Combined support cone wall and aeroengine

Abstract

The application provides a combined supporting conical wall for an aero-engine, which comprises two conical wall segments in the axial direction. An interference fit connecting column and a connecting hole are arranged on the two conical wall segments respectively, and a clearance fit connecting key and a connecting groove are arranged on the two conical wall segments respectively. The application also provides an aero-engine comprising the combined supporting conical wall. The combined supporting conical wall can improve the design space of the fuse structure.

Description

Technical Field

[0001] This invention relates to a combined support cone wall and also to an aircraft engine. Background Technology

[0002] Fusible link designs have been used in various types of aero engines. These fusible link structures can actively fail after an FBO (Fault-Break) event, changing the transmission path of unbalanced loads by reducing their own stiffness. This effectively reduces the loads transmitted to critical components and mounting sections, protecting critical components while also meeting the engine's lightweight requirements.

[0003] However, the inventors believe that the design space for traditional fusion structures is limited in terms of fusion threshold and connection stiffness after fusion.

[0004] Therefore, there is a need to provide a fusion structure that can improve design flexibility. Summary of the Invention

[0005] The purpose of this invention is to provide a combined support cone wall that can improve the design space of the fusion structure.

[0006] This invention provides a combined support cone wall for an aero-engine, comprising two cone wall sections along the axial direction. In the combined support cone wall, an interference-fit connecting post and a connecting hole are respectively disposed in the two cone wall sections, and a clearance-fit connecting key and a connecting groove are respectively disposed in the two cone wall sections.

[0007] In one embodiment, each of the two conical wall segments has mating ends that abut against each other. The mating end of each conical wall segment includes two mating end faces and an overlapping surface. The two mating end faces extend radially and are offset axially. The overlapping surface extends axially and connects the two mating end faces, which are respectively an inner mating end face and an outer mating end face located radially inward and outward, respectively. The overlapping surfaces of the two conical wall segments overlap each other, thereby positioning the inner mating end faces of the two conical wall segments opposite each other, and positioning the outer mating end faces of the two conical wall segments opposite each other.

[0008] In one embodiment, the connecting post is axially projecting onto a mating end face of a conical wall segment; and / or, the connecting key is axially projecting onto a mating end face of a conical wall segment.

[0009] In one embodiment, the connecting post and the connecting key are both located on the inner mating end face of their respective conical wall segments.

[0010] In one embodiment, the combined support cone wall includes a plurality of connecting posts and a plurality of connecting keys, which are alternately distributed circumferentially.

[0011] In one embodiment, the connecting post and the connecting key are located on the outer mating end face and the inner mating face of their respective conical wall segments, respectively.

[0012] In one embodiment, the opposing inner mating end faces of the two conical wall segments have an axial gap, and the opposing outer mating end faces of the two conical wall segments have an axial gap.

[0013] In one embodiment, the connecting post is prefabricated with a defect, thereby causing it to melt under a predetermined load.

[0014] In one embodiment, the dimensions of the connecting post are smaller than the dimensions of the connecting key in both the circumferential and radial directions.

[0015] The present invention also provides an aero-engine, including the aforementioned combined support cone wall, wherein the combined support cone wall is the front bearing support cone wall of the fan shaft.

[0016] In the aforementioned combined support cone wall, the connecting column bears the connection stiffness before melting, while the connecting key bears the connection stiffness after melting. That is, the connecting column and connecting key bearing the connection stiffness before and after melting are designed separately, which can give each a larger design space, thus improving the design space of the melting structure. Attached Figure Description

[0017] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0018] Figure 1 This is a schematic diagram of an exemplary aircraft engine.

[0019] Figure 2 This is an exemplary cross-sectional view of the connecting column of the combined support cone wall according to the first embodiment.

[0020] Figure 3 This is an exemplary cross-sectional view showing the connecting key of the combined support cone wall according to the first embodiment.

[0021] Figure 4 This is an exemplary perspective view of the front section of a portion of the conical wall according to the first embodiment.

[0022] Figure 5 This is an exemplary perspective view of the rear section of a portion of the conical wall according to the first embodiment.

[0023] Figure 6 This is an exemplary cross-sectional view of the combined support cone wall according to the second embodiment.

