A connecting structure of a three-cascade engine turbine support force case

Abstract

The application discloses a connecting structure of a three-cascade engine turbine supporting force case, which comprises a sleeve type assembled turbine supporting outer case and an outer channel case, and a plurality of eccentric sleeve tooth connecting structures with joint bearings are uniformly used between the turbine supporting outer case and the outer channel case for connection; the eccentric sleeve tooth connecting structure comprises an eccentric shaft support welded on the outer channel case and a stamping case; the stamping case is arranged on the outer side of the outer channel case in a spaced sleeve mode; a sliding groove seat with a U-shaped sliding groove with an opening facing radially inward is mounted on the inner wall surface of the stamping case; a supporting rod is mounted on the eccentric shaft support, and the outer side end of the supporting rod is provided with a sliding block which is slidably inserted into the U-shaped sliding groove. The application realizes the improvement of a traditional turbine engine into a three-cascade engine, facilitates the assembly and load transmission among the stamping case, the outer channel case and the turbine supporting outer case, improves the reliability of the turbine supporting and the outer channel case, and has a remarkable effect.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to a connection structure for a turbine support bearing casing of a three-duct engine. Background Technology

[0002] With the rapid development of the aviation industry, traditional turbofan engines can no longer meet the current dual performance requirements of high thrust and low fuel consumption. To address this, a variable cycle engine with a third bypass duct has been proposed. Traditional turbofan engines have two airflow modes: the core engine and the bypass duct. The three-bypass engine has an additional bypass duct. The third airflow in this outer duct is generated by an adaptive fan, which can improve aerodynamic efficiency and increase engine power. However, regardless of whether it is a traditional aero engine or a three-ducted engine, during its operation, the turbine components are subjected to the impact of high-temperature gas from the combustion chamber, causing the turbine components to be subjected to alternating stresses such as thermal stress, thermal shock, and vibration loads. The harsh working conditions will cause various loads to be generated on each component. Some of these loads are balanced within the parts and assemblies and are not transmitted outwards, while some loads need to be transmitted to adjacent components. For example, the inertial force and inertial torque of the rotor need to be transmitted through the support, while the aerodynamic force of some components needs to be transmitted to the turbine casing. As the main load-bearing frame, the turbine support casing bears the aerodynamic loads and external forces during engine operation. This will cause the connection of the multi-layer casing to be unable to expand freely in the axial direction, resulting in high thermal stress concentration. At the same time, under the addition of external forces, cracks will be initiated and propagated. In addition, when the multi-layer casing is cold-connected, the cumulative error of the circumferential datum machining will cause circumferential positioning eccentricity, increasing the assembly difficulty.

[0003] Modern conventional engines consist only of a turbine support and an outer casing. The connection structure design of the two casings is quite mature. For example, patent application CN117927319A discloses a connection structure between the turbine support and the outer casing of a turbofan engine. This structure is a two-casing connection structure that uses bushings, spherical bearings, and axial grooves to transfer the load from the rotor and stator components and release the stress caused by thermal deformation. This connection structure can eliminate the over-constraint of the connection point between the outer casing and the outer casing using spherical bearings, and can also achieve self-adjustment of the casing's torsional deformation during operation. At the same time, an eccentric sleeve structure composed of an internal toothed plate and an external toothed eccentric shaft is added to the bushing. The eccentric sleeve structure can ensure reliable centering connection during assembly. The slight eccentricity combined with the automatic adjustment characteristics of the spherical bearings can facilitate the circumferential positioning between the outer casing and the supporting outer casing during cold assembly, avoid assembly stress, and eliminate deviations caused by machining and assembly. At the same time, during hot operation, its own deformation coordination tolerance can greatly reduce the stress caused by complex loads.

[0004] The existing two-layer casing connection structure of CN117927319A uses multiple sets of eccentric sleeve gear connection structures with spherical bearings for connection. However, to improve the existing two-layer casing connection structure by adding a stamped casing to it, transforming it into a three-duct engine, and ensuring that the casing and load-bearing components can reliably and reasonably bear and distribute various loads, it is necessary to invent a connection structure that allows the turbine support, outer casing, and outer duct stamped duct casing to move in the axial direction, transmit torque to each other, avoid stress concentration, and reduce cold assembly stress. Summary of the Invention

[0005] The main objective of this invention is to propose a connection structure for the turbine support bearing casing of a three-duct engine, aiming to solve the aforementioned technical problems.

