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: An eddy current damper includes a magnet holding member, a first permanent magnet having a thickness (H1), a second permanent magnet having a thickness (H1), a conductive member, a ball nut, a screw shaft, and a copper layer having a thickness (H2). The second permanent magnet is adjacent to the first permanent magnets with a gap therebetween in the circumferential direction of the magnet holding member. The ball nut is fixed to the magnet holding member or the conductive member. The copper layer is fixed to the conductive member and is opposed to the first permanent magnet and the second permanent magnet with a gap therebetween. The thickness (H1) and the thickness (H2) satisfy, with respect to a distance (R1) between a central axis of the screw shaft and the center of gravity of the first permanent magnet: 0.018?H1/R1?0.060, and 0.0013?H2/R1?0.0065.

Abstract: An eddy current damper includes a screw shaft movable in an axial direction, a plurality of first permanent magnets, a plurality of second permanent magnets, a cylindrical magnet holding member, a cylindrical conductive member having conductivity, a ball nut which meshes with the screw shaft, and a heat transfer layer which covers a surface of the conductive member opposed to the first permanent magnets and the second permanent magnets. 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. The heat transfer layer has a thermal conductivity higher than that of the conductive member.

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.