[0024] Figure 7 This is an exemplary perspective view of the front section of a portion of the conical wall according to the second embodiment.

[0025] Figure 8 This is an exemplary perspective view showing the rear section of a portion of the conical wall according to the second embodiment. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual applications without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of these specific embodiments.

[0027] For example, if the first feature, subsequently described in the specification, is formed above or on the second feature, this can include embodiments where the first and second features are formed in a direct connection, or embodiments where an additional feature is formed between the first and second features, so that the first and second features are not directly connected. Furthermore, when the first element is described in a manner connected or combined with the second element, the description includes embodiments where the first and second elements are directly connected or combined with each other, as well as embodiments where one or more other intervening elements are incorporated to indirectly connect or combine the first and second elements with each other.

[0028] Most current civilian turbofan engines have a dual-rotor structure consisting of a high-pressure rotor and a low-pressure rotor. The low-pressure rotor generally includes a fan, a booster stage, a low-pressure turbine, and a shaft, supported by multiple bearings. Among them, bearing #1 and bearing #2 are located near the fan rotor and serve to support and constrain the low-pressure rotor. Bearing #1 and bearing #2 are connected by a cone-shaped support structure for bearing #1, which can transfer the load generated by the fan section of the low-pressure rotor to the intermediate casing. Therefore, during normal operation, the cone-shaped support structure for bearing #1 is a key component for transferring the fan load to the stator casing.

[0029] During turbofan engine operation, large fan blades can break or detach due to factors such as bird strikes, foreign object ingestion, or fatigue, a phenomenon known as FBO (Fan Blade Off). After an FBO event, the low-pressure rotor continues to operate at a high speed, and the detached fan blades are large in size and mass, causing the fan's center of gravity to misalign with the engine's centerline, resulting in a significant unbalanced load. This unbalanced load is transmitted along load-bearing components to the load-bearing casing and further to the aircraft through the mounting joints.

[0030] To ensure the engine's mounting section remains undamaged after an FBO event and can safely navigate the deceleration and turbine rotation phases, ultimately achieving a safe landing, it's necessary to either increase the strength of components and mounting sections along the unbalanced load transmission path or reduce the load on critical components. While increasing the strength of critical components meets safety requirements, it increases engine weight and operating costs, reducing its economic efficiency. Another solution is to design a fuse structure. Fuse design is divided into primary fuse design and secondary fuse design. The primary fuse design is mainly located near bearing #1 and includes two main categories: bearing failure and bearing support cone wall failure. Its functions primarily include: decoupling the fan rotor from the intermediate casing and other fixed support structures, reducing the unbalanced load transmitted to the intermediate casing through the bearing and its supports, thus preventing damage to other critical engine components; and reducing the support stiffness of the fan rotor at bearing #1, lowering the critical speed of the low-pressure rotor, allowing the fan rotor to pass through the critical speed at a lower speed, thereby reducing the unbalanced load. Secondary fusible link designs are generally located near bearing #2. Their purpose is to locally release the radial and pitch stiffness of bearing #2, and to avoid bending stress concentration at bearing #2 on the low-pressure shaft after the failure of the primary fusible link component.

[0031] For example, GE's GEnx-1B engine achieves active fusing of the cone wall by thinning the wall thickness of bearing #1, and reduces the unbalanced load transmitted to critical engine components and the suspension system through FBO unbalanced force reduction design. The GE90-145B engine also achieves fusing design through cone wall thinning. Pratt & Whitney's PW6000 and the GP7000 engine, jointly developed by Pratt & Whitney and GE, use roller bearings for bearing #1 and ball bearings for bearing #2. A primary fusing component is located on the support cone wall of bearing #1, and an inclined support cone wall is used at bearing #2. Under the action of FBO unbalanced force, when the support cone wall of bearing #1 fails, the fan rotor system changes from a simply supported structure to an approximately cantilever beam structure. The inclined support cone wall for bearing #2 increases the effective distance between bearings #1 and #2, further reducing the critical speed of the fan rotor. Rolls-Royce's Trent 500 and RB214 engines employ fusing bearing structures.

