A three-dimensional rolling ball isolation bearing

Abstract

The present invention belongs to the technical field of seismic isolation, and particularly relates to a three-dimensional rolling ball seismic isolation bearing. An eddy current horizontal seismic isolator is composed of an upper bearing plate, rolling balls, a lower bearing plate, a base, a permanent magnet I, a permanent magnet II, a closed conductor, and a permanent magnet III, and a vertical seismic isolator is composed of an upper connecting plate, a disc spring, a lower connecting plate, and a steel spring; the upper bearing plate and the lower bearing plate are arranged relatively up and down, and variable-frequency concave surfaces are respectively provided on the corresponding surfaces of the upper bearing plate and the lower bearing plate. Specifically: an upper bearing plate variable-frequency concave surface is opened at the bottom of the upper bearing plate, and a lower bearing plate variable-frequency concave surface is opened at the top of the lower bearing plate. The upper bearing plate variable-frequency concave surface and the lower bearing plate variable-frequency concave surface are opposite to each other in the up-and-down direction in pairs as a group, and rolling balls are arranged between each group of variable-frequency concave surfaces. The present invention can simultaneously isolate horizontal and vertical seismic forces, and has the advantages of strong energy dissipation capacity, good self-resetting ability, good anti-overturning performance, and simple structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of seismic isolation, and particularly relates to a three-dimensional rolling ball seismic isolation bearing. Background Art

[0002] The seismic isolation principle of a rolling ball bearing is to utilize a concave surface to extend the natural period of a structure, greatly reduce the dynamic amplification effect caused by seismic action, and consume seismic energy through the frictional force generated during the rolling process of the rolling ball and the upper and lower concave surfaces. At present, scholars at home and abroad have developed a variety of rolling ball seismic isolation bearings. In 1870, Touaillon invented a rolling ball placed in a bearing plate with spherical concave surfaces on the upper and lower sides; in 1995, Kemeny et al. invented a Ball-In-Cone seismic isolation bearing; in 2010, Tsai CS et al. proposed a rolling ball seismic isolation bearing with damping materials; in 2012, Sui Yingjie et al. proposed a rolling ball disc spring seismic isolation device; in 2014, Sui Yingjie et al. proposed a viscoelastic damping rolling ball seismic isolation bearing; in 2016, Zhao Jinping et al. proposed a rolling ball seismic isolation bearing with a braking spring; in 2019, Jiao Chiyu et al. proposed a multi-rolling ball seismic isolation bearing; in 2019, Xu Defeng et al. proposed a rolling ball seismic isolation bearing with a viscous damper and a variable-frequency curved surface. However, the above-developed rolling ball seismic isolation bearings have disadvantages such as weak energy dissipation ability, poor self-resetting ability, and lack of consideration of anti-overturning performance. At the same time, the above rolling ball seismic isolation bearings cannot isolate vertical seismic forces. Actual earthquake disasters have shown that the influence of vertical earthquakes cannot be ignored. For example, in the Northridge earthquake and the Kobe earthquake, it was found that the peak value of vertical acceleration was close to or even exceeded the peak value of horizontal acceleration. Therefore, it is urgent to propose a three-dimensional rolling ball seismic isolation bearing that can isolate both horizontal and vertical directions to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a three-dimensional rolling ball seismic isolation bearing, whose main purpose is to be able to isolate both horizontal and vertical seismic forces, and has the advantages of strong energy dissipation ability, good self-resetting ability, good anti-overturning performance, and simple structure.

[0004] The technical solution of the present invention is as follows:

[0005] A three-dimensional rolling ball seismic isolation bearing includes: an eddy current horizontal seismic isolator composed of an upper bearing plate, a rolling ball, a lower bearing plate, a base, a first permanent magnet attached to the side of the upper bearing plate, a second permanent magnet and a closed conductor attached to the base, and a third permanent magnet attached to the lower surface of the upper bearing plate; a vertical seismic isolator composed of an upper connecting plate, a disc spring, a lower connecting plate, and a steel spring connected in series. The specific structure is as follows:

[0006] The upper bearing plate and the lower bearing plate are arranged relatively up and down. Variable-frequency concave surfaces are respectively provided on the corresponding surfaces of the upper bearing plate and the lower bearing plate. Specifically: a variable-frequency concave surface of the upper bearing plate is opened at the bottom of the upper bearing plate, and a variable-frequency concave surface of the lower bearing plate is opened at the top of the lower bearing plate. The variable-frequency concave surface of the upper bearing plate and the variable-frequency concave surface of the lower bearing plate are opposite to each other in the up-and-down direction as a group, and rolling balls are arranged between each group of variable-frequency concave surfaces.

