A screw motion mechanism for a damping apparatus, comprising: 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; a spherical joint for coupling the at least one axial end of the threaded shaft to the first structural body, the spherical joint comprising: a spherical portion (33, 61); and a sphere receiving portion (36, 60) for housing the spherical portion, wherein relative translational motions of the nut member and the threaded shaft in the axial direction apply a rotational torque to the threaded shaft, whereas the rotational torque is dependent on an axial force applied to the threaded shaft, characterized in that a sliding torque is a torque required for rotating the spherical portion of the spherical joint relative to the sphere receiving portion of the spherical joint, whereas the sliding torque is dependent on the axial force applied to the threaded shaft,and wherein, when assuming the axial force of the threaded shaft as a variable, the threaded shaft is not rotated when the rotational torque is lower than the sliding torque in the spherical joint and at least a part of the relative translational motions is converted into a rotational motion of the threaded shaft when the rotational torque is higher than the sliding torque in the spherical joint. 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; a spherical joint for coupling the at least one axial end of the threaded shaft to the first structural body, the spherical joint comprising: a spherical portion (33, 61); and a sphere receiving portion (36, 60) for housing the spherical portion, a spherical portion (33, 61); and a sphere receiving portion (36, 60) for housing the spherical portion, wherein relative translational motions of the nut member and the threaded shaft in the axial direction apply a rotational torque to the threaded shaft, whereas the rotational torque is dependent on an axial force applied to the threaded shaft, characterized in that a sliding torque is a torque required for rotating the spherical portion of the spherical joint relative to the sphere receiving portion of the spherical joint, whereas the sliding torque is dependent on the axial force applied to the threaded shaft,and wherein, when assuming the axial force of the threaded shaft as a variable, the threaded shaft is not rotated when the rotational torque is lower than the sliding torque in the spherical joint and at least a part of the relative translational motions is converted into a rotational motion of the threaded shaft when the rotational torque is higher than the sliding torque in the spherical joint.