# US 11,898,462 B2 · Impeller for aircraft engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,462 B2 - Document ID: US11898462B2 - Status: Granted - Kind: B2 - Application number: 17/451,958 - Filed: 2021-10-22 - Published: 2023-04-27 - Granted: 2024-02-13 - Earliest claimed: 2021-10-22 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Farid Abrari - Web page: https://patentgrep.com/patent/US11898462B2 ## CPC - F01D 5/28: Selecting particular materials; {Particular measures relating thereto;} Measures against erosion or corrosion - F04D 29/284: {for compressors} - F01D 5/043: {of the axial inlet- radial outlet, or vice versa, type} - F01D 5/046: {Heating, heat insulation or cooling means} - F01D 5/30: Fixing blades to rotors; Blade roots {; Blade spacers} - F01D 9/026: {Scrolls for radial machines or engines} - F04D 29/023: {especially adapted for elastic fluid pumps} - F04D 29/444: {Bladed diffusers} - F04D 29/624: {especially adapted for elastic fluid pumps} - F01D 5/025: {Fixing blade carrying members on shafts (attachment of a member on a shaft in general F16D1/06; for non-positive displacement pumps F04D29/00)} - F01D 5/048: {Form or construction} - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2240/30: Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor - F05D 2260/36: by a form fit connection, e.g. by interlocking - F05D 2260/94: Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF] - F05D 2300/133: Titanium - F05D 2300/174: Titanium alloys, e.g. TiAl - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An impeller for a centrifugal compressor, the impeller rotatable about a central axis, has: an outer hub body including a first material and extending around the central axis, the outer hub body defining a gaspath face extending from an inlet to an outlet, the gaspath face extending radially away from the central axis from the inlet to the outlet; blades protruding from the gaspath face and circumferentially distributed around the central axis; and an inner hub body extending around the central axis, the inner hub body secured to the outer hub body, the outer hub body axially overlapping and extending around the inner hub body, the inner hub body made of a second material being more cold dwell resistant than the first material. ## Claims ### Claim 1 An impeller for a centrifugal compressor, the impeller rotatable about a central axis, comprising: a front face and a rear face axially rearward of the front face, the rear face extending radially outwardly relative to the central axis from a bore of the impeller, the impeller having an inlet and an outlet downstream of the inlet, the impeller having a gaspath face extending from the inlet to the outlet; an outer hub body including a first material and extending around the central axis, the outer hub body defining an entirety of the gaspath face, the gaspath face extending radially away from the central axis from the inlet to the outlet, an entirety of the rear face defined by the outer hub body; blades protruding from the gaspath face and circumferentially distributed around the central axis; and an inner hub body extending around the central axis, the inner hub body secured to the outer hub body, the outer hub body axially overlapping and extending around the inner hub body, the inner hub body made of a second material being more cold dwell resistant than the first material, the inner hub body located entirely radially inwardly of the gaspath face. ### Claim 2 (depends on 1) The impeller of claim 1, wherein the first material is more creep resistant than the second material. ### Claim 3 (depends on 1) The impeller of claim 1, wherein the first material is Ti-834. ### Claim 4 (depends on 3) The impeller of claim 3, wherein the second material is Ti-6246. ### Claim 5 (depends on 1) The impeller of claim 1, wherein the inner hub body defines the front face. ### Claim 6 (depends on 1) The impeller of claim 1, wherein the inner hub body has an outer face facing an inner face of the outer hub body. ### Claim 7 (depends on 6) The impeller of claim 6, comprising an annular gap between the outer face and the inner face. ### Claim 8 (depends on 7) The impeller of claim 7, wherein the annular gap extends radially towards the central axis as the annular gap extends axially toward the outlet. ### Claim 9 (depends on 1) The impeller of claim 1, wherein the outer hub body is secured to the inner hub body via at least two attachment locations being axially offset from one another. ### Claim 10 (depends on 9) The impeller of claim 9, wherein the outer hub body is free of contact with the inner hub body between the at least two attachment locations. ### Claim 11 (depends on 10) The impeller of claim 10, wherein the at least two attachment locations include a fore attachment location and a rear attachment location, the rear attachment location located radially inwardly from the fore attachment location. ### Claim 12 (depends on 10) The impeller of claim 10, wherein the outer hub body is secured to the inner hub body via a front tongue-and-groove connection proximate a front face of the impeller and a rear tongue-and-groove connection proximate a rear face of the impeller. ### Claim 13 An aircraft engine comprising: a compressor having an impeller rotatable about a central axis, the impeller having an inlet and an outlet downstream of the inlet, the impeller having a gaspath face extending from the inlet to the outlet, the impeller having: a front face and a rear face axially rearward of the front face, the rear face extending radially outwardly relative to a central axis from a bore of the impeller, the impeller having an inlet and an outlet downstream of the inlet, the impeller having a gaspath face extending from the inlet to the outlet; an outer hub body including a first material and extending around the central axis, the outer hub body defining an entirety of the gaspath face, an entirety of the rear face defined by the outer hub body; blades protruding from the gaspath face and circumferentially distributed around the central axis; and an inner hub body extending around the central axis, the inner hub body secured to the outer hub body, the inner hub body contained within a recess defined by the outer hub body, the inner hub body made of a second material being more cold dwell resistant than the first material, the inner hub body having an outer face facing an inner face of the outer hub body, an annular gap between the outer face and the inner face, the inner hub body located entirely radially inwardly of the gaspath face. ### Claim 14 (depends on 13) The aircraft engine of claim 13, wherein the first material is more creep resistant than the second material. ### Claim 15 (depends on 13) The aircraft engine of claim 13, wherein the outer hub body is secured to the inner hub body via at least two attachment locations being axially offset from one another. ### Claim 16 (depends on 15) The aircraft engine of claim 15, wherein the outer hub body is secured to the inner hub body via a front tongue-and-groove connection proximate the front face of the impeller and a rear tongue-and-groove connection proximate the rear face of the impeller. ### Claim 17 (depends on 16) The aircraft engine of claim 16, wherein the first material is Ti-834 and wherein the second material is Ti-6246.