CN103821861B - Axial eddy current damper based on spiral transmission method - Google Patents

Abstract

The invention relates to a large-scale axial eddy current damper made by means of screw transmission, which includes a screw pair transmission assembly and a rotary eddy current damping generator; The upper disc and the lower disc are made of magnetically permeable material, and a rotating disc made of conductive material or magnetically permeable material parallel to the upper disc is arranged between the upper disc and the lower disc, and the rotating disc is installed On the helical auxiliary transmission assembly and rotate with the helical auxiliary transmission assembly; multiple pairs of magnets are arranged between the upper disc and the lower disc, and the polarities of the upper magnet and the lower magnet in each pair of magnets are opposite. The damper of the present invention converts the axial motion of the controlled structure into the rotational motion of the internal structure of the damper through the helical pair for control, which greatly improves the control efficiency, and combines the damping force of the axial eddy current damper with its own weight The ratio is increased to the same level or higher than that of the viscous fluid damper.

Description

Axial Eddy Current Damper Based on Screw Transmission

technical field

The invention relates to a large-scale axial eddy current damper made by means of screw transmission, which is especially suitable for passive and semi-active vibration control of large-scale civil engineering structures with low operating frequency, large damping coefficient and long working stroke.

Background technique

The basic principle of eddy current damping is: when the conductor plate in the magnetic field cuts the magnetic force line, an eddy current will be generated in the conductor plate, and the eddy current will generate a new magnetic field opposite to the direction of the original magnetic field, thereby forming a new magnetic field between the original magnetic field and the conductor. The damping force hinders the relative movement of the two, and the resistance effect of the conductor plate converts the kinetic energy of the conductor plate into heat energy and dissipates it through eddy currents. If the conductor plate is connected with the vibrating structure, it can produce the effect of structural vibration reduction and energy consumption, and become an eddy current damper. Compared with some damping devices commonly used in the field of structural vibration control, the eddy current damper does not rely on mechanical friction to dissipate energy, and there is no problem of leakage and sealing without working fluid. It has high reliability, good durability and relatively simple structure. And other advantages, so it is especially suitable for use in working environments that require long fatigue life and are not easy to maintain. At present, eddy current dampers have been widely used as soft braking systems for trucks. Because both the magnet and the conductor plate are substances with high mass density, compared with the viscous fluid damper with the same damping coefficient and maximum damping force, the eddy current damper with the same motion method is often much heavier and larger. Calculations show that the weight of an axial eddy current damper that produces a damping force of 10kN at a speed of one centimeter per second is one to three times higher than that of a viscous fluid damper by direct axial relative motion between the magnet and the conductor. Two orders of magnitude have no practical value. Therefore, improving the ratio of the damping force of the eddy current damper to its own weight and producing an eddy current damper with a large damping coefficient is a key problem to be solved urgently in the promotion and application of the eddy current damping technology in the field of civil engineering. At present, the published invention patents of axial eddy current dampers in my country mainly improve the performance of the damper by preventing magnetic flux leakage and optimizing the design of the magnetic circuit, and have limited effect on improving the ratio of damping force to its own weight.

Contents of the invention

The purpose of the present invention is to provide an axial eddy current damper based on the screw transmission method, which can amplify the damping coefficient of the rotary eddy current damper by hundreds or even thousands of times, and transform it into a very large The axial damping coefficient solves the problem that it is difficult to make an axial damper with a large damping coefficient in the general eddy current method. It is especially suitable for vibration control of large civil engineering structures with low operating frequency and requires a large damping coefficient. The structure is simple and durable.

