Patent ID: 7492549

Claim:
An automatic balancing device comprising: a balancer made of a magnetic fluid; a rotatable enclosure having an outer circumferential wall and accommodating said balancer; a magnet provided near at least the center of rotation of said enclosure so as to be rotatable integrally with said enclosure; and a platelike projection projecting from said outer circumferential wall toward the center of rotation of said enclosure, at least a part of said platelike projection extending in a direction different from a radial direction of said enclosure at the juncture between said platelike projection and said outer circumferential wall, wherein all consecutive points disposed on each platelike projection commencing from the outer circumferential wall and toward the center of rotation of said enclosure are radially closer to the center of rotation relative to previous ones of the consecutive points, wherein each radial associated with and interconnecting each one of all of the consecutive points with the center of rotation is angularly offset from one another relative to the center of rotation and wherein all of the consecutive points are aligned relative to each other along a common straight line.