A variable stiffness support structure for engine rotor based on magnetically sensitive metal rubber

Abstract

This invention discloses a variable stiffness support structure for engine rotors based on magnetically sensitive metallic rubber, comprising a squirrel cage support, magnetically sensitive metallic rubber, an inner baffle, an outer baffle, an electromagnetic spiral ring, squirrel cage mounting bolts, and baffle mounting bolts. The stiffness of the variable stiffness support structure is jointly provided by the squirrel cage support and the magnetically sensitive metallic rubber, wherein the squirrel cage support provides fixed stiffness, and the magnetically sensitive metallic rubber provides variable stiffness. The stiffness of the squirrel cage support can be adjusted by designing the structural parameters and number of the cage bars; the variable stiffness law of the magnetically sensitive metallic rubber can be designed by designing the variation law of the magnetic field strength; and the efficiency of variable stiffness adjustment is maximized by optimizing the stiffness matching relationship between the squirrel cage support and the magnetically sensitive metallic rubber. The variable stiffness support structure of this invention has the advantages of simple structure, high load-bearing capacity, and a large adjustable stiffness range, and has broad application prospects in the field of aero-engine rotor support structure design.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine rotor support structure design, specifically involving a variable stiffness support structure for engine rotors based on magnetically sensitive metal rubber. Background Technology

[0002] Vibration issues in aero-engine rotor systems have always been a focus of attention. Excessive vibration can easily lead to rotor system failures and often becomes a significant excitation source for vibrations in other systems. Therefore, the vibration problem of the rotor system is not only related to the performance and safety of the rotor system itself, but also to the vibration response level and operational performance of the entire aero-engine.

[0003] Currently, rotor dynamics design is mostly based on avoiding resonance. This involves optimizing the stiffness of the support structure to ensure a margin at critical speeds, and using damping structures such as "squirrel cage support + squeeze oil film" to achieve passive control of vibration response. However, future advanced engines, such as adaptive variable cycle engines, operate over a wide range of speeds and experience diverse conditions. Under complex excitation loads, rotor systems based on fixed support stiffness struggle to guarantee margins at multiple critical speeds. Furthermore, the commonly used passive vibration control methods in engines, such as "squirrel cage support + squeeze oil film," cannot effectively suppress multiple critical peak values ​​under large imbalances. Active rotor vibration control is an effective way to overcome these limitations, and active variable stiffness support structures are key components for implementing active rotor vibration control.

[0004] Traditional active variable stiffness support structures mainly include variable stiffness extrusion film dampers, electromagnetic bearings, and smart material support structures. Variable stiffness extrusion film dampers achieve structural stiffness variation by changing the oil film thickness through actuators; however, existing actuators, whether mechanical or hydraulic, are complex and not yet practical. While electromagnetic bearings offer controllable stiffness and are frictionless, their load-bearing capacity is limited, making them unsuitable as the main support structure for high-load engine rotors. Smart material support structures utilize materials with variable mechanical properties, such as piezoelectric crystals, shape memory alloys, and soft magnetic materials, to adjust support stiffness; however, support structures made directly from these materials suffer from insufficient load-bearing capacity, making them unsuitable for the load environment of next-generation aero-engines.

[0005] Metal rubber is an elastic and highly efficient damping material made from metal wires through winding, drawing, weaving, and molding. It features high damping and high load-bearing capacity. By preparing magnetic sensitive metal rubber from soft magnetic materials, it not only has the advantages of a wide range of adjustable stiffness and high damping, but also improves the limitations of insufficient load-bearing capacity of the material itself. It has great application potential in the design of active variable stiffness support structures. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a variable stiffness support structure for engine rotors based on magnetically sensitive metal rubber. This structure is not only simple and has a strong load-bearing capacity, but also has a wide range of adjustable stiffness. It can efficiently achieve active vibration control of the engine rotor, ultimately reducing the vibration response of engines with a wide speed range and multiple operating conditions across the entire speed range.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber is disclosed to achieve active vibration control of the aero-engine rotor and thereby reduce its vibration response. The variable stiffness support structure includes a squirrel cage support, magnetically sensitive metal rubber, an inner baffle, an outer baffle, an electromagnetic spiral ring, squirrel cage mounting bolts, and baffle mounting bolts.

