阅读说明：本技术 一种结构紧凑的准零刚度隔振器 (Quasi-zero stiffness vibration isolator with compact structure ) 是由 蒲华燕 元书进 罗均 孙翊 王敏 丁基恒 彭艳 谢少荣 于 2019-09-23 设计创作，主要内容包括：本发明公开一种结构紧凑的准零刚度隔振器,涉及振动控制领域,壳体中形成一个贯穿壳体上下表面的腔体,导向组件固定于壳体的上端,板弹簧固定于壳体的下端,连接轴套设于导向组件内,负载平台安装于连接轴上端,导磁轴安装于连接轴下端,连接轴能够带动负载平台和导磁轴相对于壳体和导向组件沿轴向运动,磁铁环固定安装于腔体内,且磁铁环同轴间隙套设于导磁轴外部,调节组件安装于板弹簧上,且调节组件的上端与导磁轴连接,调节组件用于调节导磁轴在竖直方向上的初始位置。本发明提供的准零刚度隔振器结构简单紧凑,占用空间小,保持承载能力的同时,降低固有频率,减弱负载平台和激励源的动态耦合,扩展隔振频带,提高隔振效果。(The invention discloses a quasi-zero stiffness vibration isolator with a compact structure, which relates to the field of vibration control.A cavity penetrating through the upper surface and the lower surface of a shell is formed in the shell, a guide assembly is fixed at the upper end of the shell, a plate spring is fixed at the lower end of the shell, a connecting shaft is sleeved in the guide assembly, a load platform is installed at the upper end of the connecting shaft, a magnetic conduction shaft is installed at the lower end of the connecting shaft, the connecting shaft can drive the load platform and the magnetic conduction shaft to move axially relative to the shell and the guide assembly, a magnet ring is fixedly installed in the cavity, the magnet ring is sleeved outside the magnetic conduction shaft in a coaxial clearance manner, an adjusting assembly is installed on the plate spring, the upper end of the adjusting assembly is. The quasi-zero stiffness vibration isolator provided by the invention has the advantages of simple and compact structure, small occupied space, capability of keeping bearing capacity, reduction of natural frequency, weakening of dynamic coupling of a load platform and an excitation source, expansion of vibration isolation frequency band and improvement of vibration isolation effect.)

1. A quasi-zero stiffness vibration isolator with a compact structure is characterized by comprising a load platform, a guide assembly, a shell, a connecting shaft, a magnetic conduction shaft, a magnet ring, a plate spring and an adjusting assembly, wherein a cavity penetrating through the upper surface and the lower surface of the shell is formed in the shell, the guide assembly is fixed at the upper end of the shell, the plate spring is fixed at the lower end of the shell, the connecting shaft is sleeved in the guide assembly, the load platform is installed at the upper end of the connecting shaft, the magnetic conduction shaft is installed at the lower end of the connecting shaft, the connecting shaft can drive the load platform and the magnetic conduction shaft to move axially relative to the shell and the guide assembly, the magnet ring is fixedly installed in the cavity, the magnetic conduction shaft is sleeved with a coaxial gap of the magnet ring, the adjusting assembly is installed on the plate spring, and the upper end of the adjusting component is connected with the magnetic conduction shaft, and the adjusting component is used for adjusting the initial position of the magnetic conduction shaft in the vertical direction.

2. The compact quasi-zero stiffness vibration isolator of claim 1 wherein the housing includes a magnet housing and a leaf spring support, the magnet housing being secured to the leaf spring support at an upper end, the guide assembly being secured to the magnet housing at an upper end, the leaf spring being secured to the leaf spring support at a lower end, an annular recess being formed between the magnet housing and the leaf spring support, the magnet ring being secured in the annular recess.

3. The structurally compact quasi-zero stiffness vibration isolator of claim 1 wherein the magnet rings are axially magnetized annular permanent magnets and the magnetically permeable shaft is a cylindrical shaft of high magnetic permeability material.

4. The structurally compact quasi-zero stiffness vibration isolator of claim 1 wherein the magnet ring and the magnetically permeable shaft have different axial heights.

