A brake disc according to one embodiment includes a first disc, a second disc apart from the first disc in an axial direction, and a plurality of pins disposed at intersections of three types of virtual lines and whose one ends are connected to a side of the first disc facing the second disc. The three types of virtual lines are a plurality of virtual circles concentric with the first disc, a plurality of first virtual spiral patterns passing through the center of the first disc and curved rightward when viewed from the axial direction, and a plurality of second virtual spiral patterns passing through the center of the first disc and curved leftward when viewed from the axial direction. In one embodiment, the intersections are arranged symmetrically with respect to an imaginary line connecting any one of the intersections and the center when viewed from the axial direction.

A disc has a braking band, a bell and elastic elements. The braking band has a plurality of radial teeth projecting from a radially internal edge portion, delimiting a plurality of band seats. Each radial tooth has a radially internal edge surface, a first and a second axial tooth side, and at least one circumferential side. A plurality of axial teeth project delimiting a plurality of bell seats. The plurality of radial teeth is housed in the plurality of bell seats. The internal bell surface is aligned with the radially internal edge surface of each radial tooth. Each elastic element is removably connected to the axial teeth and embraces a portion of first and second axial tooth sides and of circumferential side of the radial teeth of the braking band, elastically preloading the radial teeth with respect to the bell.

A friction pad including a friction pad body including an annular base defining an aperture down a central axis, and first and second opposing major surfaces, where the friction pad body includes a low friction material, and where at least one of the major surfaces includes a plurality of grooves adapted to retain lubricant.

A ventilated type brake disc rotor includes: a pair of sliding plates shaped annular and disposed opposite to each other in an axle direction; and joints formed to connect between the sliding plates and arranged along lines extending in a circumferential direction of the sliding plates. The joints include first joints arranged along a first line and second joints arranged along a second line located in an outer side with respect to the first line in a radial direction of the sliding plates. Each of the second joints includes a first width part and a second width part formed in an inner side with respect to the first width part in the radial direction. The second width part is less in circumferential width than the first width part, and is shaped to decrease in circumferential width as going inwardly in the radial direction.

In one aspect of the present disclosure, a disc brake rotor assembly is provided that includes a disc brake rotor and a wheel hub. One of the disc brake rotor and the wheel hub includes a plurality of pairs of partial keyways and the other of the disc brake rotor and the wheel hub includes intermediate partial keyways configured to fit intermediate the pairs of partial keyways to form keyways. The disc brake rotor assembly further includes a plurality of fasteners configured to be received in the keyways to secure the disc brake rotor and the wheel hub together.

A friction part for a frictionally operating device includes a friction lining carrier and a friction lining. The friction lining includes friction lining pieces arranged in two rows to form an annular friction surface. The friction surface has an inner edge, an outer edge, and a groove set. The groove set has a first stem groove between the inner edge and a first branching point, a first branch groove between the first branching point and a first connecting point, a second branch groove between the first branching point and a second connecting point, a third branch groove between a second branching point and the second connecting point, and a second stem groove between the second connecting point and the outer edge. The first stem groove, and first and second branch grooves form a y shape. The second stem groove, and second and third branch grooves form an inverted y shape.

A friction part for a frictionally operating device includes a friction lining carrier and a friction lining. The friction lining includes pentagonal friction lining pieces arranged on the friction lining carrier to form an annular friction surface. Each of the pentagonal friction lining pieces has a two-dimensional shape made up of a rectangle and an isosceles triangle, and a base coinciding with a relatively long side of the rectangle. A radially inner row includes pentagonal friction lining pieces with a same first shape, a same first size, and a same first tip directed radially outward, and a radially outer row includes pentagonal friction lining pieces with a same second shape, a same second size, and a same second tip directed radially inward. The annular friction surface has an inner edge, an outer edge, and a groove set formed between the pentagonal friction lining pieces.

A brake disk (1) has a brake disk chamber (2), a friction ring (3) having two friction ring disks (3a, 3b) and a plurality of pin-shaped connecting elements (4) for connecting the brake disk chamber (2) and the friction ring (3). A cooling duct (5) is formed between the fiction ring disks (3a, 3b). The friction ring disks (3a, 3b) have respective friction surfaces (3a1, 3b1) on their outer planar surfaces and respective cooling channel surfaces (3a2, 3b2) on their inner planar surfaces. The friction ring (3) has a plurality of receiving regions (7) for receiving the pin-shaped connecting elements (4). The brake disk chamber (2) is cast to the connecting elements (4) in a separate step by means of casting. A gap (8) existing between the brake disk chamber (2) and the friction ring (3) has such a width (A) which results from the fact that, during casting of the brake disk chamber (2), at least one section (3d) of a lateral surface (3c) of the inner diameter of the friction ring (3) which is closed in itself in the circumferential direction is used as part of a casting mold (9). An axial extension of that part of the receiving area (7) of the friction ring (3) which extends from the cooling channel surface (3a2) in the direction of the cooling channel (5) is 2-10 mm, preferably 4-7.5 mm, even more preferably 5.5 mm.

A friction disk may comprise a first wear surface formed from a carbon fiber-carbon matrix composite material. A wear plug may be located in an opening defined by the carbon fiber-carbon matrix composite material. The wear plug may extend axially from the wear surface. The wear plug may comprise a rod or a particulate.

Provided is a brake disc having excellent cracking resistance. A brake disc 1 according to an aspect of the present invention comprises a plurality of drain recesses 3, each formed in an area against which a brake pad is abutted, wherein the angle of a shoulder portion 31 formed by a friction surface against which the brake pad is abutted and an inner peripheral surface of an opening of the drain recess 3 is an obtuse angle.