A quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom

Abstract

The application discloses a quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom, which comprises six electromagnetic vibration isolation structures supported at specific angles and a base for mounting the electromagnetic vibration isolation structures, a top platform supported by the electromagnetic vibration isolation structures and a high-damping rubber platform on the top platform for further isolating high-frequency vibrations, and the electromagnetic vibration isolation structure comprises a first coil, a first permanent magnet, a second coil, a second permanent magnet and a supporting shell and a transmission assembly arranged from top to bottom, wherein the first and second permanent magnets are arranged in the interiors of the first and second coils respectively, the first coil and the second coil have the same current direction, the first permanent magnet and the second permanent magnet are oppositely arranged according to the polarization direction, and the positive and negative stiffnesses are combined, so that the dynamic stiffness in six directions of the top platform is small, the large-amplitude low-frequency vibrations in multiple directions can be isolated, the current size of each coil can be changed in the current range, the load capacity is adjusted, and the vibration isolation of loads with different sizes and different positions is realized.

Description

Technical Field

[0001] This invention belongs to the field of vibration isolator technology, specifically relating to a quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom. Background Technology

[0002] Existing vibration isolation technologies have the following drawbacks: 1. Traditional vibration isolators can only effectively isolate vibrations in a single dimension, and are unable to isolate vibrations coupled in multiple directions; 2. Existing multi-dimensional vibration isolators mostly employ passive vibration isolation or dynamic vibration absorption schemes, resulting in a narrow isolation frequency band and difficulty in simultaneously suppressing low-frequency and high-frequency vibrations; 3. Multi-dimensional quasi-zero stiffness vibration isolators mostly use a single mechanical structure (such as magnetorheological fluid or air spring) to achieve vibration isolation, making it difficult to adjust according to load conditions. To address these problems, this invention designs a six-degree-of-freedom quasi-zero stiffness electromagnetic vibration isolator. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom, comprising: High-damping rubber platform, top platform, base and electromagnetic structure core.

[0005] The electromagnetic vibration isolation structure consists of an electromagnetic core, a supporting shell, and transmission components.

[0006] The core of the electromagnetic structure, from top to bottom, includes a first coil, a first permanent magnet, a second coil, and a second permanent magnet. The current directions of the first coil and the second coil are the same.

[0007] The supporting shell and transmission components are adapted to the electromagnetic structure core, connecting the vibration isolation components to the top platform.

[0008] Six electromagnetic structural cores are mounted on the base at specific angles and connected to the top platform via ball joints.

[0009] The first permanent magnet provides a positive stiffness curve in its relative motion with the first and second coils, while the second permanent magnet provides a negative stiffness curve in its relative motion with the first and second coils.

[0010] The supporting housing and transmission assembly include a supporting shaft and a ball joint. The supporting shaft is fixed to the first permanent magnet and the second permanent magnet by supporting shaft fasteners, and the ball joint is fixed to the top of the supporting shaft.

[0011] Furthermore, the supporting shell and transmission assembly also include an upper frame, a middle frame, a bottom frame, a longitudinal rubber pad layer, a transverse rubber pad layer, a connecting rod, a bottom fixing frame, a base support shaft, and a top cover.

[0012] The upper frame, middle frame, bottom frame, longitudinal rubber pad, and transverse rubber pad are all adapted to the first coil and the second coil.

[0013] The first permanent magnet is installed in the middle of the upper frame, and the second permanent magnet is installed in the middle of the bottom frame.

[0014] The base support shaft is fixed at the base insertion hole and is fixed to the bottom fixed frame by the support shaft fastener.

[0015] The central frame is adapted to the support shaft.

[0016] The top cover, upper frame, middle frame, bottom frame, and bottom fixed frame are arranged sequentially from top to bottom, connected by connecting rods, and their relative positions are fixed by connecting rod fasteners.

[0017] Furthermore, the six electromagnetic vibration isolation structures are identical in structure, installed on the base at a specific angle, and connected to the top platform via ball joints.

[0018] Furthermore, the angle between the central axis and the base plane is denoted as α1, and the angle between the planes of the adjacent vibration isolation mechanisms is denoted as α2.

[0019] By changing the angle α1 between the central axis of the electromagnetic vibration isolation structure (101) and the base plane, and the angle α2 between the planes of the adjacent vibration isolation mechanisms, mechanical analysis and synthesis are performed using the mechanical simulation software ANSYS WORKBRNCH. Furthermore, the optimal approximate solutions α1 and α2 are obtained using the lsqnonlin function in MATLAB, so that the dynamic stiffness of the vibration isolation platform in all directions approaches zero.

