# US 2021/0277799 A1 · Bearing support structure with variable stiffness > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277799 A1 - Document ID: US20210277799A1 - Status: Published application - Kind: A1 - Application number: 16/809,069 - Filed: 2020-03-04 - Published: 2021-09-09 - Earliest claimed: 2020-03-04 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: David MENHEERE; Richard KOSTKA - Web page: https://patentgrep.com/patent/US20210277799A1 ## CPC - F01D 25/164: {Flexible supports; Vibration damping means associated with the bearing} - F16C 35/06: Mounting {or dismounting} of ball or roller bearings; Fixing them onto shaft or in housing - F16C 35/067: Fixing them in a housing (with interposition of an element F16C35/07) - F05D 2220/32: in gas turbines - F05D 2230/232: by welding - F05D 2240/54: Radial bearings - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - 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 method of manufacturing a bearing support structure of a gas turbine engine, includes: obtaining a bearing support and a casing assembly, the casing assembly having first and second casings extending around a central axis and connected together via struts, the bearing support securable to the first casing at attachment points; selecting a distance between the attachment points of the bearing support and the struts as a function of a required stiffness of the bearing support structure; and adjusting a position of the bearing support relative to the casing assembly until the attachment points are distanced from the struts by the selected distance and joining the bearing support to the casing assembly at the attachment points. ## Claims ### Claim 1 A method of manufacturing a bearing support structure of a gas turbine engine, comprising: obtaining a bearing support and a casing assembly, the casing assembly having first and second casings extending around a central axis and connected together via struts, the bearing support securable to the first casing at attachment points; selecting a distance between the attachment points of the bearing support and the struts as a function of a required stiffness of the bearing support structure; and adjusting a position of the bearing support relative to the casing assembly until the attachment points are distanced from the struts by the selected distance and joining the bearing support to the casing assembly at the attachment points. ### Claim 2 (depends on 1) The method of claim 1, wherein selecting the distance includes selecting a circumferential distance relative to the central axis between the attachment points and the struts. ### Claim 3 (depends on 1) The method of claim 1, wherein the bearing support includes a ring extending around the central axis and a plurality of radially extending members protruding from the ring, the attachment points located at distal ends of the plurality of radially extending members, joining the bearing support to the casing assembly includes joining the distal ends of the plurality of radially extending members to the first casing. ### Claim 4 (depends on 1) The method of claim 1, wherein joining the bearing support to the casing assembly includes welding the bearing support to the first casing. ### Claim 5 (depends on 1) The method of claim 1, wherein one attachment point is located between each two circumferentially adjacent ones of the struts, moving the casing assembly relative to the bearing support includes rotating the bearing support and the casing assembly one relative to the other about the central axis. ### Claim 6 (depends on 1) The method of claim 1, including assembling the bearing support to the casing assembly before moving the casing assembly relative to the bearing support until the attachment points are distanced from the struts by the selected distance. ### Claim 7 (depends on 6) The method of claim 6, wherein assembling the bearing support to the casing assembly includes moving the bearing support relative to the casing assembly in an axial direction relative to the central axis until the attachment points are axially aligned with radially inner ends of the struts. ### Claim 8 A method of adjusting a stiffness of a bearing support structure of a gas turbine engine, the bearing support having first and second casings extending around a central axis and connected together via struts and having a bearing support securable to the first casing at attachment points, comprising: obtaining operating parameters of the gas turbine engine; determining a required stiffness of the bearing support structure as a function of the obtained parameters; and selecting a distance between the attachment points of the bearing support and the struts as a function of the determined required stiffness and joining the bearing support to the first casing at the attachment points. ### Claim 9 (depends on 8) The method of claim 8, wherein selecting the distance includes selecting a circumferential distance relative to the central axis between the attachment points and the struts. ### Claim 10 (depends on 8) The method of claim 8, wherein the bearing support includes a ring extending around the central axis and a plurality of radially extending members protruding from the ring, the attachment points located at distal ends of the plurality of radially extending members, joining the bearing support to the first casing includes joining the distal ends of the plurality of radially extending members to the first casing. ### Claim 11 (depends on 8) The method of claim 8, wherein joining the bearing support to the first casing includes welding the bearing support to the first casing. ### Claim 12 A bearing support structure for a gas turbine engine, the bearing support structure having a central axis and comprising: first and second casings extending around the central axis and being radially spaced apart from one another relative to the central axis, the first and second casings secured to one another by struts extending at least radially; and a bearing support secured to the first casing at attachment points circumferentially distributed around the central axis, the bearing support free of contact with the first casing between the attachment points. ### Claim 13 (depends on 12) The bearing support structure of claim 12, wherein the attachment points are offset from the struts in a circumferential direction relative to the central axis. ### Claim 14 (depends on 12) The bearing support structure of claim 12, wherein the bearing support includes a ring extending around the central axis and radially extending members protruding from the ring, the bearing support secured to the first casing via the radially extending members. ### Claim 15 (depends on 12) The bearing support structure of claim 12, wherein the bearing support is welded to the first casing. ### Claim 16 (depends on 12) The bearing support structure of claim 12, wherein one attachment point is located between each two circumferentially adjacent ones of the struts. ### Claim 17 (depends on 12) The bearing support structure of claim 12, wherein a number of the struts corresponds to a number of the attachment points. ### Claim 18 (depends on 14) The bearing support structure of claim 14, wherein a number of the struts corresponds to a number of radially extending members. ### Claim 19 (depends on 13) The bearing support structure of claim 13, wherein the attachment points are axially aligned with radially inner ends of the struts. ### Claim 20 (depends on 12) The bearing support of claim 12, wherein the bearing support is located radially inwardly of the first casing.