# US 10,309,256 B2 · Non-linear bumper bearings > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,256 B2 - Document ID: US10309256B2 - Status: Granted - Kind: B2 - Application number: 15/029,494 - Filed: 2014-10-10 - Published: 2016-09-15 - Granted: 2019-06-04 - Earliest claimed: 2013-10-15 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Loc Quang Duong; Xiaolan Hu - Web page: https://patentgrep.com/patent/US10309256B2 ## CPC - F01D 25/164: {Flexible supports; Vibration damping means associated with the bearing} - F01D 5/021: {for flow machines or engines with only one axial stage (for more than one stage F01D5/06)} - F01D 25/16: Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) - F01D 25/24: Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) - F16C 17/02: for radial load only - F16C 27/02: Sliding-contact bearings - F05D 2220/32: in gas turbines - F05D 2240/52: Axial thrust bearings - F16C 17/03: with tiltably-supported segments, e.g. Michell bearings {(hydrostatic bearings with tiltably supported bearing pads F16C32/0666; made from a plurality of rods F16C33/26; with flexible leaves F16C17/024; hydrodynamic bearings with chambers F16C33/1075)} - F16C 17/24: with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety - F16C 33/108: {with a plurality of elements forming the bearing surfaces, e.g. bearing pads} - F16C 2360/23: Gas turbine engines - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A bumper bearing assembly includes a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a bearing seat. A bumper bearing is connected to the bearing housing by a spring having a level of radial spring stiffness lower than that of the bearing housing. The bumper bearing is configured to apply the level of radial spring stiffness of the spring against a rotor with the bumper bearing spaced apart from the bearing seat. The bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the bumper bearing seated against the bearing seat. ## Claims ### Claim 1 A bumper bearing assembly comprising: a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines a first bearing seat and a second bearing seat; and a bumper bearing connected to the bearing housing by a spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the bumper bearing is configured to apply the level of radial spring stiffness of the spring against a rotor with the bumper bearing spaced apart from the first bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the bumper bearing seated against the first bearing seat; and a second bumper bearing opposed to the bumper bearing and connected to the bearing housing by a second spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the second bumper bearing is positioned to apply the level of radial spring stiffness of the second spring in a second radial direction opposed to the first radial direction against the rotor with the second bumper bearing spaced apart from the second bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the second bumper bearing seated against the second bearing seat, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in respective level of radial spring stiffness of the bearing housing. ### Claim 2 (depends on 1) The bumper bearing assembly as recited in claim 1, wherein the bumper bearing and bearing seat are arcuate. ### Claim 3 (depends on 1) The bumper bearing assembly as recited in claim 1, wherein the bumper bearing includes a coating on a bearing surface opposite the bearing seat, wherein the coating is configured to engage the rotor rotating relative to the bearing seat. ### Claim 4 (depends on 1) The bumper bearing assembly as recited in claim 1, further comprising an anti-rotation lug at one end of the bearing seat and engaged to limit circumferential rotation of the bumper bearing. ### Claim 5 (depends on 1) The bumper bearing assembly as recited in claim 1, wherein the bumper bearing includes a plurality of circumferentially spaced bumper segments each connected to the bearing housing with a respective spring including the a level of radial spring stiffness lower than that of the bearing housing. ### Claim 6 (depends on 5) The bumper bearing assembly as recited in claim 5, wherein an anti-rotation lug is disposed between each circumferentially adjacent pair of bumper segments. ### Claim 7 (depends on 5) The bumper bearing assembly as recited in claim 5, wherein the bumper segments substantially surround a rotor passage through the bearing housing. ### Claim 8 A gas turbine engine comprising: a casing; a rotor mounted for rotation about a longitudinal axis relative to the casing; and a bumper bearing assembly mounted to the casing, the bumper bearing assembly including: a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines first and second bearing seats; a first bumper bearing connected to the bearing housing by a first spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the first bumper bearing is positioned to apply the level of radial spring stiffness of the first spring in a first radial direction against the rotor with the first bumper bearing spaced apart from the first bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the first bumper bearing seated against the first bearing seat; and a second bumper bearing opposed to the first bumper