Suitable Structure of PM and Copper Plate Systems for Reducing Vibration Transmission and Improving Damping Effect in a Superconducting Seismic Isolation Device
We have investigated the basic properties of levitation force and vibration transmission in a magnetic levitation type superconducting seismic isolation device. Since it is very difficult in a real device of a seismic isolation device to keep the stationary levitation against any horizontal disturbances, we have devised a permanent magnet-permanent magnet (PM-PM) system with a copper plate and verified that the stable stationary levitation of the seismic isolation object could be achieved by using the PM-PM system with the copper plate. In addition, to improve the damping effect, we adopted vibration absorbing system composed of a copper plate and a permanent magnet. We investigated the basic properties of vibration transmission and damping effect in the model device having the PM-PM system with the copper plate and vibration absorbing system. The vibration transmission was reduced and the damping effect was greatly improved by the magnetic interaction between the copper plate and the permanent magnet in the PM-PM system with the copper plate and vibration absorbing system. We investigated the relationship between the magnetic interaction between the copper plate and the permanent magnet and obtained a suitable thickness of the copper plate in the PM-PM system and a suitable structure of vibration absorbing system for reducing the vibration transmission and improving the damping ratio effectively.