The present invention relates to a metal matrix composite (MMC). The MMC includes a preform formed from a composition having ceramic particles and ceramic fibers and defining a plurality of voids. The metal matrix composite also includes a support element, such as a metal, disposed within the voids of the preform. The MMC has a wear surface defined by both the preform and the support element.

The present invention discloses a brake drum comprising: a brake drum body, which comprises a mounting portion for connecting a wheel, a braking portion for engagement with a brake shoe, and a transitional connecting portion disposed between the mounting portion and the braking portion; a hoop device is tightly mounted to the outer peripheral surface of the brake portion. The hoop device adopts a plurality of split-type hoop ferrules, or one unibody hollowed-out hoop case. The hoop device tightly mounted to the outer peripheral surface of the brake portion can not only effectively restrain the radial expansion deformation, thereby improving the fatigue resistance of the brake drum body, but also applies a clasp force to the brake drum body, thereby avoiding the danger of burst and flying out of the brake drum body, which greatly improves service life and safety. Moreover, the thickness of the brake portion wall corresponding to the hoop device can be effectively reduced, which not only effectively decreases the temperature difference between the interior and exterior of the brake drum body, but also increases heat conductivity, thereby laying foundation for both heat dissipation and prevention of the happening of the multiple cracks in the inner wall of the brake drum body.

The present invention discloses a brake drum comprising: a brake drum body, which comprises a mounting portion for connecting a wheel, a braking portion for engagement with a brake shoe, and a transitional connecting portion disposed between the mounting portion and the braking portion; a hoop device is tightly mounted to the outer peripheral surface of the brake portion. The hoop device adopts a plurality of split-type hoop ferrules, or one unibody hollowed-out hoop case. The hoop device tightly mounted to the outer peripheral surface of the brake portion can not only effectively restrain the radial expansion deformation, thereby improving the fatigue resistance of the brake drum body, but also applies a clasp force to the brake drum body, thereby avoiding the danger of burst and flying out of the brake drum body, which greatly improves service life and safety. Moreover, the thickness of the brake portion wall corresponding to the hoop device can be effectively reduced, which not only effectively decreases the temperature difference between the interior and exterior of the brake drum body, but also increases heat conductivity, thereby laying foundation for both heat dissipation and prevention of the happening of the multiple cracks in the inner wall of the brake drum body.

A speed limited wheel includes a wheel main body defining a cavity, a urethane wheel outer overmolded to the cavity, a brake hub and a plurality of brake elements. The brake hub is disposed in the cavity and includes a cylindrical flange. The wheel main body is rotatable relative to the brake hub about a wheel rotational axis. The plurality of brake elements is disposed in the cavity and is circumferentially surrounded by the cylindrical flange of the brake hub. Each brake element is pivotally mounted to the wheel main body for pivoting between a first position spaced apart from a cylindrical flange of the brake hub and a second position engaging the cylindrical flange of the brake hub for generating friction to reduce a rotational speed of the wheel. The speed limited wheel may be a caster.

A speed limited wheel includes a wheel main body defining a cavity, a urethane wheel outer overmolded to the cavity, a brake hub and a plurality of brake elements. The brake hub is disposed in the cavity and includes a cylindrical flange. The wheel main body is rotatable relative to the brake hub about a wheel rotational axis. The plurality of brake elements is disposed in the cavity and is circumferentially surrounded by the cylindrical flange of the brake hub. Each brake element is pivotally mounted to the wheel main body for pivoting between a first position spaced apart from a cylindrical flange of the brake hub and a second position engaging the cylindrical flange of the brake hub for generating friction to reduce a rotational speed of the wheel. The speed limited wheel may be a caster.

An exemplary method for making a metal matrix composite vehicle component includes: using a mold including male and female die portions having mold surfaces and a plurality of spacers; heating the mold to a casting temperature; placing a ceramic preform on the plurality of spacers, the ceramic preform being spaced apart from at least one of the mold surfaces by the spacers; closing the mold to form a mold cavity between the mold surfaces of the male and female die portions, the ceramic preform being disposed within the mold cavity; providing molten metal into the mold cavity; and pressurizing the molten metal to a casting pressure for a casting duration to infiltrate the ceramic preform thereby forming the metal matrix composite vehicle component.

An exemplary method for making a metal matrix composite vehicle component includes: using a mold including male and female die portions having mold surfaces and a plurality of spacers; heating the mold to a casting temperature; placing a ceramic preform on the plurality of spacers, the ceramic preform being spaced apart from at least one of the mold surfaces by the spacers; closing the mold to form a mold cavity between the mold surfaces of the male and female die portions, the ceramic preform being disposed within the mold cavity; providing molten metal into the mold cavity; and pressurizing the molten metal to a casting pressure for a casting duration to infiltrate the ceramic preform thereby forming the metal matrix composite vehicle component.

A ferritically nitrocarburized rotational member of a vehicle brake is disclosed, including a rotational member having a friction surface configured for braking engagement with a corresponding friction material. A compound zone is disposed at the friction surface. An exposed surface of the compound zone is exposed to an atmosphere. The area of the exposed surface includes from about 0 percent to about 14 percent graphite.

A ferritically nitrocarburized rotational member of a vehicle brake is disclosed, including a rotational member having a friction surface configured for braking engagement with a corresponding friction material. A compound zone is disposed at the friction surface. An exposed surface of the compound zone is exposed to an atmosphere. The area of the exposed surface includes from about 0 percent to about 14 percent graphite.

The floating brake drum and hat assembly includes a brake drum (12) having a braking surface (14) and an attachment flange (16), a hat (18) having an outer diameter (20) and a brake drum mounting flange (22) for mounting to the attachment flange (16) of the brake drum, and means for coupling (24) the attachment flange of the brake drum to the brake drum mounting flange of the hat, the means for coupling structured and arranged to allow radial thermal expansion and contraction of at least a portion of the attachment flange of the brake drum and/or at least a portion of the brake drum mounting flange of the hat.