[0020] Furthermore, the first coil and the second coil have the same structure, with the inner diameter denoted as Φ1 and the outer diameter denoted as Φ2.

[0021] By adjusting the current I1, according to the electromagnetic force formula... Nonlinear positive stiffness curves under different coils can be obtained, and the synthesized stiffness parameters can be optimized using the fmincon function in MATLAB. By changing different coil currents I1, the quasi-zero stiffness operating range under different load conditions can be controlled. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the electromagnetic vibration isolation structure, base, top platform and high-damping rubber platform in this application document; Figure 2 3 is a schematic diagram of the overall structure in this application document; Figure 4 This is a schematic diagram of the external structure of the electromagnetic vibration isolation structure in this application document; Figure 5 This is a cross-sectional schematic diagram of the electromagnetic vibration isolation structure in this application document; Figure 6 This is a schematic diagram of the electromagnetic vibration isolation structure in this application (excluding the structural shell and fixed support structure). Figure 7 This is a schematic diagram of the positive and negative stiffness mechanism structure in this application document; Figure 8 This is a force-displacement curve of the electromagnetic vibration isolation structure in this application document; In the diagram: 101 Electromagnetic Vibration Isolation Structure; 1. High-damping rubber platform; 2. Top platform; 3. Base; 4. Ball joint; 5. Support shaft; 6. Upper frame; 7. Middle frame; 8. Bottom frame; 9. First coil; 10. Longitudinal rubber pad; 11. Transverse rubber pad; 12. First permanent magnet; 13. Support shaft fastener; 14. Second coil; 15. Second permanent magnet; 16. Connecting rod; 17. Bottom fixed frame; 18. Base support shaft; 19. Top cover; 20. Connecting rod fastener; Detailed Implementation

[0023] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figure 1-7 As shown, the technical solution adopted by the present invention is as follows: This embodiment provides a quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom, including: a high-damping rubber platform (1), a top platform (2), a base (3), and an electromagnetic structure core (101); wherein the electromagnetic vibration isolation structure (101) includes the electromagnetic structure core and its supporting shell and transmission components.

[0025] like Figure 5 As shown in Figure 6, in this embodiment, the core of the electromagnetic structure includes a first coil (9), a first permanent magnet (12), a second coil (14), and a second permanent magnet (15) arranged from top to bottom. The current directions of the first coil (9) and the second coil (14) are the same. like Figure 5 As shown, in this embodiment, the supporting shell and the transmission assembly are components of the electromagnetic vibration isolation structure (101). To be compatible with the core of the electromagnetic structure, the vibration isolation assembly is connected to the top platform (4).

[0026] like Figure 2As shown in Figure 3, in this embodiment, the six electromagnetic structure cores (101) are installed on the base (3) at a specific angle and connected to the top platform (2) through ball joints (4).

[0027] The first permanent magnet (12) moves relative to the first coil (9) and the second coil (14), providing a positive stiffness curve of a specific shape.

[0028] The relative motion between the second permanent magnet (15) and the first coil (9) and the second coil (14) provides a negative stiffness curve of a specific shape.

[0029] like Figure 5 As shown, in this embodiment, the supporting shell and transmission assembly include a supporting shaft (5) and a ball joint (4). The supporting shaft (5) is fixed to the first permanent magnet (9) and the second permanent magnet (14) by a supporting shaft fastener (13), and the ball joint (4) is fixed to the top of the supporting shaft (5).

[0030] In this embodiment, the supporting shell and transmission assembly further include: an upper frame (6), a middle frame (7), a bottom frame (8), a longitudinal rubber pad layer (10), a transverse rubber pad layer (11), a connecting rod (16), a bottom fixing frame (17), a base support shaft (18), and a top cover (19). The upper frame (6), middle frame (7), bottom frame (8), longitudinal rubber pad (10), and transverse rubber pad (11) are all adapted to the first coil (9) and the second coil (14); The first permanent magnet (12) is installed in the middle of the upper frame (6); The second permanent magnet (14) is installed in the middle of the bottom frame (9); The base support shaft (18) is fixed to the insertion hole in the base (3) and fixed to the bottom fixed frame (17) by the support shaft fastener (13).

[0031] The central frame (7) is adapted to the support shaft (5); The top cover (19), upper frame (6), middle frame (7), bottom frame (8), and bottom fixed frame (17) are arranged sequentially from top to bottom, connected by connecting rods (16), and fastened and fixed in relative position by connecting rod fasteners (20).

