Variable stiffness aeroengine elastic support structure

Abstract

The application provides a variable stiffness aero-engine elastic supporting structure, which comprises an inner supporting ring and an outer supporting ring, a plurality of elastic supporting members and a plurality of outward protruding bosses are arranged on the outer wall surface of the inner supporting ring, a plurality of grooves are arranged on the inner wall surface of the outer supporting ring, the inner supporting ring is connected in the outer supporting ring through the elastic supporting members, and the bosses and the grooves are matched with each other. The application can effectively reduce the axial space required by elastic supporting installation, can remove the limiter structure matched with the traditional squirrel cage elastic supporting structure, can change the supporting stiffness by designing the shape of the memory alloy under different rotating speed conditions, so that the critical rotating speed of the rotor is changed, and the excessive vibration of the rotor during the operation process over the critical rotating speed can be reduced or even eliminated.

Description

Technical Field

[0001] This invention relates to the field of aero-engines, and in particular to a variable stiffness elastic support structure for aero-engines. Background Technology

[0002] In order to maintain high compressor efficiency during the design process of aero engines, the engine rotor needs to maintain a high speed. Therefore, the rotor must pass through the first-order critical speed, the second-order critical speed, and even the third-order critical speed during operation. When the engine rotor passes through the critical speed, it will generate large vibrations, which may lead to rubbing between the rotor and stator and excessive bearing support reaction force.

[0003] To prevent the rotor's critical speed from being near its operating speed, aero-engine rotors are typically supported using elastic supports to adjust the critical speed. However, if the elastic support stiffness is too low or the vibration is too great, there is a risk of excessive deformation, excessive stress, and blade tip rubbing when using elastic supports. Therefore, limiters are usually used in conjunction with elastic supports.

[0004] Traditional elastic bearing structures are generally squirrel-cage type, requiring a large axial space for installation. While traditional squirrel-cage elastic bearings can adjust the engine rotor's critical speed, the engine rotor cannot avoid reaching the critical speed during acceleration, thus posing a vibration risk during this process. Furthermore, traditional squirrel-cage elastic bearing structures require the use of limiters, which increases the engine's mass and structural complexity to some extent.

[0005] Based on the above description, the existing aircraft engine support structure has the following problems:

[0006] I. The elastic support structure of the squirrel cage of traditional aero-engines is generally a cantilever structure. The axial dimension of the cantilever structure is relatively long, requiring a large axial installation space.

[0007] Second, the stiffness of the squirrel cage elastic support structure is a constant value. During the process of the rotor accelerating from zero speed to working speed, it is unavoidable to pass through the critical speed, which poses a risk of excessive vibration.

[0008] 3. During use, in order to avoid excessive stress on the elastic support and rotor blade rubbing, a limiter is usually used for the elastic support of the squirrel cage of the aircraft engine. The use of the limiter makes the engine structure more complicated and introduces additional weight.

[0009] In view of this, the inventors of this application have designed a variable stiffness elastic support structure for aero-engines in order to overcome the above-mentioned technical problems. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to overcome the defects of existing aero-engine support structures, such as the need for large installation space and the risk of excessive vibration, and to provide an elastic support structure for aero-engines with variable stiffness.

[0011] The present invention solves the above-mentioned technical problems through the following technical solution:

[0012] A variable stiffness elastic support structure for an aero-engine is characterized in that the variable stiffness elastic support structure includes an inner support ring and an outer support ring. The outer wall surface of the inner support ring is provided with a plurality of elastic support members and a plurality of outwardly protruding bosses. The inner wall surface of the outer support ring is provided with a plurality of grooves. The inner support ring is connected to the outer support ring through the elastic support members. The bosses and the grooves cooperate with each other.

[0013] According to one embodiment of the present invention, a gap is provided between the boss and the groove.

[0014] According to one embodiment of the present invention, a plurality of outer support rings are provided on the inner wall surface of the outer support ring, and the groove is formed on the corresponding outer support ring.

[0015] According to one embodiment of the present invention, every two of the elastic support members form a group, located between two adjacent outer support rings.

[0016] According to one embodiment of the present invention, the elastic support is an S-shaped elastic support.

[0017] According to one embodiment of the present invention, one end of the S-shaped elastic support is connected to the outer support ring, and the other end is connected to the inner support ring.

[0018] According to one embodiment of the present invention, the other end of the S-shaped elastic support member is integrally formed with the inner support ring.

[0019] According to one embodiment of the present invention, the boss is made of shape memory alloy.

[0020] According to one embodiment of the present invention, the outer support ring is connected to the bearing housing, and the inner support ring is connected to the rotor bearing.

[0021] According to one embodiment of the present invention, the elastic support member is V-shaped, W-shaped, M-shaped or N-shaped.

