Power transmission apparatus

A power transmission apparatus comprising

• a driving rotary member rotatably supported on an outer surface of a cylindrical housing of a driven device through a bearing, a driven rotary member attached to a rotating shaft coaxially arranged in said cylindrical housing of said driven device, and a torque limiter mechanism for connecting said driven rotary member and said driving rotary member to each other and limiting torque transmission from said driving rotary member to said driven rotary member when an overload is applied to said driven rotary member,
• said torque limiter mechanism having
• a plurality of holding portions fixed to either one of said driving rotary member and said driven rotary member and aligned substantially equidistantly in a circumferential direction,
• an opposing portion provided to either one of said driving rotary member and said driven rotary member and opposing said holding portions, and
• an elastic member frictionally connected to said holding portions and said opposing portion and fixed to the remaining one of said driving rotary member and said driven rotary member,
• said elastic member having
• connecting portions frictionally connected to said holding portions and said opposing portion and corresponding in number to said holding portions, and
• an elastic support fixed to the remaining one of said driving rotary member and said driven rotary member and imparted with an elastic restoration force for disengaging said connecting portions toward either one of upper and lower surfaces of said holding portions,
• wherein said connecting portions and said holding portions, and said connecting portions and said opposing portion are frictionally connected to each other, and said elastic support elastically deforms in an axial direction.