[0009] The cage support is provided with a cage mounting flange, cage bars, metal rubber radial positioning edge, and bearing positioning edge.

[0010] The magnetically sensitive metal rubber is made of soft magnetic material through winding, drawing, weaving and molding. Under different magnetic field strengths, the magnetically sensitive metal rubber exhibits different stiffness characteristics. The magnetically sensitive metal rubber is set in the installation space enclosed by the outer baffle, the inner baffle and the cage support.

[0011] The inner baffle is provided with an inner baffle mounting flange, a metal rubber axial positioning edge, and a bearing radial limiting edge.

[0012] The outer baffle is provided with an outer baffle mounting flange, a metal rubber radial constraint edge, and a metal rubber axial constraint edge.

[0013] The electromagnetic spiral coil is a spiral coil made of wire. When the wire is energized, it generates a magnetic field. By adjusting the current intensity, the magnetic field intensity can be adjusted, thereby adjusting the stiffness of the magnetic sensitive metal rubber. The electromagnetic spiral coil is set on the outer side of the outer baffle.

[0014] The cage mounting bolts pass through the cage mounting flange to support and fix the cage onto the engine load-bearing housing; the baffle mounting bolts pass through the outer baffle mounting flange and the inner baffle mounting flange in sequence to fix the outer baffle and the inner baffle onto the engine load-bearing housing.

[0015] With the pre-tightening of the baffle mounting bolts, the axial positioning edge of the inner baffle's metal rubber provides axial positioning for the magnetic sensitive metal rubber, the axial constraint edge of the outer baffle's metal rubber provides axial constraint for the magnetic sensitive metal rubber, the radial positioning edge of the squirrel cage support's metal rubber provides radial positioning for the magnetic sensitive metal rubber, and the radial constraint edge of the outer baffle's metal rubber provides radial constraint for the magnetic sensitive metal rubber.

[0016] Furthermore, the stiffness of the variable stiffness support structure is provided by both the squirrel cage support and the magnetically sensitive metal rubber, wherein the squirrel cage support provides fixed stiffness and the magnetically sensitive metal rubber provides variable stiffness.

[0017] Furthermore, the stiffness matching relationship between the squirrel cage support and the magnetically sensitive metal rubber is determined according to the support stiffness design requirements of the aero-engine rotor system, so as to maximize the efficiency of variable stiffness adjustment under the premise of efficient structural load bearing.

[0018] Furthermore, the cage bars of the rat cage support are key structures affecting the stiffness of the rat cage support, and the structural parameters and quantity of the cage bars are optimized according to the stiffness design requirements of the rat cage support.

[0019] Furthermore, the magnetically sensitive metal rubber is made of soft magnetic material, and its stiffness is modulated by a magnetic field. Under different magnetic field intensities, the magnetically sensitive metal rubber exhibits different stiffness characteristics. By designing the variation law of the magnetic field intensity, the variable stiffness law of the magnetically sensitive metal rubber is designed, thereby realizing the variable stiffness design of the supporting structure.

[0020] Furthermore, the squirrel cage support is provided with a bearing positioning edge for axial positioning of the bearing.

[0021] Furthermore, the inner baffle is provided with a bearing radial limiting edge to limit the deformation of the squirrel cage support when the dynamic load at the fulcrum is large, so as to ensure the safety of the variable stiffness support structure.

[0022] Furthermore, the rat cage mounting bolts are external hexagonal bolts. To reduce the imbalance, the rat cage mounting bolts are evenly distributed at equal angles along the circumference of the rat cage mounting flange, and the number of rat cage mounting bolts is at least 12.

[0023] Furthermore, the baffle mounting bolts are internal hex bolts to ensure the feasibility of installation. To reduce the imbalance, the baffle mounting bolts are evenly distributed at equal angles along the circumference of the outer baffle mounting flange, and the number of the baffle mounting bolts is at least 12.

[0024] The advantages of the variable stiffness support structure for engine rotors based on magnetically sensitive metal rubber of the present invention are as follows:

[0025] (1) The existing "squirrel cage support + squeeze oil film" aero-engine rotor support structure has little modification. The present invention does not need to change the structural form and structural size of the aero-engine rotor itself. The variable stiffness support structure proposed in the present invention can be directly applied to the aero-engine rotor, which has practical application value.

