# US 10,309,241 B2 ยท Compound fillet varying chordwise and method to manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server โ€” see https://patentgrep.com/llms.txt - Number: US 10,309,241 B2 - Document ID: US10309241B2 - Status: Granted - Kind: B2 - Application number: 15/066,646 - Filed: 2016-03-10 - Published: 2016-09-15 - Granted: 2019-06-04 - Earliest claimed: 2015-03-11 - Assignees: ROLLS-ROYCE plc - Applicants: Rolls-Royce Corporation - Inventors: Patrick E. Bailey - Web page: https://patentgrep.com/patent/US10309241B2 ## CPC - F01D 9/041: {using blades (F01D5/148 takes precedence)} - F01D 5/141: {Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147)} - F01D 5/143: {Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour} - F04D 27/009: {by bleeding, by passing or recycling fluid} - F04D 29/522: {especially adapted for elastic fluid pumps} - F04D 29/542: {Bladed diffusers (fixing blades to stators F01D9/042)} - F04D 29/544: {Blade shapes} - F05D 2220/32: in gas turbines - F05D 2220/36: specially adapted for the fan of turbofan engines - F05D 2230/10: by removing material - F05D 2240/121: related to the leading edge of a stator vane - F05D 2240/122: related to the trailing edge of a stator vane - F05D 2240/304: related to the trailing edge of a rotor blade - F05D 2240/80: Platforms for stationary or moving blades - F05D 2260/941: particularly aimed at mechanical or thermal stress reduction - 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 improved structure and method of manufacturing a structure such as a guide vane for a gas turbine engine includes an improved guide vane having a stress transition section called a fillet that is positioned between an airfoil and a hub. The fillet includes a constant radius section and a compound radius portion that is collectively configured to handle the stress loads of the guide vane as well as to provide aerodynamic efficiencies. An improved method of manufacturing an airfoil is provided that employs a single pass manufacturing process whereby a single tool is used to generate a resulting fillet having a constant radius and compound radius portion. ## Claims ### Claim 1 An extension member for an engine comprising: an airfoil having a leading edge portion and a trailing edge portion, the airfoil further including an aerodynamic surface extending between the leading and trailing edge portions; a hub positioned radially inward from the airfoil, the hub includes a first portion, a second portion, and an axially extending portion extending between the first and second portions; and a fillet extending axially from the leading edge portion of the airfoil to the trailing edge portion of the airfoil, the fillet including a first radius R1 and a second radius R2, the first radius R1 is a constant radius and begins at the leading edge portion of the airfoil and extends towards a transition point, the second radius R2 when combined with the first radius R1 is a compound radius and begins near the transition point and continues towards the trailing edge portion of the airfoil, wherein the first radius R1 and the second radius R2 extend around a perimeter of the airfoil. ### Claim 2 (depends on 1) The extension member as claimed in claim 1, further comprising a fan casing, the fan casing and extension member are connected to one another at an outer radial portion of the extension member. ### Claim 3 (depends on 1) The extension member as claimed in claim 1, further comprising a gas turbine engine, the extension member directs airflow that passes through the gas turbine engine, wherein the extension member is a vane or a blade. ### Claim 4 (depends on 1) The extension member as claimed in claim 1, wherein the constant radius of the fillet extends from the leading edge portion to the transition point on both a pressure side and a suction side of the airfoil, and the compound radius of the fillet extends from the transition point to the trailing edge portion on both the pressure side and the suction side of the airfoil. ### Claim 5 (depends on 1) The extension member as claimed in claim 1, further comprising a plurality of extension members positioned adjacent to one another to form an extension member assembly, the extension member assembly operates to receive bypass air and de-swirl the bypass air. ### Claim 6 (depends on 1) The extension member as claimed in claim 1, wherein the first radius R1 and the second radius R2 have a value where R2>R1. ### Claim 7 (depends on 1) The extension member as claimed in claim 1, wherein a portion of the fillet where the second radius R2 is located has more mass than the portion of the