Design and Analysis of a Novel Horizontal Large-Amplitude and Low-Frequency Vibration Isolator

This paper proposes a novel dual four-rod horizontal large-amplitude quasi-zero stiffness (QZS) vibration isolator based on the singular configuration of a planar four-rod mechanism combined with gravity compensation.

First, the mechanism design and three-dimensional model of dual four-rod horizontal vibration isolator are established. Second, kinematic characteristics are analyzed, and trajectory planning is carried out to obtain the kinematic performance. Then, based on the artificial fish swarm algorithm, the appropriate size and mass of the component are solved, and the QZS characteristics of the isolator are optimized. Third, the statics and dynamics theoretical models of isolators are established, and the transmissibility of isolators under different damping ratios and excitation amplitudes is solved by simulation experiments. Finally, the experimental prototype is established, and the experiment of resilience and acceleration transmissibility is carried out to verify the effectiveness of low-frequency vibration isolation.

The static and dynamic simulation analysis of isolator well verifies the theoretical solution of isolator. According to the theoretical model, different vibration isolation performance can be obtained with different input parameters. The experimental results of the prototype show that the isolator has lower initial vibration isolation frequency and wider vibration isolation bandwidth.

The dual four-rod horizontal large-amplitude QZS isolator designed in this paper shows good performance in isolating the external excitation of the low-frequency large vibration amplitude. Since the medical precision instrument will inevitably produce low-frequency vibration during the transportation process and reduce the accuracy and stability of the equipment, in order to reduce the possibility of the instrument being damaged during the transportation process, the vibration isolator has great application potential in the isolation of medical precision instrument.