The technical solution of the present invention is that an axial eddy current damper based on a screw transmission mode includes a transmission assembly and a rotary eddy current damping generator, the transmission assembly is a helical pair transmission assembly; the rotary eddy current damper The generator includes an upper disk and a lower disk made of a magnetically permeable material with the same size and arranged in parallel up and down. The helical auxiliary transmission assembly runs through the upper disk and the lower disk disc, and between the upper disc and the lower disc, there is a rotating disc made of conductive material or magnetically permeable material parallel to the upper disc. The rotating disc is installed on the helical pair transmission assembly and The helical auxiliary transmission assembly performs rotary motion; there are multiple pairs of magnets between the upper disc and the lower disc, and each pair of magnets includes an upper magnet and a lower magnet installed below the upper magnet along the axial direction of the upper disc. In each pair of magnets, the opposite magnetic poles of the upper magnet and the lower magnet are opposite; the rotary eddy current damping generator is also provided with a column whose two ends are respectively connected with the upper disc and the lower disc and provide a magnetic conduction circuit. Both the upper magnet and the lower magnet are placed between the column and the screw pair transmission assembly.

There is a gap between the upper magnet and the lower magnet and the column.

According to the realization mode of eddy current damping, the technical solutions adopted in the present invention include two kinds of magnet fixed schemes and magnet rotating schemes.

The magnet fixed scheme is: the upper magnet is installed on the bottom surface of the upper disc, and the lower magnet is installed on the top surface of the lower disc, and the rotating disc is made of conductive material; the uprights can be set with the same number of uprights as the upper magnets, and the uprights and the corresponding upper magnets are in the same position. On the radial straight line of the upper disk; the column can also be set as a closed ring; there is a gap between the upper magnet and the lower magnet and the rotating disk. The above two column setting methods can achieve the purpose of the shortest magnetic circuit and prevent magnetic flux leakage. Among them, when the number of uprights is the same as that of the upper magnet, the weight of the damper structure can be reduced; when the ring-shaped uprights are set, the ring-shaped uprights and the upper and lower discs can form a solid closed cavity to protect the internal structure and can Completely eliminate magnetic flux leakage.

When the rotating disk rotates, the magnetic field lines of the magnet are cut, and an electric eddy current is generated in the rotating disk immediately, and at the same time, a damping force that hinders the rotation of the rotating disk is generated. Each pair of magnets generates a strong magnetic field that passes through the rotating disc vertically, and the rotating disc should keep a distance of 2 to 3 mm from the upper and lower magnets; the planar layout of the magnets along the circumferential direction is arranged according to the principle of the shortest magnetic circuit.

The magnet generally uses a permanent magnet, and if a particularly large magnetic field strength is required or semi-active control is performed, an electromagnet should be used. The rotating disc is made of good conductive material, such as electrical copper. The upper disc, the lower disc and the column are all made of materials with good magnetic permeability, such as electrical soft iron or low carbon steel.

The rotating magnet scheme is: the upper magnet is installed on the top surface of the rotating disk, and the lower magnet is installed on the bottom surface of the rotating disk, and an upper inner disk made of conductive material is installed on the bottom surface of the upper disk. A lower inner disc made of conductive material is installed on the top surface of the lower disc, and the rotating disc is a magnetically permeable material. When the rotating disc drives the upper and lower magnets to rotate together, the magnetic field formed between the upper and lower magnets will also rotate together, so the upper inner disc and the lower inner disc will cut the magnetic field lines and generate eddy current effect. The rotating magnet scheme must design the column as a closed circular ring, so that the closed cavity cylinder formed by the column, the upper disc and the lower disc can ensure that the shortest magnetic circuit is always provided during the rotation of the magnet and will not leak. magnetic.

The screw pair transmission assembly includes a screw rod that penetrates the upper disc and the lower disc in the axial direction of the upper disc and the lower disc and moves axially, is installed on the screw rod and is placed between the upper disc and the lower disc nut, the rotating disc is installed on the nut; the top of the screw is provided with an upper connecting rod, the bottom of the lower disc is provided with a lower supporting column covering the bottom of the screw, and a lower connecting rod is provided at the bottom of the lower supporting column pole.

The nut is connected with the upper disc through the upper bearing, and the nut is connected with the lower disc through the lower bearing.

The screw transmission mode can be sliding screw transmission, rolling screw transmission, static pressure screw transmission and all other generalized screw transmission modes, and the screw auxiliary transmission component can be sliding screw transmission component, rolling screw transmission component, static pressure screw transmission Components and all other transmission components formed by the spiral pair structure.

