| 摘要 |
A clutch which can realize further reduction of drag torque, a method for reducing the drag torque of the clutch, and a clutch friction plate used in the clutch are provided. In a clutch 100, clutch plates 103 and clutch friction plates 110, both of which are flat and annular, are alternatingly arranged, and clutch oil is supplied to spaces between the clutch plates 103 and the clutch friction plate 110. Each clutch friction plate 100 has small-groove groups 113 and fan-shaped grooves 114 formed on a surface of a metal core 111, which is flat and annular. Each small-groove group 113 includes a plurality of small grooves 113a which are parallel to one another and extend from the inner peripheral side to the outer peripheral side of the metal core 111. Each fan-shaped groove 114 is formed adjacent to the corresponding small-groove group 113 such that its width increases from the inner peripheral side toward the outer peripheral side of the metal core 111. When the clutch friction plates 110 rotate, the clutch 100 leads the clutch oil present at the inner peripheral side of the metal core 111 to the outer peripheral side of the metal core 111 through the small-groove groups 113 and the fan-shaped grooves 114. |
