A compound pendulum rotating mass eddy current damper

Abstract

This invention discloses a compound pendulum rotating inertial mass eddy current damper, comprising a compound pendulum structure, a damping structure, a support structure, and an elastic device. A pendulum rod is oscillatingly mounted within the support structure, and multiple mass blocks are rotatably mounted on a rotating shaft. The damping structure includes: a support eddy current plate, an end plate, a rotating shaft eddy current plate, permanent magnets, and an arc-shaped guide rail. The end plate and the rotating shaft eddy current plate are coaxially fixed to the mass blocks. The permanent magnets are arranged in an array on both sides of the mass blocks and outside the end plate. The guide rail is mounted on the upper surface of the support base plate of the support structure. The side projection of the guide rail is arc-shaped, and its vertical projection is a horizontal line segment. The upper surface of the guide rail is rough. The support eddy current plate is located on the inner side of the support structure. This invention can significantly improve the effective mass and energy dissipation density of the damper, ensure vibration control effects, and improve the applicability of the damper in different working environments, as well as the range and fine grading of damping adjustment.

Description

Technical Field

[0001] This invention relates to the field of structural vibration reduction technology. More specifically, this invention relates to a compound pendulum rotating inertial mass eddy current damper. Background Technology

[0002] In engineering structures, poor structural stability is often caused by high slenderness ratios and low self-damping of components. Structures such as super high-rise buildings, towers / piers of large bridges, and suspenders of long-span arch bridges are prone to significant vibrations under wind and vehicle loads, affecting user comfort, causing fatigue damage, and even failure. This poses a significant challenge to the structural safety and achieving its design service life. Tuned mass dampers (TMDs), due to their highly efficient single-mode vibration reduction performance, have become the most commonly used method for structural vibration control, widely applied in high-rise buildings and bridge engineering. The energy-dissipating elements of TMDs are mainly of two types: viscous damping devices and eddy current damping devices. Viscous damping devices are prone to leakage under cyclic loads, have low durability, and are difficult to adjust damping parameters. Eddy current damping devices have neither mechanical friction nor working fluid, eliminating leakage and sealing issues, and exhibiting good durability and environmental adaptability.

[0003] Currently, the main structural forms of eddy current damping devices are flat plate type and rotary type based on ball screws or racks and pinions. Flat plate type damping devices can provide a low damping coefficient, and their energy dissipation capacity often cannot meet the damping force requirements of large engineering structures. Eddy current damping devices that use ball screw pairs or racks and pinions to convert the linear motion of the mass block into rotational motion can improve energy dissipation efficiency to a certain extent, but their efficiency index is still limited by the lead of the ball screw pair or rack and pinion and the overall axial dimension. They also have disadvantages such as a small inertia coefficient, easy wear of the transmission mechanism, and low internal space utilization for the same external volume, which greatly limits the application and promotion of eddy current damping devices. For this reason, pendulum type eddy current damping devices have emerged and have been developed. For example, the patent application CN103132628A, entitled "Pendulum-type Eddy Current Tuned Mass Damping Device," discloses a tuned mass damping device with flexible slings for multi-directional horizontal vibration and eddy current energy dissipation. Vibration control is achieved through an eddy current damping generator installed at the bottom of the mass block, and the non-contact energy dissipation improves the stability and durability of the damper. However, the use of a flexible sling to drive the movement of the mass block makes it difficult to control the dynamic stability of the mass block, failing to meet the requirements for damper stability and durability. Adjusting the damper frequency by adjusting the sling length has a small adjustable range, only applicable to lower frequencies, limiting its application scope. The patent application CN105138798A, entitled "A pendulum-type eddy current tuned mass damper and method for achieving structural vibration reduction," discloses a compound pendulum-type eddy current damper. The frequency of the damper is adjusted by adjusting the distance between the spring and the pendulum shaft. However, the damping efficiency of the flat plate-type eddy current damping device used is much lower than that of the rotary eddy current damping device, and the adjustment range is smaller. The fixed pendulum mass block provides a lower effective mass for vibration reduction under the same working space and mass conditions. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a compound pendulum rotating inertial mass eddy current damper, which can significantly improve the effective mass and energy dissipation density of the damper while maintaining the same geometric dimensions, ensuring vibration control effect, and improving the applicability of the damper in different working environments, as well as the range and fine classification of damping adjustment.

