Electromagnetic retarder design using finite element analysis

Abstract

The electromagnetic retarders are widespread in heavy vehicle and train industry. The electromagnet type and permanent magnet type retarders are developed at a variety of operating forces to reduce speeds. This paper describes the use of the finite element method with an upwind interpolation function in designing the permanent magnet type retarder. The equation of motion was solved for the analysis of the deceleration process of the conductive plate. The suitable permanent magnet anangements and the yoke constructions are made clear in the obtained numerical results. Recently, various electromagnetic retarders have been developed and put to practical use as a supple- ment brake system. Advantages of the eddy current type retarders are that it can induce the braking force with proportional to the moving speed and it has no consumption due to friction. Therefore it can be used in safety and in stability. There are two types in generating magnetic field. The one is the electromagnet type and the other is the permanent magnet type. The permanent magnet type retarder is the most economical type, because it can operate without any power supply. Although some of these retarders are usually installed, Iittle attention has been given in the literature to the designing and modeling of the retarder themselves. This paper presents results obtained in the dynamic simulations of a permanent magnetic type retarder model. In this investigation, the arrangement of magnets and the yoke construction are tested to the suitable design. The time-depending braking force is made clear for some models.