Abstract: An eddy current damper includes a screw shaft, first permanent magnets, second permanent magnets, a cylindrical magnet holding member, a cylindrical conductive member, and a ball nut meshing with a screw shaft. The screw shaft is movable in the axial direction. The first permanent magnets are arrayed along the circumferential direction around the screw shaft. The second permanent magnet is arranged between the first permanent magnets, wherein the arrangement of magnet poles is inverted between the second permanent magnet and the first permanent magnet. The magnet holding member holds the first permanent magnet and the second permanent magnet. The conductive member is opposed to the first permanent magnets and the second permanent magnets with a gap therebetween. The ball nut is disposed inside the magnet holding member and the conductive member, and is fixed to the magnet holding member or the conductive member.

Abstract: The screw motion mechanism includes: a threaded shaft having an outer peripheral surface provided with a helical thread groove, the threaded shaft having at least one axial end coupled to a first structural body; a nut member held in a rotatable manner with respect to a second structural body which is movable in an axial direction of the threaded shaft with respect to the first structural body, the nut member being threadedly engaged with the threaded shaft; and a spherical joint for coupling the at least one axial end of the threaded shaft to the first structural body, the spherical joint including: a spherical portion; and a sphere receiving portion for housing the spherical portion. When assuming an axial force applied to the threaded shaft as a variable, a line of a rotational torque intersects with a line of a sliding torque in a graph.

Abstract: The damping device includes: a fixed cylinder that is configured to be fixed to a first structural body and formed into a cylindrical shape so as to comprise a hollow portion; a shaft member that is configured to be fixed to a second structural body, the shaft member being housed in the hollow portion of the fixed cylinder and having an outer peripheral surface provided with a helical thread groove; a nut member that is threadedly engaged with the shaft member, and converts an axial motion of the shaft member into a rotational motion; a rotor member that is formed into a cylindrical shape so as to cover the fixed cylinder and to form a cylindrical accommodation chamber between the rotor member and an outer peripheral surface of the fixed cylinder, and is rotated by the nut member; and viscous fluid that is sealed in the cylindrical accommodation chamber.

Abstract: The screw motion mechanism includes: a threaded shaft having an outer peripheral surface provided with a helical thread groove, the threaded shaft having at least one axial end coupled to a first structural body; a nut member held in a rotatable manner with respect to a second structural body which is movable in an axial direction of the threaded shaft with respect to the first structural body, the nut member being threadedly engaged with the threaded shaft; and a spherical joint for coupling the at least one axial end of the threaded shaft to the first structural body, the spherical joint including: a spherical portion; and a sphere receiving portion for housing the spherical portion. When assuming an axial force applied to the threaded shaft as a variable, a line of a rotational torque intersects with a line of a sliding torque in a graph.