Study On Magnetorheological Transmission Theory And Experiments

Magnetorheological fluid(MRF) is a new type of intelligent material. Due to the outstanding controllable rheological performance, MRF has become an important branch of intelligent material development and one of hot issue of intelligent material and intelligent device researches. In the last decades, MR technology is taken account by scientific field and is invested large quantity financial and human resource. MRF, with the unique electro-mechanical coupling performance, has a marvelous advantage in terms of starting, braking, torque regulating, continuously variable transmitting, overload protecting, etc. in the transmission engineering field, so it will brings a new revolution that researching on MR technology in the transmission engineering field. In this dissertation, in view of the process of MRF fluid and MR devices, the MR transmission technology has been studied systematically, the MR transmission theory has been explained, the overall design and various performance analysis about MR transmission device(MRTD) have been completed, the prototype of MRTD has been manufactured and some experiments about it has been done in order to achieve the commercialization of MR transmission technology and promote the application development of MRF in the transmission engineering field. The main research contents in this dissertation are as follows:①Through the review of application prospect and development tendency of MRF and MR devices, the main defects of the studies on MR technology are pointed out, the necessity and importance of developing the MR transmission technology are introduced, the goal and contents of this dissertation are put forward briefly.②The studies on MR effect and MRF performance. The MR effect mechanism is explained based on chain model, the factors, which influence the MR effect are analyzed according to the model above-mentioned.③The MR transmission theory and the design of MRTD. The MR transmission theory is introduced detailedly, the working modes, characteristics and failure modes of MR transmission are discussed. The design theories of MRTD are studied systematically, including the strucuture design theory and the magnetic design theory: the working principle of MRTD is analyzed, the calculation model of transfer torque of MRTD is established based on Bingham liquid model, the magnetic design rule of MRTD is put forward and the magnetic circuit of MRTD is analyzed and calculated; According to the design theories above-mentioned, the prototype design of MRTD is completed, the main structure parameters and magnetic parameters are determined and some design results are also discussed.④The theoretical studies on performances of MRTD. The factors, which influence the transmission performance of MRTD is analyzed. By means of finite element emulation, the magnetic field distribution of MRTD is obtained. On the basis of Bingham liquid model and Navier-Stokes equation, the mathematic flow model of MRF in the MRTD is established, the hydrodynamic performances of MRTD are studied under the steady state and the transient state, including the distribution of fluid field, the formation and variation of critical yield surface and the variation of transient transfer torque. The dynamic response performances of MRTD are discussed, the influence factors of electromagnetic circuit response time and rheological response time are analyzed respectively. The thermal analysis about MRTD is carried out referring to the heat transfer theory, the heat generation and heat transfer in MRTD are discussed, and the whole temperature field of MRTD is obtained based on finite element emulation.⑤The heat dissipation studies on MRTD with new type of heat pipes. Due to the harm of heat generation for MRTD, a new heat dissipating scheme that took the integral pin-fin revolving heat pipe(PRHP) as the heat dissipating tool is put forward. The detail design and analysis about PRHP are done, including the working principle, the choice of materials, the pressure and temperature drop along the axial direction, the thermal resistance, the heat transfer power, the heat transfer limitation. The prototype of PRHP is processed and the performances of PRHP are tested through the single-tube experiment, the working effectiveness of PRHP has been proved.⑥The experimental studies on MRTD. Based on the theoretical analysis, the prototype of MRTD is manufactured, the various transmission performances of it are tested, including the no-exciting torque, the transfer torque, the regulating performance, the constant-torque performance, the transmission efficiency, the dynamic response performance, etc. Simultaneously, the contrast experiments are done for heat dissipating capacity of MRTD with and without the PRHP. The advantages of transmission performance of MRTD and the feasibility of heat transfer by PRHP have been verified.⑦Lastly, the dissertation is concluded, the main achievements of this dissertation are summed up and some problems should be deeply studied are pointed out.