# US 10,374,477 B2 · Electric machine with separable magnet carrier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,477 B2 - Document ID: US10374477B2 - Status: Granted - Kind: B2 - Application number: 15/461,654 - Filed: 2017-03-17 - Published: 2018-09-20 - Granted: 2019-08-06 - Earliest claimed: 2017-03-17 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Daniel Alan Niergarth; Darek Tomasz Zatorski; David William Crall - Web page: https://patentgrep.com/patent/US10374477B2 ## CPC - H02K 1/30: using intermediate parts, e.g. spiders - F01D 1/00: Non-positive-displacement machines or engines, e.g. steam turbines (wit working-fluid flows in opposite axial directions for balancing axial thrust F01D3/02; with other than pure rotation F01D23/00; turbines characterised by their use in special steam systems, cycles, or processes, regulating devices therefor F01K) - F01D 15/10: Adaptations for driving, or combinations with, electric generators - F04D 19/002: {Axial flow fans} - H02K 1/2796: where both axial sides of the rotor face a stator - H02K 7/1823: {structurally associated with turbines or similar engines} - F05D 2220/32: in gas turbines - H02K 21/24: with magnets axially facing the armatures, e.g. hub-type cycle dynamos - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - 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 The present disclosure is directed to an electric machine defining a longitudinal direction, a radial direction, and a circumferential direction, and an axial centerline defined along the longitudinal direction. The electric machine includes a rotor assembly that includes a plurality of carriers arranged along the circumferential direction. Each pair of carriers defines a carrier gap therebetween along the circumferential direction, and each carrier includes a rotor magnet. The rotor assembly further includes an outer ring radially outward of and surrounding the plurality of carriers along the circumferential direction, the outer ring defining a unitary structure. ## Claims ### Claim 1 An electric machine defining a longitudinal direction, a radial direction, and a circumferential direction, and an axial centerline defined along the longitudinal direction, the electric machine comprising: a rotor assembly comprising a plurality of carriers arranged along the circumferential direction, wherein each pair of carriers defines a carrier gap therebetween along the circumferential direction, and wherein each carrier includes a separate rotor magnet, wherein the carrier gaps prevent transfer of hoop stresses from one carrier to another along the circumferential direction, and further wherein the rotor assembly comprises an outer ring radially outward of and surrounding the plurality of carriers along the circumferential direction, the outer ring defining a unitary structure attached to each of the plurality of carriers so as to transfer the hoop stresses from the plurality of carriers. ### Claim 2 (depends on 1) The electric machine of claim 1, wherein the rotor assembly further comprises a hub disposed radially inward of the plurality of carriers, wherein the hub is coupled to each carrier. ### Claim 3 (depends on 2) The electric machine of claim 2, wherein the hub comprises a plurality of members, wherein each member is coupled to each carrier. ### Claim 4 (depends on 3) The electric machine of claim 3, wherein the hub further comprises an inner ring to which the plurality of members is coupled. ### Claim 5 (depends on 4) The electric machine of claim 4, wherein each member defines a first portion and a second portion, wherein the second portion is coupled to the carrier and the first portion is coupled to the inner ring of the hub. ### Claim 6 (depends on 3) The electric machine of claim 3, wherein each member defines a second portion and a third portion, wherein the third portion is disposed toward a first end of each carrier and the second portion is disposed toward a second end of each carrier opposite of the first end along the longitudinal direction, and wherein each carrier is retained within each member along the longitudinal direction and/or circumferential direction. ### Claim 7 (depends on 3) The electric machine of claim 3, wherein the electric machine defines a load path from the inner ring of the hub to each of the plurality of members, and from each member to each carrier, and from the plurality of carriers to the outer ring. ### Claim 8 (depends on 2) The electric machine of claim 2, wherein the electric machine defines a load path from the hub to each carrier to the outer ring. ### Claim 9 (depends on 1) The electric machine of claim 1, wherein the outer ring defines a tangential stress carrying member. ### Claim 10 (depends on 1) The electric machine of claim 1, further comprising: a stator assembly adjacent along the longitudinal direction to the plurality of carriers. ### Claim 11 (depends on 10) The electric machine of claim 10, wherein the stator assembly comprises a plurality of stator conductors adjacent to the rotor magnet of each carrier, and wherein a clearance gap is defined between the stator conductor and the rotor magnet. ### Claim 12 (depends on 1) The electric machine of claim 1, wherein the outer ring comprises a ceramic matrix composite, a metal matrix composite, or a polymer matrix composite. ### Claim 13 (depends on 12) The electric machine of claim 12, wherein the outer ring comprises a plurality of fibers, and wherein the fibers include para-aramid synthetic fibers, metal fibers, ceramic fibers, glass fibers, carbon fibers, boron fibers, p-phenylenetherephtalamide fibers, aromatic polyamide fibers, silicon carbide fibers, graphite fibers, nylon fibers, ultra-high molecular weight polyethylene fibers, or mixtures thereof. ### Claim 14 A gas turbine engine defining a longitudinal direction, a radial direction, and a circumferential direction, and an axial centerline defined along the longitudinal direction, the engine comprising: an electric machine comprising a plurality of carriers arranged along the circumferential direction, wherein each pair of carriers defines a carrier gap therebetween, and wherein each carrier includes a separate rotor magnet, wherein the carrier gaps prevent transfer of hoop stresses from one carrier to another along the circumferential direction, and wherein the electric machine comprises an outer ring radially outward of and surrounding the plurality of carriers along the circumferential direction, wherein the outer ring defines a unitary structure attached to each of the plurality of carriers so as to transfer the hoop stresses from the plurality of carriers, and further wherein the electric machine further comprises a hub disposed radially inward of the plurality of carriers, wherein the hub retains each carrier along at least the longitudinal direction and the circumferential direction; and a driveshaft extended along the longitudinal direction and rotatable about the axial centerline, wherein the hub of the electric machine is coupled to the driveshaft. ### Claim 15 (depends on 14) The gas turbine engine of claim 14, wherein the electric machine further defines a plurality of members, and wherein each member of the electric machine defines a first portion and a second portion, wherein the second portion is coupled to each carrier and the first portion is coupled to the inner ring. ### Claim 16 (depends on 14) The gas turbine engine of claim 14, wherein the electric machine further defines a plurality of members, and wherein each member defines a second portion and a third portion, wherein the third portion is disposed toward a first end of each carrier and the second portion is disposed toward a second end of each carrier opposite of the first end along the longitudinal direction, and wherein each carrier is retained within each member along the longitudinal direction and/or circumferential direction. ### Claim 17 (depends on 14) The gas turbine engine of claim 14, wherein the inner ring of the hub is coupled to the driveshaft. ### Claim 18 (depends on 14) The gas turbine engine of claim 14, wherein the driveshaft defines a low pressure shaft, intermediate pressure shaft, or a high pressure shaft. ### Claim 19 (depends on 14) The gas turbine engine of claim 14, the engine further comprising: a stator assembly adjacent along the longitudinal direction to the plurality of carriers, wherein the stator assembly comprises a plurality of stator conductors adjacent to the rotor magnet of each carrier, and wherein a clearance gap is defined between the stator conductor and the rotor magnet. ### Claim 20 (depends on 19) The gas turbine engine of claim 19, the engine further comprising: a frame disposed within a fan assembly, a compressor section, or a turbine section, and wherein the stator assembly is coupled to the frame.