Three-degree-of-freedom micro-vibration isolator based on active electromagnetic negative stiffness structures

Abstract

The invention relates to a three-degree-of-freedom micro-vibration isolator based on active electromagnetic negative stiffness structures, and belongs to the technical field of precise vibration isolation. The three-degree-of-freedom micro-vibration isolator comprises an upper plate, a base plate and three sets of active electromagnetic negative stiffness structures for connecting the upper platewith the base plate. The active electromagnetic negative stiffness structures utilize coaxial nested double-magnetic-ring structures to realize the negative stiffness characteristic that the stiffnesscannot be adjusted in the vertical direction, and utilize an electrified coil coaxially nested with the double-magnetic-ring negative stiffness structures to generate precise and controllable excitation magnetic flux, so that a bias magnetic field around a movable magnetic ring is changed, adjustment of a negative stiffness value is realized, and changes of vibration isolation load quality and excitation frequency are adapted. The bias magnetic field is provided by a fixed magnetic ring, and only relatively small current is needed in the coil to generate the excitation magnetic flux for adjusting the bias magnetic field, so that continuous high-energy input is not needed, and system energy consumption is low; and the double-magnetic-ring negative stiffness structures are connected with the coil in parallel to realize the adjustable negative stiffness characteristic, so that the system has high stability of a passive vibration isolation system and high vibration isolation performance of an active vibration isolation system.

Description

technical field [0001] The invention belongs to the technical field of precision vibration isolation, in particular to a three-degree-of-freedom micro-vibration isolator based on an active electromagnetic negative stiffness structure. Background technique [0002] Low-frequency micro-amplitude vibration interference in the environment has become one of the key issues that limit the accuracy of precision instruments and equipment, and the accuracy of testing and experiments. Equipping precision instruments and equipment with low-frequency vibration isolators has gradually become the main technology for suppressing environmental micro-vibrations in the field of ultra-precision engineering. means. In terms of single-degree-of-freedom vibration isolation, there have been many related studies on low-frequency vibration isolators, but there are very few researches on three-degree-of-freedom low-frequency vibration isolation that is more in line with reality. [0003] Patent No. Z...

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