# US 12,215,603 B2 · CMC airfoil with wishbone shaped fiber layup structure forming portion of platform and root > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,603 B2 - Document ID: US12215603B2 - Status: Granted - Kind: B2 - Application number: 18/340,205 - Filed: 2023-06-23 - Published: 2024-12-26 - Granted: 2025-02-04 - Earliest claimed: 2023-06-23 - Assignees: Rtx Corporation - Applicants: Rtx Corporation - Inventors: Marcus DeReimer; Michael G. McCaffrey - Web page: https://patentgrep.com/patent/US12215603B2 ## CPC - F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments} - F01D 5/12: Blades ({specially adapted for radial flow machines or engines F01D5/04}; blade roots F01D5/30; rotors with blades adjustable in operation F01D7/00; stator blades F01D9/02) - F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)} - F01D 5/284: {Selection of ceramic materials} - F01D 5/30: Fixing blades to rotors; Blade roots {; Blade spacers} - F02C 7/00: Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants (controlling F02C9/00) - F05D 2240/80: Platforms for stationary or moving blades - F05D 2300/601: Fabrics - F05D 2300/6033: Ceramic matrix composites [CMC] - F05D 2300/614: Fibres or filaments - F05D 2300/702: Reinforcement - 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 ## Abstract An airfoil includes a CMC airfoil wall that defines a platform, a root that extends radially from the platform, and an airfoil section that extends radially from the platform opposite the root. The CMC airfoil wall includes a wishbone-shaped fiber layup structure. The wishbone-shaped fiber layup structure includes first and second arms that merge into a single leg. The first and second arms are comprised of a network of fiber tows, and the single leg includes fiber tows from each of the first and second arms that are interwoven in the single leg. The single leg forms a portion of the root, and the first and second arms extend in opposite directions from the single leg and form a portion of the platform. ## Claims ### Claim 1 An airfoil comprising: a ceramic matrix composite (CMC) airfoil wall defining a platform, a root extending radially from the platform, and an airfoil section extending radially from the platform opposite the root, the CMC airfoil wall including first and second wishbone-shaped fiber layup structures, each of the first and second wishbone-shaped fiber layup structures including: first and second arms that merge into a single leg, the first and second arms being comprised of a network of fiber tows, the single leg including fiber tows from each of the first and second arms that are interwoven in the single leg, the single leg forming a portion of the root, and the first and second arms extending in opposite directions from the single leg and forming a portion of the platform, wherein the first arm of the first wishbone-shaped fiber layup structure extending axially forwardly from the single leg of the first wishbone-shaped fiber layup structure, and the first arm of the second wishbone-shaped fiber layup structure extends axially aftly from the single leg of the second wishbone-shaped fiber layup structure, the second arm of the first wishbone-shaped fiber layup structure extends axially aftly from the single leg of the first wishbone-shaped fiber layup structure, and the second arm of the second wishbone-shaped fiber layup structure extends axially forwardly from the single leg of the second wishbone-shaped fiber layup structure, and a tip of the second arm of the first wishbone-shaped fiber layup structure is adjacent a tip of the second arm of the second wishbone-shaped fiber layup structure to define a gap therebetween. ### Claim 2 (depends on 1) The airfoil as recited in claim 1, wherein the CMC airfoil wall includes radially inner and outer reinforcement fiber plies between which the second arm of the first wishbone-shaped fiber layup structure and the second arm of the of the second wishbone-shaped fiber layup structure are disposed, and the radially inner and outer reinforcement fiber plies each bridge the gap. ### Claim 3 (depends on 2) The airfoil as recited in claim 2, wherein the single leg of the first wishbone-shaped fiber layup structure defines an axially forward face of the root, and the single leg of the second wishbone-shaped fiber layup structure defines an axially aft face of the root. ### Claim 4 (depends on 1) The airfoil as recited in claim 1, wherein the second arm of each of the first and second wishbone-shaped fiber layup structure splits into a pair of fingers, and the airfoil section extends between the pair of fingers. ### Claim 5 A gas turbine engine comprising: a compressor section; a combustor in fluid communication with the compressor section; and a turbine section in fluid communication with the combustor, the turbine section having and an airfoil including: a ceramic matrix composite (CMC) airfoil wall defining a platform, a root extending radially from the platform, and an airfoil section extending radially from the platform opposite the root, the root having a fir-tree profile, the CMC airfoil wall including first and second wishbone-shaped fiber layup structures, each of the first and second wishbone-shaped fiber layup structures including: first and second arms that merge into a single leg, the first and second arms being comprised of a network of fiber tows, the single leg including fiber tows from each of the first and second arms that are interwoven in the single leg, the single leg forming a portion of the root, and the first and second arms extending in opposite directions from the single leg and forming a portion of the platform, the first arm of the first wishbone-shaped fiber layup structure extending axially forwardly from the single leg of the first wishbone-shaped fiber layup structure, the first arm of the second wishbone-shaped fiber layup structure extending axially aftly from the single leg of the second wishbone-shaped fiber layup structure, the second arm of the first wishbone-shaped fiber layup structure extending axially aftly from the single leg of the first wishbone-shaped fiber layup structure, and the second arm of the second wishbone-shaped fiber layup structure extending axially forwardly from the single leg of the second wishbone-shaped fiber layup structure, and a tip of the second arm of the first wishbone-shaped fiber layup structure is adjacent a tip of the second arm of the second wishbone-shaped fiber layup structure to define a gap therebetween. ### Claim 6 (depends on 5) The gas turbine engine as recited in claim 5, wherein the CMC airfoil wall includes radially inner and outer reinforcement fiber plies between which the second arm of the first wishbone-shaped fiber layup structure and the second arm of the of the second wishbone-shaped fiber layup structure are disposed, and the radially inner and outer reinforcement fiber plies each bridge the gap. ### Claim 7 (depends on 6) The gas turbine engine as recited in claim 6, wherein the single leg of the first wishbone-shaped fiber layup structure defines an axially forward face of the root, and the single leg of the second wishbone-shaped fiber layup structure defines an axially aft face of the root. ### Claim 8 (depends on 5) The gas turbine engine as recited in claim 5, wherein the second arm of each of the first and second wishbone-shaped fiber layup structure splits into a pair of fingers, and the airfoil section extends between the pair of fingers. ### Claim 9 (depends on 5) The gas turbine engine as recited in claim 5, wherein the turbine section includes a disk that defines a slot that has a geometry that corresponds to the fir-tree profile such that the root interlocks with the slot.