The conductive material can be electrical copper or other excellent conductive materials, and the magnetically permeable material can be other magnetically permeable materials such as electrical soft iron or low carbon steel.

The working principle of the present invention is described as follows:

After the upper and lower connecting rods of the damper are connected to the two points of relative vibration of the controlled structure, the structural vibration forces the screw to reciprocate in the axial direction, and this movement is transformed into a rotating disk by the helical pair composed of the screw and the nut. rotation movement. A stable magnetic field is formed between each pair of upper and lower magnets in the fixed magnet scheme, and the rotating disk of conductive material rotates to cut the magnetic force lines, generating eddy current effects; when the rotating magnet scheme is adopted, the magnetic field formed between each pair of magnets Rotating together with the rotating disk, the upper inner disk and the lower inner disk of the conductor cut the lines of magnetic force and generate the eddy current effect. The damping force generated by the eddy current effect forms a large torque on the rotating shaft, and this torque is converted into a large damping force that hinders the axial movement of the screw through the screw pair, so the damper obtains a large damping coefficient. Assuming that the eddy current damping coefficient at each pair of magnets is C _e , it can be proved that when the friction force is ignored, the equivalent axial damping coefficient C of the damper is

In the formula, n is the logarithm of the magnet, r is the distance from the center of the magnet to the center of the rotating shaft, and h is the lead of the screw. Since r is much greater than h , the equivalent damping coefficient C of the damper can reach hundreds to thousands of times of the damping coefficient at a single pair of magnets. Trial prototypes have confirmed this feature.

The invention is especially suitable for the vibration control of large-scale civil engineering structures with low operating frequency and large damping coefficient. In addition to the inherent advantages of simple and durable structure of the eddy current damper and almost no maintenance, it is the same as the existing viscous fluid damper. Compared with the device technology, it has the following advantages:

1) The damper converts the axial movement of the controlled structure into the rotational movement of the internal structure of the damper through the helical pair, which greatly improves the control efficiency. The damping force of the axial eddy current damper and its own weight The ratio is increased to the same level or higher than that of the viscous fluid damper.

2) The damper only needs to increase the length of the screw to increase the working stroke of the damper, and the increased cost due to the increased stroke is very little. However, the viscous fluid damper must increase the piston rod length and the oil cylinder length at the same time to increase the working stroke of the damper, which makes the large-stroke viscous fluid damper particularly expensive.

3) The damper can increase the damping coefficient of the damper by increasing the diameter of the turntable, increasing the magnetic field strength of the magnet, increasing the number of magnet pairs, and increasing the number of eddy current generators, which is suitable for manufacturing large, medium and small Type damper.

4) The screw pair transmission adopted by the damper is a standard mechanical transmission mode, so the damper is easy to achieve standardized mass production.

5) Semi-active control can be realized by using electromagnets. Compared with magnetorheological dampers, the structure is simple and the cost is low.

Description of drawings

Fig. 1 is the structural representation of embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the arrangement of the upper magnet on the upper disc in Embodiment 1 of the present invention;

Fig. 3 is a schematic diagram of the arrangement of the lower magnet on the lower disc in Embodiment 1 of the present invention;

Fig. 4 is the structural representation of embodiment 2 of the present invention;

Fig. 5 is a schematic diagram of the arrangement of the upper magnet on the top surface of the rotating disc in Embodiment 2 of the present invention;

Fig. 6 is a schematic diagram of the arrangement of the lower magnets on the bottom surface of the rotating disc in Embodiment 2 of the present invention.

