A damper device includes an input element to which a torque from an engine is transmitted, an output element, an elastic body arranged to transmit a torque between the input element and the output element, and a rotary inertia mass damper that includes a planetary gear that includes a sun gear arranged to rotate integrally with one element of the input element and the output element, a carrier that rotatably supports a plurality of pinion gears and is arranged to rotate integrally with the other element of the input element and the output element, and a ring gear that meshes with the plurality of pinion gears and works as a mass body. The other element includes two plate members that are opposed to each other and coupled with each other by means of a plurality of rivets disposed between the pinion gears.

A damper device includes rotating elements including an input element and an output element, first elastic bodies that each transmit torque between the input element and the output element, a plurality of second elastic bodies that act in parallel with the plurality of first elastic bodies when torque transmitted between the input element and the output element is greater than or equal to a predetermined value, and a rotary inertia mass damper. The rotary inertia mass damper includes a sun gear, a carrier that rotatably supports a plurality of pinion gears, and a ring gear that meshes with the plurality of pinion gears and that serves as a mass body. The plurality of second elastic bodies are located at a different position than the plurality of first elastic bodies in a radial direction of the rotating elements and are circumferentially aligned with the plurality of pinion gears.

A damper device including an input element and an output element; an elastic body transmitting torque between the input element and the output element; and a rotary inertia mass damper having a mass body. The rotary inertia mass damper includes a sun gear, a carrier rotatably supporting pinion gears, and a ring gear that meshes with the pinion gears and serving as the mass body. A pair of washers is located on both sides of each pinion gear axially. The ring gear includes an annulus gear having internal teeth meshing with the pinion gears and a weight body fixed to the annulus gear such that the weight body is in contact with a side surface of the annulus gear. An inner circumferential surface of the weight body is supported in a radial direction by a tip of the pinion gear or an outer circumferential surface of the washer.

A torsional vibration damper in which noise and vibrations in a planetary gear unit are suppressed is provided. In a planetary gear unit, as an inertial element is oscillated to establish an inertial torque by a relative rotation between a sun gear and a ring gear. Pinion gears are interposed between the sun gear and the ring gear at predetermined intervals, and gear dimensions of one of the pinion gears and gear dimensions of another one of the pinion gears are different from each other.

A vehicle vibration reducing apparatus includes: an inertial mass body; a first engagement device that is switched between a state where a running power source engages with a damper of a power transmission device so as to enable power transmission and a state where the engagement is released; a second engagement device that is switched between a state where the power transmission device engages with the inertial mass body so as to enable power transmission in a power transmission pass different from that of the first engagement device and a state where the engagement is released; and a third engagement device that is switched between a state where the running power source engages with the inertial mass body so as to enable power transmission in a power transmission path different from those of the first engagement device and the second engagement device and a state where the engagement is released.

A torsional vibration damper that damps torsional vibration effectively in a low-speed range. In the torsional vibration damper, a spring holder is formed by apertures of an input element and an output element, and an elastic member is held in the spring holder. A first moveable range of a planetary element extending from an initial position in a drive direction is wider than a second movable range of the planetary element extending from the initial position in a counter direction.

A torsional vibration damping arrangement for the drivetrain of a vehicle has an input region driven in rotation around an axis of rotation A and an output region. A first torque transmission path and a second torque transmission path parallel thereto proceed from the input region. A coupling arrangement communicates with the output region for superposing the torques guided via the torque transmission paths, and a phase shifter arrangement for the first torque transmission path generates a phase shift of rotational irregularities guided via the first torque transmission path relative to rotational irregularities guided via the second torque transmission path. The output region includes the planet gear carrier at which a planet gear is rotatably supported, and the planet gear carrier is connected to the output region to be fixed with respect to rotation relative to it.

A damper device includes first inner springs configured to transmit a torque between a drive member and an intermediate member, second inner springs configured to transmit a torque between the intermediate member and a driven member, and a rotary inertia mass damper including a sun gear serving as a mass body rotating with relative rotation of the drive member to the driven member. The rotary inertia mass damper is provided in parallel to a torque transmission path including the intermediate member, the first inner springs and the second inner springs. A damping ratio ζ of the intermediate member determined based on a moment of inertia J.sub.2 of the intermediate member and rigidities k.sub.1 and k.sub.2 of the first and the second inner springs and is less than a value.

A damper device of the present disclosure includes an input element to which torque from an engine is transmitted, an output element, and an elastic body that transmits torque between the input element and the output element. The input element is formed to enclose the elastic body. The output element includes a clearance portion that allows passage of a tool for attaching and detaching the engine and the input element. A sealing member is disposed between the input element and another member other than components of the damper device so as to restrict an entry of foreign substances into the input element on the outside the clearance portion in a radial direction. As a result, assemblability and maintenability of the damper device can be further improved while restricting the entry of foreign substances into the input element formed to enclose an elastic body.

A torsional vibration damper that a torsional vibration damper having a planetary gear unit, and a manufacturing method of the torsional vibration damper for limiting damages on gears of the planetary gear unit due to dimension errors. In the planetary gear unit, at least one of a sun gear, a ring gear, and a set of planetary gears is/are formed by a press forming method. The gear formed by the press forming method is engaged with the remaining gears in such a manner that a thinner portion of each tooth is individually engaged with a thicker portion of the adjacent teeth of the remaining gears.