# US 10,865,653 B2 · Magnetic seal system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,653 B2 - Document ID: US10865653B2 - Status: Granted - Kind: B2 - Application number: 15/074,082 - Filed: 2016-03-18 - Published: 2017-09-21 - Granted: 2020-12-15 - Earliest claimed: 2016-03-18 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Julien De La Bruere Terreault; Dany Blais - Web page: https://patentgrep.com/patent/US10865653B2 ## CPC - F01D 11/005: {Sealing means between non relatively rotating elements} - F16J 15/3444: {by magnetic attraction} - F01D 11/003: {by packing rings; Mechanical seals} - F01D 25/183: {Sealing means} - F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) - F02C 7/28: Arrangement of seals - F16J 15/54: Other sealings for rotating shafts - F05D 2220/32: in gas turbines - F05D 2240/55: Seals - F05D 2240/60: Shafts - F05D 2260/30: Retaining components in desired mutual position - F05D 2260/32: by means of magnetic or electromagnetic forces - F05D 2260/38: by a spring, i.e. spring loaded or biased towards a certain position - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A magnetic seal system adapted for use between a support structure and a rotatable shaft. The seal system includes a rotating annular seal assembly surrounding the shaft and rotating therewith, which includes an annular seal, and a non-rotating biasing assembly sealingly mounted to the support structure around the shaft and axially engaging the annular seal assembly. The biasing assembly includes an annular magnet unit axially displaceable relative to the shaft and supported surrounding the shaft. The annular magnet unit exerting an attracting force on the annular seal assembly to biasingly displace the annular magnet unit towards the annular seal. A bias member unit is also provided for non-magnetically biasing the annular magnet unit axially relative to the shaft towards the annular seal. Adjacent contacting surfaces between the annular seal and the annular magnet unit biasingly contact one another to form a sealing interface therebetween. ## Claims ### Claim 1 A magnetic seal system adapted for use between a support structure and a rotatable shaft, the seal system comprising: a rotating annular seal assembly configured to be surrounding the shaft to rotate therewith, the annular seal assembly including an annular seal, the annular seal being made from a wearable material gradually wearing off from rubbing contact with another component; and a non-rotating biasing assembly configured to be sealingly mounted to the support structure around the shaft and axially engaging the annular seal assembly, the biasing assembly including: an annular magnet unit configured to be axially displaceable relative to the shaft and to be supported surrounding the shaft, the annular magnet unit exerting an attracting force on the annular seal assembly to biasingly displace the annular magnet unit towards the annular seal for rubbing contact during rotation of the rotating annular seal assembly, and a bias member unit non-magnetically biasing the annular magnet unit axially relative to the shaft towards the annular seal, wherein adjacent contacting surfaces between the annular seal and the annular magnet unit biasingly contact one another to form a sealing interface therebetween in which the wearing off of the annular seal during rotation of the rotating annular seal assembly conforms the contacting surface of the seal to the contacting surface of the annular magnet unit. ### Claim 2 (depends on 1) The magnetic seal system as defined in claim 1, wherein the annular magnet unit includes a carrier defining a seat for receiving at least one magnet and cooperating with the bias member unit for biasing the annular magnet unit. ### Claim 3 (depends on 1) The magnetic seal system as defined in claim 1, wherein the biasing assembly further comprising an annular housing configured to be mounted to the support structure in a non-contacting relationship around the shaft and defining an annular space for receiving the annular magnet unit, the annular magnet unit axially displaceable within the annular space and the bias member unit mountable to the annular housing. ### Claim 4 (depends on 3) The magnetic seal system as defined in claim 3, wherein the annular housing includes a slot on a radial surface of the annular space receiving a protrusion of the annular magnet unit and blocking relative rotation between the annular magnet unit and the annular housing, the protrusion of the annular magnet unit axially displacing within the slot. ### Claim 5 (depends on 3) The magnetic seal system as defined in claim 3, wherein the annular housing includes a retaining ring mounted to an end of the annular housing and configured to be surrounding the shaft, the retaining ring axially blocking the displacement of the annular magnet unit upon contact between the annular magnet unit and the retaining ring. ### Claim 6 (depends on 3) The magnetic seal system as defined in claim 3, including a bellow disposed in the annular space, the bellow surrounding and covering the bias member unit. ### Claim 7 (depends on 1) The magnetic seal system as defined in claim 1, wherein the bias member unit includes discrete bias elements engaging the annular magnet unit, each bias element cooperating with another one of the bias elements for non-magnetically biasing the annular magnet unit axially towards the annular seal. ### Claim 8 (depends on 1) The magnetic seal system as defined in claim 1, further comprising an anti-rotation feature between the annular magnet unit and the support structure. ### Claim 9 An engine assembly comprising: an engine core including at least one internal combustion engine; a rotatable shaft operatively engaged with the engine core; a support structure mounted around the shaft, the support structure housing at least a section of the shaft; a magnetic seal system connected to the support structure, the magnetic seal system including: a rotating annular seal assembly surrounding the shaft to rotate therewith, the annular seal assembly including an annular seal, the annular seal being made from wearable material gradually wearing off from rubbing contact with another component; and a non-rotating biasing assembly sealingly mounted to the support structure around the shaft and axially engaging the annular seal assembly, the biasing assembly including: an annular magnet unit configured to be axially displaceable relative to the shaft and to be supported surrounding the shaft, the annular magnet unit exerting an attracting force on the annular seal assembly to biasingly displace the annular magnet unit towards the annular seal for rubbing contact during rotation of the rotating annular seal assembly, and a bias member unit non-magnetically biasing the annular magnet unit axially relative to the shaft towards the annular seal, wherein adjacent contacting surfaces between the annular seal and the annular magnet unit biasingly contact one another to form a sealing interface therebetween in which the wearing off of the annular seal during rotation of the rotating annular seal assembly conforms the contacting surface of the seal to the contacting surface of the annular magnet unit. ### Claim 10 (depends on 9) The engine assembly as defined in claim 9, wherein the annular magnet unit includes a carrier defining a seat for receiving at least one magnet and cooperating with the bias member unit for biasing the annular magnet unit. ### Claim 11 (depends on 9) The engine assembly as defined in claim 9, wherein the biasing assembly further comprising an annular housing mounted to the support structure in a non-contacting relationship around the shaft and defining an annular space for receiving the annular magnet unit, the annular magnet unit axially displaceable within the annular space and the bias member unit mountable to the annular housing. ### Claim 12 (depends on 11) The engine assembly as defined in claim 11, wherein the annular housing includes a slot on a radial surface of the annular space receiving a protrusion of the annular magnet unit and blocking relative rotation between the annular magnet unit and the annular housing, the protrusion of the annular magnet unit axially displacing within the slot. ### Claim 13 (depends on 11) The engine assembly as defined in claim 11, wherein the annular housing includes a retaining ring mounted to an end of the annular housing and surrounding the shaft, the retaining ring axially blocking the displacement of the annular magnet unit upon contact between the annular magnet unit and the retaining ring. ### Claim 14 (depends on 11) The engine assembly as defined in claim 11, including a bellow disposed in the annular space, the bellow surrounding and covering the bias member unit. ### Claim 15 (depends on 9) The engine assembly as defined in claim 9, wherein the bias member unit includes discrete bias elements engaging the annular magnet unit, each bias element cooperating with another one of the bias elements for non-magnetically biasing the annular magnet unit axially towards the annular seal. ### Claim 16 (depends on 9) The engine assembly as defined in claim 9, wherein the annular seal assembly includes a protrusion interlocked with the shaft for blocking a rotation between the annular seal assembly and the shaft.