Proposal of Magnetic Suspension with Elastic Ferromagnetic Substance for Vibration Isolation System

An improvement of magnet suspension by using elastic ferromagnetic substance is proposed. The zero-power magnetic suspension has been applied to vibration isolation system because it has a negative-stiffness property. High stiffness against direct disturbance on the isolation table can be achieved by combining it with a normal spring with a positive stiffness. It enables the system to have good characteristics in both the performances of isolation from ground and suppression of direct vibration. However, the vibration isolation system using zero-power magnetic suspension has several problems. One of them is that a large/strong permanent magnet is necessary to support the isolation table. Another problem is a technical difficulty of achieving sufficient damping for suppressing resonance. It is proposed to insert elastic ferromagnetic substance between the magnet for suspension and the object to be suspended. Since it decreases magnetic reluctance, the suspension force increase. In addition, the damping characteristics of the suspension system is improved by the elasticity of the substance.