[0007] Permanent magnet 1 is installed around the side of the upper bearing plate, and permanent magnet 3 is installed around the outside of the variable-frequency concave surface of the upper bearing plate at the bottom of the upper bearing plate. Magnetic isolation materials are arranged between the upper bearing plate and permanent magnet 1, and between the upper bearing plate and permanent magnet 3; the base is a groove-shaped structure with a groove opened in the middle and an annular groove opened around the outside of the groove at the top. A vertical shock isolator and the lower bearing plate are installed in the middle groove of the base, and a closed conductor is installed in the annular groove at the top of the base; annular anti-disengagement baffles are arranged around the top edge of the base, and permanent magnet 2 corresponding to permanent magnet 1 is installed around the inner side of the anti-disengagement baffle. A magnetic isolation material is arranged between the anti-disengagement baffle and permanent magnet 2; the vertical shock isolator includes an upper connecting plate, a disc spring, a lower connecting plate, and a steel spring that are sequentially arranged from top to bottom in the groove.

[0008] For the three-dimensional rolling ball shock isolation bearing, the steel spring is fixed at the bottom of the groove of the base, the lower connecting plate is arranged on the steel spring, two identical disc springs are buckled with their concave surfaces facing each other up and down. The lower disc spring is connected to the lower connecting plate through fixing bolt 3, and the upper disc spring is connected to the upper connecting plate through fixing bolt 2; the lower bearing plate is arranged on the upper connecting plate, and the upper connecting plate is connected to the variable-frequency concave surface of the lower bearing plate through fixing bolt 1.

[0009] For the three-dimensional rolling ball shock isolation bearing, permanent magnet 1, permanent magnet 2, and permanent magnet 3 are arranged in a closed manner. Permanent magnet 1 and permanent magnet 3 respectively form a magnetic field with permanent magnet 2, and the closed conductor is within the magnetic field.

[0010] For the three-dimensional rolling ball shock isolation bearing, the anti-disengagement baffle and the base are of an integral structure.

[0011] For the three-dimensional rolling ball shock isolation bearing, at the top edge of the variable-frequency concave surface of the lower bearing plate, the variable-frequency concave surface of the lower bearing plate is connected and fixed to the base through an adjustable buckle.

[0012] For the three-dimensional rolling ball shock isolation bearing, the variable-frequency concave surface of the upper bearing plate is evenly arranged in four, and the variable-frequency concave surface of the lower bearing plate is evenly arranged in four.

[0013] For the three-dimensional rolling ball shock isolation bearing, the steel springs are evenly arranged in four.

[0014] For the three-dimensional rolling ball shock isolation bearing, the disc spring is a bowl-shaped ordinary disc spring, and the steel spring is an ordinary steel spring.

[0015] The working principle adopted by the present invention to solve its technical problems is as follows:

[0016] The present invention is installed between the foundation (or other fixed objects) and the seismic isolation object. The lower support plate is fixedly connected to the foundation (or other fixed objects), and the metal flat plate connected to the upper support plate is fixedly connected to the seismic isolation object. When an earthquake occurs, the upper support plate of the three-dimensional rolling ball seismic isolation bearing moves on the variable-frequency concave surface through the rolling balls, isolates the horizontal seismic force by extending the natural period of the structure, and at the same time converts the seismic energy into potential energy and heat energy generated by friction to consume the seismic force. However, the energy dissipation capacity of the three-dimensional rolling ball seismic isolation bearing itself is insufficient. Therefore, the damping force (eddy current principle) generated by the closed conductor cutting the magnetic induction line in the horizontal seismic isolator is used to consume the horizontal seismic force. Specific manifestations are as follows Figures 2 to 8 As shown, when the upper support plate 1 and the lower support plate 2 move relative to each other, the magnetic fields generated by the permanent magnet one 6 (N pole), the permanent magnet three 8 (N pole) and the permanent magnet two 7 (S pole) are cut by the closed coil 9 (the magnetic field formed by the permanent magnet one 6 and the permanent magnet two 7 is shown in the appendix Figure 8 ). According to the eddy current principle, a damping force will be generated when the closed conductor cuts the magnetic field to consume the horizontal seismic force. The vertical seismic force is isolated and consumed by the vertical seismic isolator inside the lower support plate 2. For the action of the vertical seismic force on the bearing, due to the action of the vertical seismic isolator between the upper support plate 1 and the seismic isolation object, the negative stiffness generated by the disc spring 14 and the positive stiffness generated by the steel spring 17 are superimposed, making the stiffness of the vertical seismic isolator tend to zero (quasi-zero stiffness), which can extend the vertical period of the structure. According to the principle of the rolling ball seismic isolation bearing, when the period is extended, it not only plays the role of isolating the seismic force, but also increases the damping of the rolling ball seismic isolation bearing to consume the vertical seismic force.

