Abstract: A wet multi-plate clutch supplies lubricating oil via a lubricating gallery from an inner circumferential surface of a cylindrical member of a clutch hub to a plurality of plates. The lubricating oil is appropriately supplied to a space between adjacent plates even under an idle neutral control. In the wet multi-plate clutch, a cylindrical member is divided into a plurality of areas having identical length in the circumferential direction, each area is provided with a group of lubricating gallery set consisting of a plurality of lubricating galleries formed at mutually different positions in the axial direction by shifting the positions of the plurality of lubricating galleries which constitute the group of lubricating gallery set in the circumferential direction.

Abstract: A multi-plate friction clutch includes: a clutch piston 10 which is fitted to a clutch outer and capable of being hydraulically operated to press a group of first and second friction plates toward a pressure-receiving plate; an annular retaining groove formed in a pressing surface of the clutch piston; and a buffering Belleville spring accommodated in the retaining groove and capable of abutting resiliently against the group of the first and second friction plates. The retaining groove has an annular projection formed at its axial opening edge for inhibiting the disengagement of the Belleville spring from the retaining groove. Thus, even when the number of the friction plates is increased, a total gap between the clutch piston and the pressure-receiving plate can be set freely without giving consideration to the falling-off of the Belleville spring.

Abstract: A multi-plate friction clutch includes: a clutch piston 10 which is fitted to a clutch outer and capable of being hydraulically operated to press a group of first and second friction plates toward a pressure-receiving plate; an annular retaining groove formed in a pressing surface of the clutch piston; and a buffering Belleville spring accommodated in the retaining groove and capable of abutting resiliently against the group of the first and second friction plates. The retaining groove has an annular projection formed at its axial opening edge for inhibiting the disengagement of the Belleville spring from the retaining groove. Thus, even when the number of the friction plates is increased, a total gap between the clutch piston and the pressure-receiving plate can be set freely without giving consideration to the falling-off of the Belleville spring.