Study On Magnetic Powder Clutch With High Performance For Vehicle

Magnetic powder clutch has the advantages of smooth separation and joint, good controllability, quick response, wide torque transmission range independent of the slip ratio, high transmission efficiency and so on, which determined that it has a broad application prospect in the vehicle industry. However, because of the technical blockage of foreign enterprise and very few people engaged in the research of the magnetic powder clutch, the present domestic magnetic powder clutch has shortcomings of the low transferring torque capacity, heating seriously during its working process etc. As a result, it can’t satisfy the requirements of vehicle transmission system. Therefore, a kind of the high-performance vehicle magnetic powder clutch with high torque transmission performance, high reliability and low energy consumption was studied. And it is suitable for automatic transmission system or semi-automatic transmission system of the economical car. In order to improve the torque transmission performance of the magnetic powder clutch, raise the grade of the domestic magnetic powder clutch and its car product and have a better competitive, some key topics such as the torque transmission mechanism of the magnetic powder clutch, research on the methods of the performance evaluation and design of the magnetic powder clutch based on electromagnetic field analysis, influence of the material properties and structural parameters on the performance of the magnetic powder clutch, temperature field analysis model, magnetic powder clutch applied permanent magnet and so on were studied using research methods such as theoretical analysis, simulation calculation, prototype develop and test. The major contributions of this paper were as follows:(1)From the perspective of energy conservation, the torque transmission performance evaluation mathematical model of the magnetic powder clutch was established. The inherent law of its torque transmission based on energy conversion was revealed. The relation between the electromagnetic field of the working gap and the torque transmission of the magnetic powder clutch was established. The performance evaluation method for the magnetic powder clutch based on the electromagnetic field analysis was presented.(2) A further study on analysis and design methods of the magnetic powder clutch electromagnetic field was carried out. The structural and electromagnetic parameters of the vehicle magnetic powder clutch were initially designed based on the existing design methods and experiences of the magnetic powder clutch, and at the same time, it was comprehensively considered that the geometry size of the magnetic powder clutch was limited by the vehicle transmission cavity space. Electromagnetic field simulation model of the designed vehicle magnetic powder clutch was created. The performance of the vehicle magnetic powder clutch was simulated based on the simulation model.(3)According to the influences of the clutch material properties and its structural parameters on the performance of the clutch, the ways and means to improve the torque transmission performance of the magnetic powder clutch were analyzed, and the quantitative relationship was determined between its performance and its main design parameters such as working gap width, nonworking gap width, number of working gap, magnetic circuit material properties based on the designed model of the vehicle magnetic powder clutch and the analysis results. The magnetic field distribution of the magnetic powder clutch was improved by the reasonable design on powder storage chamber and magnetic powder guidance channel. And the performance of high torque transmission was realized.(4)According to the working characteristics of the vehicle magnetic powder clutch and the excellent characteristic of the permanent magnetic materials that it does not consume energy throughout the work, a kind of magnetic powder clutch was proposed with superposition principle of two magnetic fields generated by permanent magnet and the excitation coil. And its structure scheme, working process and structural parameters were designed and analyzed. The design scheme of the vehicle magnetic powder clutch that can meet the design requirements was determined. And the performance of the designed vehicle magnetic powder clutch was analyzed. And the performance of low energy consumption was realized.(5)In order to evaluate the working ability and the feasibility and to guide the design and optimization of the designed magnetic powder clutch, the simulation model of the temperature field was created. Based on the simulation model, the temperature distribution and the variation of the magnetic powder clutch under three typical stable conditions were studied. The results showed that the designed vehicle magnetic powder clutch in this paper had high working reliability.(6)The test prototype was developed and the test platform was established to test a study of static electromagnetic field on the surface of this test prototype, torque-exciting current characteristics and temperature rise. This study has verified the correctness of the design and calculations for this article and the feasibility of this designed magnetic powder clutch. The design and the calculations were verified by the test. The test results showed that the designed vehicle magnetic powder clutch in this article has advantages of high torque transmission,high working stablity and low energy consumption and that the research results reached the reached the expected requirement.