft body 1. Through this connection structure, the runway support seat and the bearing inner ring 22 are clamped together between the shoulder and the clamping nut, forming a complete axial positioning and clamping system. This structure can not only effectively resist axial thrust loads and prevent axial displacement of the bearing assembly 2 during operation, but also provide stable radial support through the runway support seat to ensure the concentricity between the sealed runway and the shaft body 1. In addition, detachable locking is achieved through threaded connection, which facilitates subsequent maintenance and inspection. Overall, this connection layout achieves integrated support and positioning of the bearing assembly 2 and the sealing assembly, greatly improving the stability and reliability of the system in high-speed and high-temperature environments.

[0049] To improve the compression nut's ability to prevent loosening under high-speed conditions, a self-locking mechanism can be preferably incorporated into the threaded connection, such as a fine-pitch thread, a self-locking thread coating, or the addition of a locking washer 35. If necessary, a mechanical anti-loosening mechanism can be formed by providing a locking hole around the compression nut and inserting it into the locking pin on the shaft 1. These measures ensure that the runway support and bearing assembly 2 maintain a stable clamping state even during prolonged high-speed operation, effectively preventing bearing positioning failure and lubrication abnormalities caused by loosening.

[0050] This embodiment forms a bearing support system with excellent sealing performance and oil return control capabilities through the systematic optimization design of the sealing oil return structure in the bearing cavity. The staggered arrangement of the sealing gap and the roller 23 effectively avoids direct erosion of the bearing oil film by the sealing gas, thereby improving the lubrication continuity of the bearing under lubricating oil interruption conditions. The tortuous oil return path constructed by the first baffle 7 and the second baffle 8 significantly weakens the radial splash momentum of the lubricating oil and enhances the stability and continuity of the lubricating oil return flow. The introduction of the runway support seat and the step structure further improves the positioning accuracy and structural rigidity of the sealing runway and the bearing assembly 2. At the same time, the rational arrangement of the axial limit ring 34, the wave spring 33 and the gasket 35 inside the sealing housing 31 realizes the organic combination of floating sealing and elastic compensation functions, thereby improving the adaptability of the sealing system to vibration, temperature rise and thermal deformation. In general, the solution of the present invention can effectively control lubricating oil leakage, improve the bearing oil film retention capability, extend the service life of the bearing assembly 2, and significantly improve the operating reliability and durability of the gas turbine engine under high speed, high temperature, and high load conditions.

[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 shall be included within the scope of protection of the present invention.

Claims

1. The sealing oil return structure in the bearing cavity is characterized by: It includes a bearing assembly (2) and a carbon seal assembly (3); The bearing assembly (2) comprises a bearing inner ring (22), a bearing outer ring (21), and a roller (23) disposed between the bearing outer ring (21) and the bearing inner ring (22), wherein the bearing inner ring (22) is used for being fixed on the shaft body (1); The carbon sealing assembly (3) comprises a sealing raceway, a sealing housing (31), and a graphite ring assembly (32) disposed in the sealing housing (31); the sealing raceway is used to be fixed on a bearing and rotate synchronously with the shaft (1); a sealing gap is formed between the graphite ring assembly (32) and the sealing raceway; The radial distance of the sealing gap relative to the shaft is different from the radial distance of the roller (23) relative to the shaft, so that the sealing gap and the roller (23) are misaligned.

2. The bearing cavity sealed oil return structure according to claim 1, characterized in that: An oil return structure is provided between the bearing assembly (2) and the carbon seal assembly (3), the oil return structure forming a tortuous oil return channel, with the two ends of the oil return channel corresponding to the sealing gap and the roller (23) respectively.

3. The bearing cavity sealed oil return structure according to claim 2, characterized in that: The oil return structure comprises a first baffle (7) arranged on the sealing housing (31) and a second baffle (8) arranged on the bearing outer ring (21), wherein the first baffle (7) extends axially in a direction close to the bearing assembly (2), and one end of the first baffle (7) away from the sealing housing (31) is bent radially to fit the bearing outer ring (21), and the second baffle (8) extends axially in a direction close to the carbon sealing assembly (3), so that a first axial channel is formed between the first baffle (7) and the sealing runway, and a second axial channel is formed between the second baffle (8) and the sealing runway, and a first bend is formed at a position where the first axial channel and the second axial channel are connected.

4. The bearing cavity sealed oil return structure according to claim 3, characterized in that: The oil return structure further comprises a runway support seat, the runway support seat being used to connect the sealing runway and the shaft body (1) and to form a radial height difference between the working surface of the sealing runway and the surface of the shaft body (1); a third axial channel being formed between the second baffle (8) of the runway support seat and the runway support seat; and a second bend being formed at a position where the third axial channel communicates with the second axial channel.

5. The bearing cavity sealed oil return structure according to claim 3, characterized in that: The second baffle (8) is annular, and its inner diameter is consistent with the inner diameter of the bearing outer ring (21).

6. The bearing cavity sealed oil return structure according to claim 5, characterized in that: The outer diameter of the second baffle (8) is smaller than the outer radius of the bearing ring, so that a step structure is formed at the connection position between the second baffle (8) and the bearing outer ring (21), and the end of the first baffle (7) away from the sealing housing (31) extends radially to the step structure position.

7. The bearing cavity sealed oil return structure according to claim 6, characterized in that: An axial limit ring (34) is provided in the sealing housing (31), and a wave spring (33) is provided between the axial limit ring (34) and the graphite ring assembly (32).

8. The bearing cavity sealed oil return structure according to claim 7, characterized in that: A washer (35) is provided between the wave spring (33) and the graphite ring assembly (32).

9. The bearing cavity sealed oil return structure according to claim 8, characterized in that: An oil guide groove corresponding to the oil supply hole on the shaft body (1) is provided on the inner wall of the bearing inner ring (22), and an oil hole communicating with the oil guide groove is provided on the bearing inner ring (22) along the radial direction.

10. The bearing cavity sealed oil return structure according to claim 4, characterized in that: One end of the runway support seat is used to abut against a shaft shoulder on the shaft body (1), and the other end is tightly attached to the bearing inner ring (22); a compression nut for threaded connection with the shaft body (1) is provided on the side of the bearing inner ring (22) away from the runway support seat.

Images