Abstract: A damper which uses a magnetic viscous fluid, includes a cylinder, a bobbin which is housed in the cylinder and on which a coil generating a magnetic field is wound, a yoke which is housed in the cylinder and provided on an end of the bobbin, and a shaft which is inserted into the cylinder so as to extend through the bobbin and the yoke and so as to be axially reciprocable relative to the bobbin and the yoke. The magnetic viscous fluid fills a space defined between the bobbin and the yoke in the cylinder. The coil, the bobbin and the yoke are fixed together by a resin.

Abstract: A washing machine includes an outer casing, a tub mounted in the outer casing, a rotating tub rotatably mounted in the tub and a vibration damping device located in the outer casing for damping vibration of the tub using a cylinder enclosing an operating fluid. The operating fluid includes a functional fluid. The washing machine further includes a control unit which is configured to control a viscosity of the functional fluid. The control unit is configured to change the viscosity of the functional fluid according to rotation of the rotating tub in a dehydration step to vary a damping force of the vibration damping device.