A frictional part for a frictionally operating device includes friction lining pieces, which are spaced apart from one another to form an annular disc-like friction surface having grooves, and the friction lining pieces have the shape of triangles and pentagons. The pentagonal friction lining pieces may be provided with a radially inward or outward directed top and may be intrinsically symmetrical with respect to a radial. The pentagonal friction lining pieces may be oriented with the tops thereof alternating radially inward and radially outward. The triangular friction lining pieces may have the shape of acute-angled or right-angled triangles having one short and two longer sides. The triangular friction lining pieces may each have a longest side which is arranged radially inward or radially outward. The pentagonal friction lining pieces may each be arranged in the circumferential direction between four triangular friction lining pieces.

A friction plate includes a core plate. The core plate includes an interior core surface, an exterior core surface, a first clutch face having a first plane extending, and a second clutch face having a second plane. The friction plate also includes a friction material disposed on at least one of the first and second clutch faces. The core plate includes a plurality of projections. At least one of the projections extends away from the first and second planes with respect to the axis such that the at least one of the projections is configured to provide a spring force to the other friction plate of the clutch assembly during disengagement of the friction plate from the other friction plate, and to direct the lubricant axially away from the first clutch face along the axis during rotation of the core plate for limiting drag torque in the clutch assembly.

A friction disc has a flat carrier ring which includes a first surface and a second surface, wherein a first annular friction lining is arranged on the first surface, the first annular friction lining including a geometry that deviates from the circular ring shape, wherein the carrier ring also includes the geometry of the first friction lining, each as viewed in the axial direction, and/or the first annular friction lining including at least one opening in the axial direction, which extends in the axial direction also through the carrier ring, wherein the opening is formed to start at the inner circumference or at the outer circumference of the carrier ring.

A friction disk includes a friction disk core having an inner diameter edge, an outer diameter edge, and a first surface with multiple mortises extending radially across the first surface. The friction disk further includes a first wear liner having two wear liner segments each including a wear surface and a non-wear surface having a tenon with a complimentary shape to each of the multiple mortises, the tenon of each wear liner segment being configured to be received by a corresponding mortise of the multiple mortises to couple the wear liner segments to the friction disk core to form an annular liner.

A wet running friction lining includes a plastic matrix, which contains at least one filler. The wet running friction lining contains bentonite as a filler.

A friction disk of a braking system may include a friction disk core and a first wear liner. The friction disk core has an outer surface that defines a recess extending gradually inward from the outer surface, according to various embodiments. The wear liner mates to the outer surface of the friction disk core and includes a wear surface and a first non-wear surface, according to various embodiments. The first wear liner further includes a notch extending gradually outward from the first non-wear surface of the wear liner, according to various embodiments. In an installed state, the notch is received within the recess, according to various embodiments.

A friction disk includes a friction disk core having a first surface with multiple channels extending radially across the first surface. The friction disk may further include a first wear liner having two wear liner segments each configured to be coupled to the first surface of the friction disk core to form an annular liner and each including a wear surface, a non-wear surface, and a rib extending from the non-wear surface and configured to be received by one of the multiple channels.

A friction disk of a braking system may include a friction disk core and a first wear liner. The friction disk core has a first surface and defines a first channel extending radially across the first surface, according to various embodiments. The first wear liner is coupled to the first surface of the friction disk core and includes a first wear surface and a first non-wear surface, according to various embodiments. The first wear liner further includes a first rib protruding from and extending radially across the first non-wear surface of the first wear liner, according to various embodiments. In an installed state, the first rib is received within the first channel, according to various embodiments.

A friction engagement device of an automatic transmission is provided, which includes a rotational member comprised of at least one of a drum member and a hub member including a spline part engaged with a friction plate to be movable in axial directions of the automatic transmission, and a drive force transmitting part for exchanging a drive force with another rotational element. The drive force transmitting part of the rotational member is made of a ferrous metal. A part of the rotational member other than the drive force transmitting part is made of a clad material containing a first material that is easily joined to the ferrous metal and a second material that is less easily joined to the ferrous metal compared to the first material and weighs less than the ferrous metal.

A method of making a wet friction material layer includes joining filler particles and fibers together to form a material base; adding water based phenolic resin to the material base; and curing the water based phenolic resin.