Abstract
Washing/Spin-Dryer machine is different from general machinery in the following points. It has a relative large unbalance when the clothes tend to clump in a rotating washing/spin-dryer machine. In addition, the magnitude and the direction of this unbalance also easy change because the amount of laundry varies in every operation. As the result, extremely large vibrations occur. Although various methods for vibration suppression have been used in a washing/spin-dryer machine, the effect of these method is not enough and large vibrations still appear. In this paper, we propose to use the vibration suppression method utilizing discontinuous spring characteristics together with an automatic ball balancer to suppress those vibrations. The results show that amplitude of vibration can be suppressed to a small amplitude in the vicinity of the major critical speed and a zero amplitude in the speed range higher than the major critical speed. The validity of proposed method is confirmed theoretically, numerically and experimentally.
