# US 11,996,746 B2 · Method and apparatus for transfer molding of electric motor cores and magnetizable inserts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,996,746 B2 - Document ID: US11996746B2 - Status: Granted - Kind: B2 - Application number: 17/161,175 - Filed: 2021-01-28 - Published: 2022-07-28 - Granted: 2024-05-28 - Earliest claimed: 2021-01-28 - Assignees: Ford Global Technologies, LLC; ABB AB - Applicants: Ford Global Technologies, LLC; ABB Inc. - Inventors: Mark E. Briscoe; Nick Sochacki; Al Marrocco; Jeffrey Cameron; Michael Mollan - Web page: https://patentgrep.com/patent/US11996746B2 ## CPC - H02K 15/03: having permanent magnets - H02K 15/12: Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines - H02K 1/2766: {having a flux concentration effect} - H02K 2201/06: Magnetic cores, or permanent magnets characterised by their skew - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A method of securing magnetizable inserts within cores of an electric converter includes placing an assembly of rotor cores in a transfer molding press, the magnetizable inserts being disposed within cavities of the rotor cores and the cavities of the rotor cores being in fluid communication, placing a polymer preform proximate a central portion of the assembly of rotor cores, displacing the polymer preform such that the polymer preform changes state and flows radially and then axially through each of the cavities of the rotor cores, removing the assembly of rotor cores from the transfer molding press, and removing polymer waste from the assembly of rotor cores. ## Claims ### Claim 1 A method of securing magnetizable inserts within cores of an electric converter, the method comprising: placing an assembly of rotor cores in a transfer molding press, the magnetizable inserts being disposed within cavities of the rotor cores and the cavities of the rotor cores being in fluid communication; placing a polymer preform proximate a central portion of the assembly of rotor cores; displacing the polymer preform such that the polymer preform changes state and flows radially and then axially through the cavities of the rotor cores; removing the assembly of rotor cores from the transfer molding press; and removing polymer waste from the assembly of rotor cores, wherein the assembly of rotor cores is weighed before being placed into the transfer molding press and is weighed after being removed from the transfer molding press, wherein a difference in weight is compared with a predefined weight value to determine a fill volume of the cavities. ### Claim 2 (depends on 1) The method according to claim 1, wherein the assembly of rotor cores is preheated before being placed into the transfer molding press. ### Claim 3 (depends on 1) The method according to claim 1, wherein the polymer preform is preheated before being placed into the transfer molding press. ### Claim 4 (depends on 1) The method according to claim 1, wherein the assembly of rotor cores is placed into the transfer molding press and removed from the transfer molding press by a robot. ### Claim 5 (depends on 1) The method according to claim 1, wherein the polymer preform defines a cylindrical geometry. ### Claim 6 (depends on 1) The method according to claim 1, wherein the polymer preform is a thermoset material. ### Claim 7 (depends on 1) The method according to claim 1, wherein the polymer preform is displaced vertically such that the polymer flows distally, in a gravitational direction, through the cavities. ### Claim 8 (depends on 1) The method according to claim 1, wherein the assembly of rotor cores further comprises upper and lower tooling. ### Claim 9 (depends on 1) The method according to claim 1, wherein the cavities of the rotor cores are radially staggered between adjacent rotor cores. ### Claim 10 A method of securing magnetizable inserts within cores of an electric converter, the method comprising: weighing an assembly of rotor cores, the magnetizable inserts being disposed within cavities of the rotor cores and the cavities of the rotor cores being in fluid communication; preheating the assembly of rotor cores; placing the assembly of rotor cores in a transfer molding press; preheating a polymer preform; placing the preheated polymer preform proximate a central portion of the assembly of rotor cores; displacing the polymer preform such that the polymer preform changes state and flows radially and then axially through the cavities of the rotor cores to form a bonded assembly; removing the bonded assembly from the transfer molding press; removing polymer waste from the bonded assembly; and weighing the bonded assembly. ### Claim 11 (depends on 10) The method according to claim 10, wherein the assembly of rotor cores further comprises upper and lower tooling, wherein the upper tooling and the polymer waste are removed before weighing the bonded assembly. ### Claim 12 (depends on 11) The method according to claim 11, wherein the assembly of rotor cores is placed into the transfer molding press and removed from the transfer molding press by a robot. ### Claim 13 (depends on 10) The method according to claim 10, wherein the polymer preform defines a cylindrical geometry. ### Claim 14 (depends on 10) The method according to claim 10, wherein the polymer preform is a thermoset material. ### Claim 15 (depends on 10) The method according to claim 10, wherein the cavities of the rotor cores are radially staggered between adjacent rotor cores. ### Claim 16 (depends on 10) The method according to claim 10, wherein the polymer preform is displaced vertically such that the polymer flows distally, in a gravitational direction, through the cavities. ### Claim 17 (depends on 10) The method according to claim 10, wherein a difference in weight between the weight of the bonded assembly and the weight of the assembly of rotor cores is compared with a predefined weight value to determine a fill volume of the cavities. ### Claim 18 (depends on 10) The method according to claim 10, wherein the polymer preform is displaced by applying heat and pressure. ### Claim 19 (depends on 10) The method according to claim 10, further comprising curing the polymer preform before removing the bonded assembly from the transfer molding press.