# US 11,999,471 B2 · Weight balanced rotor blade with thermoplastic composite weight > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,471 B2 - Document ID: US11999471B2 - Status: Granted - Kind: B2 - Application number: 17/856,579 - Filed: 2022-07-01 - Published: 2024-01-04 - Granted: 2024-06-04 - Earliest claimed: 2022-07-01 - Assignees: Rohr, Inc. - Applicants: Rohr, Inc. - Inventors: Daniel O. Ursenbach; Nathaniel M. Gray - Web page: https://patentgrep.com/patent/US11999471B2 ## CPC - B64C 27/473: Constructional features - F04D 29/662: {Balancing of rotors (compensating imbalance G01M1/36)} - B29C 70/30: Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core - B64C 27/008: {Rotors tracking or balancing devices} - F04D 29/023: {especially adapted for elastic fluid pumps} - F04D 29/324: {Blades} - B29L 2031/082: {Blades, e.g. for helicopters} - B64C 2027/4736: {from composite materials} - F05D 2240/303: related to the leading edge of a rotor blade - F05D 2300/10: Metals, alloys or intermetallic compounds - F05D 2300/603: Composites; e.g. fibre-reinforced - B64C: AEROPLANES; HELICOPTERS - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A rotor blade is provided that includes an airfoil extending spanwise from a base to a tip. The airfoil extends longitudinally (e.g., chordwise) from a leading edge to a trailing edge. The airfoil extends laterally between a first side and a second side. The airfoil includes a body and a weight. The body includes a plurality of body layers. Each of the body layers includes fiber reinforcement within a body thermoplastic matrix. The weight includes a weight layer embedded within the body. The weight layer includes metal powder within a weight thermoplastic matrix. ## Claims ### Claim 1 A rotor blade, comprising: an airfoil extending spanwise from a base to a tip, the airfoil extending longitudinally from a leading edge to a trailing edge, the airfoil extending laterally between a first side and a second side, and the airfoil including a body and a weight; the body comprising a plurality of body layers, each of the plurality of body layers including fiber reinforcement within a body thermoplastic matrix; and the weight comprising a weight layer embedded within the body, the weight layer including metal powder within a weight thermoplastic matrix; wherein the weight layer is configured without fiber reinforcement. ### Claim 2 (depends on 1) The rotor blade of claim 1, wherein the body thermoplastic matrix and the weight thermoplastic matrix comprise a common thermoplastic material. ### Claim 3 (depends on 1) The rotor blade of claim 1, wherein the plurality of body layers include a first body layer and a second body layer; and the weight layer is embedded within the body between the first body layer and the second body layer. ### Claim 4 (depends on 3) The rotor blade of claim 3, wherein the weight layer is adjacent the first body layer and the second body layer. ### Claim 5 (depends on 3) The rotor blade of claim 3, wherein the plurality of body layers further include a third body layer; the weight further comprises a second weight layer embedded within the body between the second body layer and the third body layer; and the second weight layer includes metal powder within a weight thermoplastic matrix. ### Claim 6 (depends on 1) The rotor blade of claim 1, wherein the weight further comprises a second weight layer embedded within the body; and the second weight layer includes metal powder within a weight thermoplastic matrix. ### Claim 7 (depends on 1) The rotor blade of claim 1, wherein the weight is located at the leading edge. ### Claim 8 (depends on 1) The rotor blade of claim 1, wherein the weight has an arcuate cross-sectional geometry that follows an arcuate cross-sectional geometry of one of the plurality of body layers. ### Claim 9 (depends on 1) The rotor blade of claim 1, wherein the weight extends spanwise along at least a major portion of a span of the airfoil from the base to the tip. ### Claim 10 (depends on 1) The rotor blade of claim 1, wherein the weight layer has a thickness that changes as the weight layer extends spanwise. ### Claim 11 (depends on 1) The rotor blade of claim 1, wherein the weight layer has a thickness that changes as the weight layer extends circumferentially about a span line of the airfoil. ### Claim 12 (depends on 1) The rotor blade of claim 1, wherein the metal powder comprises at least one of lead or tungsten. ### Claim 13 (depends on 1) The rotor blade of claim 1, wherein the rotor blade is configured as one of a helicopter blade or a propeller blade. ### Claim 14 A rotor blade, comprising: an airfoil extending spanwise from a base to a tip, the airfoil extending longitudinally from a leading edge to a trailing edge, the airfoil extending laterally between a first side and a second side, and the airfoil including a body and a weight; the body comprising a body thermoplastic matrix and fiber reinforcement within the body thermoplastic matrix; and the weight fused to the body, the weight comprising a weight thermoplastic matrix and metal filler material within the weight thermoplastic matrix, and the weight configured without fiber reinforcement. ### Claim 15 (depends on 14) The rotor blade of claim 14, wherein the metal filler material comprises metal powder. ### Claim 16 (depends on 14) The rotor blade of claim 14, wherein the body is formed from a plurality of body layers of the fiber reinforcement within the body thermoplastic matrix, and the plurality of body layers include a first body layer and a second body layer; and the weight comprises a weight layer of the metal filler material within the weight thermoplastic matrix, and the weight layer is disposed within the body between the first body layer and the second body layer.