A Quasi-Zero Stiffness Vibration Isolator Using Ring Permanent Magnets to Generate Negative Stiffness

Abstract

A quasi-zero stiffness vibration isolator with annular permanent magnets used for generating negative stiffness comprises a base and an outer cylinder connected with the base, the outer permanent magnet is arranged in a top notch of the outer cylinder, an upper cover is connected with the outer cylinder, a sliding bearing is combined with a central hole of the upper cover in a sleeved mode, and a central shaft is sleeved with the sliding bearing and is in clearance fit with the sliding bearing. A sleeve and an adjusting sleeve are sequentially connected to the position, located on the lower portion of the sliding bearing, of the central shaft, and the inner permanent magnet is installed in the sleeve. A spring is arranged at the bottom of the central shaft in a sleeving mode, the bottom end of the spring is fixed to the base, and the top end of the spring is fixed to the adjusting sleeve. A mark line on the central shaft is used for representing the position of the inner permanent magnet relative to the outer permanent magnet. When the mark line coincides with the upper end face of the sliding bearing, the inner permanent magnet exactly faces the outer permanent magnet, and the isolator is in a normal working state. The quasi-zero stiffness vibration isolator has the advantages of being high in static stiffness and low in dynamic stiffness, basic stimulation with large amplitude can be isolated, and the mass of a vibration-isolated objected can be adjusted.

Description

technical field [0001] The invention relates to the technical field of vibration isolators, in particular to a quasi-zero-stiffness vibration isolator which adopts an annular permanent magnet to generate negative stiffness. Background technique [0002] The occurrence of vibration will cause various hazards: it will not only affect the performance of machinery and equipment, but also affect our quality of life. For example, the vibration of a car will reduce the comfort of driving. Therefore, researchers have proposed various vibration suppression methods and designed various vibration isolators. However, the natural frequency of the traditional vibration isolator is high, and it is difficult to meet the needs of low frequency vibration isolation. [0003] For a single-degree-of-freedom system with mass m and stiffness k, the natural frequency of the system is According to the linear vibration isolation theory, when the base excitation frequency is greater than , the vi...

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Problems solved by technology

Therefore, it can only be considered from the perspective of reducing the stiffness of the system. For a vibration isolator that is isolated in the vertical direction, if the stiffness is too small, the static deformation of the supporting spring will be large, which will be limited by the actual space; and the supporting spring Excessive deformations can lead to anelastic effects

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