Characteristic analysis of planar electromagnetic dampers

Electromagnetic dampers can cause the oscillation of the dynamic systems to dissipate rapidly by making use of eddy current damping effect. In some industrial applications, multi-degree-of-freedom damping forces are needed. Traditional method is to adopt several single degree-of-freedom dampers which will bring about complex system structure. A planar electromagnetic damper is presented in this paper. The novel damper can provide two orthogonal damping forces with only one mover, which has the features of simple structure, high safety coefficient and so on. It can be used in fast positioning systems, such as wafer stage. The structure and working principle of the planar electromagnetic damper are introduced. The three dimensional magnetic field distribution and the damping forces are derived analytically by using the magnetic surface charge method and the image method. The main dimension parameters which have influence on damping forces are analyzed by finite element analysis. The variation tendency of damping forces and damping coefficient are obtained. Experiment results are in good agreement with the theoretical calculation. That verifies the validity of the theoretical analysis.