[0032] The inventors analyzed the following issues: First, traditional fusion-type structures have limited design space in terms of fusing threshold and post-fusing connection stiffness, resulting in poor design flexibility. Second, considering FBO (Fuel-Based Booster) conditions, traditional designs tend to be conservative, leading to excessively large load-bearing structures and significant strength redundancy in non-FBO conditions. Third, the design of the No. 1 bearing support structure considering FBO conditions is often complex, leading to reduced structural reliability. Fourth, changing the stiffness of the load-bearing structure under FBO conditions redistributes the FBO load, reducing the load on critical components and ensuring engine safety. Fifth, reducing the unbalanced load generated by the low-pressure rotor during an FBO event. Sixth, traditional fusion-type designs cause the No. 1 bearing support structure to completely fracture after an FBO event, completely losing its load-bearing capacity, resulting in the low-pressure rotor completely losing support and constraint at the No. 1 bearing. This increases the fan rotor's swing radius, causing stress concentration at the No. 2 bearing. To alleviate this stress concentration, other mechanisms need to be designed at this location, increasing design complexity and structural weight. Seventh, incorporating primary fusing of bearing #1 and secondary fusing of bearing #2 can solve the problems arising from the failure of bearing #1 alone. However, this leads to complex bearing #1 and bearing #2 support structures. Furthermore, the design requires that bearing #2 not completely fuse; otherwise, it would cause rubbing between the high and low pressure rotors and increase vibration during wind turbine rotation. However, due to machining and assembly errors, there is uncertainty in load redistribution after the primary fusing structure fails, making it difficult to calculate the secondary fusing threshold value and potentially leading to unexpected structural failure. Therefore, this invention aims to provide an improved support cone wall that can at least partially or even completely solve the above problems.

[0033] Figure 1 A partial schematic diagram of an exemplary aero-engine 100 is shown, illustrating the front section structure of the engine. The exemplary aero-engine 100, as an example, is configured as a high- and low-pressure dual-rotor system. Typically, the rotor support scheme involves the low-pressure rotor being supported by bearings #1, #2, and #5, where bearings #1 and #5 are roller bearings, and bearing #2 is a ball bearing. Bearing #1 is hereinafter referred to as the front bearing, and bearing #2 is hereinafter referred to as the rear bearing.

[0034] like Figure 1 As shown, in the aero-engine 100, the fan shaft 40 is supported by both a front bearing 20 and a rear bearing 30. The front bearing 20 can be a roller bearing, providing radial constraint on the fan shaft 40. The rear bearing 30 can be a ball bearing, providing both radial and axial constraint on the fan shaft 40. A combined support cone wall 10 serves as the support structure, connecting the front bearing 20 to the intermediate housing. The combined support cone wall 10 is a crucial path for transferring fan rotor loads to the stator intermediate housing; it can be designed with a fusible link, thus allowing it to fail under a predetermined load.

[0035] Figure 1 The document also shows the intake direction L1, engine axial centerline O1, intake cone 91, nacelle 92, fan blades 93, booster stage blades 94, and intermediate casing outlet guide vanes 95 of the aero engine 100. Additionally, the document references the axial X0, radial R0, and circumferential C0 of the aero engine 100. Figure 4 (As shown in the image) for ease of description.

[0036] Figures 2 to 5 An example construction of the combined support cone wall 10 according to the first embodiment is shown.

[0037] like Figure 2 and Figure 3 As shown, the combined support cone wall 10 is used in an aero-engine 100. The combined support cone wall 10 includes two cone wall segments 1 along the axial direction X0, respectively... Figure 1 The anterior segment 11 and the posterior segment 12 of the middle cone wall.

[0038] The combined support cone wall 10 also includes an interference-fit connecting post 2 and a connecting hole 3. The connecting post 2 and the connecting hole 3 are respectively located in the two cone wall sections 1. That is, when the connecting post 2 is located in the front section 11 of the cone wall, the connecting hole 3 is located in the rear section 12 of the cone wall, as shown below. Figure 2 As shown. Alternatively, the connecting post 2 can be located at the rear section 12 of the cone wall, in which case the connecting hole 3 is located at the front section 11 of the cone wall, as will be described in detail in the second embodiment later.