[0032] The longitudinal rubber pad (10) is disposed in the gap between the first coil (9) and the upper frame (6) and the second coil (14) and the bottom frame (8) to secure the first coil (9) and the second coil (14) and prevent them from sliding in the horizontal direction. The transverse rubber pad layer (10) is provided in the gap between the first coil (9) and the top cover (19) and the second coil (14) and the bottom frame (8) to secure the first coil (9) and the second coil (14) and prevent them from sliding in the vertical direction; The six electromagnetic vibration isolation structures (101) have the same structure and are installed on the base (3) at a specific angle. They are connected to the top platform (4) through ball joints (4). The angle between the central axis of the electromagnetic vibration isolation structure (101) and the base plane is denoted as α1, and the angle between the planes of the adjacent vibration isolation mechanisms is denoted as α2. By changing the angle α1 between the central axis of the electromagnetic vibration isolation structure (101) and the base plane, and the angle α2 between the planes of the adjacent vibration isolation mechanisms, mechanical analysis and synthesis are performed using the mechanical simulation software ANSYS WORKBRNCH. Furthermore, the optimal approximate solutions α1 and α2 are obtained using the lsqnonlin function in MATLAB, so that the dynamic stiffness of the vibration isolation platform in all directions approaches zero.

[0033] The first coil (9) and the second coil (14) have the same structure. The inner diameter of the first coil (9) or the second coil (14) is denoted as Φ1, and the outer diameter is denoted as Φ2. By changing the current I1 of the first coil (9) and the second coil (14) and applying the electromagnetic force formula Calculate the nonlinear positive stiffness curves corresponding to different coils; optimize the synthesized stiffness parameters using the fmincon function in MATLAB. In this embodiment: The first coil (9) and the second coil (14) have the same structure. The inner diameter of the first coil (9) and the second coil (14) is denoted as Φ1, the outer diameter of the first coil (9) and the second coil (14) is denoted as Φ2, and the height of the first coil (9) and the second coil (14) is denoted as h1. The first permanent magnet (12) and the second permanent magnet (15) have the same structure. The inner diameter of the first permanent magnet (12) and the second permanent magnet (15) is Φ3, the outer diameter of the first permanent magnet (12) and the second permanent magnet (15) is Φ4, and the height of the first permanent magnet (12) and the second permanent magnet (15) is h3. Let h2 be the distance between the first coil (9) and the first permanent magnet (12); Let l1 be the distance between the first coil (9) and the second coil (14); Let l2 be the distance between the first permanent magnet (12) and the second permanent magnet (15); By constraining parameters Φ1, Φ2, Φ3, Φ4, h1, h2, h3, and designing the position parameters l1, l2 of the coil and permanent magnet, the structural parameters with a quasi-zero stiffness range are determined.

[0034] In this embodiment, the first coil (9) and the second coil (14) have the same structure. The inner diameter of the first coil (9) or the second coil (14) is denoted as Φ1, and the outer diameter is denoted as Φ2. The current I1 of the first coil (9) and the second coil (14) is changed, and the nonlinear positive stiffness curves corresponding to different coils are calculated by using the electromagnetic force formula; the synthesized stiffness parameters are optimized by using the fmincon function in MATLAB. The six electromagnetic vibration isolation structures (101) have the same structure and are installed on the base (3) at a specific angle. They are connected to the top platform (4) through ball joints (4). The angle between the central axis of the electromagnetic vibration isolation structure (101) and the base plane is denoted as α1, and the angle between the planes of the adjacent vibration isolation mechanisms is denoted as α2. By changing the angle α1 between the central axis of the electromagnetic vibration isolation structure (101) and the base plane, and the angle α2 between the planes of the adjacent vibration isolation mechanisms, mechanical analysis and synthesis are performed using the mechanical simulation software ANSYS WORKBRNCH. Furthermore, the optimal approximate solutions α1 and α2 are obtained using the lsqnonlin function in MATLAB, so that the dynamic stiffness of the vibration isolation platform in all directions approaches zero.

[0035] like Figure 8 As shown, in this embodiment, during the downward movement of the first permanent magnet (12), the second permanent magnet (15) and the support shaft (), the electromagnetic force generated by the first coil (9) and the second coil (14) on the first permanent magnet (12) is a "convex" nonlinear positive stiffness curve, and the electromagnetic force generated by the first coil (9) and the second coil (14) on the second permanent magnet (15) is a "convex" nonlinear negative stiffness curve. Through parameter design, the nonlinear force-displacement curves can be combined into a curve with dynamic stiffness approaching zero, that is, quasi-zero stiffness.

