# US 11,112,348 B2 · Wear sensors for monitoring seal wear in bearing arrangements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,348 B2 - Document ID: US11112348B2 - Status: Granted - Kind: B2 - Application number: 16/365,031 - Filed: 2019-03-26 - Published: 2020-10-01 - Granted: 2021-09-07 - Earliest claimed: 2019-03-26 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: James S. Elder - Web page: https://patentgrep.com/patent/US11112348B2 ## CPC - F16C 41/002: {Conductive elements, e.g. to prevent static electricity} - G01N 17/00: Investigating resistance of materials to the weather, to corrosion, or to light - F16C 17/246: {related to wear, e.g. sensors for measuring wear} - F16C 19/52: with devices affected by abnormal or undesired conditions - F16C 33/72: Sealings - F16J 15/3492: {with monitoring or measuring means associated with the seal} - F16C 33/664: {Retaining the liquid in or near the bearing} - F16C 33/76: of ball or roller bearings - F16C 2233/00: Monitoring condition, e.g. temperature, load, vibration - F16C 2360/23: Gas turbine engines - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS ## Abstract A sensor assembly includes a wear sensor and a seal member. The wear sensor has an encapsulation body with a wear face, a sacrificial conductor embedded within the encapsulation body and spaced apart from the wear face, and a monitoring lead extending into the encapsulation body and connected to the sacrificial conductor. The wear sensor is fixed relative to the seal member and the encapsulation body has a wear coefficient that is greater than a wear coefficient of the seal member. Bearing arrangements and methods of monitoring seal wear in bearing arrangements are also described. ## Claims ### Claim 1 A bearing arrangement, comprising: a bearing compartment housing a bearing assembly; a seal assembly configured to impound a lubricant within the bearing compartment, the seal assembly comprising: a first seal member having a first seal member contact face; a second seal member having a second seal member contact face, wherein, in operation, the second seal member contact face is fixed relative to an inner race of the bearing assembly; seal member biasing means that bias the first seal member contact face into frictional engagement with the second seal member contact face to impound the lubricant within the bearing compartment; a wear sensor fixed relative to the first seal member having: an encapsulation body with a wear face, wherein the encapsulation body has a wear coefficient greater than a wear coefficient of the first seal member; a sacrificial conductor embedded within the encapsulation body and spaced apart from the wear face; and a monitoring lead extending into the encapsulation body and connected to the sacrificial conductor; and a resistance meter in electrical communication with the sacrificial conductor, wherein the resistance meter comprises a processor in communication with a non-transitory machine readable medium with instructions recorded on it that, when read by the processor, cause the processor to: apply a voltage to the sacrificial conductor; measure an electrical parameter of the sacrificial conductor; and provide an indication of seal wear when the measurement of the electrical parameter indicates that the sacrificial conductor is electrically discontinuous. ### Claim 2 (depends on 1) The bearing arrangement of claim 1, wherein the encapsulation body is formed from a polymeric material. ### Claim 3 (depends on 1) The bearing arrangement of claim 1, wherein the sacrificial conductor is electrically insulated by the encapsulation body. ### Claim 4 (depends on 1) The bearing arrangement of claim 1, wherein the sacrificial conductor is electrically continuous within the encapsulation body. ### Claim 5 (depends on 1) The bearing arrangement of claim 1, wherein the sacrificial conductor is electrically discontinuous within the encapsulation body. ### Claim 6 (depends on 1) The bearing arrangement of claim 1, wherein the sacrificial conductor comprises a wire loop with a monitoring end and a wear face end, the wear face end of the wire loop arranged between the wear face of the encapsulation body and the monitoring end of wire loop. ### Claim 7 (depends on 1) The bearing arrangement of claim 1, wherein the sacrificial conductor is a first sacrificial conductor and further comprising a second sacrificial conductor, the second sacrificial conductor connected to the first sacrificial conductor. ### Claim 8 (depends on 7) The bearing arrangement of claim 7, wherein the second sacrificial conductor is connected electrically in series with the first sacrificial conductor. ### Claim 9 (depends on 7) The bearing arrangement of claim 7, wherein the second sacrificial conductor is connected electrically in parallel with the first sacrificial conductor. ### Claim 10 (depends on 1) The bearing arrangement of claim 1, wherein the instructions cause the resistance meter to measure seal wear based on at least two stepwise changes in the electrical parameter. ### Claim 11 (depends on 1) The bearing arrangement of claim 1, wherein the electrical parameter is one of electrical resistance and current flow. ### Claim 12 (depends on 1) The bearing arrangement as recited in claim 1, wherein the bearing assembly comprises: the inner race, wherein the inner race is arranged along a rotation axis; an outer race extending about the inner race; and a plurality of roller elements distributed about the rotation axis and between the inner race and the outer race, wherein the first seal member is fixed in rotation relative to the outer race. ### Claim 13 (depends on 1) The bearing arrangement as recited in claim 1, further comprising a shaft supported for rotation by the bearing assembly, wherein the first seal member comprises a carbon material, wherein the second seal member comprises a steel material, wherein the shaft is low pressure shaft or a high pressure shaft of a gas turbine engine.