# US 12,184,122 B2 · Enhancements to cooling means for axial flux generators > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,122 B2 - Document ID: US12184122B2 - Status: Granted - Kind: B2 - Application number: 17/299,935 - Filed: 2019-12-06 - Published: 2022-02-17 - Granted: 2024-12-31 - Earliest claimed: 2018-12-06 - Assignees: Time To Act Limited - Applicants: Time to Act Limited - Inventors: Hugh-Peter Granville Kelly - Web page: https://patentgrep.com/patent/US12184122B2 ## CPC - H02K 1/20: with channels or ducts for flow of cooling medium - H02K 1/2798: where both axial sides of the stator face a rotor - H02K 3/24: with channels or ducts for cooling medium between the conductors - H02K 9/02: by ambient air flowing through the machine - H02K 9/06: with fans or impellers driven by the machine shaft - H02K 9/10: by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing - H02K 16/02: Machines with one stator and two {or more} rotors - H02K 16/04: Machines with one rotor and two stators - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A generator comprising a series of spaced annular stators sandwiched between a series of rotors, the rotors each being separated by annular collars, the annular collars defining a central cavity; at least one cooling gas source for supplying gas to the central cavity; vents through the annular collars for providing a means of egress for the cooling gas from the central cavity radially outwards over the rotors and the annular stators and the front, rear and side walls of coils embedded in the annular stators. ## Claims ### Claim 1 A generator comprising: at least one annular stator having an inner circumference and an outer circumference and a plurality of spaced coils within and around an axis of the annular stator; and at least one cooling gap for the flow of cooling fluid in the annular stator between adjacent coils of the plurality of spaced coils, the at least one cooling gap having an inner opening in the inner circumference and an outer opening in the outer circumference, wherein the at least one cooling gap between adjacent coils of the plurality of coils accommodates a sealed channel for conveying the cooling fluid. ### Claim 2 (depends on 1) The generator of claim 1, wherein the sealed channel is formed of a non-magnetic material with a thermal conductivity of at least 0.5 W/mK. ### Claim 3 (depends on 1) The generator of claim 1, wherein the sealed channel is formed of a non-electrically conducting material or has slits in it to prevent eddy currents being induced along its length. ### Claim 4 (depends on 1) The generator of claim 1, wherein the sealed channel is formed of a metal. ### Claim 5 (depends on 1) The generator of claim 1, wherein the sealed channel is formed as a tube. ### Claim 6 (depends on 1) The generator of claim 1, further comprising an inlet for the cooling fluid into the at least one cooling gap which is positioned axially in-line with the coils of the associated adjacent coils and/or circumferentially in-line with the at least one cooling gap. ### Claim 7 (depends on 1) The generator of claim 1, further comprising an outlet for the cooling fluid out of the at least one cooling gap which is positioned axially in-line with the coils of the associated adjacent coils and/or circumferentially in-line with the at least one cooling gap. ### Claim 8 (depends on 1) The generator of claim 1, wherein the coils are embedded in a material with a thermal conductivity of at least 0.5 W/mK. ### Claim 9 (depends on 1) The generator of claim 1, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps, and wherein each separate gap is shaped to maintain a distance to an associated coil of the adjacent coils substantially constant. ### Claim 10 (depends on 1) The generator of claim 1, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps, and wherein separate gaps from adjacent cooling gaps meet at a radially outer apex of a coil. ### Claim 11 (depends on 1) The generator of claim 1, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps, and wherein each of the separate gaps has a shape substantially corresponding to a shape of a radially outer portion of an associated coil. ### Claim 12 (depends on 1) The generator of claim 1, further comprising at least one accessible flow regulator for regulating the flow of cooling fluid through at least one of the at least one cooling gap. ### Claim 13 (depends on 1) The generator of claim 1, further comprising at least one rotor spaced apart from the at least one stator and comprising a plurality of magnets. ### Claim 14 (depends on 1) The generator of claim 1, wherein the sealed channel is formed of a non-magnetic material with a thermal conductivity of at least 1 W/mK. ### Claim 15 (depends on 1) The generator of claim 1, wherein the sealed channel is formed of a non-magnetic material with a thermal conductivity of at least 10 W/mK. ### Claim 16 (depends on 1) The generator of claim 1, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps at a radially outer end. ### Claim 17 A generator comprising: at least one annular stator having an inner circumference and an outer circumference and a plurality of spaced coils within and around an axis of the annular stator; and at least one cooling gap for the flow of cooling fluid in the annular stator between adjacent coils of the plurality of spaced coils, the at least one cooling gap having an inner opening in the inner circumference and an outer opening in the outer circumference, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps at a radially outer end; and at least one accessible flow regulator for regulating the flow of cooling fluid through at least one of the at least one cooling gap. ### Claim 18 (depends on 17) The generator of claim 17, wherein the flow regulator is a passive flow regulator. ### Claim 19 (depends on 17) The generator of claim 17, comprising a plurality of said flow regulators each associated with one of the at least one cooling gap, wherein said flow regulators are active flow regulators. ### Claim 20 (depends on 17) The generator of claim 17, further comprising a controller, wherein the controller controls the plurality of flow regulators according to signals representative of the temperature of a coil adjacent the associated cooling gap and/or pressure and/or flow rate of the cooling fluid cooling it. ### Claim 21 A generator comprising: at least one annular stator having an inner circumference and an outer circumference and a plurality of spaced coils within and around an axis of the annular stator; and at least one cooling gap for the flow of cooling fluid in the annular stator between adjacent coils of the plurality of spaced coils, the at least one cooling gap having an inner opening in the inner circumference and an outer opening in the outer circumference, wherein the at least one cooling gap between adjacent coils of the plurality of coils comprises two outer separate gaps at a radially outer end, and wherein the coils are embedded in a material with a thermal conductivity of at least 0.5 W/mK.