| 主权项 |
1. A clutch that couples an input member and an output member to each other such that power is transferred from the input member to the output member and that decouples the input member and the output member from each other, comprising:
an annular member attached to the input member; a clutch hub provided to the input member or the annular member; a first friction engagement plate fitted with the clutch hub; a clutch drum coupled to the output member and disposed on a radially outer side of the clutch hub such that the clutch hub is surrounded; a second friction engagement plate fitted with the clutch drum; and a piston that is disposed between the input member and the annular member and that is movable in an axial direction to press the first and second friction engagement plates, wherein: the first and second friction engagement plates are each a one-sided friction plate that includes an annular plate, a friction material affixed to one surface of the annular plate, and a plate oil passage formed on the one surface of the annular plate such that the plate oil passage is dented with respect to a surface of the friction material; an engagement oil chamber, to which working oil is supplied, is defined in one of a space between the piston and the annular member and a space between the piston and the input member, and a supply oil passage, through which cooling oil is supplied to the first and second friction engagement plates via an opening formed in the clutch hub, is defined in the other of the spaces; and a return oil passage for the cooling oil which has passed through the first and second friction engagement plates is defined along a back surface of the annular member on a side opposite to the piston, and the return oil passage communicates with the supply oil passage. |
