Design and experimental study of a compact quasi-zero-stiffness isolator using wave springs

The quasi-zero-stiffness (QZS) vibration isolation has been proven to be an effective way to isolate low-frequency vibration. However, most of the existing QZS isolators are space-consuming, which could not be employed in the space-limited circumstances. In this paper, a quite compact QZS isolator is engineered by connecting a pair of mutually repulsive magnet rings and a space-saving wave spring in parallel, called WQZS isolator. The restoring force of the magnet ring is derived by the equivalent magnetic charge method, and an empirical formula for the restoring force of the wave spring is derived by the least squares method based on experimental data The dynamic model of the WQZS vibration isolation system is built, and the vibration isolation performance is evaluated through transmissibility. Finally, an experimental prototype is fabricated, and the experimental tests on frequency sweep are carried out. The results show that compared with the linear counterpart, the vibration isolation frequency of the WQZS isolator is reduced by 48.89%, and the peak transmissibility is decreased by 59.33%. Most importantly, the space occupancy of the WQZS isolator designed in this paper is much lower than that of the traditional QZS isolators, and thus it should be a potential solution for low-frequency vibration isolation in the space-limited environment.