Patent ID: 8371948

Claim:
A flywheel device, in which a flywheel assembly includes: a mass-side rotor including a mass ring and a pair of holder plates having outer peripheral portions connected to the mass ring with the mass ring sandwiched therebetween; a driven plate which includes an output hub disposed coaxially with the mass ring and which is disposed between the holder plates rotatably relative to the holder plates; and a torque damper interposed between the holder plates and the driven plate, the mass-side rotor is connected to a crankshaft with a drive plate therebetween, and a positioning apparatus for positioning the mass-side rotor and the drive plate coaxially with each other is provided between the mass-side rotor and the drive plate, wherein the positioning apparatus includes: identical annular positioning protrusions press formed on each of the pair of holder plates to project laterally outward therefrom, and disposed coaxially with the mass-side rotor; and a positioning recessed portion which is press formed on the drive plate coaxially with the crankshaft, and which is fitted to one of the positioning protrusions of one of the holder plates.