Research On Rotary Magnetorheolgical Damper Based On Helical Flow

Magneto-rheological(MR) fluid is a kind of smart material, which can occur fast, controllable, reversible changes in the magnetic field. The magneto-rheological fluid damping technology has been received much attention due to its rapid response and controllable damping characteristics. Many MR damping devices have been investigated based on the MR fluid technology. Those MR dampers can be classified into two types including linear MR dampers and rotary MR dampers according to the working principle. Compared to the linear MR dampers Rotary MR damper has many advantages such as a small proportion of the space, less resistant to damage from foreign objects, working distance without restrictions. Therefore, In general, the design structures of rotary MR dampers are mostly based on the working principle of shear mode. The damping torque and torque density generated under this operation mode are relatively small. So it is difficult to meet the high torque applications. In order to improve the torque of rotary MR damper, a novel rotary MR damper based on helical flow is proposed in this paper. The nonlinear fluid correction model based on Herschel-Bulkley(H-B) mode and multi-objective optimization design theory are used for the optimized design. The model of rotary MR damper is established and verified, using Bingham model, adaptive neural network fuzzy inference system(ANFIS) and Polynomial model. The main contributions of this paper include the following.(1)A novel design of rotary MR damper based on helical flow is proposed, according to analysis of the existing rotary magneto-rheological damper on the structure and mode of operation. On the basis of modified nonlinear fluid correction model based on H-B model, the equations of the damping force and the dynamic range are formulated for the proposed rotary MR damper. The genetic algorithm is applied to improve the solotions.And the geometric quantities are determined.(2)Rotary MR damper is fabricated in terms of the design and the piston geometric quantities. The dynamic performance of the damper is tested. According to working condition, torque of high speed motion and sinusoidal motion are tested, respectively testing the relationship between the torque and speed, current. The temperature rise of damper is tested, testing the temperature change over time in certain conditions. And the change of the torque is analyzed while the temperature rises. Finally, the response time test is carried out, testing the response time of the burst of excitation.(3)The dynamic model of out torque of rotary MR damper is derived based on the theory of the Bingham model, ANFIS and Polynomial mode. And each model is verified and forecasting. Finally the advantages and disadvantages of every model is summarized.