[0022] The positive and progressive effects of this invention are as follows:

[0023] The variable stiffness elastic support structure for aero-engines of this invention has the following advantages:

[0024] First, it can effectively reduce the axial space required for the installation of elastic supports;

[0025] Second, the limiter structure that is used in conjunction with the traditional squirrel cage spring support structure can be removed;

[0026] Third, the support stiffness can be changed by designing the shape of the shape memory alloy under different speed conditions, thereby changing the critical speed of the rotor and reducing or even eliminating excessive vibration at the critical speed during rotor operation. Attached Figure Description

[0027] 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, in which the same reference numerals always denote the same features, wherein:

[0028] Figure 1 This is a perspective view of the variable stiffness elastic support structure for aero-engines according to the present invention.

[0029] Figure 2 This is a front view of the variable stiffness elastic support structure for aero-engines according to the present invention.

[0030] Figure 3 This is a schematic diagram of the variable stiffness elastic support structure for aero-engines of the present invention after the bearing is installed.

[0031] [Attached image labels]

[0032] Inner support ring 10

[0033] Outer support ring 20

[0034] Elastic support 11

[0035] 12 convex surfaces

[0036] Groove 21

[0037] Rotor bearing 30

[0038] Inner ring of bearing 31

[0039] 32 ball bearings

[0040] Bearing outer ring 33 Detailed Implementation

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0042] Embodiments of the invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the invention will now be described in detail, examples of which are shown in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0043] Furthermore, although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been selected by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein.

[0044] Furthermore, the invention should be understood not only through the actual terminology used, but also through the meaning implied by each term.

[0045] Figure 1 This is a perspective view of the variable stiffness elastic support structure for aero-engines according to the present invention. Figure 2 This is a front view of the variable stiffness elastic support structure for aero-engines according to the present invention. Figure 3 This is a schematic diagram of the variable stiffness elastic support structure for aero-engines of the present invention after the bearing is installed.

[0046] like Figures 1 to 3 As shown, the present invention discloses a variable stiffness elastic support structure for aero-engines, which includes an inner support ring 10 and an outer support ring 20. The outer wall surface of the inner support ring 10 is provided with a plurality of elastic support members 11 and a plurality of outwardly protruding bosses 12. The inner wall surface of the outer support ring 20 is provided with a plurality of grooves 21. The inner support ring 10 is connected to the outer support ring 20 through the elastic support members 11, and the bosses 12 and the grooves 21 cooperate with each other.

[0047] Preferably, there is a gap between the boss 12 and the groove 21.

[0048] Furthermore, multiple outer support rings 20 are provided on the inner wall surface of the outer support ring 20, and the grooves 21 are formed on the corresponding outer support rings 20.

[0049] Preferably, every two elastic support members 11 can be grouped together and located between two adjacent outer support rings 20.

[0050] Preferably, in this embodiment, the elastic support member 11 is configured as an S-shaped elastic support member, with one end connected to the outer support ring 20 and the other end connected to the inner support ring 10. Furthermore, the other end of the S-shaped elastic support member and the inner support ring 10 can be integrally formed.

[0051] Preferably, the boss 12 can be made of shape memory alloy.

[0052] like Figure 3As shown, the variable stiffness aero-engine elastic support structure is installed by connecting the outer support ring 20 to the bearing housing and the inner support ring 10 to the rotor bearing 30 (including the inner bearing ring 31, balls 32, and outer bearing ring 33). Furthermore, the elastic support member 11 can preferably be V-type, W-type, M-type, or N-type.

[0053] According to the above structural description, the variable stiffness elastic support structure for aero-engines of the present invention consists of two parts. One part comprises multiple evenly distributed S-shaped elastic support members (e.g., eight) and multiple evenly distributed shape memory alloy bosses (e.g., four). The other part is an outer support ring 20, which has groove structures that mate with the inner support ring. The grooves 21 mate with the bosses 12, and there is a certain gap between the bosses 12 and the grooves 21. The outer support ring 20 and the inner support ring 10 are connected by eight S-shaped elastic support members, which are bolted to the outer support ring 20. The outer support ring 20 is connected to the bearing housing for fixation. The inner support ring 10 is connected to the rotor bearing.

[0054] When the rotor is at low speed, the gap between the boss 12 of the inner support ring 10 and the groove 21 of the outer support ring 20 is zero, resulting in high support stiffness. When the rotor's operating speed exceeds the critical speed of the rotor under the stiffness of 8 S-shaped elastic supports, the shape is changed by the shape memory alloy. At this time, the gap between the inner and outer support rings becomes a fixed value, and the rotor support stiffness becomes the stiffness of 8 S-shaped elastic supports. During operation, the rotor avoids the critical speed of the rotor under the actual working state support stiffness. When the rotor is at its operating speed, if the rotor vibration is large, the vibration amplitude is sufficient to compensate for the gap between the boss and the outer support ring. At this time, the outer support ring can also act as a limiter.