[0039] The combined support cone wall 10 also includes a clearance-fit connecting key 4 and a connecting groove 5. The connecting key 4 and the connecting groove 5 are respectively located in the two cone wall sections 1. That is, when the connecting key 4 is located in the front section 11 of the cone wall, the connecting groove 5 is located in the rear section 12 of the cone wall, as shown below. Figure 3 As shown. Alternatively, the connecting key 4 can be located at the rear section 12 of the cone wall, in which case the connecting groove 5 is located at the front section 11 of the cone wall.

[0040] The connecting post 2 and the connecting hole 3 are interference-fitted, that is, the connecting post 2 is inserted into the connecting hole 3, and the interference between the connecting post 2 and the connecting hole 3 generates elastic pressure between the surfaces of the parts, thereby achieving a tight connection.

[0041] The connecting key 4 and the connecting groove 5 are fitted with a clearance, that is, the connecting key 4 is inserted into the connecting groove 5, and there is a gap between the connecting key 4 and the connecting groove 5, which allows the connecting key 4 to move in the connecting groove 5.

[0042] It is understood that "along" or "in" a certain direction means that there is at least a component in that direction. Preferably, the angle with that direction is within 45°, and more preferably, the angle is within 20° or even 5°. Furthermore, the terms "perpendicular," "consistent," and "parallel" mentioned in the text do not need to meet strict mathematical angle requirements, but rather allow for a certain tolerance range, for example, a difference of within 20° compared to the mathematically required angle. Moreover, the text mentions "front" and "rear," which are defined with reference to the air intake direction L1 of the aero-engine 100. The direction upstream relative to the air intake direction L1 is considered "front," and the direction downstream is considered "rear."

[0043] When the engine is working normally, the two conical wall sections 1 are connected by the interference fit of the connecting column 2 and the connecting hole 3, which bears and transmits the load and provides support rigidity for the front bearing 20. At this time, the connecting key 4 and the connecting groove 5 do not make contact due to the gap.

[0044] When the load on connecting column 2 exceeds its strength limit, it will actively fail. After connecting column 2 fails, due to the fit clearance between connecting key 4 and connecting groove 5, a certain range of rigid body displacement is allowed between the two conical wall sections 1. After connecting key 4 and connecting groove 5 come into contact, the combined support conical wall 10 regains its connection rigidity and can transfer part of the load.

[0045] The aforementioned combined support cone wall 10 is a combined splicing structure. During normal operation, the connecting column 2 bears the connection stiffness, while after the connecting column 2 melts, the connecting key 4 bears the connection stiffness. This separate design of the structure bearing the connection stiffness before and after melting allows each to have greater design space, thus increasing the design space of the melted structure and enhancing design flexibility.

[0046] Furthermore, the aforementioned combined support cone wall 10 is connected via an interference fit, which provides connection and support stiffness and transmits loads during normal engine operation, while also exhibiting good structural integrity and reliability. Simultaneously, after a meltdown, the mechanical connection is maintained through a slot / key fit, providing support stiffness and transmitting part of the load. This allows for, for example, constraint of the rigid displacement of the low-pressure rotor and the front section 1a of the cone wall. This helps reduce stress concentration and design complexity at the rear bearing, alters the transmission path of unbalanced loads, and improves the safety margin of the intermediate casing.

[0047] In the illustrated embodiment, each of the two conical wall segments 1 has mating ends 14 that abut against each other. The mating ends 14 of each conical wall segment 1 may include two mating end faces 15 and an overlapping surface 16. The two mating end faces 15 may both extend radially R0 and be offset axially X0. The overlapping surface 16 may extend axially X0 and connect the two mating end faces 15. The two mating end faces 15 may be an inner mating end face 151 and an outer mating end face 152 located radially inward and outward, respectively. The overlapping surfaces 16 of the two conical wall segments 1 may overlap each other, thereby making the inner mating end faces 151 of the two conical wall segments 1 face each other, and the outer mating end faces 152 of the two conical wall segments 1 face each other. Specifically, Figure 2 and Figure 3 In the middle, the rear section 12 of the cone wall overlaps the front section 11 of the cone wall, which can ensure the sealing of the structure.