[0005] The technical solution adopted by the present invention to solve this technical problem is: a compound pendulum rotating inertial mass eddy current damper, comprising a compound pendulum structure, a damping structure, a support structure and an elastic device;

[0006] The compound pendulum structure includes a pendulum rod, a rotating shaft, and mass blocks; the pendulum rod is oscillatingly mounted in the support structure, the lower end of the pendulum rod is connected to the rotating shaft, and the mass blocks are disc-shaped with multiple mass blocks rotatably mounted on the rotating shaft.

[0007] The damping structure includes: a support vortex plate, an end plate, a rotating shaft vortex plate, permanent magnets, and an arc-shaped guide rail; the end plate and the rotating shaft vortex plate are both fixed coaxially with the mass block, the permanent magnets are arranged in an array on both sides of the mass block and the outside of the end plate, the guide rail is set on the upper surface of the support base plate of the support structure, the side projection of the upper surface of the guide rail is arc-shaped, the vertical projection is a horizontal line segment, the upper surface of the guide rail is a rough surface, and the support vortex plate is set on the inner side of the side of the support structure;

[0008] The elastic device, mechanically connected to the pendulum rod, provides restoring force to the mass block, ensuring the compound pendulum structure remains stationary at its lowest point in the middle of the slide rail. In the TMD (Transmission Modulation Device), the elastic device is not only the mechanical link but also the core for achieving frequency tuning, energy transfer, and dynamic balance. Its stiffness parameters directly affect the vibration reduction performance of the TMD and must be optimized in conjunction with the mass block's mass and the energy dissipation characteristics of the damping elements to achieve the best vibration reduction effect.

[0009] As a further aspect of the present invention, the support structure includes: a support top plate, a support vertical rod, and a support bottom plate; the upper and lower ends of the support vertical rod are respectively connected to the support top plate and the support bottom plate to form a frame structure.

[0010] As a further aspect of the present invention, the elastic device includes: an elastic element, an elastic element back plate, and an elastic element limiting member;

[0011] The elastic element back plate is connected to the support vertical rod through a reserved hole and bolts. The distance between the elastic element back plate and the support top plate is adjustable. The elastic element is set between the elastic element back plate and the swing rod. The swing rod is provided with an elastic element limiting member that can be adjusted along the swing rod axis. The elastic element limiting member is used to connect the elastic element.

[0012] As a further aspect of the present invention, the compound pendulum structure further includes: a pendulum shaft, a pendulum shaft lug plate, a pendulum shaft bearing, and a bearing cover plate;

[0013] The swing shaft lug is vertically fixed to the lower surface of the top plate of the bracket. The swing shaft is connected to the swing shaft lug via a swing shaft bearing. The bearing cover is used to limit the displacement of the swing shaft bearing along the thickness direction of the swing shaft lug during operation. The swing rod is a rigid rod, with its two ends connected to the swing shaft and the rotating shaft, respectively. The swing rod is set perpendicular to the swing shaft, while the swing shaft and the rotating shaft are set parallel to each other.

[0014] As a further aspect of the present invention, a stiffening plate is provided at the connection between the pendulum shaft and the pendulum rod.

[0015] As a further aspect of the present invention, the rotating shaft vortex plate is fixedly connected to the rotating shaft, and the side of the rotating shaft vortex plate is parallel to the side of the mass block and the distance between them is adjustable.

[0016] As a further aspect of the present invention, the side of the eddy current plate of the bracket is parallel to the side of the end plate and the distance between the two is adjustable, and a permanent magnet is provided on the outer side of the end plate.

[0017] As a further aspect of the present invention, the permanent magnets are arranged in a Halbach array on both sides of the mass block and on the outer side of the end plate.

