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.