[0048] Figure 2 In the middle, the connecting column 2 is convexly disposed along the axial direction X0 on a section of the mating end face 15 of a conical wall section 1. Figure 3 In this configuration, the connecting key 4 can also be axially protruding along X0 onto a mating end face 15 of a conical wall segment 1. It can be understood that the conical wall segment 1 corresponding to the connecting key 4 can be the same as or different from the conical wall segment 1 corresponding to the connecting post 2. Taking "the conical wall segment 1 corresponding to the connecting key 4" as an example, this refers to the conical wall segment 1 from which the connecting key 4 protrudes in one of the two conical wall segments 1. Figure 2 In the middle, that is, the anterior segment 11 of the cone wall. Combined with... Figure 2 and Figure 3 The connecting column 2 is provided in the inner mating end face 151 of the front section 11 of the cone wall, which protrudes backward along the axial direction X0, while the connecting key 4 is also provided in the inner mating end face 151 of the front section 11 of the cone wall, which protrudes forward along the axial direction X0.

[0049] In the illustrated embodiment, the connecting post 2 is integrally formed with the corresponding conical wall section 1 (i.e., the front section 11 of the conical wall). The connecting key 4 is also integrally formed with the corresponding conical wall section 1 (i.e., the front section 11 of the conical wall).

[0050] Combination Figure 2 and Figure 3 The connecting post 2 and the connecting key 4 can both be located on the inner mating end face 151 of their respective conical wall sections 1 (both are the front sections 11 of the conical wall).

[0051] See Figure 1 and Figure 2 The inner mating end faces 151 of the two conical wall segments 1 that are opposite each other may have a gap in the axial direction X0. Furthermore, the outer mating end faces 152 of the two conical wall segments 1 that are opposite each other may also have a gap in the axial direction X0. This allows for axial rigid body displacement after melting.

[0052] The aforementioned combined support cone wall 10 may include a plurality of connecting posts 2 and a plurality of connecting keys 4. The plurality of connecting posts 2 and the plurality of connecting keys 4 may be alternately distributed along the circumferential direction C0. That is, the plurality of connecting posts 2 are distributed, for example, evenly distributed along the circumferential direction C0, and the plurality of connecting keys 4 are also distributed, for example, evenly distributed along the circumferential direction C0, and the connecting posts 2 and connecting keys 4 are alternately distributed, such as... Figure 4 As shown. Correspondingly, the connecting holes 3 and connecting grooves 5 are also distributed alternately and discretely along the circumferential direction C0. It can be understood that "multiple" in the text means two or more, including two, three, four, five, etc.

[0053] Figure 4 In this embodiment, the dimensions of the connecting post 2 are smaller than those of the connecting key 4 in both the circumferential direction (C0) and the radial direction (R0). In the first embodiment, both the connecting post 2 and the connecting key 4 are cylindrical, meaning the diameter of the connecting post 2 is smaller than the diameter of the connecting key 4. Correspondingly, the connecting hole 3 and the connecting groove 5 also have circular cross-sections. This makes the connecting post 2 easier to fuse. The specific diameter of the connecting post 2 can be determined based on the designed fusing load.

[0054] Figure 2 In the example of the front section 11 of the cone wall, the outer mating end face 152 is located behind the inner mating end face 151. That is, from... Figure 2 See, the rear section 12 of the cone wall overlaps the front section 11 of the cone wall. In fact, both the front section 11 and the rear section 12 of the cone wall are truncated cone shapes.

[0055] See also Figure 3 The key 4 and the connecting groove 5 are fitted with a clearance such that the key 4 has a radial clearance between itself and the sidewall of the connecting groove 5 on both its outer and inner radial sides. The cylindrical key 4 can have a clearance with the circular hole-shaped connecting groove 5 along the circumference of the cylinder, that is, a clearance throughout the entire circumference. Furthermore, Figure 3 In the middle, there is also an axial gap between the bottom of the connecting key 4 and the groove of the connecting groove 5.

