Michael J. Chrzan

MR fluid sponge devices and their use in vibration control of washing machines

High-strength, stable, magnetorheological (MR) fluids and devices such as rotary brakes and linear vibration dampers that enable the benefits of controllable fluid technology are now commercially available. Recently, a new way of using MR fluids in which the fluid is contained in an absorbent matrix has been developed. Such MR fluid sponge devices enable the benefits of controllable MR fluids to be realized in cost sensitive applications. Most of the high-cost components normally associated with a fluid-filled device can be eliminated with this approach. Low-cost, controllable MR sponge dampers are particularly appropriate for moderate-force vibration control problems where a high degree of control authority is desired. One attractive area for their application is in next-generation high-performance home washing machines. These new machines operate under varying agitation rates, load imbalances, and often at very high speeds, and as such require varying damping charateristics. Test results have shown the MR sponge damper to be an ideal way to control vibration in these new washing machines.