[Problem] To provide a rotary damper wherein damping torque generated by rotation can be easily adjusted using a simple configuration. [Solution] A rotary damper 1 limits the movement of viscous fluid contained in a circular cylinder chamber 111, thereby generating damping torque against applied rotational force. This rotary damper 1 is configured such that: a lid 15 is screwed into a case 11; and the gap g1 between the lower surface 153 of the lid 15 and the upper surface 119 of a partition section 115 and the gap g2 between the lower surface 153 of the lid 15 and the upper surface 129 of a vane 122 can be adjusted by adjusting the amount of screwing of the lid 15 into the case 11. This means that adjusting the amount of movement of viscous fluid through the gaps g1, g2 can adjust damping torque generated by rotation.

A dynamic damper assembly may include a plurality of bodies arranged at predetermined intervals on an outer peripheral surface of a drive shaft, and an elastic body formed to surround each of the bodies and fixing each body to the drive shaft.

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 spring for sun visors includes a torque application section that extends from a holding section and applies torque when a main section is rotating. The holding section has a flat section that receives torque from a shaft. The torque application section has a first spring piece extending from one end of the holding section and a second spring piece extending from the other end of the holding section and being bent so as to fold back. The first spring piece has a first tip section that includes overhanging sections that are narrower than the width of the holding section. The second spring piece has a second tip section that is arranged so as to overlap on the outside of the overhanging sections. The overhanging sections are provided in an area extending from the torque receiving section to the first tip section.

A torque generation device includes a rotor connected to a shaft and rotatable about a rotary axis of the shaft; an external member disposed outside the rotor and rotatable about the rotary axis relative to the rotor; a magnetically responsive material in a gap between the rotor and external member; a magnetic field generating unit generating a magnetic field passing the magnetically responsive material; and an adjusting unit between the shaft and external member along an outer circumference of the shaft, wherein the adjusting unit has a containing space where an adjusting sealing member is provided, the magnetically responsive material is sealed in the gap, containing space, and path connecting these and in an adjustment space from a position where the adjusting sealing member is provided to the path, and a capacity of the adjustment space is changeable according to a change in volume of the magnetically responsive material.

A torsion absorber is provided for attachment to a cylindrical section of a shaft. The torsion absorber includes a flywheel and at least one tensioner. The at least one tensioner is configured to brace a first segment and a second segment of the flywheel against the cylindrical section of the shaft.

A damper device includes a damper unit and a torque limiter unit. The damper unit includes first and second plates each including a plurality of window portions, a hub flange including a plurality of window holes, and a stopper mechanism. The first plate includes an engaging portion and a fixing portion fixed to the second plate. The engaging portion and the fixing portion are disposed radially outside the plurality of window portions. The hub flange includes a protrusion disposed circumferentially between and radially outside adjacent two of the plurality of window holes. The stopper mechanism is configured to be actuated by contact of the protrusion with the engaging portion. A fixation member, by which the first plate and the torque limiter unit are fixed, is disposed circumferentially between adjacent two of the plurality of window portions as seen in a direction along a rotational axis.

A torque limiter embedded damper device includes a torque limiter unit and a damper unit. The damper unit includes a first rotor, a second rotor, and a stopper mechanism. The second rotor includes a flange axially opposed to the first rotor. The stopper mechanism restricts an angle of relative rotation between the first rotor and the second rotor to a predetermined angular range. The stopper mechanism includes a cutout and a stop pin. The cutout is provided in the flange of the second rotor. The stop pin is fixed to the first rotor. The torque limiter unit includes a friction plate having an annular shape. The annular friction plate is fixed at an inner peripheral part thereof to an outer peripheral part of first rotor or the second rotor by a fixation member. The fixation member is fastened in a state of penetrating the cutout of the flange.

A viscous torsional-vibration damper has a damper housing with an axis of rotation, an annular working chamber filled with a damping medium, an inertia ring arranged inside the working chamber, and a cover for media-tight closure of the working chamber. The cover is connected to the damper housing peripherally on one side by a sequence of a butt seam and an overlap seam.

A dynamic balancing apparatus includes a dynamic balancing assembly and a plurality of damping particles. The dynamic balancing assembly includes at least two structural members separately arranged on a rotating shaft connected to a rotor, wherein each structural member includes at least one recess portion. The plurality of damping particles are introduced into at least one recess portion of each structural member, such that a centroid of each structural member deviates from the axis. Accordingly, each structural member generates inertial force and moment of inertia as rotation of the rotor to offset another inertial force and moment of inertia generated by centroid deviation of the rotor while rotating to achieve dynamic balance. The plurality of damping particles can move in the recess portion as rotation of the rotor to induce friction and collision so as to achieve the effects of vibration reduction and noise reduction.