[0018] The present invention has at least the following beneficial effects:

[0019] 1. The disk-shaped mass used in this patent amplifies the equivalent inertial mass through the rotational inertial mass effect. The composite design of the pendulum and the rotational inertial mass significantly enhances the inertial mass effect, achieving the characteristics of "small volume and large inertia".

[0020] 2. For the same TMD mass ratio, the integrated compound pendulum and rotating inertial mass structure have a more compact arrangement. Eddy current damping offers the advantages of being contactless and without a fluid medium, allowing for stable operation in environments ranging from -40℃ to 80℃. The shaft can utilize sealed bearings with anti-corrosion coatings, making it suitable for high-temperature and fume-filled environments.

[0021] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0022] Figure 1 This is an elevation view of the compound pendulum rotating inertial mass eddy current damper of the present invention;

[0023] Figure 2 This is a side view of the compound pendulum rotating inertial mass eddy current damper of the present invention.

[0024] Among them, 1-swing shaft ear plate, 2-stiffening plate, 3-swing shaft, 4-swing shaft bearing, 5-elastic element back plate, 6-elastic element, 7-rotating shaft, 8-rotating shaft bearing, 9-mass block, 10-permanent magnet, 11-end plate, 12-support eddy current plate, 13-rotating shaft eddy current plate, 14-swing rod, 15-bearing cover plate, 16-support top plate, 17-elastic element limiting component, 18-guide rail, 19-support bottom plate, 20-support vertical rod, 21-bolt. Detailed Implementation

[0025] The present invention will now be described in detail and completely with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be particularly noted that the technical solutions and features provided in various parts of the present invention, including the following description, can be combined with each other without conflict.

[0026] Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows:

[0028] like Figures 1-2 As shown, the present invention provides a compound pendulum rotating inertial mass eddy current damper, comprising a compound pendulum structure, a damping structure, a support structure, and an elastic device;

[0029] The compound pendulum structure includes a pendulum rod 14, a rotating shaft 7, and a mass block 9. The pendulum rod 14 is oscillatingly mounted in the support structure, and the lower end of the pendulum rod 14 is connected to the rotating shaft 7. The mass block 9 has a disc-shaped structure, and multiple mass blocks 9 with the same structure are rotatably mounted on the rotating shaft 7. The number of mass blocks 9 is determined according to actual needs. In this embodiment, the mass block 9 is connected to the rotating shaft 7 through a rotating shaft bearing 8.

[0030] The damping structure includes: a support vortex plate 12, an end plate 11, a rotating shaft vortex plate 13, permanent magnets 10, and an arc-shaped guide rail 18. The end plate 11 and the rotating shaft vortex plate 13 are coaxially fixed to the mass block 9. The permanent magnets 10 are arranged in an array on both sides of the mass block 9 and outside the end plate 11. The guide rail 18 is located on the upper surface of the support base plate 19 of the support structure. The side projection of the upper surface of the guide rail 18 is arc-shaped, and the elevation projection is a horizontal line segment. The upper surface of the guide rail 18 is rough. The radius of curvature R of the arc-shaped guide rail 18 is equal to the sum of the equivalent pendulum length of the compound pendulum and the radius of the disk-shaped mass block 9. The mass block 9 rolls freely along the arc-shaped track, and its axis of rotation is always orthogonal to the tangent direction of the compound pendulum's swing. The support vortex plate 12 is located on the inner side of the support structure, i.e., the support vortex plate 12 is located inside the support vertical rod 20. The rotating shaft vortex plate 13 and the support vortex plate 12 can be made of aluminum or copper.

[0031] The elastic device, which is mechanically connected to the pendulum rod, provides a restoring force to the mass block, so that the static position of the compound pendulum structure is located at the lowest position in the middle of the slide rail.

