# US 2023/0067680 A1 · Electric motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0067680 A1 - Document ID: US20230067680A1 - Status: Published application - Kind: A1 - Application number: 17/895,788 - Filed: 2022-08-25 - Published: 2023-03-02 - Earliest claimed: 2021-08-25 - Assignees: Milwaukee Electric Tool Corporation - Applicants: Milwaukee Electric Tool Corporation - Inventors: Keith M. KLOSTERMAN; Matthew R. BAILEY; Jorge L. IBARRA; Lu YANG; Hongru HUANG - Web page: https://patentgrep.com/patent/US20230067680A1 ## CPC - H02K 3/522: {for generally annular cores with salient poles} - H02K 7/145: {Hand-held machine tool} - H02K 5/15: Mounting arrangements for bearing-shields or end plates - H02K 5/1732: {radially supporting the rotary shaft at both ends of the rotor (H02K5/1737 takes precedence)} - H02K 11/33: Drive circuits, e.g. power electronics (H02K11/38 takes precedence) - H02K 9/06: with fans or impellers driven by the machine shaft - H02K 2203/03: Machines characterised by the wiring boards, i.e. printed circuit boards or similar structures for connecting the winding terminations - H02K 2203/09: Machines characterised by wiring elements other than wires, e.g. bus rings, for connecting the winding terminations - H02K 2211/03: Machines characterised by circuit boards, e.g. pcb - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A power tool includes a housing and an electric motor. The electric motor includes a rotor assembly including a rotor shaft and a stator assembly including a plurality of stator segments. Each stator segment includes a core, an insulator at least partially covering the core, and a coil winding. The insulator includes a mounting portion. The electric motor also includes a printed circuit board assembly configured to direct electric current to each coil winding, and a bus bar assembly attached to at least one of the mounting portions and configured to electrically connect the coil windings to the printed circuit board assembly. The bus bar assembly includes a molded body and a plurality of conductors. The bus bar assembly defines a bearing pocket. The electric motor further includes rotor bearing that is received into the bearing pocket and that supports the rotor shaft for rotation relative to the stator assembly. ## Claims ### Claim 1 A power tool comprising: a housing; and an electric motor including a rotor assembly including a rotor shaft, a stator assembly including a plurality of stator segments, each stator segment including a core, an insulator at least partially covering the core, and a coil winding, the insulator including a mounting portion, a printed circuit board assembly configured to direct electric current to each coil winding, a bus bar assembly attached to at least one of the mounting portions and configured to electrically connect the coil windings to the printed circuit board assembly, the bus bar assembly including a molded body and a plurality of conductors, the bus bar assembly defining a bearing pocket, and a rotor bearing that is received into the bearing pocket and that supports the rotor shaft for rotation relative to the stator assembly. ### Claim 2 (depends on 1) The power tool of claim 1, wherein the stator assembly further comprises a tubular housing that receives the plurality of stator segments. ### Claim 3 (depends on 1) The power tool of claim 1, wherein the plurality of stator segments comprises a first stator segment and a second stator segment adjacent the first stator segment in a circumferential direction. ### Claim 4 (depends on 3) The power tool of claim 3, wherein the first stator segment is affixed to the second stator segment by laser welding. ### Claim 5 (depends on 3) The power tool of claim 3, wherein the first stator segment includes a protrusion and the second stator segment includes a notch that receives the protrusion. ### Claim 6 (depends on 1) The power tool of claim 1, wherein the molded body includes a central hub that defines the bearing pocket and a plurality of arms extending radially outward from the central hub. ### Claim 7 (depends on 6) The power tool of claim 6, further comprising a fastener that extends through the printed circuit board assembly, through at least one arm of the plurality of arms, and into the at least one of the mounting portions. ### Claim 8 (depends on 1) The power tool of claim 1, wherein each conductor includes a terminal that protrudes in an axial direction of the motor. ### Claim 9 (depends on 8) The power tool of claim 8, wherein the printed circuit board assembly includes a plurality of apertures configured to receive the terminals. ### Claim 10 (depends on 9) The power tool of claim 9, wherein the terminals are soldered to the printed circuit board assembly. ### Claim 11 (depends on 8) The power tool of claim 8, wherein the conductors include tangs and the coil windings include wire leads that connect to the tangs. ### Claim 12 (depends on 11) The power tool of claim 11, wherein the wire lead is at least one of soldered to the tang or fused to the tang. ### Claim 13 (depends on 1) The power tool of claim 1, wherein the molded body defines a plurality of axially extending protrusions and the printed circuit board assembly defines a plurality of recesses that receive the axially extending protrusions. ### Claim 14 An electric motor comprising: a rotor assembly including a rotor shaft; a stator assembly including a plurality of stator segments, each stator segment including a core, an insulator at least partially covering the core and including a mounting portion, and a coil winding including a wire lead, the plurality of stator segments including a first stator segment and a second stator segment adjacent the first stator segment in a circumferential direction; and a printed circuit board assembly coupled to the mounting portions and configured to direct electric current to each coil winding; wherein the printed circuit board assembly includes a plurality of peripheral slots formed at intervals about a periphery thereof, and wherein the wire leads are received into the peripheral slots and soldered to electrically connect the wire leads to the printed circuit board assembly. ### Claim 15 (depends on 14) The electric motor of claim 14, wherein the plurality of stator segments comprises a first stator segment and a second stator segment adjacent the first stator segment in a circumferential direction. ### Claim 16 (depends on 15) The electric motor of claim 15, wherein the first stator segment is affixed to the second stator segment by laser welding. ### Claim 17 (depends on 15) The electric motor of claim 15, wherein the first stator segment includes a protrusion and the second stator segment includes a notch that receives the protrusion. ### Claim 18 (depends on 14) The electric motor of claim 14, wherein the printed circuit board assembly is coupled to the mounting portions via fasteners. ### Claim at position 19 -56. (canceled)