Numerical Simulation Study on Braking Performance of a New Eddy Current-Hydrodynamic Hybrid Retarder

Based on the principle of eddy current braking and hydraulic braking, a new eddy current-hydrodynamic hybrid retarder (ECHHR) is proposed. Based on the introduction of the working principle and structure of the ECHHR, the finite element analysis models of the electromagnetic field and the flow field of the ECHHR were established, respectively. The electromagnetic field distribution, the flow field velocity, and the flow field pressure in the ECHHR were numerically simulated. The air gap magnetic density, the eddy current braking torque, and the hydraulic braking torque under different excitation currents and different liquid filling rates were calculated. Finally, the braking performance of the EHHR was tested via experiments, and the effectiveness of the finite element analysis method was verified. The test results indicated that as the speed increased, the composite braking torque of the ECHHR increased approximately linearly. When the speed was 1000 r/min, the composite braking torque reached 2100 N center dot m. Compared to separate hydraulic braking and eddy current braking, the composite braking torque was relatively high in the full-speed range.