The brake disk 110 includes a pair of opposed friction plates 206 and 208, a plurality of vanes 212 disposed between the friction plates and defining a plurality of channels 214 between the friction plates, and a plurality of ribs 216 disposed within the channels 214. The brake disk 110 further defines a center hole 218. Each of the friction plates 206 and 208 includes an outer face 220 and an inner face 210. The outer faces 220 of the friction plates 206 and 208 may also define a plurality of crescent shaped-grooves 222.
The friction plates 206 and 208 are interconnected by the plurality of vanes 212. The vanes 212 may be formed or cast as part of either friction plate 206 or 208 on the friction plate inner faces 210. The vanes 212 may instead be formed as part of both friction plates 206 and 208 or may be formed as a separate structure. The vanes 212 extend in a curved or other aerodynamic manner between the inner diameter of the brake disk 110 and the outer diameter of the brake disk 110. The vanes 212 can instead begin and terminate at any other point within the brake disk 110, and may have any other suitable configuration in accordance with other embodiments.
A plurality of the ribs 216 are disposed within each of the channels 214. The ribs 216 extend from the inner face 210 of each of the friction plates 206 and 208, between the vanes 212. The ribs 216 interconnect the vanes 212. However, the ribs 216 may also not interconnect the vanes 212. The ribs 216 are chevron or āvā shaped with the apex being disposed nearest the inner diameter brake disk 110, opposing the air flow.
The ribs 216 on the friction plate 206 are offset relative to the ribs 216 of the friction plate 208. The ribs 216 on each friction plate can also be directly across from each other. An offset of ribs 216 is generally desirable, however, to minimize the reduction in air flow through the channels 214. The spacing, placement, shape and number of the ribs 216 can be optimized for the given circumstances.
The ribs 216 may be disposed anywhere else within the channels 214 in accordance with other embodiments. The ribs 216 can be added to the vanes 212 in addition to or instead of the friction plates 206 and 208. The ribs 216 also can be formed or otherwise disposed on only one friction plate or otherwise arranged or disposed in any other suitable manner. The ribs 216 can also be individually located within the channel 214, without contacting either vane 212.
Each of the ribs 216 has a rectangular cross-section. The ratio of the height of the ribs 216 divided by the height of the vanes 212 may be roughly equal to 0.125. The ribs 216, however, may have any other suitable cross-section. For example, the cross section of the ribs 216 can be rounded, pointed, or have any other suitable cross-section. The ribs 216 can also have any suitable height. The height, width, shape, length, number, and position of the ribs 216 can be widely varied. The ribs 216 can have any other shape in accordance with other embodiments. For example, the ribs 216 can be straight, curved, convex, concave, reverse chevron etc. The ribs 216 also can have any geometric shape, including rectangular or cylindrical discrete appendages.
The ribs 216 consist of cast iron and are manufactured with a conventional method for this type of product; using a rigid sand core produced from a split corebox placed in a hard sand mould produced by a pattern. The ribs 216 are cast as a part of the friction plates 206 and 208. The ribs 216 can be made from any suitable material for these temperatures, can be formed using any manufacturing process, and can be attached via a welding process or mechanically or with an adhesive rather than being cast as part of the friction plates 206 and 208. The ribs 216 can also be cast onto or attached to the vanes 212 instead of the friction plates 206 and 208. The ribs 216 can be cast onto any structure within the channel 214. In addition, the entire brake disk 110, with friction plates 206 and 208, vanes 212, and ribs 216, can be cast as a single component using an investment casting process with a dissolvable core or other suitable casting technique.
In operation of the disk brake system 100, the vehicle wheel turns the center hub 130, which turns the brake disk 110. During braking, pistons within the caliper 112 are engaged and pads within the caliper 112 move to contact the outer faces 220 of the friction plates of the brake disk 110. The contact with the outer faces 220 of the friction plates 206 and 208 and pads causes friction as the kinetic energy of the vehicle is converted to thermal energy or heat. As a result, the brake disk 110, center hub 130, and vehicle wheel slow and the brake disk 110 becomes heated. As the brake disk 110 rotates, air is drawn into the channels 214 at the brake disk 110 inside diameter and exits at the brake disk 110 outer diameter. As the air travels within the channels 214, heat is extracted from the brake disk 110. The crescent shaped-grooves 222 may perform various functions, such as, for example, drainage of foreign material from the friction plate outer faces 220 and pads, and counter acting brake shudder or pulsing.
The ribs 216 inside the channels 214 of the brake disk 110 in accordance with the illustrated embodiment improve massflow and heat transfer coefficients by causing turbulence and high heat transfer flow features within the channels 214. This turbulence may improve aerodynamic mixing between air traveling in the center of the channel 214 and air traveling closer to the disk inner faces 210 and vanes 212, create local attachment points which increase local heat transfer coefficient, and create secondary flows of air which promote the redistribution of massflow to enhance heat transfer. The shape of ribs 216 may reduce total pressure loss.
While the above description contains many specificities, these should not be construed as limitations on the scope of the disclosure but rather as an explanation of one preferred embodiment thereof. Many other variations are possible. Accordingly the scope of the disclosure should be determined not by the embodiment illustrated but by the appended claims and their legal equivalents.
This application claims priority to Provisional Application Number 60/826185, filed Sep. 19, 2006, which is incorporated herein by reference.
Number | Date | Country | |
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60826185 | Sep 2006 | US |