5. The quasi-zero stiffness vibration isolator with the compact structure according to claim 2, wherein the guide assembly comprises a bearing seat and a linear bearing, the bearing seat is fixed at the upper end of the magnet housing, the linear bearing is fixedly sleeved in the bearing seat, and the connecting shaft is sleeved in the linear bearing.

6. The compact quasi-zero stiffness vibration isolator of claim 2 wherein the leaf spring includes a central ring and a plurality of support arms attached to the edge of the central ring, the support arms being secured to the lower end of the leaf spring bracket.

7. The compact quasi-zero stiffness vibration isolator of claim 6 wherein the end of the support arm distal from the intermediate ring has a through hole through which a bolt passes to secure the support arm to the lower end of the leaf spring bracket.

8. The structurally compact quasi-zero stiffness vibration isolator of claim 6 wherein the plurality of support arms are evenly distributed circumferentially about the perimeter of the intermediate ring.

9. The vibration isolator with quasi-zero stiffness and compact structure according to claim 1, wherein the adjusting assembly includes a shaft end bolt and an adjusting nut, the shaft end bolt passes through the plate spring from the lower end to extend into the cavity, the upper end of the shaft end bolt is connected with the bottom end of the magnetic conduction shaft, the adjusting nut is screwed on the shaft end bolt, the adjusting nut is pressed on the upper surface of the plate spring, and the adjusting nut is used for adjusting the initial positions of the load platform and the magnetic conduction shaft relative to the magnet ring.

Technical Field

The invention relates to the field of vibration control, in particular to a quasi-zero stiffness vibration isolator with a compact structure.

Background

Vibration is ubiquitous in nature, engineering and everyday life. The reasonable utilization of vibration energy has positive effects on human beings, but in most cases, vibration brings inconvenience and even great harm to human production and life, for example, vibration interference can reduce the machining precision of a machine tool, and environmental noise can seriously affect the working efficiency and rest quality of people after reaching a certain decibel value. The vibration control method which is widely concerned at present is to introduce a vibration isolation element between a vibration source and a receiving structure, namely, the vibration isolation element is used for achieving the purpose of isolating the vibration by changing the transmission path. However, passive vibration isolators in widespread use today have an inherent conflict between vibration isolation performance and load carrying capacity: the natural frequency of the linear vibration isolator is required to be lower than 0.7 times of the external excitation frequency for isolating vibration, and under the condition that the load cannot be increased, the natural frequency can be reduced only by reducing the rigidity of the vibration isolator, but the problem of overlarge static deformation and instability caused by too low rigidity causes low bearing capacity of the system. This conflict can be overcome by introducing nonlinear elements with high static and low dynamic stiffness characteristics, and such systems are realized by connecting a negative stiffness structure in parallel with a common positive stiffness element to cancel out the dynamic stiffness near the equilibrium position, also called quasi-zero stiffness. The vibration isolator has lower natural frequency, can realize good vibration isolation effect, has smaller static deformation and can realize large bearing capacity. The relative negative stiffness and positive stiffness means that the slope of the force-displacement curve is negative, and the negative stiffness is unstable. Mechanical negative stiffness springs are generally realized by combining specific geometric relationships of positive stiffness springs, the performance is influenced by material fatigue and processing stress, the value of negative stiffness is also influenced by the assembling process such as prepressing and the like, and the mechanical negative stiffness springs are large in size and complex to assemble. The permanent magnet has wide application prospect in the field of ultra-precision vibration reduction, and the magnetic negative stiffness can be realized by specially configuring the permanent magnet.