Detailed ways

Example 1

As shown in Figure 1, an axial eddy current damper based on a screw transmission method includes a helical auxiliary transmission assembly and a rotary eddy current damping generator. The rotary eddy current damping generator includes An upper disc 3 and a lower disc 9 made of magnetically permeable materials are provided, and the helical auxiliary transmission assembly penetrates the upper disc 3 and the lower disc 9 along the axial direction of the upper disc 3 and the lower disc 9, And between the upper disk 3 and the lower disk 9, a rotating disk 4 made of conductive material parallel to the upper disk 3 is provided. The rotating disk 4 is installed on the screw pair transmission assembly and moves with the screw pair. The transmission assembly rotates; 8 pairs of magnets are arranged between the upper disk 3 and the lower disk 9, and each pair of magnets includes an upper magnet 1 and a lower magnet installed below the upper magnet 1 along the axial direction of the upper disk 3 15. The polarity of the upper magnet 1 and the lower magnet 15 in each pair of magnets is opposite; the rotary eddy current damping generator is also provided with two ends connected to the upper disc 3 and the lower disc 9 respectively and provides The column 2 of the magnetic conduction circuit, the upper magnet 1 and the lower magnet 15 are all placed between the column 2 and the helical auxiliary transmission assembly. There is a gap between the upper magnet 1 and the lower magnet 15 and the column 2, and there is a gap between the upper magnet 1 and the lower magnet 15 and the rotating disc.

The screw pair transmission assembly includes a screw rod 7 that penetrates the upper disc 3 and the lower disc 9 along the axial direction of the upper disc 3 and the lower disc 9 and moves axially, is installed on the screw rod 7 and is placed between the upper disc 3 and the lower disc 9 The nut 8 between the lower discs 9, the rotating disc 4 is installed on the nut 8; the top of the screw rod 7 is provided with an upper connecting rod 6, and the bottom surface of the lower disc 9 is provided with a cover at the bottom of the screw rod 7 The lower support column 11 is provided with a lower connecting rod 12 at the bottom of the lower support column 11 . The nut 8 is connected with the upper disc 3 through the upper bearing 5 , and the nut 8 is connected with the lower disc 9 through the lower bearing 10 .

As shown in FIGS. 2 and 3 , the upper magnet 1 is installed on the bottom surface of the upper disc 3 , and the lower magnet 15 is installed on the top surface of the lower disc 9 . Eight columns 2 are arranged, and the columns 2 and the corresponding upper magnets 1 are on the radial straight line of the upper disc 3 .

The conductive material is electrical copper, and the magnetic material is electrical soft iron.

Example 2

As shown in Figure 4, an axial eddy current damper based on a screw transmission method includes a screw auxiliary transmission assembly and a rotary eddy current damping generator, and the rotary eddy current damping generator includes An upper disc 3 and a lower disc 9 made of magnetically permeable materials are provided, and the helical auxiliary transmission assembly penetrates the upper disc 3 and the lower disc 9 along the axial direction of the upper disc 3 and the lower disc 9, And between the upper disc 3 and the lower disc 9, there is a rotating disc 4 made of magnetically permeable material parallel to the upper disc 3. The rotating disc 4 is installed on the helical auxiliary transmission assembly and moves with the helical Auxiliary transmission assembly makes rotary motion; there are 8 pairs of magnets between the upper disk 3 and the lower disk 9, each pair of magnets includes an upper magnet 1 and a lower magnet installed below the upper magnet 1 along the axial direction of the upper disk 3. Magnets 15, the magnetic poles of the upper magnet 1 and the lower magnet 15 in each pair of magnets are opposite in polarity; The column 2 of the magnetic conduction circuit is provided, and the upper magnet 1 and the lower magnet 15 are both placed between the column 2 and the helical auxiliary transmission assembly. There is a gap between the upper magnet 1 and the lower magnet 15 and the column 2 .

The screw pair transmission assembly includes a screw rod 7 that penetrates the upper disc 3 and the lower disc 9 along the axial direction of the upper disc 3 and the lower disc 9 and moves axially, is installed on the screw rod 7 and is placed between the upper disc 3 and the lower disc 9 The nut 8 between the lower discs 9, the rotating disc 4 is installed on the nut 8; the top of the screw rod 7 is provided with an upper connecting rod 6, and the bottom surface of the lower disc 9 is provided with a cover at the bottom of the screw rod 7 The lower support column 11 is provided with a lower connecting rod 12 at the bottom of the lower support column 11 . The nut 8 is connected with the upper disc 3 through the upper bearing 5 , and the nut 8 is connected with the lower disc 9 through the lower bearing 10 .

