Three-magnet-ring quasi-zero stiffness isolator for low-frequency vibration isolation

A three-magnet-ring quasi-zero stiffness (QZS-TMR) isolator is designed to solve the problem of low-frequency vibration isolation in the vertical direction of precision equipment. QZS-TMR has both positive and negative stiffness structures. The positive stiffness structure consists of two mutually repelling magnetic rings and the negative stiffness structure consists of two magnetic rings nested within each other. By modulating the relative distance between positive and negative stiffness structures, the isolator can have QZS characteristics. Compared with other QZS isolators, the QZS-TMR is compact and easy to manufacture. In addition, the working load of QZS-TMR can be flexibly adjusted by varying the radial widths of the inner magnetic ring. In this paper, the static analysis of QZS-TMR is carried out to guide the design, and the low-frequency vibration isolation performance is studied. In addition, the experimental prototype of QZS-TMR is designed and manufactured. The static and vibration isolation experiments are carried out on the prototype. The results show that the initial vibration isolation frequency of the experimental prototype is about 4 Hz. The results show an excellent low-frequency vibration isolation effect, which is consistent with the theoretical research. This paper introduces a new approach to the design of the QZS isolator.