[0036] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom, characterized in that, include: High-damping rubber platform (1), top platform (2), base (3), electromagnetic structure core (101). An electromagnetic vibration isolation structure (101) includes an electromagnetic structure core, its supporting shell, and a transmission assembly. The electromagnetic structure core includes a first coil (9), a first permanent magnet (12), a second coil (14), and a second permanent magnet (15) arranged from top to bottom, wherein the current direction of the first coil (9) and the second coil (14) is the same; Support shell and transmission assembly, which are components of the electromagnetic vibration isolation structure (101), are connected to the top platform (4) to be adapted to the core of the electromagnetic structure. The six electromagnetic structure cores (101) are installed on the base (3) at a specific angle and connected to the top platform (2) through ball joints (4); The first permanent magnet (12) moves relative to the first coil (9) and the second coil (14), providing a positive stiffness curve of a specific shape; The relative motion between the second permanent magnet (15) and the first coil (9) and the second coil (14) provides a negative stiffness curve of a specific shape.

2. The quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom according to claim 1, characterized in that: The supporting housing and transmission assembly include a supporting shaft (5) and a ball joint (4). The supporting shaft (5) is fixed to the first permanent magnet (9) and the second permanent magnet (14) by a supporting shaft fastener (13), and the ball joint (4) is fixed to the top of the supporting shaft (5).

3. The quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom according to claim 1, characterized in that: The supporting shell and transmission assembly also include: an upper frame (6), a middle frame (7), a bottom frame (8), a longitudinal rubber pad (10), a transverse rubber pad (11), a connecting rod (16), a bottom fixing frame (17), a base support shaft (18), and a top cover (19). The upper frame (6), middle frame (7), bottom frame (8), longitudinal rubber pad (10), and transverse rubber pad (11) are all adapted to the first coil (9) and the second coil (14); The first permanent magnet (12) is installed in the middle of the upper frame (6); The second permanent magnet (14) is installed in the middle of the bottom frame (9); The base support shaft (18) is fixed to the insertion hole in the base (3) and fixed to the bottom fixed frame (17) by the support shaft fastener (13); The central frame (7) is adapted to the support shaft (5); The top cover (19), upper frame (6), middle frame (7), bottom frame (8), and bottom fixed frame (17) are arranged sequentially from top to bottom, connected by connecting rods (16), and fastened and fixed in relative position by connecting rod fasteners (20); The longitudinal rubber pad (10) is disposed in the gap between the first coil (9) and the upper frame (6) and the second coil (14) and the bottom frame (8) to secure the first coil (9) and the second coil (14) and prevent them from sliding in the horizontal direction. The transverse rubber pad (10) is placed in the gap between the first coil (9) and the top cover (19) and the second coil (14) and the bottom frame (8) to secure the first coil (9) and the second coil (14) and prevent them from sliding in the vertical direction.

4. The quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom according to claim 1, characterized in that: The six electromagnetic vibration isolation structures (101) have the same structure and are installed on the base (3) at a specific angle. They are connected to the top platform (4) through ball joints (4). The angle between the central axis of the electromagnetic vibration isolation structure (101) and the base plane is denoted as α1, and the angle between the planes of the adjacent vibration isolation mechanisms is denoted as α2. By changing the angle α1 between the central axis of the electromagnetic vibration isolation structure (101) and the base plane, and the angle α2 between the planes of the adjacent vibration isolation mechanisms, mechanical analysis and synthesis are performed using the mechanical simulation software ANSYSWORKBRNCH. Furthermore, the optimal approximate solutions α1 and α2 are obtained using the lsqnonlin function in MATLAB, so that the dynamic stiffness of the vibration isolation platform in all directions approaches zero.

5. The quasi-zero stiffness electromagnetic vibration isolator with six degrees of freedom according to claim 1, characterized in that: The first coil (9) and the second coil (14) have the same structure. Let the inner diameter of the first coil (9) or the second coil (14) be denoted as Φ1 and the outer diameter as Φ2. Change the current I1 of the first coil (9) and the second coil (14). And through the electromagnetic force formula Calculate the nonlinear positive stiffness curves corresponding to different coils; optimize the synthesized stiffness parameters using the fmincon function in MATLAB.

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