[0032] In the above technical solution, when the pendulum 14 swings, the rotating shaft 7 drives the mass block 9 (including permanent magnet 10), the rotating shaft eddy current plate 13, and the end plate 11 (including permanent magnet 10) to swing together around the axis of the pendulum shaft 3. This swing causes the mass block 9 to roll along the upper surface of the guide rail 18, and the rotating shaft eddy current plate 13 and the end plate 11 to translate along the upper surface of the guide rail 18. The permanent magnets 10 embedded on both sides of the mass block 9 rotate relative to the rotating shaft eddy current plate 13, generating a rotational eddy current damping effect (rotational damping device); the permanent magnets 10 on the outer surface of the end plate 11 translate relative to the support eddy current plate 12, generating a flat plate eddy current effect (flat plate damping device); thus achieving a highly efficient and easily finely adjustable composite eddy current damping, while maintaining the function of the existing flat plate damping device, a more efficient rotational damping device is added.

[0033] For conventional engineering applications, a design with a surface roughness Ra of 0.4 μm for mass block 9 (grinding) and a surface roughness Ra of 0.8 μm for the arc-shaped guide rail 18 (laundering) can be used to balance performance and cost. Alternatively, a surface roughness gradient can be set along the rolling direction of mass block 9, with the middle (lowest) position of guide rail 18 as the vertical plane of symmetry. The roughness Ra at the middle position and extending 5 mm to both sides is 0.8 μm (accelerating the removal of static friction), the roughness Ra from 5 mm to 30 mm is 0.4 μm (stabilizing rolling), and the roughness Ra at the 30 mm boundary of guide rail 18 is 0.6 μm (suppressing relative motion). The rolling surface roughness of mass block 9 can be set to 0.2~0.4 μm. In the above technical solutions, the surface roughness gradient design can significantly improve the system's dynamic response speed, motion smoothness, and durability. The rolling surface roughness can significantly optimize the system's friction performance, motion accuracy, and environmental resistance, making it particularly suitable for engineering scenarios with stringent requirements for response speed and durability (such as bridges).

[0034] In a preferred embodiment of this application, the support structure includes: a support top plate 16, a support vertical rod 20, and a support bottom plate 19; the upper and lower ends of the support vertical rod 20 are respectively connected to the support top plate 16 and the support bottom plate 19 to form a frame structure.

[0035] In a preferred embodiment of this application, the elastic device includes: an elastic element 6, an elastic element back plate 5, and an elastic element limiting member 17;

[0036] The elastic element back plate 5 is connected to the support vertical rod 20 through a pre-drilled hole and bolts 21. The distance between the elastic element back plate 5 and the support top plate 16 is adjustable. A pair of elastic elements 6 are symmetrically arranged between the elastic element back plate 5 and the swing rod 14, providing restoring force for swinging in both directions, keeping its restoring position in the middle (lowest) position of the slide rail. The swing rod 14 is provided with an elastic element limiting member 17 whose position can be adjusted along the axial direction of the swing rod 14. The elastic element limiting member 17 is used to connect the elastic element 6. By changing the position, the TMD frequency can be finely and continuously adjusted.

[0037] In a preferred embodiment of this application, the compound pendulum structure further includes: a pendulum shaft 3, a pendulum shaft lug plate 1, a pendulum shaft bearing 4, and a bearing cover plate 15;

[0038] The swing shaft lug 1 is vertically fixed to the lower surface of the bracket top plate 16. The swing shaft 3 is connected to the swing shaft lug 1 via the swing shaft bearing 4. The swing shaft 3 drives the swing rod 14 to rotate. The bearing cover plate 15 is used to limit the displacement of the swing shaft bearing 4 along the thickness direction of the swing shaft lug 1 during operation. The swing rod 14 is a rigid rod. Both ends of the swing rod 14 are connected to the swing shaft 3 and the rotating shaft 7 respectively. It can be a fixed connection (such as welding) or a detachable connection (such as bolting) to enhance the adaptability of the component. The swing rod 14 is set perpendicular to the swing shaft 3, and the swing shaft 3 and the rotating shaft 7 are set parallel to each other.

[0039] In a preferred embodiment of this application, a stiffening plate 2 is provided at the connection between the swing shaft 3 and the swing rod 14 to enhance the fatigue performance of the connection position.