[0017] After the earthquake occurs, since the closed conductor moves in the magnetic field, according to Lenz's law, the conductor will be subjected to a force that inhibits its movement. At this time, due to the relative movement between the conductor and the magnetic field, the conductor generates electric potential energy, causing the charge to move to generate eddy current. These eddy currents are subjected to the Lorentz force of the external magnetic field on them (F = BqVsinθ, B is the magnetic induction intensity T, q is the charge quantity of the charge, V is the velocity of the charge when the conductor cuts the magnetic field), and the direction is always opposite to the movement direction of the conductor, thus forming a resistance. This resistance F is related to the velocity V. When the movement velocity of the upper support plate becomes smaller, the damping force becomes smaller, and the rolling balls between the upper and lower support plates are more likely to reset. For the three-dimensional rolling ball seismic isolation bearing of the present invention, in order to prevent the upper support plate from detaching, an anti-detachment baffle is provided around the lower support plate.

[0018] The advantages and beneficial effects of the present invention are as follows:

[0019] 1. The three-dimensional rolling ball seismic isolation bearing of the present invention can not only effectively isolate the horizontal seismic force, but also can better isolate the vertical seismic force.

[0020] 2. The present invention adopts a variable-frequency concave surface, which has better seismic isolation effect compared with the traditional surface form.

[0021] 3. The eddy current horizontal seismic isolator adopted by the present invention can effectively solve the problems of the traditional rolling ball friction pendulum bearing, such as small self-rolling friction and poor energy dissipation. At the same time, the horizontal seismic isolator has a simple structure and low cost.

[0022] 4. The vertical seismic isolator adopted by the present invention can cleverly isolate and consume the vertical seismic force by using the principle of quasi-zero stiffness. At the same time, it cooperates with the horizontal damper without interfering with each other.

[0023] 5. The damping force generated by the horizontal seismic isolator of the present invention is related to the speed, enabling the rolling ball bearing to have a better self-resetting function.

[0024] 6. As a three-dimensional rolling ball seismic isolation bearing with good seismic isolation effect, strong mobility and convenient installation, the present invention can be used for seismic isolation protection of precious cultural relics in museums and important precision equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the top view of the three-dimensional rolling ball seismic isolation bearing in the embodiment of the present invention.

[0026] Figure 2 is in the embodiment of the present invention Figure 1 The A-A sectional view in.

[0027] Figure 3 is in the embodiment of the present invention Figure 2 The B-B sectional view in.

[0028] Figure 4 is in the embodiment of the present invention Figure 2 The C-C sectional view in.

[0029] Figure 5 is the variable-frequency concave surface plan view (a), its top view sectional view (b) and side view sectional view (c) in the embodiment of the present invention.

[0030] Figure 6 is in the embodiment of the present invention Figure 2 The D-D sectional view in.

[0031] Figure 7 is in the embodiment of the present invention Figure 2 The E-E sectional view in.

[0032] Figure 8 is in the embodiment of the present invention Figure 2 The magnetic field formed by the permanent magnet 6 (N pole) and the permanent magnet 7 (S pole).

[0033] In the figure: 1 upper support plate, 2 base, 3 rolling ball, 4 variable-frequency concave surface of the upper support plate, 5 variable-frequency concave surface of the lower support plate, 6 permanent magnet I, 7 permanent magnet II, 8 permanent magnet III, 9 closed conductor, 10 anti-disengagement baffle, 11 magnetic isolation material, 12 adjustable buckle, 13 upper connecting plate, 14 disc spring, 15 fixing bolt I, 16 lower connecting plate, 17 steel spring, 18 lower support plate, 19 fixing bolt II, 20 fixing bolt III. Detailed implementation mode

[0034] Next, the present invention will be further described in conjunction with the drawings and embodiments.

