Abstract: The invention relates to a brake rotor having improved damping characteristics and a method for producing the same. A surface of the brake rotor is EDG machined, also known as EDM machined, for improving the damping characteristics of the rotor. The decay rate of the brake rotor is increased and the Q factor of the brake rotor is reduced. The portion of the brake rotor which is EDG machined is formed of an electrically conductive material, preferably a ferrous material, more preferably a cast iron material, a gray iron material or a damped iron material. The brake rotor may include a solid friction section or a ventilated friction section. The brake rotor is preferably cast from a single material, although alternatively, it may be a composite rotor formed of more than one material.

Abstract: A method of increasing the length, thickness, and density of graphite flakes in a brake rotor includes forming a brake rotor of gray iron, cast iron, or damped iron. The method further includes EDG machining a surface of the brake rotor.

Abstract: This invention relates to an improved apparatus and method for finish machining brake components. The apparatus includes an electrode ring adapted to be secured to a rotatable shaft. The electrode ring includes at least one plurality of circumferentially spaced apart electrodes adapted to be electrically connected to a power supply. Each one of the at least one plurality of electrodes are arranged adjacent each other around the circumference of the electrode ring. The apparatus further includes a positioning mechanism for positioning a rotating, electrically grounded rotor adjacent the electrode ring until sparks are formed between the electrode ring and the rotor. The sparks vaporize a portion of the rotor surface thereby creating a finished surface on the rotor having the desired dimensions.

Abstract: The invention is a brake rotor. The rotor includes a radially inner mounting section with a central mounting face for attaching the rotor to a wheeled vehicle. The mounting face has a plurality of fastener apertures and a central aperture. A hat wall extends axially from the periphery of the mounting face. The rotor also includes a radially outer annular friction section. The friction section has a pair of opposite friction surfaces machined to predetermined dimensions. Each machined friction surface is non-directional in that it does not include directional indentations. The non-directional friction surfaces include non-directional indentations such as dimples or pits.

Abstract: This invention relates to an improved apparatus and method for finish machining brake components. The apparatus includes an electrode ring adapted to be secured to a rotatable shaft. The electrode ring includes at least one plurality of circumferentially spaced apart electrodes adapted to be electrically connected to a power supply. Each one of the at least one plurality of electrodes are arranged adjacent each other around the circumference of the electrode ring. The apparatus further includes a positioning mechanism for positioning a rotating, electrically grounded rotor adjacent the electrode ring until sparks are formed between the electrode ring and the rotor. The sparks vaporize a portion of the rotor surface thereby creating a finished surface on the rotor having the desired dimensions.

Abstract: This invention relates to an improved method for producing aluminum MMC rotors. The method comprises the steps of initially casting an aluminum MMC rotor casting having a central pilot aperture, cold forming the friction section, cold forming the mounting section, punching the central pilot aperture to remove excess aluminum MMC material, and then forming fastener apertures in the mounting section. In the step of cold forming the friction section a plurality of cylindrical rollers are pressed against each side of the friction section and the rollers are moved in a circumferential direction around the friction section to finish the friction section to the desired dimensions. In the step of cold forming the mounting section a plurality of cylindrical rollers are pressed against each side of the mounting section and the rollers are moved in a circumferential direction around the mounting section to finish the mounting section to the desired dimensions.

Abstract: The noise created by a vehicle rotor is reduced by adjusting the natural or resonant frequency at which the rotor tends to vibrate. The resonant frequency is moved away from the frequencies of excitation of such sources as the brake pads and vehicle drive train components. The resonant frequency of the rotor is adjusted by manipulating the geometry and mass of the rotor by adjusting the number, size, shape, spacing and location of cooling vents formed in the hat section of the rotor. The resulting rotor exhibits improved vibrational control.

Abstract: A vented rotor for caliper disc brakes and the like includes an outer friction portion having two ring sections with a plurality of radially extending ribs extending therebetween. The ribs include support ribs extending from the hat wall, and secondary ribs space radially from the hat wall. The support ribs and secondary ribs fixedly interconnect the ring sections in a mutually parallel, spaced apart relationship in such a manner that the inner diameter of each the ring section is spaced apart from the hat wall. Vents are formed between the support ribs and secondary ribs. The vents have a constant cross sectional area along their length to enhance the airflow therethrough. As a result, cooling air is permitted to flow into the vents between the inboard and the outboard ring sections from both the inboard and outboard sides of the outer friction portion of the rotor, providing enhanced overall air flow past the ring sections.

Abstract: The invention relates to an air flow test apparatus for determining the amount of air moving through vents in a turning ventilated rotor. The air flow test apparatus includes an elongated cylindrical shaft journalled for rotation in spaced apart bearing blocks mounted in a frame. A conventional belt drive couples the shaft to a variable speed motor for rotation. An adapter is mounted to the shaft and a work piece is mounted to the adapter end for rotation with the shaft. The work piece includes a hub secured to the adapter for receiving a plurality of different sized rotors, and a ventilated rotor mounted to the hub. The work piece may also include other vehicle components such as the caliper, a wheel, even an entire corner portion of a vehicle for simulation purposes. A pressure gauge is disposed adjacent the rotor, near the vents, to measure the air pressure near the turning rotor.

Abstract: A composite brake drum for a motor vehicle or the like is comprised of a cast metal drum section, a stamped steel drum back, and a cast metal mounting face. The drum section and mounting face are preferably formed of cast iron. The composite drum of the invention provides a reduction in weight and in the amount of machining required as compared with a full cast brake drum. At the same time, the composite brake drum of the invention permits an increase in the thickness of the mounting face as compared with conventional composite brake drums, allowing motor vehicle manufacturers to use the same hubs and keep the vehicle track the same regardless of whether a particular vehicle includes a disc/drum or a disc/disc brake system.

Abstract: The invention is directed to a rotor having a vented hat section and a method of forming the same. Such a rotor includes a hat section having a central mounting face and a cylindrical shoulder or hat wall extending axially from the mounting face to an annular peripheral section having friction surfaces disposed on opposite sides. A plurality of spaced apart vents are defined in the wall of the hat section. The vented rotor is formed by first casting a rotor to the desired configuration including at least the hat section. The initial casting is formed in such a manner that one or more depressions are provided in the radially inner surface of the wall of the hat section. These depressions do not extend through the wall of the hat section. Then, material is removed in one or more machining steps from the radially outer surface of the wall of the hat section proximate the depressions.

Abstract: The invention is directed to a method of forming a vented rotor for caliper disc brakes and the like. Such a vented rotor includes an outer friction portion having one or more ring sections with opposed friction surfaces adapted to interface with associated friction members. The vented rotor is formed by first casting a rotor to the desired configuration including at least the ring section. This initial casting is formed in such a manner that one or more depressions are provided a surface of the ring section. Then, material is removed in one or more machining steps from portions of the friction surface opposite the friction surface having the depressions, to the point that the depressions extend completely through the ring section to form the vents.