Abstract: In order to overcome the braking performance thermal recession problem of the conventional permanent magnet eddy current brake (PM-ECB), a new type of PM-ECB is designed by using water-cooled method. The structure and working principle of new type PM-ECB are presented, and the characteristics of the cooling cycle system are highlighted. To prevent the magnetic saturation, the magnetic field distribution is obtained by using magnetic field finite element method. The relationship between static suction and magnet thickness is shown by magnetic circuit method. There is nearly linear relationship between test braking torque and calculation suction by fitting data. The temperature and braking torque of the two types of devices are tested. The calculated temperature agrees fairly well with the measured results. The results show that the water-cooled PM-ECB maintains low working temperature, braking performance does not occur thermal recession and the continuing work capacity is improved greatly.

Key words: Eddy current brake, Permanent magnet, Thermal field, Water-cooled