A brake disk or drum has at least one working surface which opposes a braking member such as a brake pad or shoe. A plurality of spaced, raised island formations are provided across the working surface, with channels extending between the island formations. Each raised island formation has an outer surface which contacts a brake pad or brake shoe during braking.

In some implementations of the current subject matter, a brake rotor can include a supporting layer applied to a friction surface of a brake rotor substrate, which can optionally include cast iron, and a coating applied over the supporting layer. The supporting layer can include a preparatory metal, and the coating can impart wear and corrosion resistant properties to the friction surface. Related systems, methods, articles of manufacture, and the like are disclosed.

Provided are a wet friction plate and a wet multiplate clutch device capable of reduction drag torque while suppressing a decrease in the area of a friction member. The wet friction plate includes multiple friction members through oil grooves on a flat plate annular core metal. The friction member has first fine grooves opening at an inner peripheral edge of the friction member and extending to an outer peripheral edge side and second fine grooves opening at an outer peripheral edge of the friction member and extending to an inner peripheral edge side. The first fine groove and the second fine groove are formed to have a groove width of equal to or greater than 0.1 mm and equal to or less than 0.8 mm, and overlap portions overlapping with each other in a circumferential direction at the same position in a radial direction of the core metal.

A brake disk with a friction ring or to a friction ring, which comprises a PMMC (particle metal matrix composite), at least in the region of its friction surface. The friction surface of the friction ring is provided with mechanically applied microgrooves, which extend in a radial direction with respect to a circumferential direction of rotation of the friction ring, non-tangentially angled thereto.

A brake pad includes a backing plate that defines a first plane. A brake lining is attached to the backing plate, and has a first layer, a second layer and a third layer. The first layer includes a first material, a first side fixed to the brake lining attachment surface and a second side opposite the first side. The second side defines a second plane non-parallel to the first plane. The second layer includes a second material, a first side and a second side. The first side of the second layer extends along the second side of the first layer and along the second plane. The second material is different from the first material. The third layer includes the first material, overlays and attaches to the second side of the second layer, and has a friction surface that is parallel to the first plane.

There is provided a method for producing a wet friction plate that can improve the retention property of lubricating oils in a fine groove formed by laser light. In a method for producing a wet friction plate (200), a friction material (210) is produced by sheet making processing in a first step. Thereafter, in a second step, a fine groove (211) is formed on the friction material (210). The friction material (210) is produced such that thermosetting resin therein is in a semi-cured state. The cross-sectional shape of the fine groove (211) is formed into a V shape by laser light. Subsequently, in a third step, the friction material (210) is disposed on a core metal (201) via an adhesive agent including thermosetting resin. Subsequently, in a fourth step, the friction material (210) is pressed while heated to crush the fine groove (211). In this manner, unevenness is formed on an intra-groove surface (212), and the thermosetting resin is completely cured.

A brake rotor for a vehicle that includes an easy to view accurate visual inspection system. The brake rotor includes at least one annular disk including inboard and outboard planar brake contact surfaces and at least two visual wear indicators formed as circular depressions in at least the outboard brake contact surface within the outer brake contact region. These visual wear indicators include a first wear indicator that has a depth that corresponds to a predetermined minimum useable thickness of the outboard planar brake contact surface and a second wear indicator that has a depth that corresponds to an intermediate useable thickness of the outboard planar brake contact surface. Thus, the difference in wear from the elimination of the second wear indicator compared to the first provides an indication of the remaining acceptable service life of the rotor.

A wet friction disk that can achieve a further reduction in the drag torque, which includes a ring-shaped core plate having a wave shape in a circumferential direction thereof, a friction member disposed on a principal surface of the core plate so as to being substantially shaped into a ring with a plurality of oil grooves, and the oil grooves each have a shape with a groove width that is narrowed from an inner circumference side toward an outer circumference side of the core plate.

Problem—To provide a friction plate with reduced drag torque.

Solution—The friction plate is formed with oil grooves having the sectorial shapes spreading toward the inner circumference and the perimeter. The adjacent edges of the friction material segments are provided with the perimeter side vertex and the inner circumference side vertex respectively. The sectorial oil groove opening toward the perimeter side from the inner circumferential side vertexes can discharge a lube oil to the perimeter side efficiently by a centrifugal force. Also, owing to the sectorial oil groove opening toward the inner circumference side from the perimeter side vertexes, a lube oil can be made to run aground onto the friction material segments due to a centrifugal force, thus, reducing the drag torque markedly compared with the conventional plates.

The invention is aimed at solving issues of pad suction and drag torque, which occur during driving in disk brake systems. The invention relates to a brake disk for a disk brake system, having at least one friction surface, which is at least sectionally delimited by at least one protrusion, protruding from the at least one friction surface, at an outer circumferential side and/or at an inner circumferential side of the at least one friction surface. The invention also relates to a brake system having a brake disk of this type.