# US 12,597,813 B2 · Electric motor with coolant flow at stator slots > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,597,813 B2 - Document ID: US12597813B2 - Status: Granted - Kind: B2 - Application number: 18/121,087 - Filed: 2023-03-14 - Published: 2024-09-19 - Granted: 2026-04-07 - Earliest claimed: 2023-03-14 - Assignees: BorgWarner Inc. - Applicants: BorgWarner Inc. - Inventors: Michael D. Bradfield - Web page: https://patentgrep.com/patent/US12597813B2 ## CPC - H02K 1/20: with channels or ducts for flow of cooling medium - H02K 3/24: with channels or ducts for cooling medium between the conductors - H02K 5/203: {specially adapted for liquids, e.g. cooling jackets} - H02K 9/19: for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil - H02K 9/197: in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract An electric motor can be employed for use in a hybrid electric vehicle (HEV) or in a battery electric vehicle (BEV), as example applications. In an implementation, the electric motor has a stator assembly with a multitude of laminations exhibiting an axially-stacked arrangement. The laminations establish coolant channels at a radially-outboard location thereof, and establish slots at a radially-inboard location thereof. Conductors such as windings are disposed at the slots. Some or more of the coolant channels and some or more of the slots are in fluid communication with each other whereby coolant flows through the coolant channels, to the slots, and into contact with the conductors. Enhanced cooling effectiveness at the stator and elsewhere results. ## Claims ### Claim 1 An electric motor, comprising: a housing; a rotor assembly at least partially located in the housing; and a stator assembly at least partially located in the housing, the stator assembly including a plurality of laminations, at least some of the plurality of laminations having a plurality of fins at a radially-outboard location of the plurality of laminations, the plurality of fins establishing coolant channels among the plurality of laminations at the radially-outboard location, the plurality of laminations establishing slots at a radially-inboard location of the plurality of laminations, wherein at least some of the coolant channels and at least some of the slots fluidly communicate with each other for coolant flow through the coolant channels and to the slots and into contact with conductors residing at the slots. ### Claim 2 (depends on 1) The electric motor as set forth in claim 1, wherein sets of the plurality of fins have a circumferentially staggered arrangement in order to establish the coolant channels among the plurality of laminations at the radially-outboard location. ### Claim 3 (depends on 1) The electric motor as set forth in claim 1, wherein the fluid communication between the at least some coolant channels and the at least some slots is established via radially-overlapping regions of working coolant channels and working slots, coolant passages residing at the radially-overlapping regions and coolant flow passing through the coolant passages and to the slots and into contact with the conductors residing at the slots. ### Claim 4 (depends on 1) The electric motor as set forth in claim 1, wherein the fluid communication between the at least some coolant channels and the at least some slots is established via axially-interfacial regions of working coolant channels and working slots, coolant passages residing at the axially-interfacial regions and coolant flow passing through the coolant passages and to the slots and into contact with the conductors residing at the slots. ### Claim 5 (depends on 1) The electric motor as set forth in claim 1, wherein the fluid communication between the at least some coolant channels and the at least some slots is established via increased radially-outward extents of working slots of a set of laminations of the plurality of laminations. ### Claim 6 (depends on 1) The electric motor as set forth in claim 1, wherein the fluid communication between the at least some coolant channels and the at least some slots is via a set of laminations of the plurality of laminations, the set of laminations having an axially-central location relative to axially-end locations of the plurality of laminations, and coolant flows at the slots from the axially-central locations to the axially-end locations. ### Claim 7 (depends on 1) The electric motor as set forth in claim 1, further comprising a plurality of liners situated in the slots at least partially around the conductors, at least some of the plurality of liners having at least one coolant hole residing therein and adjacent the fluid communication between the at least some coolant channels and the at least some slots, coolant flow passing through the at least one coolant holes and to interiors of the at least some liners and into contact with the conductors residing thereat. ### Claim 8 (depends on 7) The electric motor as set forth in claim 7, further comprising a plurality of inserts situated in working slots of the at least some slots and adjacent the at least one coolant holes