[0035] As Figures 1 to 7 shown, the three-dimensional rolling ball isolation bearing of the present invention mainly includes: an eddy current horizontal isolation device composed of an upper support plate 1, a stainless steel rolling ball 3, a lower support plate 18, a base 2, a permanent magnet I 6 (N pole) attached to the side of the upper support plate 1, a permanent magnet II 7 (S pole) attached to the base 2 and a closed conductor 9, and a permanent magnet III 8 (N pole) attached to the bottom of the upper support plate 1; a quasi-zero stiffness vertical isolation device composed of an upper connecting plate 13, a disc spring 14, a lower connecting plate 16, and a steel spring 17 connected in series. The specific structure is as follows:

[0036] As Figures 1 - 4 shown, the upper support plate 1 and the lower support plate 18 are arranged relatively up and down, and variable-frequency concave surfaces are respectively provided on the corresponding surfaces of the upper support plate 1 and the lower support plate 18. Among them: four variable-frequency concave surfaces 4 of the upper support plate are opened at the bottom of the upper support plate 1, and four variable-frequency concave surfaces 5 of the lower support plate are opened at the top of the lower support plate 18. The variable-frequency concave surfaces 4 of the upper support plate and the variable-frequency concave surfaces 5 of the lower support plate are pairwise opposite in the up and down direction as a group, and rolling balls 3 are arranged between each group of variable-frequency concave surfaces.

[0037] As Figure 2 shown, permanent magnet I 6 (N pole) is installed around the side of the upper support plate 1, and permanent magnet III 8 (N pole) is installed around the outside of the variable-frequency concave surface 4 at the bottom of the upper support plate 1. Magnetic isolation materials 11 are arranged between the upper support plate 1 and the permanent magnet I 6, and between the upper support plate 1 and the permanent magnet III 8; the base 2 is a groove-type structure with a groove opened in the middle and an annular groove opened around the outside of the groove at the top. A vertical isolation device and a lower support plate 2 are installed in the middle groove of the base 2, and a closed conductor 9 is installed in the annular groove at the top of the base 2; an annular anti-disengagement baffle 10 is arranged around the top edge of the base 2. The anti-disengagement baffle 10 and the base 2 are of an integral structure. Permanent magnet II 7 (S pole) corresponding to the permanent magnet I 6 (N pole) is installed around the inner side of the anti-disengagement baffle 10, and a magnetic isolation material 11 is arranged between the anti-disengagement baffle 10 and the permanent magnet II 7; among them, the permanent magnet I 6, the permanent magnet II 7 and the permanent magnet III 8 are arranged in a closed manner, the permanent magnet I 6 and the permanent magnet III 8 respectively form a magnetic field with the permanent magnet II 7, and the closed conductor 9 is in the magnetic field.

[0038] As Figure 2 , Figures 5 to 7 , the vertical isolator includes an upper connecting plate 13, a disc spring 14, a lower connecting plate 16, and a steel spring 17 that are sequentially arranged in the groove from top to bottom. Among them: Four steel springs 17 are evenly fixed at the bottom of the groove of the base 2, the lower connecting plate 16 is arranged on the steel springs 17, two identical disc springs 14 are buckled together with their concave surfaces facing each other up and down, the lower disc spring 14 is connected to the lower connecting plate 16 through a fixing bolt three 20, and the upper disc spring 14 is connected to the upper connecting plate 13 through a fixing bolt two 19. The lower support plate 2 is arranged on the upper connecting plate 13, and the upper connecting plate 13 is connected to the variable-frequency concave surface 5 of the lower support plate through a fixing bolt one 15. At the top edge of the variable-frequency concave surface 5 of the lower support plate, the variable-frequency concave surface 5 of the lower support plate is connected and fixed to the base 2 through an adjustable buckle 12. The function of the adjustable buckle 12 is: it can adjust the disc spring 14 and the steel spring 17 to be in a zero stiffness state according to the weight of the isolated object. After an earthquake occurs, the variable-frequency concave surface 5 of the lower support plate will not break away from the adjustable buckle 12.

[0039] As Figure 2 , Figure 5 , Figure 6 shown, the disc spring 14 is a bowl-shaped ordinary disc spring, the steel spring 17 is an ordinary steel spring, and the stiffness values of the disc spring 14 and the steel spring 17 are determined according to the weight of the upper isolated object. In addition, the magnetic isolation material 11 can use a magnetic force superconducting ceramic material.

[0040] In the present invention, the meaning of the variable-frequency concave surface is: the variable-frequency surface function is transformed from an elliptic function, and the function formula: where the constant b is the length of the short axis of the ellipse (mm), and d is a constant related to the long axis of the ellipse and the displacement of the support. See the literature: Pranesh Murnal and RaviSinha.Behavior of Torsionally Coupled Structures with Variable FrequencyPendulum Isolator[J].JOURNAL OF STRUCTURAL ENGINEERING,2004,130:1041-1054.

