A clutch mechanism designed to be installed between an engine and a motor vehicle transmission, wherein the clutch mechanism includes at least one cooling duct arranged to make a cooling fluid circulate toward the clutch, wherein each cooling duct includes an axially extending part and at least one radially extending part, the axially extending part of each cooling duct is situated radially between a transmission shaft and an interior face of the clutch support, and at least one radially extending part of each cooling duct is situated axially between the support bearing and the output hub.

A piston assembly for a clutch pack including a piston in form of a ring-shaped plate, a stator connected to the piston, the stator having a circular stator main part and at least one radial protrusion extending radially outwardly from the circular stator main part, each of the at least one radial protrusion of the stator having a first side and a second side, and including a rotor that is connected to the stator, the rotor having a circular rotor main part and at least one radial protrusion extending radially inwardly from the circular rotor main part, each of the at least one radial protrusion of the rotor having a first side and a second side. A pressure chamber is formed between the second side of the at least one radial protrusion of the stator and the first side of an adjacent one of the at least one radial protrusion of the rotor, and an expandable vessel being provided in the pressure chamber between the radial protrusions of the stator and the rotor with the expandable vessel having an expandable volume.

A clutch mechanism designed to be installed between an engine and a motor vehicle transmission, wherein the clutch mechanism includes at least one cooling duct arranged to make a cooling fluid circulate toward the clutch, wherein each cooling duct includes an axially extending part and at least one radially extending part, the axially extending part of each cooling duct is situated radially between a transmission shaft and an interior face of the clutch support, and at least one radially extending part of each cooling duct is situated axially between the support bearing and the output hub.

A piston assembly for a clutch pack including a piston in form of a ring-shaped plate, a stator connected to the piston, the stator having a circular stator main part and at least one radial protrusion extending radially outwardly from the circular stator main part, each of the at least one radial protrusion of the stator having a first side and a second side, and including a rotor that is connected to the stator, the rotor having a circular rotor main part and at least one radial protrusion extending radially inwardly from the circular rotor main part, each of the at least one radial protrusion of the rotor having a first side and a second side. A pressure chamber is formed between the second side of the at least one radial protrusion of the stator and the first side of an adjacent one of the at least one radial protrusion of the rotor, and an expandable vessel being provided in the pressure chamber between the radial protrusions of the stator and the rotor with the expandable vessel having an expandable volume.