# US 11,309,760 B2 · Rotary electric machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,760 B2 - Document ID: US11309760B2 - Status: Granted - Kind: B2 - Application number: 16/734,450 - Filed: 2020-01-06 - Published: 2020-07-23 - Granted: 2022-04-19 - Earliest claimed: 2019-01-22 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Masashi Matsumoto; Hazuki Kawamura; Kohei Watanabe; Yuki Tanaka; Haruki Kusamaki - Web page: https://patentgrep.com/patent/US11309760B2 ## CPC - H02K 3/24: with channels or ducts for cooling medium between the conductors - H02K 1/20: with channels or ducts for flow of cooling medium - H02K 1/32: with channels or ducts for flow of cooling medium - H02K 3/12: arranged in slots - H02K 3/22: consisting of hollow conductors - H02K 3/34: between conductors or between conductor and core, e.g. slot insulation - H02K 3/48: in slots - H02K 9/19: for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A rotary electric machine includes a stator core having a plurality of teeth arranged in a row along a circumferential direction of the stator core, and a stator coil composed of a winding wire wound around the teeth. The stator coil includes coil end portions extending, outside the stator core in an axial direction thereof, along a substantially circumferential direction of the stator core, and straight portions extending along the axial direction, the straight portions being at least partially housed in a slot which is a void defined by two adjacent teeth of the plurality of teeth. In the rotary electric machine, a cooling groove is formed at least in the straight portion, the cooling groove functioning as a cooling channel through which a cooling fluid flows, and each straight portion includes only one cooling channel. ## Claims ### Claim 1 A rotary electric machine comprising: a stator core including a plurality of teeth arranged in a row along a circumferential direction of the stator core; and a stator coil composed of a winding wire wound around one or more of the plurality of teeth, wherein: the stator coil includes coil end portions extending, outside the stator core in an axial direction thereof, along a substantially circumferential direction of the stator core, and straight portions extending along the axial direction, the straight portions being at least partially housed in a slot which is a void defined by two adjacent teeth of the plurality of teeth, a cooling groove is formed at least in the straight portion, the cooling groove being configured to function as a cooling channel through which a cooling fluid flows, only one cooling groove is formed for each of the straight portions, the cooling groove being formed only in the straight portion, and is not formed in the coil end portion, and the stator coil further includes a first segment coil functioning as the straight portion, and a second segment coil functioning as the coil end portion, the second segment coil being an independent member separated from the first segment coil and joined to the first segment coil by a joint pipe. ### Claim 2 (depends on 1) The rotary electric machine according to claim 1, wherein: each slot houses two or more of the straight portions; and among the two or more of the straight portions, adjacent straight portions within the slot are placed in a position where cooling grooves of the adjacent straight portions are opposed to each other. ### Claim 3 (depends on 1) The rotary electric machine according to claim 1 further comprising: a rotor concentrically arranged inside a stator, the rotor including a cooling channel which extends to an outer circumferential end of the rotor along a radial direction thereof, wherein one of the straight portions that is arranged at a radial innermost position within the slot has the cooling groove formed in a radial inner end face of the one of the straight portions. ### Claim 4 (depends on 1) The rotary electric machine according to claim 1, wherein the cooling groove has a substantially semicircular shape in cross section. ### Claim 5 A rotary electric machine comprising: a stator core including a plurality of teeth arranged in a row along a circumferential direction of the stator core; a stator coil composed of a winding wire wound around one or more of the plurality of teeth, wherein the stator coil includes coil end portions extending, outside the stator core in an axial direction thereof, along a substantially circumferential direction of the stator core, and straight portions extending along the axial direction, the straight portions being at least partially housed in a slot which is a void defined by two adjacent teeth of the plurality of teeth, a cooling groove is formed at least in the straight portion, the cooling groove being configured to function as a cooling channel through which a cooling fluid flows, and only one cooling groove is formed for each of the straight portion, the cooling groove being formed on one of circumferential end faces of the straight portion, and wherein the rotary electric machine is installed in a position in which an axial direction of the rotary electric machine intersects the direction of gravity and further includes a cooling pipe configured to discharge a cooling fluid toward the coil end portion from above the coil end portion in the direction of gravity, and the cooling groove is formed in only one of the circumferential end faces of the straight portion, the one being located on an upper side of the straight portion in the direction of gravity. ### Claim 6 A rotary electric machine comprising: a stator core including a plurality of teeth arranged in a row along a circumferential direction of the stator core; and a stator coil composed of a winding wire wound around one or more of the plurality of teeth, wherein the stator coil comprises coil end portions extending, outside the stator core in an axial direction thereof, along a substantially circumferential direction of the stator core, and straight portions extending along the axial direction, the straight portions being at least partially housed in a slot which is a void defined by two adjacent teeth of the plurality of teeth, a cooling groove is formed at least in the straight portion, the cooling groove being configured to function as a cooling channel through which a cooling fluid flows, and only one cooling groove is formed for each of the straight portions, the cooling groove being formed in only one of circumferential end faces of the straight portion that is located upstream in a direction of forward rotation of the rotor.