of the at least some liners. ### Claim 9 (depends on 1) The electric motor as set forth in claim 1, wherein the fluid communication between the at least some coolant channels and the at least some slots is established via increased radially-outward extents of working slots of a set of laminations of the plurality of laminations, and the electric motor further comprises: a plurality of liners situated in the slots at least partially around the conductors, the plurality of liners having at least one coolant hole residing therein, coolant flow passing through the at least one coolant holes and into contact with the conductors residing at the slots; and a plurality of inserts situated in the increased radially-outward extents of the working slots. ### Claim 10 (depends on 9) The electric motor as set forth in claim 9, wherein the plurality of inserts is positioned radially-outward of the at least one coolant holes of the plurality of liners. ### Claim 11 (depends on 10) The electric motor as set forth in claim 10, wherein coolant passages reside between the plurality of inserts and the plurality of liners, and coolant flow passes through the coolant passages and through the at least one coolant holes and into contact with the conductors residing at the slots. ### Claim 12 An electric motor, comprising: a stator assembly comprising: a plurality of laminations with an axially-stacked arrangement, the plurality of laminations establishing coolant channels among the plurality of laminations at a radially-outboard location of the plurality of laminations, the plurality of laminations establishing slots at a radially-inboard location of the plurality of laminations, working slots of the slots having increased radially-outward extents, the increased radially-outward extents fluidly communicable with working coolant channels of the coolant channels; conductors residing at the slots; and a plurality of liners situated in the slots at least partially around the conductors, the plurality of liners having at least one coolant hole residing therein, the at least one coolant holes fluidly communicable with the increased radially-outward extents of the working slots. ### Claim 13 (depends on 12) The electric motor as set forth in claim 12, wherein the stator assembly further comprises a plurality of inserts situated in the increased radially-outward extents of the working slots. ### Claim 14 (depends on 13) The electric motor as set forth in claim 13, wherein the plurality of inserts is positioned radially-outward of the at least one coolant holes of the plurality of liners in order to provide electrical isolation thereat between the plurality of laminations and the conductors. ### Claim 15 (depends on 12) The electric motor as set forth in claim 12, wherein the plurality of laminations has a plurality of fins, the plurality of fins establishing the coolant channels at the radially-outboard location of the plurality of laminations. ### Claim 16 (depends on 12) The electric motor as set forth in claim 12, wherein the working slots reside in a set of laminations of the plurality of laminations, the set of laminations having axially-central locations in the axially-stacked arrangement of the plurality of laminations. ### Claim 17 An electric motor, comprising: a housing; a rotor assembly at least partially located in the housing; and a stator assembly at least partially located in the housing, the stator assembly comprising: a plurality of laminations with an axially-stacked arrangement, the plurality of laminations having a plurality of fins, the plurality of fins establishing coolant channels among the plurality of laminations at a radially-outboard location of the plurality of laminations, the plurality of laminations establishing slots at a radially-inboard location of the plurality of laminations, working slots of the slots fluidly communicable with working coolant channels of the coolant channels; conductors residing at the slots; a plurality of liners situated in the slots at least partially around the conductors, the plurality of liners having at least one coolant hole residing therein, the at least one coolant holes fluidly communicable with the working slots; and a plurality of inserts situated in the working slots. ### Claim 18 (depends on 17) The electric motor as set forth in claim 17, wherein the plurality of inserts is positioned radially-outward of the at least one coolant holes of the plurality of liners. ### Claim 19 (depends on 18) The electric motor as set forth in claim 18, wherein the working slots reside in a set of laminations of the plurality of laminations, the set of laminations having axially-central locations in the axially-stacked arrangement of the plurality of laminations. ### Claim 20 (depends on 19) The electric motor as set forth in claim 19, wherein, amid use of the electric motor, coolant flow passes through the working coolant channels, through the working slots, through the at least one coolant holes, into contact with the conductors, and to axially-end locations in the axially-stacked arrangement of the plurality of laminations.