Patent ID: 7424939

Claim:
A rotary damper, comprising: a driven-to-rotate member having integrally a driven-to-rotate part for coupling to a drive member, a first inner cylindrical wall, a first outer cylindrical wall situated outside the first inner cylindrical wall with a space therebetween, and first and second holding flange parts extending radially outwardly from the first outer cylindrical wall with a space therebetween, said second holding flange part being located lower than the first holding flange part and having a radial length less than that of the first holding flange part; a fixed support member for holding said driven-to-rotate member so as to rotate freely, said fixed support member having a second inner cylindrical wall inserted between the first inner cylindrical wall and the first outer cylindrical wall so as to be capable of relative rotation, a second outer cylindrical wall disposed outside the second inner cylindrical wall, and a step projecting toward the second inner cylindrical wall from a lower part of the second outer cylindrical wall so that the first holding flange faces the second outer cylindrical wall and said second holding flange faces the step; a receiving part formed between said second inner cylindrical wall and the step at the fixed support member; an O-ring as seal means disposed under the first holding flange part and above the second holding flange part and the step, for sealing an outer perimeter of said receiving part so that said driven-to-rotate member and said fixed support member are capable of relative rotation; and a viscous fluid received inside said receiving part for damping relative rotation between said driven-to-rotate member and said fixed support member.