Research On Electromagnetic Retarder With External Rotor

Thirty years of reform and opening up, China’s economy has achieved remarkable results, at the same time the road traffic has also developed rapidly and traffic conditions have been greatly improved. With the development of science and technology, the dynamic performance of the vehicle has been greatly improved which led to a dramatic increase in the running speed and mileage. This means that under the same brake time and the same brake conditions, the vehicle brakes are increasing, thus increasing wear and tear of the vehicle braking apparatus and the frequency of traffic accidents. Automotive safety, energy conservation, environmental protection had become a hot topics of social concern. The auxiliary braking device for automobile retarder is also put forward more requirements. The promotion of car retarder in our country is beginning from 2002 and the domestic passenger cars mainly base on eddy current retarder, but the severe hot recession and short service life are the fatal weakness. Because our country lacks the relevant installation regulations and lack of suitable for large trucks of the high price of retarder, the big truck retarder installation rate is less than 1%. With the October 2014 released a new version of the GB12676-2014 automobile braking system of experimental conditions, has already put into effect on July 1, 2015, afterwards there will be enormous demand in domestic market. The mainstream retarder abroad is hydraulic retarder, and they have carried out earlier research, so the installation rate is higher in foreign countries, such as Europe, America, Japan and other developed countries. But due to its high price, complex structure, so it is not suitable for the domestic market. This thesis based on shortcomings of the above products and combined with the domestic market, puts forward two new types of electromagnetic retarder with external rotor: The liquid-cooled eddy current retarder with external rotor and the air-cooled eddy current retarder with external rotor. The systematic researches on two new types retarder are as follows:The first chapter introduces the main auxiliary braking devices at home and abroad, including the principle of work, the advantages and disadvantages of the structure.The second chapter is the comparative introduced the basic structure and the working principle of the traditional electro hydraulic retarder and the new liquid-cooled eddy current retarder with external rotor, and the new retarder control unit and installation position are introduced in this paper, discusses the advantages of the external rotor electric hydraulic retarder.In the third chapter, the liquid-cooled eddy current retarder with external rotor of the magnetic field is studied to deduce the braking torque, the use of finite element method, a numerical simulation is performed for the new retarder. Analysis of the influence factor of the braking torque including effect of electromagnetic field, eddy current field, current, speed, material and coating of the new retarder braking torque.In the fourth chapter, the liquid-cooled eddy current retarder with external rotor of bench test, bench test scheme is introduced in this paper. By bench test of current and speed of braking torque characteristics, to verify the correctness of the theoretical derivation and simulation analysis. Through the external rotor electric hydraulic retarder continued hot and recession were studied. The test results show that the the new hydraulic retarder has the heat recession, persistent good.The fifth chapter on the basis of the above proposed a model of the external rotor electric air-cooled eddy current retarder, on its structure and working principle are introduced in detail, the finite element numerical simulation of the new type retarder, influencing factors and characteristics of the braking torque of, the with the traditional electric air-cooled eddy current retarder of bench experiments, were tested their persistent and thermal recession. At last, the paper introduces the advantages of the structure of the new type retarder, performance advantage.In this paper, the innovation is that we propose and study two new types of retarder rotors: liquid-cooled eddy current retarder with external rotor and the air-cooled eddy current retarder with external rotor. And we have done in-depth study of its outer rotor, stator, windings etc., which make them more competitive with advantages of optimized structure, simple and reliable, thermal recession, stable performance, long life, low price and so on.