# US 10,502,230 B2 · Integrally bladed rotor having double fillet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,230 B2 - Document ID: US10502230B2 - Status: Granted - Kind: B2 - Application number: 15/652,385 - Filed: 2017-07-18 - Published: 2019-01-24 - Granted: 2019-12-10 - Earliest claimed: 2017-07-18 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Carney R. Anderson - Web page: https://patentgrep.com/patent/US10502230B2 ## CPC - F04D 29/384: {characterised by form} - F01D 5/143: {Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour} - F01D 5/34: Rotor-blade aggregates of unitary construction {, e.g. formed of sheet laminae; (discs formed of sheet laminae F01D5/028; ceramic materials F01D5/284, composite materials F01D5/282)} - F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) - F04D 29/324: {Blades} - F04D 29/325: {for axial flow fans (blade mountings F04D29/34, blades F04D29/38)} - F05D 2220/32: in gas turbines - F05D 2240/301: Cross-sectional characteristics - F05D 2240/35: Combustors or associated equipment - F05D 2250/71: curved - F05D 2250/713: inflexed - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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 - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An integrally bladed rotor according to an example of the present disclosure includes a hub, and a plurality of rotor airfoils integrally formed with the hub, and extending radially outward from an outer platform of the hub. Each rotor airfoil has a main body that extends radially outward from a root to a tip. A first fillet has a first radius that provides a transition from the outer platform of the hub, and a second fillet situated adjacent to and radially outward of the first fillet, that provides a transition between the first fillet and the main body. The second fillet has a second radius that is less than the first radius. ## Claims ### Claim 1 An integrally bladed rotor comprising: a hub; and a plurality of rotor airfoils integrally formed with the hub, and extending radially outward from an outer platform of the hub, each rotor airfoil comprising: a main body extending radially outward from a root to a tip; a first fillet having a first radius and providing a transition from the outer platform of the hub; and a second fillet situated adjacent to and radially outward of the first fillet, and providing a transition between the first fillet and the main body, the second fillet having a second radius that is less than the first radius; wherein the first and second fillets meet at a rim, and wherein for at least one of the rotor airfoils, a height of the rim, defined as a radial distance from a beginning point of the first fillet, is 1%-20% of a maximum radial length of the airfoil between the beginning point and the tip. ### Claim 2 (depends on 1) The integrally bladed rotor of claim 1, wherein for each of the airfoils, a ratio of the first radius to the second radius is from 1.2:1 to 4:1. ### Claim 3 (depends on 2) The integrally bladed rotor of claim 2, wherein for each of the airfoils, a ratio of the first radius to the second radius is from 2:1 to 3:1. ### Claim 4 (depends on 1) The integrally bladed rotor of claim 1, wherein for at least one of the rotor airfoils, the first and second fillets extend around a leading edge of the rotor airfoil, a trailing edge of the rotor airfoil, or both. ### Claim 5 (depends on 1) The integrally bladed rotor of claim 1, wherein for at least one of the rotor airfoils, the first and second fillets extend around a majority of a perimeter of the root. ### Claim 6 (depends on 1) The integrally bladed rotor of claim 1, wherein the integrally bladed rotor is part of a compressor stage of a gas turbine engine. ### Claim 7 (depends on 1) The integrally bladed rotor of claim 1, wherein the integrally bladed rotor is part of a fan section of a gas turbine engine. ### Claim 8 An integrally bladed rotor comprising: a hub; and a plurality of rotor airfoils integrally formed with the hub, and extending radially outward from an outer platform of the hub, each rotor airfoil comprising: a main body extending radially outward from a root to a tip; a first fillet having a first radius and providing a transition from the outer platform of the hub; and a second fillet situated adjacent to and radially outward of the first fillet, and providing a transition between the first fillet and the main body, the second fillet having a second radius that is less than the first radius; wherein the first and second fillets meet at a rim, and wherein for at least one of the rotor airfoils, a ratio of a maximum width of the rim measured in a dimension perpendicular to a mean camber line of the rotor airfoil to a width of the main body measured along the same dimension between respective points where the second fillet ends on opposing outer sides of the airfoil is greater than 1:1 and less than or equal to 3:1. ### Claim 9 An integrally bladed rotor comprising: a hub; and a plurality of rotor airfoils integrally formed with the hub, and extending radially outward from an outer platform of the hub, each rotor airfoil comprising: a main body extending radially outward from a root to a tip; a first fillet having a first radius and providing a transition from the outer platform of the hub; and a second fillet situated adjacent to and radially outward of the first fillet, and providing a transition between the first fillet and the main body; wherein the first and second fillets meet at a rim that provides a stepped platform between the first and second fillets, and a ratio of the first radius to the second radius is from 0.5:1 to 1.2:1. ### Claim 10 A gas turbine engine comprising: a compressor comprising a plurality of stages; a fan operable to deliver air to the compressor; and a combustor operable to ignite a mixture of fuel and compressed air from the compressor; wherein at least one of the stages comprises an integrally bladed rotor having a hub and a plurality of rotor airfoils extending radially outward from the hub, each of the rotor airfoils including: a main body extending radially outward from a root to a tip; a first fillet having a first radius and providing a transition from the outer platform of the hub; and a second fillet situated adjacent to and radially outward of the first fillet, and providing a transition between the first fillet and the main body, the second fillet having a second radius that is less than the first radius; wherein the first and second fillets meet at a rim, and wherein the rim of at least one rotor airfoil of one of the stages has a different height defined as a radial distance from a beginning point of the first fillet, different maximum width measured along a dimension perpendicular to an airfoil mean camber line, or both than the rim of at least one rotor airfoil of another of the stages. ### Claim 11 (depends on 10) The gas turbine engine of claim 10, wherein each of the plurality of the stages comprises an integrally bladed rotor comprising rotor airfoils having the first fillet and second fillet. ### Claim 12 (depends on 10) The gas turbine engine of claim 10, wherein the compressor comprises a high pressure compressor and a low pressure compressor, and said at least one of the stages is a first stage of the high pressure compressor. ### Claim 13 (depends on 10) The gas turbine engine of claim 10, wherein for each of the airfoils having the first and second fillet, a ratio of the first radius to the second radius is from 1.2:1 to 4:1. ### Claim 14 (depends on 10) The gas turbine engine of claim 10, wherein for each of the airfoils having the first and second fillet, a ratio of the first radius to the second radius is from 2:1 to 3:1. ### Claim 15 (depends on 10) The gas turbine engine of claim 10, wherein for at least one of the rotor airfoils having the first and second fillet, the first and second fillets extend around a leading edge of the rotor airfoil, a trailing edge of the rotor airfoil, or both. ### Claim 16 (depends on 10) The gas turbine engine of claim 10, wherein for at least one of the rotor airfoils having the first and second fillet, the first and second fillets extend around a majority of a perimeter of the root. ### Claim 17 (depends on 10) The gas turbine engine of claim 10, wherein for at least one of the rotor airfoils, a height of the rim, defined as a radial distance from a beginning point to the first fillet, is 1%-20% of a maximum radial length of the airfoil between the beginning point and the tip. ### Claim 18 (depends on 10) The gas turbine engine of claim 10, wherein for at least one of the rotor airfoils, a ratio of a maximum width of the rim measured in a dimension perpendicular to a mean camber line of the rotor airfoil to a width of the main body measured along the same dimension between respective points where the second fillet ends on opposing outer sides of the airfoil is greater than 1:1 and less than or equal to 3:1.