抄録
A "fluid balancer" is a device to prevent the excessive vibration of washing machines. The balancer is a rectangular ring pipe partially filled with liquid. Due to the basic mechanism of rotating structures, the fluid takes the same position as an unbalanced weight before the critical speed of the washing machine, and it shifts to the position against the weight after the critical speed. However, it is desired that the position of the weight stays the same before the second critical speed. This report shows this fundamental mechanism using a simple model-equipment, and shows some tries on how to prevent the shift of the fluid after the first critical speed.