bearing and connected to the bearing housing by a second spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the second bumper bearing is positioned to apply the level of radial spring stiffness of the second spring in a second radial direction opposed to the first radial direction against the rotor with the second bumper bearing spaced apart from the second bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the second bumper bearing seated against the second bearing seat, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in respective level of radial spring stiffness of the bearing housing. ### Claim 9 (depends on 8) The gas turbine engine as recited in claim 8, wherein the first and second bearing seats are spaced apart from one another axially relative to the longitudinal axis for counteracting thermally induced warpage in the rotor. ### Claim 10 (depends on 9) The gas turbine engine as recited in claim 9, wherein the first and second bumper bearings each have an arcuate inner surface for engaging the rotor, wherein the arcuate inner surfaces define a bearing radius, and wherein a bumper span is defined axially from a center of the first bumper bearing to a center of the second bumper bearing, and wherein the ratio of the bumper span to the bearing radius is between 1 and 5. ### Claim 11 (depends on 8) The gas turbine engine as recited in claim 8, wherein the first and second bumper bearings each include a coating on a bearing surface configured to engage the rotor for rotation of the rotor relative to the first and second bearing seats. ### Claim 12 (depends on 8) The gas turbine engine as recited in claim 8, further comprising a respective anti-rotation lug at one end of each bearing seat and engaged to limit circumferential rotation of a respective one of the first and second bumper bearings. ### Claim 13 (depends on 8) The gas turbine engine as recited in claim 8, wherein each of the first and second bumper bearings includes a plurality of circumferentially spaced bumper segments each connected to the bearing housing with a respective spring. ### Claim 14 (depends on 13) The gas turbine engine as recited in claim 13, wherein an anti-rotation lug is disposed between each circumferentially adjacent pair of bumper segments. ### Claim 15 (depends on 13) The gas turbine engine as recited in claim 13, wherein the bumper segments substantially surround the rotor. ### Claim 16 A bumper bearing assembly comprising: a bearing housing having a level of radial spring stiffness, wherein the bearing housing defines first and second bearing seats; a first bumper bearing connected to the bearing housing by a first spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the first bumper bearing is positioned to apply the level of radial spring stiffness of the first spring in a first radial direction against a rotor with the first bumper bearing spaced apart from the first bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the first bumper bearing seated against the first bearing seat; and a second bumper bearing opposed to the first bumper bearing and connected to the bearing housing by a second spring having a level of radial spring stiffness lower than that of the bearing housing, wherein the second bumper bearing is positioned to apply the level of radial spring stiffness of the second spring in a second radial direction opposed to the first radial direction against the rotor with the second bumper bearing spaced apart from the second bearing seat, and wherein the bearing housing is configured to apply the level of radial spring stiffness of the bearing housing against the rotor with the second bumper bearing seated against the second bearing seat, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in respective level of radial spring stiffness of the bearing housing. ### Claim 17 (depends on 16) The bumper bearing assembly as recited in claim 16, wherein the first and second bearing seats are spaced apart from one another axially relative to the longitudinal axis for counteracting thermally induced warpage in the rotor. ### Claim 18 (depends on 17) The bumper bearing assembly as recited in claim 17, wherein the first and second bumper bearings each have an arcuate inner surface for engaging the rotor, wherein the arcuate inner surfaces define a bearing radius, and wherein a bumper span is defined axially from a center of the first bumper bearing to a center of the second bumper bearing, and wherein the ratio of the bumper span to the bearing radius is between 1 and 5. ### Claim 19 (depends on 16) The bumper bearing as recited in claim 16, wherein each of the first and second bumper bearings includes a plurality of circumferentially spaced bumper segments each connected to the bearing housing with a respective spring. ### Claim 20 (depends on 16) The bumper bearing as recited in claim 16, wherein each of the first and second bumper bearings is individually tuned so the first and second bumper bearings differ from one another in at least one of respective bearing axial length, respective level of radial spring stiffness of the spring, respective bumper bearing angular arc length, respective bumper bearing clearance to the rotor, and respective gap between the bumper bearing and the bearing seat.