# US 12,009,702 B2 · Permanent magnet generator systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,702 B2 - Document ID: US12009702B2 - Status: Granted - Kind: B2 - Application number: 17/747,799 - Filed: 2022-05-18 - Published: 2023-12-28 - Granted: 2024-06-11 - Earliest claimed: 2022-05-18 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Andrew R. Wilkinson; Dhaval S. Patel - Web page: https://patentgrep.com/patent/US12009702B2 ## CPC - H02K 1/30: using intermediate parts, e.g. spiders - H02K 11/24: Devices for sensing torque, or actuated thereby (H02K11/27 takes precedence) - H02K 1/278: Surface mounted magnets; Inset magnets - H02K 21/024: {Radial air gap machines} - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A permanent magnet generator (PMG) system can include a stator configured to output a voltage, and a rotor assembly configured to be magnetically coupled to the stator and to rotate relative to the stator to induce the voltage. The rotor assembly can be configured to passively attenuate the voltage output from the stator in response to acceleration of the rotor assembly at or above an impulse acceleration threshold. ## Claims ### Claim 1 A permanent magnet generator (PMG) system, comprising: a stator configured to output a voltage; and a rotor assembly configured to be magnetically coupled to the stator and to rotate relative to the stator to induce the voltage, wherein the rotor assembly is configured to passively attenuate the voltage output from the stator in response to acceleration of the rotor assembly at or above an impulse acceleration threshold, wherein the rotor assembly includes: a rotor having one or more permanent magnets disposed therein, wherein the rotor is configured to move between a maximum coupling position and a misaligned position where the rotor is at least partially decoupled from the stator to cause the stator to output less voltage than in the maximum coupling position; and a biasing member configured to bias the rotor to the maximum coupling position, wherein the biasing member is configured to hold the rotor in the maximum coupling position until the rotor accelerates at or above the impulse acceleration threshold. ### Claim 2 (depends on 1) The system of claim 1, wherein the rotor assembly includes: a shaft; wherein the rotor is slidably connected to the shaft to slide between the maximum coupling position where the rotor is magnetically coupled to the stator to cause the stator to output a maximum voltage, and the misaligned position where the rotor is at least partially decoupled from the stator to cause the stator to output less than the maximum voltage. ### Claim 3 (depends on 2) The system of claim 2, wherein the biasing member is a coil spring disposed coaxially around the shaft. ### Claim 4 (depends on 3) The system of claim 3, wherein the rotor assembly includes one or more linear guides configured to rotationally fix the rotor to the shaft, and to allow the rotor to slide relative to the shaft. ### Claim 5 (depends on 4) The system of claim 4, wherein the one or more linear guides extend from the shaft. ### Claim 6 (depends on 5) The system of claim 5, wherein the rotor includes one or more guide channels configured to receive the one or more linear guides. ### Claim 7 (depends on 6) The system of claim 6, wherein the rotor assembly includes a backstop assembly configured to provide a back stop to the biasing member. ### Claim 8 (depends on 7) The system of claim 7, wherein the rotor includes a threaded end. ### Claim 9 (depends on 8) The system of claim 8, wherein the backstop assembly includes a lock nut configured to mesh to the threaded end of the shaft, wherein the biasing member is disposed between the lock nut and the rotor to bias the rotor. ### Claim 10 (depends on 9) The system of claim 9, wherein the backstop assembly includes a tuning collar disposed between the lock nut and the biasing member to act as a backstop surface for the biasing member. ### Claim 11 (depends on 10) The system of claim 10, wherein the tuning collar includes one or more guide channels defined therein to receive the one or more linear guides. ### Claim 12 A rotor assembly for a permanent magnet generator (PMG), wherein the rotor assembly is configured to be magnetically coupled to a stator and to rotate relative to the stator to induce a voltage output from the stator, wherein the rotor assembly is configured to passively attenuate the voltage output from the stator in response to acceleration of the rotor assembly at or above an impulse acceleration threshold, wherein the rotor assembly includes: a rotor having one or more permanent magnets disposed therein, wherein the rotor is configured to move between a maximum coupling position and a misaligned position where the rotor is at least partially decoupled from the stator to cause the stator to output less voltage than in the maximum coupling position; and a biasing member configured to bias the rotor to the maximum coupling position, wherein the biasing member is configured to hold the rotor in the maximum coupling position until the rotor accelerates at or above the impulse acceleration threshold. ### Claim 13 (depends on 12) The assembly of claim 12, further comprising: a shaft; wherein the rotor is slidably connected to the shaft to slide between the maximum coupling position where the rotor is magnetically coupled to the stator to cause the stator to output a maximum voltage, and the misaligned position where the rotor is at least partially decoupled from the stator to cause the stator to output less than the maximum voltage. ### Claim 14 (depends on 13) The assembly of claim 13, wherein the biasing member is a coil spring disposed coaxially around the shaft. ### Claim 15 (depends on 13) The assembly of claim 13, wherein the rotor assembly includes one or more linear guides configured to rotationally fix the rotor to the shaft, and to allow the rotor to slide relative to the shaft. ### Claim 16 (depends on 15) The assembly of claim 15, wherein the one or more linear guides extend from the shaft. ### Claim 17 (depends on 16) The assembly of claim 16, wherein the rotor includes one or more guide channels configured to receive the one or more linear guides. ### Claim 18 (depends on 17) The assembly of claim 17, wherein the rotor assembly includes a backstop assembly configured to provide a back stop to the biasing member. ### Claim 19 (depends on 18) The assembly of claim 18, wherein the rotor includes a threaded end. ### Claim 20 (depends on 19) The assembly of claim 19, wherein the backstop assembly includes a lock nut configured to mesh to the threaded end of the shaft, wherein the biasing member is disposed between the lock nut and the rotor to bias the rotor.