[0026] (2) The variable stiffness support structure proposed in this invention has a simple structural layout and high reliability.

[0027] (3) The variable stiffness support structure proposed in this invention is supported by a squirrel cage spring support and a magnetic sensitive metal rubber, and the support stiffness can reach the order of 1E7 N / m, which has the advantage of strong load-bearing capacity.

[0028] (4) The variable stiffness support structure proposed in this invention uses magnetic sensitive metal rubber as a variable stiffness element. The elastic modulus of magnetic sensitive metal rubber can vary up to 300%, which has the advantage of a large range of adjustable stiffness.

[0029] (5) By designing the structural parameters and number of cage bars of the squirrel cage support, the stiffness of the squirrel cage support can be adjusted; by designing the variation law of magnetic field strength, the design of the variable stiffness law of magnetic sensitive metal rubber can be realized; by optimizing the stiffness matching relationship between the squirrel cage support and the magnetic sensitive metal rubber, the efficiency of variable stiffness adjustment can be maximized under the premise of efficient structural load bearing. Attached Figure Description

[0030] Figure 1 This is an exploded view of an engine rotor variable stiffness support structure based on magnetically sensitive metal rubber.

[0031] Figure 2 This is a schematic diagram of the installation of a variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber on an engine.

[0032] Figure 3 This is a schematic diagram of the squirrel cage support structure in the variable stiffness support structure of the engine rotor based on magnetically sensitive metal rubber.

[0033] Figure 4 This is a schematic diagram of the inner baffle structure in the variable stiffness support structure of the engine rotor based on magnetically sensitive metal rubber.

[0034] Figure 5 This is a schematic diagram of the outer baffle structure in the variable stiffness support structure of the engine rotor based on magnetically sensitive metal rubber.

[0035] Figure 6 This is a schematic diagram of the variable stiffness mechanical properties of magnetically sensitive metal rubber in the variable stiffness support structure of engine rotor based on magnetically sensitive metal rubber.

[0036] Figure 7 This is a schematic diagram of the vibration response of a rotor system with active variable stiffness support.

[0037] In the diagram: 1. Squirrel cage support, 2. Magnetic sensitive metal rubber, 3. Inner baffle, 4. Outer baffle, 5. Electromagnetic spiral ring, 6. Squirrel cage mounting bolt, 7. Baffle mounting bolt, 8. Bearing, 9. Engine load-bearing casing;

[0038] 1a. Squirrel cage mounting flange edge, 1b. Cage bars, 1c. Metal rubber radial positioning edge, 1d. Bearing positioning edge;

[0039] 3a. Inner baffle mounting flange edge; 3b. Metal rubber axial positioning edge; 3c. Bearing radial limiting edge;

[0040] 4a. Outer baffle mounting flange edge, 4b. Metal rubber radial constraint edge, 4c. Metal rubber axial constraint edge. Detailed Implementation

[0041] To make the technical solution and key points of the present invention clearer, the following will be combined with Figures 1-7 The invention is fully described with specific examples.

[0042] like Figures 1-5 As shown, the present invention relates to a variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber. The variable stiffness support structure can achieve a large range of adjustable stiffness under the premise of simple structure and strong load-bearing capacity, thereby realizing active vibration control of the engine rotor to reduce the vibration response of the engine in a wide speed range and multiple operating conditions across the entire speed range.