A magnetic negative stiffness mechanism with an authorization notice number of CN 105805204B proposed by the shiitake utilizes the displacement weakening type negative stiffness characteristic generated by the repulsion of the homopolarity of a transverse static magnet and a transverse moving magnet and the displacement strengthening type negative stiffness characteristic generated by the attraction of the heteropolarity of a longitudinal static magnet and a longitudinal moving magnet, and the moving magnet groups are connected together through an iron core, so that the displacement strengthening type stiffness and the displacement weakening type stiffness can be combined together, the size and the strength of the static magnet groups and the arrangement of magnetic poles can form a proper magnetic field in a static magnet fixing frame after being designed, and a force with the linear negative stiffness characteristic is applied to the moving magnet groups. The magnetic negative stiffness mechanism with the authorization notice number of CN 102808883B proposed by Huazhong university of science and technology has the advantages that the magnetic pole parts are arranged in parallel by adopting a plurality of groups of magnets, the magnetization directions of two groups of adjacent magnets are opposite, the negative stiffness characteristic is formed by utilizing the repulsive effect of the reverse arrangement of the magnets, and the negative stiffness can be changed by adjusting the distance between the magnets by a negative stiffness adjusting component. The above negative stiffness mechanism has the disadvantages of complex structure and large occupied space.

Disclosure of Invention

In order to solve the technical problems, the invention provides the quasi-zero stiffness vibration isolator which is compact in structure, simple and compact in structure, small in occupied space, capable of reducing the inherent frequency, weakening the dynamic coupling of a load platform and an excitation source, expanding the vibration isolation frequency band and improving the vibration isolation effect while keeping the bearing capacity.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a quasi-zero stiffness vibration isolator with a compact structure, which comprises a load platform, a guide assembly, a shell, a connecting shaft, a magnetic conduction shaft, a magnet ring, a plate spring and an adjusting assembly, wherein a cavity penetrating through the upper surface and the lower surface of the shell is formed in the shell, the guide assembly is fixed at the upper end of the shell, the plate spring is fixed at the lower end of the shell, the connecting shaft is sleeved in the guide assembly, the load platform is arranged at the upper end of the connecting shaft, the magnetic conduction shaft is arranged at the lower end of the connecting shaft, the connecting shaft can drive the load platform and the magnetic conduction shaft to move axially relative to the shell and the guide assembly, the magnet ring is fixedly arranged in the cavity, the magnet ring is coaxially sleeved outside the magnetic conduction shaft in a clearance manner, the adjusting assembly is arranged on the plate spring, and the upper end of the adjusting assembly is connected with the, the adjusting component is used for adjusting the initial position of the magnetic conduction shaft in the vertical direction.

Preferably, the casing includes magnet shell and leaf spring support, the magnet shell is fixed in leaf spring support upper end, the direction subassembly is fixed in magnet shell upper end, leaf spring is fixed in leaf spring support lower extreme, the magnet shell with form annular groove between the leaf spring support, the magnet ring is fixed in the annular groove.

Preferably, the magnet ring is an axially magnetized annular permanent magnet, and the magnetic conduction shaft is a cylindrical shaft made of a high-permeability material.

Preferably, the magnet ring and the magnetic conductive shaft have different axial heights.

Preferably, the guide assembly comprises a bearing seat and a linear bearing, the bearing seat is fixed at the upper end of the magnet shell, the linear bearing is fixedly sleeved in the bearing seat, and the connecting shaft is sleeved in the linear bearing.

Preferably, the plate spring includes a middle ring and a plurality of support arms connected to an edge of the middle ring, the support arms being fixed to a lower end of the plate spring support.

Preferably, one end of the support arm, which is far away from the middle ring, is provided with a through hole, and a bolt penetrates through the through hole to fix the support arm at the lower end of the plate spring support.

Preferably, a plurality of the supporting arms are evenly distributed on the periphery of the middle ring along the circumferential direction.

Preferably, the adjusting part includes axle head bolt and adjusting nut, the axle head bolt is passed by the lower extreme the leaf spring extends in the cavity, just the upper end of axle head bolt with the bottom of magnetic conduction axle is connected, the top of axle head bolt has screwed connection adjusting nut, adjusting nut compresses tightly the upper surface of leaf spring, adjusting nut is used for adjusting load platform and the magnetic conduction axle for the initial position of magnet ring.