[0055] For example, in this embodiment, the elastic support is designed with eight evenly distributed S-shaped elastic support members. These S-shaped elastic support members function as elastic supports, with different thicknesses and widths corresponding to elastic supports of different stiffness. The inner support ring 10, containing the eight S-shaped elastic support members, has four evenly distributed bosses 12, which have a certain gap with the outer support ring 20. The bosses 12 are designed as shape memory alloys, and their deformation capacity fills the gap between the inner support ring 10 and the outer support ring 20, thereby changing the stiffness of the elastic support. When the four bosses 12 are not in contact with the outer support ring 20, if the rotor vibration is large in this state, the outer support ring 20 can act as a type of limiter to prevent excessive rotor vibration.

[0056] The variable stiffness aero-engine elastic support structure has eight evenly distributed S-shaped supports. Different thicknesses, widths, and structural forms of the S-shaped supports correspond to different stiffnesses. The S-shaped elastic supports are radial springs, requiring relatively little axial space. The eight S-shaped supports connect the inner support ring 10 and the outer support ring 20. The inner support ring 10 houses a bearing, and the outer support ring 20 connects to the bearing housing for fixation. The inner support ring 10 not only has eight S-shaped elastic supports but also four evenly distributed bosses made of shape memory alloy. The outer support ring 20 has grooves with a certain gap that mate with the bosses of the inner support ring 10. When the engine is in operation, there is a certain gap between the bosses of the inner support ring 10 and the outer support ring 20.

[0057] As the engine rotor accelerates and approaches its critical speed, the shape memory alloy deforms to fill the gap between the boss of the inner support ring 10 and the groove of the outer support ring 20. At this point, the eight S-shaped elastic supports fail, and the support stiffness is mainly determined by the boss portion; different stiffness values ​​correspond to different critical speeds.

[0058] Therefore, when the rotor approaches its critical speed, by changing the stiffness of the elastic support, the rotor's real-time operating speed can be kept away from the critical speed of the rotor system, thus ensuring that the rotor system does not pass the critical speed during the entire acceleration process. Furthermore, when the engine rotor is at its operating speed, if the vibration is significant, the gap between the boss and the outer support ring can act as a limiter.

[0059] In summary, the variable stiffness elastic support structure for aero-engines of the present invention has the following advantages:

[0060] First, it can effectively reduce the axial space required for the installation of elastic supports;

[0061] Second, the limiter structure that is used in conjunction with the traditional squirrel cage spring support structure can be removed;

[0062] Third, the support stiffness can be changed by designing the shape of the shape memory alloy under different speed conditions, thereby changing the critical speed of the rotor and reducing or even eliminating excessive vibration at the critical speed during rotor operation.

[0063] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A variable stiffness aeroengine elastomeric support structure, characterised in that, The variable stiffness aero-engine elastic support structure includes an inner support ring and an outer support ring. The outer wall of the inner support ring is provided with multiple elastic support members and multiple outwardly protruding bosses. The bosses are made of shape memory alloy. The inner wall of the outer support ring is provided with multiple grooves. The inner support ring is connected to the outer support ring through the elastic support members. The bosses and the grooves cooperate with each other.

2. The variable stiffness aeroengine elastomeric support structure as claimed in claim 1, wherein, There is a gap between the boss and the groove.

3. The variable stiffness elastic support structure for aero-engines as described in claim 1, characterized in that, Multiple outer support rings are provided on the inner wall surface of the outer support ring, and the groove is formed on the corresponding outer support ring.

4. The variable stiffness elastic support structure for aero-engines as described in claim 3, characterized in that, Each pair of the elastic support members forms a group, located between two adjacent outer support rings.

5. The variable stiffness elastic support structure for aero-engines as described in claim 4, characterized in that, The elastic support is an S-shaped elastic support.

6. The variable stiffness elastic support structure for aero-engines as described in claim 5, characterized in that, One end of the S-shaped elastic support is connected to the outer support ring, and the other end is connected to the inner support ring.

7. The variable stiffness elastic support structure for aero-engines as described in claim 6, characterized in that, The other end of the S-shaped elastic support is integrally formed with the inner support ring.

8. The variable stiffness elastic support structure for aero-engines as described in claim 1, characterized in that, The outer support ring is connected to the bearing housing, and the inner support ring is connected to the rotor bearing.

9. The variable stiffness elastic support structure for aero-engines as described in claim 1, characterized in that, The elastic support member is V-shaped, W-shaped, M-shaped, or N-shaped.

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