[0056] When the engine is operating normally, the front section 11 and the rear section 12 of the cone wall are connected by an interference fit between the connecting post 2 and the connecting hole 3. The cylindrical connecting key 4 and the connecting groove 5 do not contact each other. At the same time, the rear section 12 overlaps the front section 11 of the cone wall to ensure the sealing of the structure. The connecting post 2 can achieve mechanical connection when the engine is operating normally, bear and transmit loads, and provide support rigidity for the front bearing.

[0057] After an FBO event, the rotor generates an unbalanced load. When the load on connecting column 2 exceeds its strength limit, it will actively fail. When connecting column 2 fails, the overlap between the front section 11 and the rear section 12 of the cone wall becomes misaligned. Due to the fit clearance between the connecting key 4 and the connecting groove 5, the front section 11 of the cone wall can undergo small-range rigid body displacements in the axial (X0), circumferential (C0), and radial (R0) directions while maintaining overlap with the rear section 12. This reduces the impact load on the stator while maintaining structural integrity, and accelerates the speed reduction through the friction between the fan blades and the casing. When the rigid body displacement of the low-pressure rotor and the front section 11 of the cone wall becomes excessive, the connecting key 4 and the connecting groove 5 come into contact, thus limiting the rigid displacement of the front section 11 of the cone wall and the low-pressure rotor, preventing excessive fan rotor oscillation, which could damage the fan casing 4 and cause stress concentration at the rear bearing of the fan shaft 40 and the low-pressure shaft. After the connecting key 4 and the connecting groove 5 come into contact, the combined support cone wall 10 regains its connection rigidity and can transfer part of the load.

[0058] The combined support cone wall 10 adopts an integrated design of the cone wall main structure and connecting structure, which can improve the integrity and reliability of the structure. Utilizing interference fits and clearance fits, the support cone wall 10 is a complete connecting structure under normal operation. It can actively fuse after an FBO event, but still retains connection stiffness after fusing, enabling it to transfer loads and provide support. Simultaneously, it allows for a small range of stiffness displacement of the low-pressure rotor and the front section 11 of the cone wall while ensuring the structural integrity of the cone wall. This fusing design has strong design flexibility; the fusing threshold, the connection stiffness after fusing, and the range of rigid movement can all be adjusted according to requirements. For example, different fusing thresholds can be obtained by designing different numbers and sizes of connecting columns 2. Furthermore, the size and number of connecting keys 4 can change the connection stiffness of the front and rear sections of the combined support cone wall 10 after fusing. Finally, the size of the fit clearance between the connecting key 4 and the connecting groove 5 can control the range of rigid displacement of the low-pressure rotor after the cone wall fuses.

[0059] like Figure 1 As shown, the aero-engine 100 provided by the present invention includes the aforementioned combined support cone wall 10. The combined support cone wall 10 can be the front bearing support cone wall of the fan shaft 40.

[0060] The aforementioned combined support cone wall is divided into front and rear sections, connected by an interference fit. Under normal operation, it forms a complete assembly, providing mechanical connection, support stiffness, and load transfer. The integrated design of the cone wall main structure and connecting structure improves structural integrity and reliability. In the event of an FBO (Fault-Boil-Off) event, the combined support cone wall actively melts at the connection between the front and rear sections, altering the load transfer path. This process also absorbs some of the FBO impact energy, reducing the peak FBO load on critical components. Even after an FBO event, if the combined support cone wall melts but does not completely fail, the front and rear sections maintain a mechanical connection through a slot / key fit, providing support stiffness and transferring some load. This constrains the rigid displacement of the low-pressure rotor and the front section of the cone wall, reducing stress concentration and design complexity at the rear bearing, altering the unbalanced load transfer path, and improving the safety margin of the intermediate casing. After an FBO event occurs, due to the certain fit clearance between the slots / keys in the front and rear sections of the cone wall, the front section of the cone wall can undergo a small range of rigid body displacement while maintaining overlap with the rear section of the cone wall. This can reduce the impact load on the stator while maintaining structural integrity, and at the same time increase the friction between the fan blades and the fan casing, thus accelerating the decrease in rotational speed.

[0061] This fusion design can reduce the radial and axial support stiffness provided by the front bearing to the fan shaft after an FBO event, reduce the critical speed of the low-pressure rotor, change the load transmission path, reduce the unbalanced load transmitted to the stator, and protect critical components.