Compared with the prior art, the invention has the following technical effects:

the quasi-zero stiffness vibration isolator with a compact structure comprises a load platform, a guide assembly, a shell, a connecting shaft, a magnetic conduction shaft, a magnet ring, a plate spring and an adjusting assembly, wherein the magnet ring and the magnetic conduction shaft form a negative stiffness mechanism, the plate spring is used as a positive stiffness mechanism, and under the condition that the negative stiffness mechanism is connected with the positive stiffness mechanism in parallel at a balance position, the negative stiffness enables the force of the load platform far away from the balance position and the force of the positive stiffness enabling the load platform to return to the balance position to be mutually offset, so that the quasi-zero stiffness can be realized. Meanwhile, the quasi-zero stiffness vibration isolator adopts the plate spring and the compact magnetic negative stiffness spring which are connected in parallel, and has the advantages of simple and compact structure, simple and convenient assembly and small occupied space.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is an angle sectional isometric view of the quasi-zero stiffness vibration isolator with a compact structure provided by the invention;

FIG. 2 is a cross-sectional view of the quasi-zero stiffness vibration isolator in a compact configuration provided by the present invention;

FIG. 3 is a schematic structural view of a negative stiffness mechanism of the present invention;

fig. 4 is a schematic structural view of a plate spring according to the present invention.

Description of reference numerals: 1. a plate spring support; 2. a magnet housing; 3. a bearing seat; 4. a linear bearing; 5. a connecting shaft; 6. a load platform; 7. a magnetically conductive shaft; 8. a magnet ring; 9. a shaft end bolt; 10. adjusting the nut; 11. a plate spring; 1101. a middle ring; 1102. a support arm.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a quasi-zero stiffness vibration isolator with a compact structure, which is simple and compact in structure, small in occupied space, capable of reducing natural frequency, weakening dynamic coupling of a load platform and an excitation source, expanding vibration isolation frequency band and improving vibration isolation effect while keeping bearing capacity.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1-4, the embodiment provides a quasi-zero stiffness vibration isolator with a compact structure, which includes a load platform 6, a guide assembly, a housing, a connecting shaft 5, a magnetic conduction shaft 7, a magnet ring 8, a plate spring 11 and an adjusting assembly, wherein a cavity penetrating through the upper and lower surfaces of the housing is formed in the housing, the guide assembly is fixed at the upper end of the housing, the plate spring 11 is fixed at the lower end of the housing, the connecting shaft 5 is sleeved in the guide assembly, the load platform 6 is mounted at the upper end of the connecting shaft 5, the magnetic conduction shaft 7 is mounted at the lower end of the connecting shaft 5, the connecting shaft 5 can drive the load platform 6 and the magnetic conduction shaft 7 to move axially relative to the housing and, and the magnet ring 8 is coaxially sleeved outside the magnetic conduction shaft 7 in a clearance manner, the magnet ring 8 and the magnetic conduction shaft 7 form a negative stiffness mechanism, the plate spring 11 serves as a positive stiffness mechanism, and the negative stiffness mechanism and the positive stiffness mechanism are connected in parallel. The adjusting component is installed on the plate spring 11, the upper end of the adjusting component is connected with the magnetic conduction shaft 7, and the adjusting component is used for adjusting the initial position of the magnetic conduction shaft 7 in the vertical direction.

Specifically, the magnet ring 8 is coaxially arranged with the magnetic conduction shaft 7, the magnet ring 8 is an axially magnetized annular permanent magnet, and the magnetic conduction shaft 7 needs to be made of a high-permeability material, such as electrician pure iron, and can be magnetized; accordingly, other parts of the vibration isolator should be made of non-magnetic conductive material, such as aluminum alloy, so as not to affect the magnetic field distribution.

The casing includes magnet shell 2 and leaf spring support 1, and magnet shell 2 is fixed in 1 upper ends of leaf spring support, and the direction subassembly is fixed in 2 upper ends of magnet shell, and leaf spring 11 is fixed in 1 lower extreme of leaf spring support, forms annular groove between magnet shell 2 and the leaf spring support 1, and magnet ring 8 is fixed in the annular groove. Specifically, the magnet housing 2 and the plate spring support 1 are fixedly connected by bolts.

The guide assembly comprises a bearing seat 3 and a linear bearing 4, the bearing seat 3 is fixed at the upper end of the magnet shell 2, the linear bearing 4 is fixedly sleeved in the bearing seat 3, and the connecting shaft 5 is sleeved in the linear bearing 4. Specifically, the bearing housing 3 and the magnet housing 2 are fixedly connected by bolts, and the linear bearing 4 and the bearing housing 3 are fixedly connected by bolts. The linear bearing 4 is used for reducing friction in motion and reducing the damping rate of the system.

