Gear wheel that is provided with spokes (17) which extend between a rim (16) supporting a gear mesh (15) and a corresponding gear hub (18), whereby free spaces (19) are located between the spokes (17) which extend between the rim (16) and the gear hub (18), characterised in that at least one of said free spaces (19) is filled with a block (20) made of a rigid, incompressible material, whereby between the gear wheel (10) on the one hand and the block (20) on the other hand a viscoelastic material (21) is located.

A fluid transmission device is provided. The device comprises a rotatable case having a rotational axis, coupled to a drive source, and provided therein with a pump shell for integrally rotating with the case and a turbine shell facing the drive source side of the pump shell, a drive force being transmitted between the pump shell and the turbine shell via fluid, and a dynamic vibration absorber having a swing body and for reducing vibration caused by the drive source. The dynamic vibration absorber overlaps with at least one of the pump shell and the turbine shell in an axial direction of the case.

A coupling device that connects a first shaft and a second shaft that includes a primary inner ring member mounted on the first shaft, a primary outer ring member disposed on an outer circumferential side of the primary inner ring member, a primary elastic member for connecting the primary inner ring member and the primary outer ring member, a secondary inner ring member mounted on the second shaft, a secondary outer ring member disposed on an outer circumferential side of the secondary inner ring member, a secondary elastic member for connecting the secondary inner ring member and the secondary outer ring member, and a weight attaching plate interposed between the primary outer ring member and the secondary outer ring member.