The Hybrid Brake Model and Its Validation

Abstract

As an extension of a paper published at the 24th International Conference on Mechatronics Technology, ICMT 2021 conference, this paper shows the concept, design method, and model of a hybrid brake with additional validation. An eddy current brake cannot be used to decelerate a vehicle to a standstill. However, the magnetic attraction force between the rotor and stator of an eddy current brake can be used to generate an additional mechanical friction torque. By using a disc spring between the rotor and stator, the eddy current brake is extended to a so-called hybrid brake. In particular, the model and design method of the disc spring are the focus of this work. Using a system model that includes the electromagnetic and mechanical domains, the wear reduction compared to a conventional friction brake and the dynamic behaviour depending on the spring parameters are investigated. Finally, a disc spring is designed in FEM with the desired force–displacement curve. In addition, a working demonstrator of a hybrid brake is constructed, and the electromagnetic and mechanical system models are compared with the experimental results. For the first time, it is shown that the concept of using the magnetic attraction force between the rotor and stator of an eddy current brake for braking to a stop is working. In a speed range of 0–7500 rpm, it is possible to generate a torque of 100 Nm, whereby at speeds higher than 3500 rpm, the torque is generated in a wear-free manner by eddy currents. However, in order to be valid, the model must be extended to represent the deformation of the rotor.