ROTATING DEVICE AND IMAGE FORMATION DEVICE

To prevent contact parts or a rotating body from abruptly restoring from a deformed state.SOLUTION: A rotating device includes: a rotating body that has a recess formed on its outer peripheral surface and rotates in a predetermined rotational direction; a contact part that contacts the outer peripheral surface with a predetermined amount of penetration within a range from the upstream end to the downstream end of the recess in the rotational direction; and a contacted surface that is formed at the upstream end in the rotational direction within the range and with which the contact part contacts with a second amount of penetration that is smaller than the first amount of penetration in the downstream portion relative to the upstream end.SELECTED DRAWING: Figure 4 【課題】接触部又は回転体が変形状態から急激に復原することを抑制する。【解決手段】回転装置は、外周面に凹部が形成され、予め定められた回転方向へ回転する回転体と、前記凹部の回転方向の上流端から下流端までの前記外周面の範囲に対して予め定められた食い込み量を有して接触する接触部と、前記範囲における回転方向の上流端部に形成され、当該上流端部に対する下流側の部分における第一食い込み量よりも小さい第二食い込み量にて前記接触部が接触する被接触面と、を備える。【選択図】図４