Magnetorheological elastomer with stiffness-variable characteristics based on induced current applied to differential mount of vehicles

摘要

A differential mount with elastomers is installed to insulate vibration transmitted from the engine to the body through the propeller shaft. Since existing differential mounts adopt an elastomer of uniform stiffness, it is difficult to meet both the requirements for steering performance and driving comfort at the same time. In order to overcome this limitation, this study suggests a magnetorheological elastomer (MRE)-based stiffness-variable differential mount which allows the mount's stiffness to vary reversibly or instantly. The stiffness-variable differential mount was designed with a new inner structure where a magnetic field can be induced in the MRE. Further, the geometry of the MRE was optimized by means of the response surface method to achieve a targeted level of stiffness. The variable performance of the stiffness-variable differential mount was evaluated with the dynamic stiffness when a current of 3 A (0.287 T) was applied. As a result, it was found that the average increase in dynamic stiffness was 4.41 kgf mm-1 over an excitation frequency range of 60-100 Hz, a critical point of variation for dynamic stiffness, and 3.60 kgf mm-1 over an excitation frequency range of less than 100 Hz.