The invention discloses a quasi-zero stiffness vibration
isolator with positive and
negative stiffness in parallel connection. The vibration
isolator comprises a base, an upper cover, a supporting rod, spiral springs, spacers, an annular iron core, fan-shaped permanent
magnet bodies, stators, a permanent
magnet body clamping mechanism, working air gaps and a guide plate. The fan-shaped permanent
magnet bodies, stators, permanent magnet body clamping mechanism, and working air gaps form a magnetic flow loop, and form magnetic springs with negative magnetic stiffness. The spiral springs are connected with the supporting rod and the upper cover, and initial positive stiffness of the vibration
isolator is provided and is in parallel connection with magnetic
negative stiffness. The
dynamic stiffness of the annular iron core in the equilibrium position is reduced. The guide plate is mounted on the lower portion of the base, and is in sliding-fit with the supporting rod. Compared with an existing quasi-zero stiffness vibration isolator, the vibration isolator has the advantages that
load bearing is high, and the mechanism is compact; and as a passive vibration isolator, the vibration isolator can effectively reduce the
natural frequency of the
vibration isolation system, broaden a
vibration isolation frequency band, and has the advantages of easy maintenance and high reliability.