# US 10,371,208 B2 · Bearing assemblies with electrodynamically matched races > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,208 B2 - Document ID: US10371208B2 - Status: Granted - Kind: B2 - Application number: 15/668,663 - Filed: 2017-08-03 - Published: 2019-02-07 - Granted: 2019-08-06 - Earliest claimed: 2017-08-03 - Assignees: Goodrich Corporation - Applicants: Goodrich Corporation - Inventors: William Edward Bialke; Eric Hansell - Web page: https://patentgrep.com/patent/US10371208B2 ## CPC - F16C 33/585: {of raceways, e.g. ribs to guide the rollers} - B23H 1/00: Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric - B23H 9/00: Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects (heat treatment by cathodic discharge C21D1/38) - F16C 19/02: with bearing balls essentially of the same size in one or more circular rows - F16C 19/06: with a single row or balls - F16C 19/22: with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings - F16C 19/26: with a single row of rollers - F16C 33/64: Special methods of manufacture - B23H 2200/10: for making bearings - F16C 2220/68: by electrical discharge or electrochemical machining - F16C 2361/55: Flywheel systems - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - B23H: WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL (processes for the electrolytic or electrophoretic production of coatings, electroforming, or apparatus therefor C25D; processes for the electrolytic removal of material from objects C25F; manufacturing printed circuits using precipitation techniques to apply the conductive material to form the desired conductive pattern H05K3/18) ## Abstract A method of electro-dynamically matching a bearing assembly includes electrically separating inner and outer races from rolling elements of the bearing assembly with lubricant and rotating the inner race relative to the outer race. A voltage differential is applied across the inner and the outer races and via isolated rolling elements and the race eroded an electrical discharge event across a gap defined between the one or more of the races and rolling elements. Electro-dynamically matched bearing assemblies and reaction/momentum flywheel arrangements for artificial satellites are also described. ## Claims ### Claim 1 A method of electro-dynamically matching a bearing assembly, comprising: electrically separating inner and outer races from rolling elements with lubricant; rotating the inner race relative to the outer race; applying a voltage differential across the inner race and the outer race; and eroding at least one of the inner race and the outer race with an electrical discharge event across a lubricant disposed between the one inner race or the outer race and a rolling element. ### Claim 2 (depends on 1) The method as recited in claim 1, further comprising mechanically matching the inner and outer races to the rolling elements prior to electrically separating the inner and outer races. ### Claim 3 (depends on 1) The method as recited in claim 1, further comprising seating one of the inner race and the outer race in a flywheel operably connected to a source of mechanical rotation. ### Claim 4 (depends on 3) The method as recited in claim 3, further comprising seating the other of the inner race and the outer race a shaft that is static relative to the flywheel. ### Claim 5 (depends on 1) The method as recited in claim 1, further comprising reducing a minimum speed to achieve elasto-hydrodynamic operation between the inner race and the rolling elements. ### Claim 6 (depends on 1) The method as recited in claim 1, further comprising reducing a minimum speed to achieve elasto-hydrodynamic operation between the outer race and the rolling elements. ### Claim 7 (depends on 1) The method as recited in claim 1, further comprising smoothing the inner race by reducing one or more mechanical asperity disposed on the inner race with an uncontrolled electrical discharge event. ### Claim 8 (depends on 1) The method as recited in claim 1, further comprising smoothing the outer race by reducing a mechanical asperity disposed on the outer race with an uncontrolled electrical discharge event. ### Claim 9 (depends on 1) The method as recited in claim 1, wherein applying the voltage differential includes applying an alternating current voltage differential across the inner race and the outer race. ### Claim 10 (depends on 1) The method as recited in claim 1, further comprising removing the voltage potential by comparison of one or more of a lubricant property, load, temperature, and rotational speed with a selected value. ### Claim 11 A bearing assembly, comprising: an inner race arranged about an axis with a radially outer race surface; a plurality of rolling elements circumferentially distributed about the outer race surface of the inner race; an outer race with a radially inner race surface extending about the inner race with the rolling elements captive therebetween, wherein at least one of the outer race surface and the inner race surface has an electro-dynamically eroded asperity bounding a lubricant EHD layer defined between the race surface and the rolling elements; and an alternating current (AC) source with a positive and a negative terminal, wherein the positive terminal is electrically connected to the negative terminal through the inner race and the outer race. ### Claim 12 (depends on 11) The bearing assembly as recited in claim 11, further comprising a lead electrically connected to the inner race. ### Claim 13 (depends on 11) The bearing assembly as recited in claim 11, further comprising a lead electrically connected to the outer race. ### Claim 14 (depends on 11) The bearing assembly as recited in claim 11, further comprising a flywheel fixed relative to one of the inner race and the outer race and a static structure connected to the other of the inner race and the outer race. ### Claim 15 (depends on 14) The bearing assembly as recited in claim 14, further comprising a mechanical rotation source operably connected to the flywheel. ### Claim 16 (depends on 11) The bearing assembly as recited in claim 11, wherein at least one of the inner race, the outer race, and the rolling elements comprises a carbide-containing metallic material. ### Claim 17 (depends on 11) The bearing assembly as recited in claim 11, further comprising a lubricant disposed between the rolling elements, the inner race, and the outer race. ### Claim 18 A reaction/momentum wheel arrangement for an artificial satellite, comprising: a flywheel; and a bearing assembly comprising: an inner race arranged about an axis with a radially outer race surface; a plurality of rolling elements circumferentially distributed about the outer race surface of the inner race; and an outer race with a radially inner race surface extending about the inner race with the rolling elements captive therebetween, wherein at least one of the outer race surface and the inner race surface has an electro-dynamically eroded asperity bounding a lubricant EHD layer defined between the race surface and the rolling elements; and a lubricant disposed between the rolling elements and the inner and outer races, wherein the rolling elements and inner and outer races include a carbide-containing metallic material, wherein a minimum lubricant-film distance between at least one of the inner and outer races and the rolling elements is defined between an electro-dynamically eroded asperity and one of the rolling elements. ### Claim 19 (depends on 18) An artificial satellite, comprising: a reaction/momentum wheel as recited in claim 18; where the flywheel is fixed relative to one of the inner race and the outer race and a static structure connected to the other of the inner race and the outer race; and a mechanical rotation source operably connected to the flywheel.