[0062] Figures 6 to 8 A combined support cone wall 10a according to a second embodiment is shown. The same or similar designations are used in the second embodiment to indicate the same or similar technical features as in the first embodiment; similar descriptions are omitted below.

[0063] It is understood that specific terms used in this document to describe embodiments of the present invention, such as "one embodiment," "another embodiment," and / or "some embodiments," refer to a particular feature, structure, or characteristic related to at least one embodiment of the present invention. Therefore, it should be emphasized and noted that "one embodiment" or "another embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the present invention can be appropriately combined.

[0064] like Figure 6 As shown, the connecting post 2a can be prefabricated with defects, thereby causing it to melt and break under a predetermined load. For example, Figure 6In this embodiment, the connecting post 2a narrows at location A1, meaning the diameter of the connecting cylinder serving as the connecting post 2a decreases at location A1, thereby pre-introducing a defect at location A1. In another embodiment, the connecting post 2a may also pre-introduce a crack, thereby pre-introducing a defect. Introducing defects into the connecting post 2a ensures that all connecting posts 2a will fail at a designated location after an FBO event occurs, and introducing different defects can also change the fusing threshold.

[0065] like Figure 7 As shown, the connecting key 4a can be a rectangular key, that is, a connecting key with a rectangular cross-section. Correspondingly, the connecting groove 7a is also a rectangular groove. The rectangular key / groove fit provides connection stiffness to the support cone wall after fusion. The thickness and width of the rectangular connecting key can respectively affect the radial and circumferential connection stiffness of the combined support cone wall 10a after fusion, increasing the design flexibility of the connection stiffness after fusion compared to a cylindrical connecting key. Simultaneously, the rectangular key / groove fit allows for separate design of radial and circumferential clearances, enabling more targeted control of the rigid displacement range of the front section of the cone wall in both directions.

[0066] In the aforementioned combined support cone wall 10a, the connecting column 2a and the connecting key 4a, which bear the connection stiffness before and after the melting, are designed separately, so that each has more design space and will not affect each other.

[0067] The connecting post 2a and the connecting key 4a can be located on the outer mating end face 152a and the inner mating face 151a of their respective conical wall segments 1, respectively. For example... Figure 6 As shown, the connecting post 2a is located on the outer mating end face 152a of the corresponding rear section 12a of the cone wall, while the connecting key 4a is located on the inner mating end face 151a of the corresponding front section 11a of the cone wall.

[0068] In the aforementioned combined support cone wall 10a, taking the front section 11a of the cone wall as an example, the outer mating end face 152a is located in front of the inner mating end face 151a. That is, from... Figure 6 See, the front section 11a of the cone wall overlaps the rear section 12a of the cone wall.

[0069] When the engine is operating normally, in the aforementioned combined support cone wall 10a, the front section 11a and the rear section 12a of the cone wall are connected by an interference fit of a defective connecting post 2a and a connecting hole 3a, while the connecting key 4a and the connecting groove 5a are clearance fits and do not make any contact. The defective connecting post 2a ensures the mechanical connection between the front section 11a and the rear section 12a of the cone wall, bears the load during normal engine operation, and provides support rigidity for the front bearing. After an FBO event occurs, the connecting post 2a breaks at the defect and loses its connecting function. The overlapping position of the front section 11a and the rear section 12a of the cone wall becomes misaligned. Since the connecting key 4a of the front section 11a and the connecting groove 5a of the rear section 12a of the cone wall are clearance fits, this allows the low-pressure rotor to drive the front section 11a to undergo small-range rigid displacements in the axial direction (X0), circumferential direction (C0), and radial direction (R0) while maintaining overlap with the rear section 12a. When the rigid displacement of the front section 11a of the cone wall is greater than the fitting clearance, the connecting key 4a and the connecting groove 5a begin to contact and restrict the rigid displacement of the low-pressure rotor. At this time, the combined support cone wall 10a regains its connection rigidity and can transmit part of the load.

[0070] The aforementioned combined support cone wall 10a offers significant design flexibility in terms of the fusing threshold and the connection stiffness after fusing. The fusing threshold can be designed by changing the number, size, shape, and initial defects of the connecting columns, while the connection stiffness and rigid body displacement range after fusing can be adjusted by changing the dimensions of the connecting key and connecting groove.