[0006] To achieve the above objectives, this invention proposes a connection structure for a turbine support bearing casing of a three-ducted engine, comprising a turbine support outer casing and an outer bypass casing assembled in a sleeve-type manner. The turbine support outer casing and the outer bypass casing are connected circumferentially using multiple sets of eccentric sleeve tooth connection structures with spherical bearings. The eccentric sleeve tooth connection structure includes an eccentric shaft bracket welded to the outer bypass casing and a stamped casing. The stamped casing is spaced and sleeved on the outer side of the outer bypass casing. A sliding groove seat is installed on the inner wall of the stamped casing, and the sliding groove seat has a U-shaped sliding groove with its opening facing radially inward. A support rod is installed on the eccentric shaft bracket, and the outer end of the support rod is configured as a slider, which is slidably inserted into the U-shaped sliding groove.

[0007] Preferably, the U-shaped groove is parallel to the engine axis.

[0008] Preferably, the slide seat has integrally formed flange plates on both sides, and bolt holes are provided on the flange plates; a connection hole is provided on the stamping housing; the slide seat and the stamping housing are connected by bolts; the bolts pass through the bolt holes on the flange plates from the inside to the outside, and through the connection holes of the stamping housing, and are then screwed with lock nuts.

[0009] Preferably, a bolt bushing is provided on the connecting hole of the stamping housing; an annular washer is integrally formed on the outer end of the bolt bushing; the annular washer is located between the outer surface of the stamping housing and the locking nut.

[0010] Preferably, the bolt holes on the slide seat are oblong holes.

[0011] Preferably, the top surface of the slider at the outer end of the support rod is spaced apart from the bottom of the U-shaped groove.

[0012] Preferably, the slider at the outer end of the support rod slides in surface contact with both sides of the U-shaped groove.

[0013] Preferably, the lower end of the support rod has ear plates integrally formed on both sides, and the ear plates are connected to the external tooth eccentric shaft by a first screw; a light-reducing hole is provided in the center of the support rod.

[0014] Preferably, the eccentric toothed connection structure includes an internal toothed plate, and the top of the eccentric shaft bracket is provided with a mounting boss; the internal toothed plate is disposed between the bottom end face of the support rod and the mounting boss of the eccentric shaft bracket; the first screw passes through the ear plate and the internal toothed plate from top to bottom and is then screwed onto the mounting boss of the eccentric shaft bracket.

[0015] Preferably, the outer surface of the slide seat is configured as an arc-shaped surface, the diameter of which is the same as the inner diameter of the stamping housing.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0017] (1) By adding a support rod, a stamping casing and a slide seat on the basis of existing technology, and installing the support rod on the eccentric shaft bracket in the existing eccentric sleeve tooth connection structure, and setting the outer end of the support rod as a slider, and installing the slide seat on the inner surface of the stamping casing, the slider at the outer end of the support rod can be slidably inserted into the U-shaped slide of the slide seat, the traditional turbine engine is improved into a three-duct engine, and the assembly and load transfer between the stamping casing, the outer bypass casing and the turbine support outer casing are facilitated, and the reliability of the turbine support and the outer bypass casing is improved, with significant effect.

[0018] (2) In this invention, since the U-shaped groove of the slide seat is parallel to the axis of the engine, the slider at the outer end of the support rod can slide in the U-shaped groove in a direction parallel to the engine axis, thereby achieving coordinated axial expansion deformation displacement of the turbine support outer casing and outer bypass casing relative to the stamping casing when working in cold and hot states. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the connection structure of the turbine support bearing casing of the three-ducted engine provided by the present invention.

[0021] Figure 2 for Figure 1 A cross-sectional view along direction B after removing the stamping chamber and slide block;

[0022] Figure 3 This is a front sectional view of the support rod in this invention;

[0023] Figure 4 This is a top view of the support rod in this invention;

[0024] Figure 5 This is a schematic diagram of the connection structure between the stamping chamber and the slide seat in this invention;

[0025] Figure 6 This is a front view of the slide seat in this invention;

[0026] Figure 7 This is a bottom view of the slide seat in this invention;

[0027] Figure 8 This is a schematic diagram of the external tooth eccentric shaft in this invention;

[0028] Figure 9 This is a schematic diagram of the internal toothed plate in this invention.

