The washer is conventionally classified into the wave whirling type, the agitating type and the cylinder type, all of which are single powered. The cylinder type and the agitating type are popular in Europe and the wave whirling type is still popular in Asia. Recently, the double powered washer in the new type is developed in China by combining all of these three types. Technical and qualitative change is realized in the washer field. As this washer is rotated by two powers at the same time, development of water seal performance enhancement is required to respond to the operating environment more severely than the conventional single powered system.