Optimization design and test of dual air-gaps and liquid-cooled eddy current retarder

Abstract

We propose a novel dual air-gaps and liquid-cooled eddy current retarder (ECR) based upon observing the (1) heat fade of the continuous braking and (2) large rotor weight of the traditional ECR for heavy vehicles. The new ECR maintains a low working temperature because of the liquid cooling stator structure. The eddy current distribution and braking torque characteristic curves are obtained by finite element method (FEM). Combining with 3-D FEM, Kriging approximation model is employed to optimize the structural parameters of rotor tooth. Based on the optimization method, the number of rotor teeth is determined to be 12. The braking torque increases by 14.8% after optimization and the rotor tooth weight decreases by 9.5%, which reduces the adverse influence on the vehicle transmission system. The bench test was carried out to verify the optimized calculation results and the braking torque can be stepless controlled by adjusting the excitation current. Compared with traditional ECR, the dual air-gaps and liquid-cooled ECR has better continuous braking performance and is more suitable for heavy vehicle auxiliary braking.