fillet where the first radius R1 is located. ### Claim 8 (depends on 1) The extension member as claimed in claim 1, wherein the compound radius of the fillet begins axially downstream of the constant radius near the transition point and extends to the trailing edge portion of the airfoil. ### Claim 9 A vane assembly for an engine comprising: an airfoil having a leading surface and a trailing surface; a hub that has an outer surface, the hub is circular shaped and the airfoil extends from the outer surface; a constant radius fillet extends axially and between the airfoil and the hub; and a compound radius fillet extends axially and between the airfoil and the hub; wherein the constant radius fillet and compound radius fillet circumscribe the airfoil, and wherein the constant radius fillet begins at the leading surface of the airfoil and extends on both a pressure side and a suction side of the airfoil. ### Claim 10 (depends on 9) The vane assembly for an engine as claimed in claim 9, wherein the constant radius filet defines a first radius R1 and the compound radius fillet defines a second radius R2, and wherein R2>R1. ### Claim 11 (depends on 10) The vane assembly for an engine as claimed in claim 10, wherein the compound radius fillet has the first radius R1 and the second radius R2. ### Claim 12 (depends on 9) The vane assembly for an engine as claimed in claim 9, wherein the compound radius fillet is located near the trailing surface of the airfoil, and is on both the pressure side and the suction side of the airfoil. ### Claim 13 (depends on 9) The vane assembly for an engine as claimed in claim 9, wherein the constant radius fillet extends chordwise about โ…” of the distance of the airfoil, and the compound radius fillet extends about โ…“ of the distance of the airfoil. ### Claim 14 A method of manufacturing a guide vane for an engine, comprising the following steps: providing a tool having a radius R1 and a radius R2; establishing pressure and suction side surfaces of a vane; establishing a tangency path for radius R2 of the tool with respect to the pressure and suction side surfaces of the vane; programming a machine to follow the tangency path so the tool advances to maintain the tangency of radius R2 of the tool with the surface of the vane while maintaining the tangency of radius R1 relative to a hub; and machining a fillet along the tangency path that has been created in order to produce a fillet structure m a single manufacturing pass; whereby R1 is a constant radius fillet, and R2 is a compound fillet, and the fillets vary chordwise. ### Claim 15 (depends on 14) The method of manufacturing as claimed in claim 14, whereby the machining step includes first machining a constant radius at a leading edge of the vane, and then indexing the tool relative to the vane, and then machining a compound radius towards a trailing edge of the vane. ### Claim 16 (depends on 15) The method of manufacturing as claimed in claim 15, further comprising the step of machining a transition fillet between the constant radius and compound radius portions of the fillet. ### Claim 17 (depends on 14) The method of manufacturing as claimed in claim 14, wherein the step of providing a tool includes determining the radius R2 based upon stresses that are exerted on a trailing edge portion of the vane. ### Claim 18 (depends on 14) The method of manufacturing as claimed in claim 14, wherein the step of machining a fillet includes either moving the tool relative to the vane, and/or moving the vane relative to the tool. ### Claim 19 (depends on 14) The method of manufacturing as claimed in claim 14, wherein the step of machining a fillet includes machining a fillet around an entire perimeter of the vane. ### Claim 20 An extension member for an engine comprising: an airfoil having a leading edge portion and a trailing edge portion, the airfoil further including an aerodynamic surface extending between the leading and trailing edge portions; a hub positioned radially inward from the airfoil, the hub includes a first portion, a second portion, and an axially extending portion extending between the first and second portions; and a fillet extending axially from the leading edge portion of the airfoil to the trailing edge portion of the airfoil, the fillet including a first radius R1 and a second radius R2, the first radius R1 begins at the leading edge portion of the airfoil and extends towards a transition zone, the second radius R2 begins near the transition zone and continues towards the trailing edge portion of the airfoil, wherein the first radius R1 and the second radius R2 have a value where R2>R1.