[0029] Reference numerals: 1. Stamping housing; 2. Slide seat; 2a. U-shaped slide; 2b. Flange plate; 2c. Bolt hole; 2d. Arc surface; 3. Support rod; 3a. Slider; 3b. Ear plate; 4. Eccentric shaft bracket; 4a. Mounting boss; 5. External gear eccentric shaft; 5a. External gear section; 5b. Rotary shaft section; 5c. Eccentric shaft section; 6. Bushing; 7. Turbine support outer housing; 8. Outer bypass housing; 9. Bolt; 10. Bolt bushing; 10a. Annular washer; 11. Locking nut; 12. First screw; 13. Internal gear plate; 13a. Internal gear hole; 14. Second screw; 15. Mounting seat; 16. Bushing bracket; 16a. Axial slide. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0032] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0033] Combination Figure 1 , Figure 2 As shown, a connection structure for a turbine support bearing casing of a three-ducted engine includes a turbine support outer casing 7 and an outer bypass casing 8 assembled in a sleeve-type configuration. The turbine support outer casing 7 and the outer bypass casing 8 are connected circumferentially using 12 sets of eccentric toothed connection structures with spherical bearings. The eccentric toothed connection structure includes an eccentric shaft bracket 4 welded to the outer bypass casing 8. The turbine support outer casing 7 and the outer bypass casing 8 are assembled in a sleeve-type configuration, providing the turbine support outer casing 7 with axial movement allowance within the outer bypass casing 8. The eccentric toothed connection structure has been described in patent application publication number CN117927319A and is considered prior art.

[0034] Furthermore, the connection structure of the turbine support bearing casing of the three-ducted engine provided in this embodiment also includes a stamped casing 1; the stamped casing 1 is spaced and sleeved on the outside of the outer bypass casing 8; a sliding groove seat 2 is installed on the inner wall surface of the stamped casing 1, and the circumferential position of the sliding groove seat 2 on the stamped casing 1 corresponds to the position of the eccentric sleeve tooth connection structure. The sliding groove seat 2 has a U-shaped sliding groove 2a with its opening facing radially inward; a support rod 3 is installed on the eccentric shaft bracket 4, and the outer end of the support rod 3 is configured as a slider 3a, which is slidably inserted into the U-shaped sliding groove 2a.

[0035] By adopting the above structure, a support rod 3, a stamping housing 1, and a sliding seat 2 are added to the existing eccentric sleeve tooth connection structure. The support rod 3 is installed on the eccentric shaft bracket 4, and the outer end of the support rod 3 is set as a slider 3a. The sliding seat 2 is installed on the inner surface of the stamping housing 1. The slider 3a at the outer end of the support rod 3 is slidably inserted into the U-shaped sliding groove 2a of the sliding seat 2. This realizes the transformation of the traditional turbine engine into a three-duct engine, and facilitates the assembly and load transfer between the stamping housing 1, the outer bypass housing 3, and the turbine support outer housing 7. It also improves the reliability of the turbine support 7 and the outer bypass housing 8, with significant effects.

[0036] Combination Figure 1 , Figure 5 As shown, the U-shaped groove 2a is parallel to the engine axis. Figure 1 The center line represented by the letter A indicates the engine's axis. Figure 5 The view shown is taken along the engine axis, and it can be seen that the U-shaped groove 2a is parallel to the engine's central axis A. By adopting this structure, the slider 3a at the outer end of the support rod 3 can slide within the U-shaped groove 2a in a direction parallel to the engine axis A, thereby achieving coordinated axial expansion and deformation displacement of the turbine support outer casing 7 and outer bypass casing 8 relative to the stamping casing 1 during cold and hot operation.

[0037] Combination Figures 5 to 7 As shown, the slide seat 2 has integrally formed flange plates 2b on both sides, and bolt holes 2c are provided on the flange plates 2b; a connecting hole 1b is provided on the stamping housing 1; the slide seat 2 and the stamping housing 1 are connected by bolts 9; the bolts 9 pass through the bolt holes 2c on the flange plates 2b from the inside to the outside, and through the connecting hole 1b on the stamping housing 1, and are then screwed with a lock nut 11. By using bolt connection, the slide seat 2 and the stamping housing 1 are securely connected.

[0038] Combination Figure 5 As shown, in order to avoid direct contact between the stamping housing 1 and the bolt 9, which would cause wear to the connecting hole 1b, and to avoid direct contact between the locking nut 11 and the stamping housing 1, which would also cause wear to the stamping housing 1, a bolt bushing 10 is provided on the connecting hole 1b of the stamping housing 1, and the bolt 9 is inserted into the inner hole of the bolt bushing 10; an annular washer 10b is integrally formed on the outer end of the bolt bushing 10; the annular washer 10b is located between the outer surface of the stamping housing 1 and the locking nut 11, and the annular washer 10b acts as a gasket.