[0071] Overall, the aforementioned combined support cone wall consists of a front section and a rear section. Both sections integrate the main cone wall structure and the connecting structure, achieving connection through interference fits. During normal engine operation, it provides connection and support stiffness and transmits loads, while exhibiting good structural integrity and reliability. The combined support cone wall offers high design flexibility; the melting threshold of the cone wall can be adjusted by the size and number of connecting columns and initial defects. The connection stiffness after melting and the allowable rigid body displacement can be adjusted by the size and fit clearance of the connecting groove / key.

[0072] When the aforementioned combined support cone wall serves as the front bearing support cone wall, after an FBO event, the low-pressure rotor experiences a large unbalanced load due to blade shedding. This load is transferred to the potentially failing front bearing support cone wall, causing damage at its connection point until complete failure. This alters the FBO load transmission path, reducing the unbalanced load on the intermediate casing. Simultaneously, the front bearing support cone wall absorbs some transient impact energy, reducing the impact load on the stator components. Moreover, even after an FBO event, the front bearing support cone wall does not completely fail; its front and rear sections remain mechanically connected via a slot / key fit. This allows it to transfer some load and provide support stiffness for the front bearing and low-pressure rotor, while also constraining the rigid displacement of the front section of the cone wall and the low-pressure rotor. After an FBO event, the front and rear sections of the cone wall are mechanically connected via a slot / key clearance fit. This clearance allows the front section of the support cone wall to achieve small-range rigid body movements in the axial, circumferential, and radial directions while maintaining overlap with the rear section. This can reduce the impact load on the stator and increase the friction between the fan blades and the fan casing, accelerating the decrease in speed and thus reducing the unbalanced load.

[0073] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A combined support cone wall for an aero-engine, comprising two cone wall sections along the axial direction, characterized in that, The combined support cone wall also includes: An interference-fit connecting post and a connecting hole are respectively provided in the two conical wall sections; and A clearance fit connecting key and a connecting groove are respectively provided on the two conical wall sections.

2. The combined support cone wall as described in claim 1, characterized in that, Each of the two conical wall segments has mating ends that meet each other; The mating end of each conical wall segment includes two mating end faces and an overlapping surface. The two mating end faces extend radially and are offset axially. The overlapping surface extends axially and connects the two mating end faces. The two mating end faces are respectively an inner mating end face and an outer mating end face located radially inside and outside. The overlapping surfaces of the two conical wall segments overlap each other, thereby making the inner mating end faces of the two conical wall segments face each other, and the outer mating end faces of the two conical wall segments face each other.

3. The combined support cone wall as described in claim 2, characterized in that, The connecting post is axially protruding from a section of the mating end face of a conical wall segment; and / or The connecting key is axially protruding and disposed on a mating end face of a conical wall segment.

4. The combined support cone wall as described in claim 3, characterized in that, Both the connecting post and the connecting key are located on the inner mating end face of their respective conical wall segments.

5. The combined support cone wall as described in claim 4, characterized in that, The combined support cone wall includes multiple connecting columns and multiple connecting keys, which are alternately distributed circumferentially.

6. The combined support cone wall as described in claim 3, characterized in that, The connecting post and the connecting key are respectively located on the outer mating end face and the inner mating face of their respective conical wall segments.

7. The combined support cone wall as described in claim 2, characterized in that, The inner mating end faces of the two conical wall segments that are opposite each other have a gap in the axial direction, and the outer mating end faces of the two conical wall segments that are opposite each other have a gap in the axial direction.

8. The combined support cone wall as described in claim 1, characterized in that, The connecting column is prefabricated with defects, thereby causing it to melt and break under a predetermined load.

9. The combined support cone wall as described in claim 1, characterized in that, The dimensions of the connecting post are smaller than the dimensions of the connecting key in both the circumferential and radial directions.

10. An aircraft engine, characterized in that, Includes the combined support cone wall as described in any one of claims 1 to 9, wherein the combined support cone wall is the front bearing support cone wall of the fan shaft.

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