# US 10,770,994 B2 · Variable torque electric motor assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,994 B2 - Document ID: US10770994B2 - Status: Granted - Kind: B2 - Application number: 16/246,587 - Filed: 2019-01-14 - Published: 2019-05-30 - Granted: 2020-09-08 - Earliest claimed: 2017-10-26 - Assignees: Hamilton Sunstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Richard A. Poisson; Naison E. Mastrocola - Web page: https://patentgrep.com/patent/US10770994B2 ## CPC - H02P 6/32: Arrangements for controlling wound field motors, e.g. motors with exciter coils - H02K 19/12: characterised by the arrangement of exciting windings, e.g. for self-excitation, compounding or pole-changing - H02K 21/042: {with permanent magnets and field winding both rotating} - H02P 6/08: Arrangements for controlling the speed or torque of a single motor (H02P6/10, H02P6/28 take precedence) - H02P 25/03: with brushless excitation - H02K 2213/06: Machines characterised by the presence of fail safe, back up, redundant or other similar emergency arrangements - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract An actuator assembly includes an electric motor including a rotor assembly and a stator assembly configured to be actuated to cause the rotor assembly to rotate based on an amount of magnetic flux in the rotor assembly is disclosed. The assembly also includes a controllable magnetic device coupled to the rotor assembly, an actuator coupled to the rotor assembly; and a controller configured to apply electric current to the controllable magnetic device to adjust an amount of torque provided by the electric motor by adjusting the magnetic flux in the rotor assembly. ## Claims ### Claim 1 An actuator assembly comprising: an electric motor including a rotor assembly and a stator assembly configured to be actuated to cause the rotor assembly to rotate based on an amount of magnetic flux in the rotor assembly; a controllable magnetic device coupled to the rotor assembly; an actuator coupled to the rotor assembly; and a controller configured to apply electric current to the controllable magnetic device to adjust an amount of torque provided by the electric motor by adjusting the magnetic flux in the rotor assembly; wherein the controller includes field coupler coupled to the rotatable member and configured to rotate with the rotor assembly. ### Claim 2 (depends on 1) The actuator assembly of claim 1, wherein the controller is configured to apply the electric current in a first direction to increase the amount of torque by increasing the magnetic flux in the rotor assembly. ### Claim 3 (depends on 2) The actuator assembly of claim 2, wherein the controller is configured to apply the electric current in a second direction to decrease the amount of torque by decreasing the magnetic flux in the rotor assembly. ### Claim 4 (depends on 1) The actuator assembly of claim 1, wherein the field coupler is configured to be energized by stationary windings. ### Claim 5 (depends on 1) The actuator assembly of claim 1, wherein the controller includes a rectifier device configured to convert alternating current generated by the field coupler to direct current and apply the direct current to the controllable magnetic device. ### Claim 6 (depends on 1) The actuator assembly of claim 1, wherein the controllable magnetic device includes one or more windings coupled to the rotatable member. ### Claim 7 (depends on 1) The actuator assembly of claim 1, wherein the rotor assembly includes a permanent magnet. ### Claim 8 (depends on 7) The actuator assembly of claim 7, wherein the rotor assembly and the stator assembly form at least part of a brushless direct current (DC) motor. ### Claim 9 A method of controlling an actuator assembly comprising: actuating an electric motor by applying a first electric current to a stator assembly to cause rotation of a rotor assembly, the rotor assembly configured to rotate based on an amount of magnetic flux in the rotor assembly; causing movement of an actuator coupled to the rotor assembly; and applying a second electric current to a controllable magnetic device coupled to the rotor assembly, the second electric current causing an amount of torque provided by the electric motor to change by adjusting the magnetic flux in the rotor assembly; wherein the first electric current is applied in a first direction to increase the amount of torque by increasing the magnetic flux in the rotor assembly. ### Claim 10 (depends on 9) The method of claim 9, wherein the first electric current is applied in a second direction to decrease the amount of torque by decreasing the magnetic flux in the rotor assembly. ### Claim 11 (depends on 9) The method of claim 9, wherein the controllable magnetic device includes one or more windings coupled to the rotatable member. ### Claim 12 (depends on 9) The method of claim 9, wherein the rotor assembly includes a permanent magnet. ### Claim 13 (depends on 12) The method of claim 12, wherein the rotor assembly and the stator assembly form at least part of a brushless direct current (DC) motor. ### Claim 14 A method of controlling an actuator assembly comprising: actuating an electric motor by applying a first electric current to a stator assembly to cause rotation of a rotor assembly, the rotor assembly configured to rotate based on an amount of magnetic flux in the rotor assembly; causing movement of an actuator coupled to the rotor assembly; and applying a second electric current to a controllable magnetic device coupled to the rotor assembly, the second electric current causing an amount of torque provided by the electric motor to change by adjusting the magnetic flux in the rotor assembly; wherein the second electric current is applied via a field coupler coupled to the rotatable member and configured to rotate with the rotor assembly. ### Claim 15 (depends on 14) The method of claim 14, wherein the field coupler is configured to be energized by stationary windings. ### Claim 16 (depends on 14) The method of claim 14, wherein the field coupler is connected to a rectifier device configured to convert alternating current generated by the field coupler to direct current and apply the direct current to the controllable magnetic device.