Patent ID: 8096551

Claim:
A medium transportation apparatus, comprising: a plurality of medium transportation units; a drive source; a sun gear connected to the drive source; a planetary gear engaging the sun gear for transmitting a drive force to one of the medium transportation units according to a rotational direction of the sun gear; and a rotational load, member for applying a rotational load to the planetary gear, said rotational load member being disposed on an outer side relative to a rotational shaft of the planetary gear in a radial direction of a rotational shaft of the sun gear, wherein said rotational load member includes a first rotational load member disposed on one end portion of the rotational shaft of the planetary gear along a circumferential direction thereof and a stationary second rotational load member disposed on a bearing portion of the rotational shaft of the planetary gear, and said first rotational load member is arranged to slide against the second rotational load member at an edge surface thereof in an axial direction of the rotational shaft of the planetary gear to apply the rotational load to the planetary gear.