[0041] The results show that the eddy current principle is adopted for the horizontal isolator of the present invention. Since the damping force generated by this damper is related to the speed, it can not only improve the energy dissipation capacity of the support, but also does not affect the self-resetting of the support. The vertical isolator adopts the zero stiffness principle. Since this vertical device has good isolation of vertical seismic forces, it solves the problem that the traditional rolling ball isolation bearing cannot isolate vertical seismic forces and is located below the variable-frequency concave surface of the lower support plate, and can work in coordination with the horizontal isolation device without interfering with each other. In addition, a metal anti-tilting baffle is provided to prevent the upper support plate from tipping over.

Claims

1. A three-dimensional rolling ball isolation bearing, characterized in that, Comprising: An eddy current horizontal isolator composed of an upper bearing plate, rolling balls, a lower bearing plate, a base, a permanent magnet 1 attached to the side of the upper bearing plate, a permanent magnet 2 attached to the base, a closed conductor, and a permanent magnet 3 attached to the underside of the upper bearing plate, and a vertical isolator composed of an upper connecting plate, a disc spring, a lower connecting plate, and a steel spring connected in series. The specific structure is as follows: The upper bearing plate and the lower bearing plate are arranged relatively up and down. Variable-frequency concave surfaces are respectively provided on the corresponding surfaces of the upper bearing plate and the lower bearing plate. Specifically: a variable-frequency concave surface of the upper bearing plate is opened at the bottom of the upper bearing plate, and a variable-frequency concave surface of the lower bearing plate is opened at the top of the lower bearing plate. The variable-frequency concave surface of the upper bearing plate and the variable-frequency concave surface of the lower bearing plate are pairwise opposite in the up-and-down direction as a group, and rolling balls are arranged between each group of variable-frequency concave surfaces; Permanent magnet 1 is installed around the side of the upper bearing plate, and permanent magnet 3 is installed around the outside of the variable-frequency concave surface of the upper bearing plate at the bottom of the upper bearing plate. Magnetic isolation materials are arranged between the upper bearing plate and permanent magnet 1, and between the upper bearing plate and permanent magnet 3; The base is a trough-shaped structure with a groove opened in the middle and an annular groove opened around the outside of the groove at the top. The vertical isolator and the lower bearing plate are installed in the middle groove of the base, and the closed conductor is installed in the annular groove at the top of the base; An annular anti-disengagement baffle is arranged around the top edge of the base, and a magnet 2 corresponding to permanent magnet 1 is installed around the inner side of the anti-disengagement baffle. A magnetic isolation material is arranged between the anti-disengagement baffle and permanent magnet 2; The vertical isolator includes an upper connecting plate, a disc spring, a lower connecting plate, and a steel spring arranged in sequence from top to bottom in the groove; The steel spring is fixed at the inner bottom of the groove of the base. The lower connecting plate is arranged on the steel spring. Two identical disc springs are buckled with their concave surfaces facing each other up and down. The lower disc spring is connected to the lower connecting plate through fixing bolt 3, and the upper disc spring is connected to the upper connecting plate through fixing bolt 2; The lower bearing plate is arranged on the upper connecting plate, and the upper connecting plate is connected to the variable-frequency concave surface of the lower bearing plate through fixing bolt 1; Permanent magnet 1, permanent magnet 2, and permanent magnet 3 are arranged in a closed manner. Permanent magnet 1 and permanent magnet 3 respectively form magnetic fields with permanent magnet 2, and the closed conductor is within the magnetic fields; At the top edge of the variable-frequency concave surface of the lower bearing plate, the variable-frequency concave surface of the lower bearing plate is connected and fixed to the base through an adjustable buckle.

2. The three-dimensional rolling ball isolation bearing according to claim 1, characterized in that, The anti-disengagement baffle and the base are of an integral structure.

3. The three-dimensional rolling ball isolation bearing according to claim 1, characterized in that, The variable-frequency concave surfaces of the upper bearing plate are evenly arranged in four, and the variable-frequency concave surfaces of the lower bearing plate are evenly arranged in four.

4. The three-dimensional rolling ball isolation bearing according to claim 1, characterized in that, The steel springs are evenly arranged in four.

5. The three-dimensional rolling ball isolation bearing according to claim 1, characterized in that, The disc spring is a bowl-shaped ordinary disc spring, and the steel spring is an ordinary steel spring.

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