Abstract: A power transmission device disposed in a path from a drive source to a wheel in a vehicle is disclosed. The power transmission device includes an input-side rotary member, an output-side rotary member, and a magnetic damper mechanism. A torque is inputted from the drive source to the input-side rotary member. The output-side rotary member is disposed to be rotatable relative to the input-side rotary member. The magnetic damper mechanism is configured to elastically couple the input-side rotary member and the output-side rotary member in a rotational direction by a magnetic force of attraction. The magnetic damper mechanism has a variable stiffness.

Abstract: A power transmission device includes a first rotary member, a second rotary member disposed to be rotatable relative to the first rotary member, a first damper part, a second damper part, an intermediate member, and a bearing. The first damper part is configured to transmit a power together with the first rotary member therebetween. The second damper part is configured to transmit the power together with the second rotary member therebetween. The intermediate member is configured to couple the first damper part and the second damper part therethrough. The bearing causes the intermediate member to be rotatably supported by the first rotary member therethrough.

Abstract: A power transmission device includes a first rotary member, a second rotary member, and a damper mechanism. The first rotary member includes a chamber in an interior thereof. The second rotary member is disposed to be rotatable relative to the first rotary member. The damper mechanism is configured to elastically couple the first rotary member and the second rotary member in a rotational direction. The damper mechanism includes a first damper part disposed inside the chamber and configured to transmit power together with the first rotary member therebetween, a second damper part disposed outside the chamber and radially inward of the first damper part and configured to transmit the power together with the second rotary member therebetween, and an intermediate member including an inertia portion disposed outside the chamber and configured to couple the first damper part and the second damper part.