[0043] like Figure 1 , Figure 2 , Figure 3 As shown, the variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber of the present invention includes a squirrel cage support 1, magnetically sensitive metal rubber 2, an inner baffle 3, an outer baffle 4, an electromagnetic spiral coil 5, a squirrel cage mounting bolt 6, and a baffle mounting bolt 7. The squirrel cage mounting bolt 6 passes through the squirrel cage mounting flange 1a of the squirrel cage support 1, fixing the squirrel cage support 1 to the engine load-bearing housing 9. The baffle mounting bolt 7 passes sequentially through the outer baffle mounting flange 4a of the outer baffle 4 and the inner baffle mounting flange 3a of the inner baffle 3, fixing the outer baffle 4 and the inner baffle 3 to the engine load-bearing housing 9. The magnetically sensitive metal rubber 2 is disposed within the mounting space formed by the outer baffle 4, the inner baffle 3, and the squirrel cage support 1. The electromagnetic spiral coil 5 is disposed on the outer side of the outer baffle 4 and is integrally connected to the outer baffle 4 by spot welding. The cage mounting bolts 6 are external hexagonal bolts. To reduce imbalance, the cage mounting bolts 6 are evenly distributed at equal angles along the circumference of the cage mounting flange edge 1a, and the number is at least 12. The baffle mounting bolts 7 are internal hexagonal bolts to ensure installation feasibility. To further reduce imbalance, the baffle mounting bolts 7 are evenly distributed at equal angles along the circumference of the outer baffle mounting flange edge 4a, and the number is at least 12. The bearing 8 is axially positioned via the bearing positioning edge 1d of the cage support 1.

[0044] The stiffness of the variable stiffness support structure is provided jointly by the squirrel cage support 1 and the magnetically sensitive metal rubber 2. The squirrel cage support 1 provides fixed stiffness, while the magnetically sensitive metal rubber 2 provides variable stiffness. The support stiffness can reach the order of 1E7 N / m, exhibiting the advantage of high load-bearing capacity. The stiffness matching relationship between the squirrel cage support 1 and the magnetically sensitive metal rubber 2 needs to be determined according to the support stiffness design requirements of the aero-engine rotor system, in order to maximize the efficiency of variable stiffness adjustment while ensuring efficient structural load-bearing.

[0045] like Figure 3 As shown, the squirrel cage support 1 is sequentially provided with a squirrel cage mounting flange side 1a, cage bars 1b, a metal rubber radial positioning side 1c, and a bearing positioning side 1d. Among them, the cage bars 1b are the key structures affecting the stiffness of the squirrel cage support 1, and the structural parameters and quantity of the cage bars 1b need to be optimized according to the stiffness design requirements of the squirrel cage support 1; the bearing positioning side 1d is used for the axial positioning of the bearing 8.

[0046] like Figure 4 As shown, the inner baffle 3 is sequentially provided with an inner baffle mounting flange edge 3a, a metal rubber axial positioning edge 3b, and a bearing radial limiting edge 3c. The bearing radial limiting edge 3c is used to limit the deformation of the squirrel cage support 1 when the dynamic load at the fulcrum is large, thereby ensuring the safety of the support structure.

[0047] like Figure 5 As shown, the outer baffle 4 is sequentially provided with an outer baffle mounting flange edge 4a, a metal rubber radial constraint edge 4b, and a metal rubber axial constraint edge 4c. With the baffle mounting bolts 7 pre-tightened, the metal rubber axial positioning edge 3b of the inner baffle 3 provides axial positioning for the magnetically sensitive metal rubber 2, the metal rubber axial constraint edge 4c of the outer baffle 4 provides axial constraint for the magnetically sensitive metal rubber 2, the metal rubber radial positioning edge 1c of the squirrel cage support 1 provides radial positioning for the magnetically sensitive metal rubber 2, and the metal rubber radial constraint edge 4b ​​of the outer baffle 4 provides radial constraint for the magnetically sensitive metal rubber 2.

[0048] The magnetically sensitive metallic rubber 2 is made of soft magnetic material, and its stiffness is modulated by a magnetic field. Under different magnetic field strengths, the magnetically sensitive metallic rubber exhibits different stiffness characteristics. The variable stiffness mechanical properties of the magnetically sensitive metallic rubber 2 are as follows: Figure 6 As shown, the solid line represents the mechanical properties of the magnetically sensitive metal rubber 2 without an applied magnetic field, while the dashed line represents the mechanical properties after applying a 500mT magnetic field. After applying a 500mT magnetic field, the elastic modulus of the magnetically sensitive metal rubber 2 increases by 300%, exhibiting the advantage of a wide adjustable stiffness range. By designing the variation law of the magnetic field strength, the variable stiffness law of the magnetically sensitive metal rubber can be designed, thereby realizing the variable stiffness design of the supporting structure.