As shown in Figures 5 and 6, the upper magnet 1 is installed on the top surface of the rotating disk 4, while the lower magnet 15 is correspondingly installed on the bottom surface of the rotating disk 4, and is installed on the bottom surface of the upper disk 3 and is made of conductive material. The upper inner disc 13 of the lower disc 9 is installed with a lower inner disc 14 made of conductive material. Column 2 is a closed circular ring.

The conductive material is electrical copper, and the magnetic material is electrical soft iron.

Claims (8)

1., based on an axial eddy current damper for screw drive mode, comprise transmitting assemblies and rotary electric eddy current damping producer, it is characterized in that, described transmitting assemblies is screw pair transmitting assemblies; Described rotary electric eddy current damping producer comprises in the same size and by the upper disk (3) be made up of permeability magnetic material be arranged in parallel up and down and lower disc (9), described screw pair transmitting assemblies runs through upper disk (3) and lower disc (9) along the axial direction of upper disk (3) and lower disc (9), and between upper disk (3) with lower disc (9), being provided with the rotating disk (4) of conductive material or permeability magnetic material be made up parallel with upper disk (3), described rotating disk (4) to be arranged on screw pair transmitting assemblies and to rotate with screw pair transmitting assemblies; Multipair magnet is also provided with between described upper disk (3) and lower disc (9), often pair of magnet comprises upper magnet (1) and is arranged on the lower magnet (15) of upper magnet (1) below along upper disk (3) axial direction, and the pole polarity that in described often pair of magnet, upper magnet (1) is relative with lower magnet (15) is contrary; Described rotary electric eddy current damping producer is also provided with two ends and is connected with upper disk (3), lower disc (9) respectively and the column (2) providing magnetic conductive loop, and described upper magnet (1) and lower magnet (15) are all placed between column (2) and screw pair transmitting assemblies.

2. according to claim 1 based on the axial eddy current damper of screw drive mode, it is characterized in that, described upper magnet (1), lower magnet (15) all and between column (2) leave space.

3. according to claim 2 based on the axial eddy current damper of screw drive mode, it is characterized in that, described upper magnet (1) is arranged on disk (3) bottom surface, and lower magnet (15) is arranged on lower disc (9) end face, and described rotating disk (4) is made up of conductive material.

4. according to claim 3 based on the axial eddy current damper of screw drive mode, it is characterized in that, the column (2) consistent with upper magnet (1) quantity is set, and column (2) and corresponding upper magnet (1) are in the radial alignment of upper disk (3), and upper magnet (1), lower magnet (15) all and between rotating disk (4) leave space.

5. according to claim 2 based on the axial eddy current damper of screw drive mode, it is characterized in that, described upper magnet (1) is arranged on the end face of rotating disk (4), and lower magnet (15) correspondence is arranged on the bottom surface of rotating disk (4), and the upper interior disk (13) be made up of conductive material is installed in the bottom surface of upper disk (3), the end face of lower disc (9) installs the lower interior disk (14) be made up of conductive material, and described rotating disk (4) is made up of permeability magnetic material.

6. according to claim 3 or 5 based on the axial eddy current damper of screw drive mode, it is characterized in that, described column (2) be close ring.

7. according to claim 1 or 2 based on the axial eddy current damper of screw drive mode, it is characterized in that, described screw pair transmitting assemblies comprises and runs through upper disk (3) and lower disc (9) along upper disk (3) and lower disc (9) axial direction and make the screw rod (7) of axial motion, be arranged on screw rod (7) and go up and be placed in the nut (8) between upper disk (3) and lower disc (9), and described rotating disk (4) is arranged on nut (8); The top of described screw rod (7) is provided with upper connecting rod (6), and described lower disc (9) bottom surface is provided with the lower support post (11) covering on screw rod (7) bottom, and is provided with lower connecting rod (12) in lower support post (11) bottom.

8. according to claim 7 based on the axial eddy current damper of screw drive mode, it is characterized in that, described nut (8) is connected with upper disk (3) by upper bearing (metal) (5), and described nut (8) is connected with lower disc (9) by lower bearing (10).