[0040] In a preferred embodiment of this application, the rotating shaft vortex plate 13 is fixedly connected to the rotating shaft 7, and the side of the rotating shaft vortex plate 13 is parallel to the side of the mass block 9 and the distance between them is adjustable.

[0041] In a preferred embodiment of this application, the side of the support vortex plate 12 is parallel to the side of the end plate 11 and the distance between them is adjustable, and a permanent magnet 10 is provided on the outer side of the end plate 11 (the side closest to the support vortex plate 12).

[0042] In a preferred embodiment of this application, the permanent magnets 10 are arranged in a Halbach array on both sides of the mass block 9 and the outside of the end plate 11. The Halbach array significantly enhances the magnetic field on one side (such as the side of the end plate 11 and the rotating shaft eddy plate 13) through the orderly arrangement of the magnet directions, while weakening the magnetic field on the other side (such as the side of the disk-shaped mass block 9 towards the center), forming a "magnetic monopole" effect, which can greatly reduce magnetic field interference.

[0043] The disk-shaped mass block 9 used in this application amplifies the equivalent inertial mass through the rotational inertial mass effect. The composite design of the pendulum and the rotational inertial mass significantly enhances the inertial mass effect, achieving the characteristics of "small volume, large inertia". Each parameter can be designed according to specific requirements.

[0044] Furthermore, this application organically integrates the functions of damping and equivalent mass. The damping is a rotating eddy current damping, and the equivalent mass has a rotational inertial mass amplification effect. During the swing of the pendulum 14, each disc-shaped mass 9 rotates on an arc-shaped track, driving each disc-shaped mass 9 to rotate around its own central axis 7. The eddy current plate 13 of the axis is fixed to the axis 7, meaning there is relative motion between the eddy current plate and the permanent magnet 10 fixed on the surface of the disc-shaped mass 9, generating rotating eddy current damping. The damping power increases with the square of the rotational speed. There is also relative motion between the eddy current plate 12 of the support and the permanent magnet 10 on the surface of the end plate 11 of the axis 7, generating flat plate eddy current damping. Overall, the oscillation and rotation achieve coordinated energy dissipation, further improving damping efficiency. In particular, the dynamic adjustment capability of the rotating eddy current can solve the performance degradation problem of traditional dampers under high-frequency vibration. The coordinated energy dissipation is as follows:

[0045] When the pendulum moves, assuming its linear velocity is v, for the outermost magnet, the electromagnetic damping force generated by its eddy current circuit during the pendulum's motion is:

[0046] (1)

[0047] Where B is the magnetic field strength, a is the length of the magnet, l is the magnet dimension (width) in the direction orthogonal to v, t is the thickness of the conductor plate, ρ is the resistivity of the conductor plate, and n is the magnetic field strength. c This represents the number of permanent magnets.

[0048] When the pendulum moves, it drives the electromagnetic wheel to roll. According to the principles of physics, the linear velocity of the electromagnetic wheel is equal to the linear velocity of the pendulum's oscillation. Therefore, the angular velocity of the wheel's oscillation can be obtained as:

[0049]

[0050] In the formula: v is the velocity of the simple pendulum, and r is the radius of the electromagnetic wheel.

[0051] Obviously, when the electromagnetic wheel rotates, the electromagnetic damping force generated by its eddy current circuit is calculated using the same principle as formula (1), and thus we can obtain:

[0052] (2)

[0053] in, The magnetic field strength of the electromagnetic wheel. The length of the electromagnetic wheel magnet is , The dimensions (length) of the electromagnetic wheel magnet in the direction orthogonal to v, and the thickness of the electromagnetic wheel conductor plate. , The resistivity of the electromagnetic wheel conductor plate, This represents the number of permanent magnets on the electromagnetic wheel.

