# US 11,441,625 B1 · Periodic-wave disc brake rotor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,625 B1 - Document ID: US11441625B1 - Status: Granted - Kind: B1 - Application number: 16/904,224 - Filed: 2020-06-17 - Granted: 2022-09-13 - Earliest claimed: 2020-06-17 - Assignees: United States of America as represented by the Administrator of NASA - Applicants: United States of America as represented by the Administrator of NASA - Inventors: Jonathan A. Lee - Web page: https://patentgrep.com/patent/US11441625B1 ## CPC - F16D 65/128: {characterised by means for cooling} - B60T 5/00: Vehicle modifications to facilitate cooling of brakes - F16D 65/127: {characterised by properties of the disc surface; Discs lined with friction material} - F16D 65/847: with open cooling system, e.g. cooled by air - F16D 2065/1304: {Structure} - F16D 2065/1332: {external ribs, e.g. for cooling or reinforcement} - F16D 2065/1372: {outer circumference} - F16D 2065/1376: {inner circumference} - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES ## Abstract A disc brake rotor includes an annular portion having a first surface and a second surface in opposition to the first surface. The first surface and second surface traverse a periodic wave. An inner radial edge of the annular portion traverses an inner periodic wave and an outer radial edge of the annular portion traverses an outer periodic wave. A pattern and a period are the same for the periodic wave, the inner periodic wave, and the outer periodic wave. Thermal radiation elements are coupled to portions of at least one of the inner radial edge and the outer radial edge. ## Claims ### Claim 1 A disc brake rotor, comprising: an annular portion having a first surface and a second surface in opposition to said first surface, said annular portion having an axial thickness T between said first surface and said second surface, said first surface and said second surface traversing a periodic wave wherein an inner radial edge of said annular portion traverses an inner periodic wave and an outer radial edge of said annular portion traverses an outer periodic wave, and wherein a pattern and a period are the same for said periodic wave, said inner periodic wave, and said outer periodic wave; and thermal radiation elements coupled to said inner radial edge between adjacent crests of said inner periodic wave and coupled to said outer radial edge between adjacent crests of said outer periodic wave. ### Claim 2 (depends on 1) A disc brake rotor as in claim 1, further comprising: first dimples in said first surface; second dimples in said second surface; and each of said first dimples being aligned with a corresponding one of said second dimples wherein a lamina is defined there between. ### Claim 3 (depends on 2) A disc brake rotor as in claim 2, wherein said first dimples and said second dimples comprise circular dimples. ### Claim 4 (depends on 3) A disc brake rotor as in claim 3, wherein said circular dimples have a diameter D and a depth d, wherein said lamina has an axial thickness m at said depth d, wherein a ratio of D/d is in a range of 2 to 20, and wherein a ratio of m/T is in a range of 0.1 to 0.3. ### Claim 5 (depends on 2) A disc brake rotor as in claim 2, wherein said first dimples and said second dimples comprise elongated dimples. ### Claim 6 (depends on 5) A disc brake rotor as in claim 5, wherein said elongated dimples have a width W and a depth d, wherein said lamina has an axial thickness m at said depth d, wherein a ratio of W/d is in a range of 2 to 20, and wherein a ratio of m/T is in a range of 0.1 to 0.3. ### Claim 7 (depends on 1) A disc brake rotor as in claim 1, wherein at least one of said first surface and said second surface includes dimples. ### Claim 8 (depends on 7) A disc brake rotor as in claim 7, further comprising a material coating surfaces of said dimples wherein said material has a thermal emissivity value in a range of 0.30 to 0.99. ### Claim 9 (depends on 1) A disc brake rotor as in claim 1, wherein said thermal radiation elements have an axial thickness t, and wherein a ratio of t/T is in a range of 0.1 to 0.3. ### Claim 10 A disc brake rotor, comprising: an annular portion having a first surface and a second surface in opposition to said first surface, said annular portion having an axial thickness T between said first surface and said second surface, said first surface and said second surface traversing a periodic wave wherein an inner radial edge of said annular portion traverses an inner periodic wave and an outer radial edge of said annular portion traverses an outer periodic wave, and wherein a pattern and a period are the same for said periodic wave, said inner periodic wave, and said outer periodic wave; thermal radiation elements coupled to said inner radial edge between adjacent crests of said inner periodic wave and coupled to said outer radial edge between adjacent crests of said outer periodic wave, said thermal radiation elements having an axial thickness t, and wherein a ratio of t/T is in a range of 0.1 to 0.3; and at least one of said first surface and said second surface includes dimples. ### Claim 11 (depends on 10) A disc brake rotor as in claim 10, wherein said dimples comprise: first dimples in said first surface; second dimples in said second surface; and each of said first dimples being aligned with a corresponding one of said second dimples wherein a lamina is defined there between. ### Claim 12 (depends on 11) A disc brake rotor as in claim 11, wherein said first dimples and said second dimples comprise circular dimples. ### Claim 13 (depends on 12) A disc brake rotor as in claim 12, wherein said circular dimples have a diameter D and a depth d, wherein said lamina has an axial thickness m at said depth d, wherein a ratio of W/d is in a range of 2 to 20, and wherein a ratio of m/T is in a range of 0.1 to 0.3. ### Claim 14 (depends on 11) A disc brake rotor as in claim 11, wherein said first dimples and said second dimples comprise elongated dimples. ### Claim 15 (depends on 14) A disc brake rotor as in claim 14, wherein said elongated dimples have a width W and a depth d, wherein said lamina has an axial thickness m at said depth d, wherein a ratio of D/d is in a range of 2 to 20, and wherein a ratio of m/T is in a range of 0.1 to 0.3. ### Claim 16 (depends on 11) A disc brake rotor as in claim 11, further comprising a material coating surfaces of said dimples wherein said material has a thermal emissivity value in a range of 0.30 to 0.99.