Design, Testing and Analysis of a Novel Multiple-Disc Magnetorheological Braking Applied in Vehicles

摘要

This paper presents a new magnetorheological braking which can be used in vehicles. Magneto-rheological (MR) fluid is a novel material which can be used in different components of vehicle. Magneto-rheological fluids (MRF) are suspensions of micron size whose yield stress varies rapidly as the change of magnetic field. The use of MRF in vehicles has been gaining popular recently due to its strong rheological effect, fast response and low energy consumption. Besides, these performances give designers more choice in automotive designs. However, most of the related research of MRF brake is about the construction of small prototype to verify its rheological performance. As a result, research progress is limited to calculation and simulation which make the braking force of prototype can hardly meet the requirement of vehicle due to a lack of optimal design and the understanding of MRF in the situation of high sheer stress and magnetic field. In the recent research reported in SAE Brake Colloquium 31nd and 32nd Annual, [1, 2] a prototype had been proposed and manufactured. Based on properties of MRF, analysis results showed the design precept of MRF brake is of great significance and the improvement measures were proposed to improve the magnetic induction intensity in the working gaps. This article is about the further study of MR braking and presents a novel vehicle braking utilizing magneto-rheological fluid and multiple-disc structure. In the design progress, performances of MRF under high shear speed and high magnetic field are discussed to get the method of fitting calculation. Based on the method and finite element simulation results, high performance MRF brake was created and manufactured. The prototype was tested by the way of increasing the loading weight to get its load curve and power consumption curve. Experimental results showed that the torque is up to 1000Nm consuming about 600W and the braking torque of this system can be linearly adjusted by the current applied to the electromagnet. On the whole, the proposed brake system has a higher torque capacity which validate the feasible application of magnetorheological fluids in automotive braking system.