A multiple disc clutch includes an axially displaceable outer disc hooked into an outer disc carrier to provide a first friction surface, and an axially displaceable inner disc hooked into an inner disc carrier to provide a second friction surface for a friction pairing with the first friction surface. The outer disc has an outer coupling element for coupling to the outer disc carrier and the inner disc has an inner coupling element for coupling to the inner disc carrier. The outer disc has an outer ring, the outer coupling element extends radially from the outer ring, and the first friction surface is connected to the outer ring by an outer leaf spring element; or the inner disc has an inner ring, the inner coupling element extends radially from the inner ring, and the second friction surface is connected to the inner ring by an inner leaf spring element.

A wet-type friction engaging device includes a first friction member and a second friction member defining a groove formed on a surface of a base facing the first friction member.

A wet friction disc includes a friction surface and a lubrication groove through which a lubricant supplied to the friction surface flows. The lubrication groove has a plurality of circumferential groove portions that extends in a circumferential direction and a plurality of intersecting groove portions that extends in directions intersecting the circumferential direction. At least one of the circumferential groove portions has a through-hole that extends through the wet friction disc between an opposite surface facing s mating member and a surface on the opposite side in an axial direction.

A wet friction disc includes a friction surface and a lubrication groove through which a lubricant supplied to the friction surface flows. The lubrication groove has a plurality of circumferential groove portions that extends in a circumferential direction and a plurality of intersecting groove portions that extends in directions intersecting the circumferential direction. At least one of the circumferential groove portions has a through-hole that extends through the wet friction disc between an opposite surface facing s mating member and a surface on the opposite side in an axial direction.

A method for producing friction discs for a, in particular radial, dual clutch, includes the following steps: providing a first disc ring with a first inner diameter, providing a second disc ring with a second outer diameter, wherein the second outer diameter is smaller than the first inner diameter, and processing the first disc ring and the second disc ring in a tool for producing the friction discs. The second disc ring is arranged within the first disc ring, and the second and the first disc rings are processed in the tool together.

Provided are a joint component formed with fine recessed portions so that degradation of the flatness of a metal base body, such as a core, to which a joint object such as a friction member is joined can be reduced, a multiplate clutch device including the joint component, and a joint component manufacturing method. At a friction plate (200) as the joint component, many fine recessed portions (204) are formed at a joint surface (203) as a portion of a core (201) joined to friction members (207). The joint surface (203) is formed in a circular ring shape along a peripheral direction of the core (201), and is formed with a flatness of equal to or less than 0.15 mm. The fine recessed portions (204) are formed at the joint surface (203) such that adjacent ones of the fine recessed portions (204) do not overlap with each other and a formation density per unit area (Ua) at the joint surface (203) is uniform. The fine recessed portions (204) are formed as laser processing marks formed at the core (201) by irradiation with laser light L.

A progressivity device for a friction clutch disc includes a support flange, having a central axis of rotation, in which an annular central part is designed to cooperate with a torsional vibration damper, and an external part bears progressivity blades and friction pads attached to the progressivity blades. The progressivity blades extend circumferentially over at least one of the faces of the support flange. The progressivity blade include one end fixed to the external part, another free end and folds delimiting a support region for the friction pad.

A progressivity device for a friction clutch disc includes a support flange, having a central axis of rotation, in which an annular central part is designed to cooperate with a torsional vibration damper, and an external part bears progressivity blades and friction pads attached to the progressivity blades. The progressivity blades extend circumferentially over at least one of the faces of the support flange. The progressivity blade include one end fixed to the external part, another free end and folds delimiting a support region for the friction pad.

A clutch plate and a clutch assembly for use in a powertrain of a vehicle, the clutch plate being configured to be connected for common rotation with a driven shaft extending in an axial direction, the clutch plate including a support member and a first friction member attached thereto, the first friction member having a first friction surface configured to face and selectively engage a corresponding second friction surface of a flywheel, the clutch plate further including an electrically conducting element extending from the first friction surface toward the support member in a direction having an axial component, the electrically conducting element being configured to be electrically connected to a terminal, so that, upon engagement of the first and second friction surfaces, an electric signal may be passed between the flywheel and the terminal via the electrically conducting element.

A clutch plate and a clutch assembly for use in a powertrain of a vehicle, the clutch plate being configured to be connected for common rotation with a driven shaft extending in an axial direction, the clutch plate including a support member and a first friction member attached thereto, the first friction member having a first friction surface configured to face and selectively engage a corresponding second friction surface of a flywheel, the clutch plate further including an electrically conducting element extending from the first friction surface toward the support member in a direction having an axial component, the electrically conducting element being configured to be electrically connected to a terminal, so that, upon engagement of the first and second friction surfaces, an electric signal may be passed between the flywheel and the terminal via the electrically conducting element.