Study On The Key Technology Of Magnet Retarder For Vehicle

In order to ensure driving safety,large and medium passenger vehicles need to install retarder devices to improve the braking performance of the vehicle.The permanent magnet retarder for vehicles has the advantages of compact structure,no power consumption,and easy control.It is very suitable for installation on small and medium-sized trucks.However,at present,permanent magnet retarders still have problems such as large volume and unrecoverable heat energy.In view of the existing problems,it is necessary to carry out research on the related technology and characteristics of the magnetically concentrated permanent magnet retarder.First,the working principle of the permanent magnet retarder is studied,and the selection of the permanent magnet concentration method of the permanent magnet retarder and the design of the overall structure are carried out.The Halbach permanent magnet array structure with unilateral magnetization effect is selected to replace the traditional permanent magnet retarder radial magnetization structure.On the basis of air-cooled heat dissipation,the concentrated magnetic permanent magnet retarder is provided with a layer of temperature difference power generation piece between the vortex ring and the heat dissipation ring to play the role of heat recovery.Carry out simulation analysis of optimization and optimization of permanent magnet structure and other structures in permanent magnet retarder.Based on the size of the existing permanent magnet retarder,the magnet rotation angle,magnetic pole ratio,and magnetic pole pairs of the Halbach array structure are optimized.Based on the optimized permanent magnet structure,the thickness of the copper ring,the thickness of the inner yoke,and the air gap width are analyzed.The impact on the braking torque,and select the optimal size.Carry out an optimization study with the smallest structural size of a single permanent magnet.Compared with the traditional radial magnetized permanent magnet retarder,the optimized size of the concentrated magnetic permanent magnet retarder is about 75% of the traditional volume.The radial width is two-thirds of the traditional one.Carry out the calculation of the braking torque of the permanent magnet retarder and the temperature of the eddy current ring.Based on the optimized permanent magnet structure,a two-dimensional magnetic field analytical model and an equivalent magnetic circuit diagram are established,and the expressions of braking torque and eddy current loss of the magnetically concentrated permanent magnet retarder are derived.Based on reasonable assumptions,the temperature field model of the magnetically concentrated permanent magnetretarder is established,and the temperature expression of the eddy current ring is obtained.Carry out magneto-thermal joint simulation analysis of magnetically concentrated permanent magnet retarder.According to the optimized size of the retarder,a simulation model is established,and the static and transient magnetic field analysis of the magnetically concentrated permanent magnet retarder is performed using Maxwell software.The eddy current loss calculated by the electromagnetic field is used as a heat source into ANSYS Workbench,a two-way coupled simulation model is established,and a temperature distribution cloud diagram of the eddy current ring is obtained.Through theoretical analysis and simulation research,the proposed magnetically concentrated permanent magnet retarder can significantly reduce the volume while achieving the specified braking torque.It is more suitable for installation on small and medium-sized passenger trucks and can achieve the expected retarding system.The hierarchical control of dynamic effect and braking torque has been optimized to achieve a more compact structure with good application prospects.