[0049] like Figure 7As shown, when the support stiffnesses are k1 and k2, the critical speeds of the rotor system are n c1 and n c2 The corresponding rotor system vibration response curves are as follows: Figure 7 As shown by the dashed lines on the right and left, both exhibit obvious resonance response peaks. By adjusting the stiffness of the variable stiffness support structure, active vibration control of the engine rotor can be achieved, thereby realizing a wide-range, multi-condition engine vibration response across the entire speed range. Specifically, during rotor acceleration, a high magnetic field strength is used at low speeds to give the variable stiffness support structure high support stiffness k1. When the speed reaches n... A At that time, a small magnetic field strength is used to make the variable stiffness support structure have a low support stiffness k2. After the support structure actively changes stiffness, the vibration response of the rotor system during the acceleration process is as follows: Figure 7 As shown by the solid black line, the vibration response of the rotor system is at a low level over a wide operating speed range, which helps to ensure the high performance and safety of the rotor system and the entire aero-engine.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber, characterized in that: Includes cage support, magnetically sensitive metal rubber, inner baffle, outer baffle, electromagnetic spiral ring, cage mounting bolts, and baffle mounting bolts; The cage support is provided with a cage mounting flange, cage bars, metal rubber radial positioning edge, and bearing positioning edge. The magnetically sensitive metal rubber is made of soft magnetic material through winding, drawing, weaving and molding. Under different magnetic field strengths, the magnetically sensitive metal rubber exhibits different stiffness characteristics. The magnetically sensitive metal rubber is set in the installation space enclosed by the outer baffle, the inner baffle and the cage support. The inner baffle is provided with an inner baffle mounting flange, a metal rubber axial positioning edge, and a bearing radial limiting edge. The outer baffle is provided with an outer baffle mounting flange, a metal rubber radial constraint edge, and a metal rubber axial constraint edge. The electromagnetic spiral coil is a spiral coil made of wire. When the wire is energized, it generates a magnetic field. By adjusting the current intensity, the magnetic field intensity can be adjusted, thereby adjusting the stiffness of the magnetic sensitive metal rubber. The electromagnetic spiral coil is set on the outer side of the outer baffle. The cage mounting bolts pass through the cage mounting flange to support and fix the cage onto the engine load-bearing housing; the baffle mounting bolts pass through the outer baffle mounting flange and the inner baffle mounting flange in sequence to fix the outer baffle and the inner baffle onto the engine load-bearing housing. With the pre-tightening of the baffle mounting bolts, the axial positioning edge of the inner baffle's metal rubber provides axial positioning for the magnetic sensitive metal rubber, the axial constraint edge of the outer baffle's metal rubber provides axial constraint for the magnetic sensitive metal rubber, the radial positioning edge of the squirrel cage support's metal rubber provides radial positioning for the magnetic sensitive metal rubber, and the radial constraint edge of the outer baffle's metal rubber provides radial constraint for the magnetic sensitive metal rubber.

2. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The stiffness of the variable stiffness support structure is provided by both the squirrel cage support and the magnetically sensitive metal rubber, wherein the squirrel cage support provides fixed stiffness and the magnetically sensitive metal rubber provides variable stiffness.

3. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The structural parameters and quantity of the cage bars are designed according to the stiffness design requirements of the rat cage support.

4. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The magnetically sensitive metal rubber is designed to adapt to the changing magnetic field strength, thereby achieving the variable stiffness design of the variable stiffness support structure.

5. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The squirrel cage support is provided with a bearing positioning edge for axial positioning of the bearing.

6. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The radial limiting edge of the bearing is used to limit the deformation of the squirrel cage support when the dynamic load at the fulcrum is large, so as to ensure the safety of the variable stiffness support structure.

7. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The rat cage mounting bolts are external hexagonal bolts, and the rat cage mounting bolts are evenly distributed at equal angles along the circumference of the rat cage mounting flange. The number of rat cage mounting bolts is at least 12.

8. The variable stiffness support structure for an engine rotor based on magnetically sensitive metal rubber according to claim 1, characterized in that: The baffle mounting bolts are hexagon socket head cap screws, and the baffle mounting bolts are evenly distributed at equal angles along the circumference of the outer baffle mounting flange edge. The number of baffle mounting bolts is at least 12.

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