As shown in fig. 4, the plate spring 11 includes a middle ring 1101 and a plurality of support arms 1102 connected to the edge of the middle ring 1101, and the support arms 1102 are fixed to the lower end of the plate spring support 1. Specifically, one end of the support arm 1102 away from the middle ring 1101 is provided with a through hole, and a bolt penetrates through the through hole to fix the support arm 1102 at the lower end of the plate spring support 1. In this embodiment, the plurality of supporting arms 1102 are uniformly distributed around the middle ring 1101 along the circumferential direction, and the number of the supporting arms 1102 is three.

The adjusting assembly comprises an axle end bolt 9 and an adjusting nut 10, the axle end bolt 9 penetrates through a plate spring 11 from the lower end to extend into the cavity, the upper end of the axle end bolt 9 is connected with the bottom end of the magnetic conduction shaft 7, the adjusting nut 10 is screwed on the axle end bolt 9, the adjusting nut 10 is tightly pressed on the upper surface of the plate spring 11, the magnetic conduction shaft 7 is pressed on the upper surface of the plate spring 11 through the adjusting nut 10, and the adjusting nut 10 is used for adjusting the initial positions of the load platform 6 and the magnetic conduction shaft 7 relative to the magnet ring 8. In the initial working position without vibration, the center of the magnet ring 8 and the center of the magnetic conduction shaft 7 should be at the same height, and when in use, the distance between the magnetic conduction shaft 7 and the middle ring 1101 of the plate spring 11 can be adjusted by rotating the adjusting nut 10, while the compression amount of the plate spring 11 under static load is unchanged, that is to say, the relative static load positions of the magnetic conduction shaft 7 and the magnet ring 8 are adjusted, so that the stiffness loading mechanism under static load is in a balanced position.

Due to the magnetic convergence effect of the shaft ends, the magnet ring 8 can attract the two shaft ends of the magnetic conduction shaft 7 to approach towards the middle, and the attraction force of the shaft ends to the magnet ring 8 is larger as the shaft ends are closer. When the magnetic conduction shaft 7 is in the middle position of the magnet ring 8, the attraction force of the magnet ring 8 to the two ends of the magnetic conduction shaft 7 is equal, the resultant force applied to the magnetic conduction shaft 7 is 0, and the negative stiffness mechanism is in the balance position. But this balance is not as stable as the static balance of a positive rate spring. For a positive rate spring to carry a mass, the positive rate force and gravity will cause the load to return to a static equilibrium position in the event of an external force disturbance. For the negative stiffness mechanism, once the middle magnetic conduction shaft 7 deviates from the equilibrium position, one shaft end is closer to the magnet ring 8, and the shaft end is attracted more, so that the magnetic conduction shaft 7 deviates from the equilibrium position, that is, the negative stiffness mechanism cannot recover once deviating from the equilibrium position without external force. Under the static load without vibration, the flux guide shaft 7 is positioned at the middle position of the magnet ring 8 by rotating the adjusting nut 10, and the negative stiffness mechanism is positioned at the balance position, which is an ideal initial state of the vibration isolator.

Under the condition that the negative stiffness mechanism is connected with the positive stiffness mechanism in parallel at the balance position, the force of the negative stiffness, which enables the load platform 6 to be far away from the balance position, and the force of the positive stiffness, which enables the load platform 6 to return to the balance position, are mutually offset, so that quasi-zero stiffness can be realized. The quasi-zero stiffness reduces the inherent frequency of the vibration isolator, weakens the dynamic coupling of the load platform 6 and the excitation source, expands the vibration isolation frequency band, improves the vibration isolation effect, does not influence the static deflection of the vibration isolator at the same time, and keeps the bearing capacity of the positive stiffness. In addition, the vibration isolator in the embodiment uses the plate spring and the compact magnetic negative stiffness spring which are connected in parallel, and has the advantages of simple and compact structure, simple and convenient assembly and small occupied space.

The principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.