Being Drive feature and the Drive feature which converts

摘要

PROBLEM TO BE SOLVED: To suppress eccentric wear of an eccentric shaft disposed at an offset position in a radial direction from a rotating shaft in a driving mechanism of converting a rotational motion to a reciprocal motion of a driven body such as an agitator.SOLUTION: In outer dimensions of an eccentric shaft 29B, a dimension H of a portion parallel to an eccentric direction D1 is controlled to be smaller than a dimension W of a direction perpendicular to the eccentric direction D1 and to an axial direction of the eccentric shaft 29B. A cylindrical inner face 25G of an agitator 25 including the eccentric shaft 29B is cylindrical with a radius of curvature approximately equal to a half of the dimension W or larger. Thereby, the eccentric shaft 29B contacts the cylindrical inner face 25G of the agitator 25 at a plurality of points, which suppress progress of wear and eccentric wear of the eccentric shaft 29B, compared with an eccentric shaft 29B having a cross section of a perfect circle.