[0054] During this period, the eddy current plate, permanent magnet 10, rotating shaft 7, and bearings are all part of the effective mass of the TMD, significantly increasing the damper's mass ratio and further improving its vibration reduction effect. Permanent magnets 10 are arranged on both sides of the disc-shaped mass block 9, and a rotating shaft eddy current plate 13 is arranged on each side. Damping is adjustable by adjusting the distance between the permanent magnets 10 and the rotating shaft eddy current plates 13. Combined with the adjustable number of disc-shaped mass blocks 9 and rotating shaft eddy current plates 13 arranged laterally, the TMD damping ratio can be finely adjusted.

[0055] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A compound pendulum-type rotating inertial mass eddy current damper, characterized in that, It includes a compound pendulum structure, a damping structure, a support structure, and an elastic device; The compound pendulum structure includes a pendulum rod, a rotating shaft, and mass blocks; the pendulum rod is oscillatingly mounted in the support structure, the lower end of the pendulum rod is connected to the rotating shaft, and the mass blocks are disc-shaped with multiple mass blocks rotatably mounted on the rotating shaft. The damping structure includes: a support vortex plate, an end plate, a rotating shaft vortex plate, permanent magnets, and an arc-shaped guide rail; the permanent magnets are arranged in an array on both sides of the mass block and on the outside of the end plate, the guide rail is set on the upper surface of the support base plate of the support structure, the side projection of the upper surface of the guide rail is arc-shaped, the vertical projection is a horizontal line segment, the upper surface of the guide rail is a rough surface, and the support vortex plate is set on the inner side of the side of the support structure. An elastic device, which is mechanically connected to the pendulum rod, provides a restoring force to the mass block, so that the static position of the compound pendulum structure is located at the lowest position in the middle of the slide rail; A rotating shaft vortex plate is arranged on each side of the mass block; the rotating shaft vortex plate is fixedly connected to the rotating shaft, and the side of the rotating shaft vortex plate is parallel to the side of the mass block and the distance between them is adjustable. During the swing of the pendulum, each mass block rotates on the arc-shaped track. The vortex plate of the rotating shaft moves relative to the permanent magnet fixed on the surface of the mass block, and the vortex plate of the support moves relative to the permanent magnet on the surface of the end plate.

2. The compound pendulum rotating inertial mass eddy current damper as described in claim 1, characterized in that, The support structure includes: a support top plate, support vertical rods, and a support bottom plate; the upper and lower ends of the support vertical rods are respectively connected to the support top plate and the support bottom plate to form a frame structure.

3. The compound pendulum rotating inertial mass eddy current damper as described in claim 2, characterized in that, The elastic device includes: an elastic element, an elastic element back plate, and an elastic element limiting member; The elastic element back plate is connected to the support vertical rod through a reserved hole and bolts. The distance between the elastic element back plate and the support top plate is adjustable. The elastic element is set between the elastic element back plate and the swing rod. The swing rod is provided with an elastic element limiting member that can be adjusted along the swing rod axis. The elastic element limiting member is used to connect the elastic element.

4. The compound pendulum rotating inertial mass eddy current damper as described in claim 3, characterized in that, The compound pendulum structure also includes: a pendulum shaft, a pendulum shaft lug plate, a pendulum shaft bearing, and a bearing cover plate; The swing shaft lug is vertically fixed to the lower surface of the top plate of the bracket. The swing shaft is connected to the swing shaft lug via a swing shaft bearing. The bearing cover is used to limit the displacement of the swing shaft bearing along the thickness direction of the swing shaft lug during operation. The swing rod is a rigid rod, with its two ends connected to the swing shaft and the rotating shaft, respectively. The swing rod is set perpendicular to the swing shaft, while the swing shaft and the rotating shaft are set parallel to each other.

5. The compound pendulum rotating inertial mass eddy current damper as described in claim 4, characterized in that, A stiffening plate is provided at the connection between the pendulum shaft and the pendulum rod.

6. The compound pendulum rotating inertial mass eddy current damper as described in claim 1, characterized in that, The side of the vortex plate of the bracket is parallel to the side of the end plate, and the distance between them is adjustable.

7. The compound pendulum rotating inertial mass eddy current damper as described in claim 1, characterized in that, The permanent magnets are arranged in a Halbach array on both sides of the mass block and on the outside of the end plate.

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