# US 2023/0412013 A1 · Synchronous electrical machine, and associated propulsion oriented drive device, boat, and method for cooling such a machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0412013 A1 - Document ID: US20230412013A1 - Status: Published application - Kind: A1 - Application number: 18/319,341 - Filed: 2023-05-17 - Published: 2023-12-21 - Earliest claimed: 2022-05-17 - Assignees: GE Energy Power Conversion Technology Limited - Applicants: Ge Energy Power Conversion Technology Limited - Inventors: Nicolas LEBOEUF; Lionel JULLIAND; Theo GRALL - Web page: https://patentgrep.com/patent/US20230412013A1 ## CPC - H02K 1/20: with channels or ducts for flow of cooling medium - B63H 21/17: by electric motor - B63H 21/383: {for handling cooling-water (in outboard drives B63H20/28; in machines or engines in general F01P3/00)} - H02K 9/12: wherein the cooling medium circulates freely within the casing - B63H 2005/1258: {with electric power transmission to propellers, i.e. with integrated electric propeller motors} - H02K 5/207: {with openings in the casing specially adapted for ambient air} - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) ## Abstract Provided is a synchronous electrical machine that includes a machine housing having a stator and a rotor lodged in the stator, the rotor being separated from the stator by an airgap, and the machine housing dissipating thermal losses generated by the stator. The stator having stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or spacers to form an extraction duct connected to the channel, the machine housing further having an extraction opening so that a fluid injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the opening to cool the stator and the rotor. ## Claims ### Claim 1 A synchronous electrical machine comprising: a machine housing including a stator and a rotor lodged in the stator, the rotor being separated from the stator by an airgap, the machine housing being configured to dissipate thermal losses generated by the stator, characterized in that the stator comprises stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or spacers to form an extraction duct connected to the channel, the machine housing further comprising an extraction opening so that a fluid injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the opening to cool the stator and the rotor. ### Claim 2 (depends on 1) The synchronous electrical machine according to claim 1, wherein the stator comprises a plurality of tie rods passing through the stacks of laminations and evenly distributed along a diameter of the stator to maintain the stacks of lamination compacted, the channel being disposed on the said diameter. ### Claim 3 (depends on 2) The synchronous electrical machine according to claim 2, wherein the stator comprises a plurality of channels evenly distributed along the said diameter, at least one channel being interposed between two tie rods. ### Claim 4 (depends on 2) The synchronous electrical machine according to claim 2, wherein the tie rods are made of non-magnetic material. ### Claim 5 (depends on 1) The synchronous electrical machine according to claim 1, wherein the rotor comprises permanent magnets. ### Claim 6 (depends on 4) The synchronous electrical machine according to claim 4, wherein the rotor comprises permanent magnets. ### Claim 7 (depends on 6) The synchronous electrical machine according to claim 6, wherein the permanent magnets are arranged in U or V shapes. ### Claim 8 (depends on 1) The synchronous electrical machine according to claim 1, wherein the rotor comprises a plurality of magnetic rotor pole cores evenly distributed around the rotor and rotor coils, each rotor coil being wounded around a different magnetic rotor pole core, the said machine comprising supply means to fed the rotor coils. ### Claim 9 (depends on 1) A propulsion oriented drive device for a boat comprising: a propulsion module intended to be submerged in another fluid and a synchronous electrical machine according to claim 1, the machine housing being inserted in a casing of the propulsion module so that a part of the thermal losses generated by the machine is transferred to the casing and evacuated in the other fluid, the propulsion oriented drive device further comprising cooling means to cool the machine with the fluid, the cooling means comprising injecting means to inject the fluid in the air gap at each ends of the stator and evacuation means connected to the extraction opening so that the fluid heated by the machine escapes the machine. ### Claim 10 (depends on 9) The propulsion oriented drive device for a boat according to claim 9, wherein the supply means comprising at least one supply pipe connecting the ends of the machine and configured to supply the fluid, and the evacuation means comprise an evacuation pipe connected to the evacuation opening. ### Claim 11 (depends on 9) A boat comprising a hull and a propulsion oriented drive device according to claim 9, and a cooling fluid unit configured to cool the fluid flowing through the evacuation means and configured to feed the injecting means with cooled fluid. ### Claim 12 (depends on 11) The boat according to claim 11, wherein the cooling fluid unit is located in the casing. ### Claim 13 A method for cooling a synchronous electrical machine comprising a machine housing including a stator and a rotor lodged in the stator, the rotor being separated from the stator by an airgap, the stator comprises stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or spacers to form an extraction duct connected to the channel, the machine housing further comprising an extraction opening, the method comprising: injecting a fluid in the airgap at the ends of the stator so that the fluid flows in the extraction duct and in the channel and is extracted from the machine through the opening to cool the stator, and transferring the thermal losses conducted by the machine housing to another fluid.