[0039] Combination Figure 7 As shown, the bolt hole 2c on the slide seat 2 is an oblong hole, meaning that the length dimension a of the bolt hole 2c is greater than the width dimension b. By using this oblong hole to cooperate with the bolt 9, during assembly, the position of the slide seat 2 in the circumferential direction of the stamping housing 11 can be slightly adjusted along the length direction of the oblong hole, eliminating the slight circumferential eccentricity between the outer casing 8 and the stamping housing 1 during assembly. After the position of the slide seat 2 is adjusted to the correct position, the locking nut 11 is tightened for secure fastening.

[0040] Combination Figure 1 As shown, the top surface of the slider 3a at the outer end of the support rod 3 is spaced apart from the bottom of the U-shaped groove 2a, i.e., there is a gap T. By setting the gap T, the radial expansion deformation displacement of the turbine support outer casing 7 and outer bypass casing 8 relative to the stamping casing 1 is coordinated during cold and hot operation.

[0041] Combination Figure 3 , Figure 5As shown, the slider 3a at the outer end of the support rod 3 slides in surface contact with the two sides of the U-shaped groove 2a. Specifically, the M and N surfaces of the slider 3a are planes, which slide in surface contact with the two straight surfaces of the U-shaped groove 2a respectively. Using surface contact sliding helps to improve the smoothness of the slider 3a sliding in the U-shaped groove 2a.

[0042] Combination Figure 3 , Figure 4 As shown, the lower end of the support rod 3 has integrally formed ear plates 3b on both sides, which are connected to the external toothed eccentric shaft 4 by a first screw 12; a light-reducing hole 3c is provided in the center of the support rod 3. Further, the eccentric toothed connection structure includes an internal toothed plate 13, and a mounting boss 4a is provided on the top of the eccentric shaft bracket 4; the internal toothed plate 13 is disposed between the bottom end face of the support rod 3 and the mounting boss 4a of the eccentric shaft bracket 4; the first screw 12 passes through the ear plates 3b and the internal toothed plate 13 from top to bottom and is then screwed onto the mounting boss 4a of the eccentric shaft bracket 4. The support rod 3 and the internal toothed plate 13 can be simultaneously mounted on the mounting boss 4a of the eccentric shaft bracket 4 using two first screws 12.

[0043] Combination Figure 6 As shown, the outer surface of the slide seat 2 is configured as an arc-shaped surface 2d, the diameter of which is the same as the inner diameter of the stamping housing 1. When the slide seat 2 is assembled on the stamping housing 1, the arc-shaped surface 2d of the slide seat 2 can fit against the inner surface of the stamping housing 1, improving the stability of the assembly.

[0044] Combination Figure 1 , Figure 2 as well as Figure 8 , Figure 9As shown, the eccentric gear connection structure includes an eccentric shaft support 4, an external gear eccentric shaft 5, a bushing 6, an internal gear plate 13, and a bushing support 16. A mounting base 15 is provided on the turbine support outer casing 7. A positioning hole is provided in the center of the mounting base 15 for positioning the bushing support 16. Specifically, a positioning ring at the lower end of the bushing support 16 is inserted into the positioning hole in the center of the mounting base 15 for positioning. The bushing support 16 is fastened to the mounting base 15 of the turbine support outer casing 7 by two second screws 14. An axial groove 16a is fixedly provided on the top of the bushing support 16. The axial groove 16a is parallel to the central axis A of the engine. The bushing 6 is slidably mounted in the axial groove 16a, and a spherical bearing is provided inside the bushing 6. The external toothed eccentric shaft 5 includes an external toothed section 5a, a rotating shaft section 5b, and an eccentric shaft section 5c. The axes of the external toothed section 5a and the rotating shaft section 5b coincide, and the axis of the eccentric shaft section 5c is offset by a distance L relative to the axis of the rotating shaft section 5b. External teeth are provided on the outer circumferential surface of the external toothed section 5a. The center of the internal toothed plate 13 has an internal toothed hole 13a, and the inner circumferential surface of the internal toothed hole 13a is provided with internal teeth. The rotating shaft section 5b of the external toothed eccentric shaft 5 is rotatably inserted into the eccentric shaft bracket 4. The external toothed section 5a of the external toothed eccentric shaft 5 mates with the internal toothed hole 13a of the internal toothed plate 13. The eccentric shaft section 5c of the external toothed eccentric shaft 5 is inserted into the spherical bearing inside the bushing 6.

