Abstract: The fundamental of permanent magnet eddy braking is analyzed and the math model about the parameters of braking force,the number of the magnet pole pair,the thickness and bottom diameter of the magnet and so on is developed on the basis of electromagnetic theory.Additionally,the results of math model and Ansoft Maxwell are analyzed to verify its correctness and the practicability.The influence mechanism of the number of the magnet pole pair,the thickness and bottom diameter of the magnet and so on to the braking force is explored to gain the characteristic relation among them.The dynamic model is developed according to the characteristic of bridge crane and design the parameter of the permanent magnet eddy current brake.At the last,the simulation of the dynamics is performed to provide the basis to the design of permanent magnet eddy current brake of the crane.

Key words: permanent magnet eddy current, brake force, bridge crane, trolley traveling mechanism