[0045] Since the bushing 6 can slide axially within the axial groove 16a of the bushing support 16, the turbine support outer casing 7 can coordinate with the outer bypass casing 8 in terms of axial dimensional expansion, deformation and displacement during cold and hot operation.

[0046] An adjusting screw hole is provided at the top of the external gear eccentric shaft 5. During assembly, when it is necessary to adjust the slight circumferential eccentricity between the turbine support outer casing 7 and the outer bypass casing 8, an adjusting bolt (not shown in the figure) is installed in the adjusting screw hole at the top of the external gear eccentric shaft 5. Rotating the adjusting bolt will drive the external gear eccentric shaft 5 to rotate, thereby adjusting the slight circumferential eccentricity between the turbine support outer casing 7 and the outer bypass casing 8. After the adjustment is completed, the adjusting bolt in the adjusting screw hole at the top of the external gear eccentric shaft 5 is removed, and the internal gear plate 13 and the support rod 3 are installed in sequence and tightened with the first screw 12. The internal gear hole 13a of the internal gear plate 13 and the external gear section 5a of the external gear eccentric shaft 5 can be used to restrict the external gear eccentric shaft 5 from rotating on its own.

[0047] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A connection structure for a turbine support bearing casing of a three-duct engine, comprising a turbine support outer casing (7) and an outer bypass casing (8) assembled in a sleeve-type manner, wherein the turbine support outer casing (7) and the outer bypass casing (8) are connected circumferentially by multiple sets of eccentric sleeve tooth connection structures with spherical bearings; the eccentric sleeve tooth connection structure includes an eccentric shaft bracket (4) welded to the outer bypass casing (8), characterized in that: It also includes a stamping housing (1); the stamping housing (1) is spaced out and sleeved on the outside of the outer duct housing (8); A slide seat (2) is installed on the inner wall surface of the stamping housing (1). The slide seat (2) has a U-shaped slide groove (2a) with its opening facing radially inward. The U-shaped slide groove (2a) is parallel to the axis of the engine. A support rod (3) is installed on the eccentric shaft bracket (4), and the outer end of the support rod (3) is set as a slider (3a). The slider (3a) is slidably inserted into the U-shaped groove (2a). The slide seat (2) has integrally formed flange plates (2b) on both sides, and bolt holes (2c) are provided on the flange plates (2b); a connecting hole (1b) is provided on the stamping housing (1); the slide seat (2) and the stamping housing (1) are connected by bolts (9); the bolts (9) pass through the bolt holes (2c) on the flange plates (2b) from the inside to the outside, and through the connecting holes (1b) of the stamping housing (1) and then are screwed with lock nuts (11); A bolt bushing (10) is provided on the connection hole (1b) of the stamping housing (1); an annular washer (10a) is integrally formed on the outer end of the bolt bushing (10); the annular washer (10a) is located between the outer surface of the stamping housing (1) and the locking nut (11).

2. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 1, characterized in that: The bolt holes (2c) on the slide seat (2) are oblong holes.

3. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 1, characterized in that: The top surface of the slider (3a) at the outer end of the support rod (3) is spaced apart from the bottom of the U-shaped groove (2a).

4. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 1, characterized in that: The slider (3a) at the outer end of the support rod (3) slides in surface contact with the two sides of the U-shaped groove (2a).

5. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 1, characterized in that: The lower end of the support rod (3) has ear plates (3b) integrally formed on both sides. The ear plates (3b) are connected to the eccentric shaft bracket (4) by the first screw (12). A light-reducing hole (3c) is provided in the center of the support rod (3) through the top and bottom.

6. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 5, characterized in that: The eccentric toothed connection structure includes an inner toothed plate (13), and the top of the eccentric shaft bracket (4) is provided with a mounting boss (4a); the inner toothed plate (13) is disposed between the bottom end face of the support rod (3) and the mounting boss (4a) of the eccentric shaft bracket (4); the first screw (12) passes through the ear plate (3b) and the inner toothed plate (13) from top to bottom and then screws onto the mounting boss (4a) of the eccentric shaft bracket (4).

7. The connection structure of the turbine support bearing casing of a three-ducted engine as described in claim 1, characterized in that: The outer surface of the slide seat (2) is set as an arc surface (2d), the diameter of which is the same as the inner diameter of the stamping housing (1).

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