# US 10,873,252 B2 · Turning device for a turbomachine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,252 B2 - Document ID: US10873252B2 - Status: Granted - Kind: B2 - Application number: 15/772,412 - Filed: 2016-10-27 - Published: 2018-11-08 - Granted: 2020-12-22 - Earliest claimed: 2015-10-30 - Assignees: Nuovo Pignone Tecnologie Srl - Applicants: Nuovo Pignone Tecnologie Srl - Inventors: Sergio Defranciscis; Lorenzo Naldi; Duccio Fioravanti; Massimiliano Ortiz Neri - Web page: https://patentgrep.com/patent/US10873252B2 ## CPC - H02K 49/046: {with an axial airgap} - F01D 25/36: using electric motors - H02K 1/182: {to stators axially facing the rotor, i.e. with axial or conical air gap} - H02K 7/104: with eddy-current brakes - H02K 7/20: Structural association with auxiliary dynamo-electric machines, e.g. with electric starter motors or exciters - H02K 49/04: of the eddy-current hysteresis type - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) ## Abstract A turning device for a turbomachine comprises a plurality of electromagnets connectable to an electric power source; a rotor magnetically coupled with the electromagnets, connectable to a main shaft of the turbomachine and having a rotation axis, the electromagnets are arranged facing the rotor in order to induce eddy currents on a surface of the rotor and apply a torque to the rotor, thus rotating the main shaft. ## Claims ### Claim 1 A turning device for a turbomachine, the turning device comprising: a rotor connectable to a shaft of the turbomachine and having a rotation axis and two surfaces forming opposite sides of the rotor; and at least two sets of electromagnets connectable to an electric power source, at least one of the at least two sets of electromagnets acts on one of the two surfaces of the rotor and at least another of the at least two sets of electromagnets acts on the other of the two surfaces of the rotor, and at least one of the at least two sets of electromagnets comprises at least one first electromagnet arranged to act on a peripheral zone of one of the two surfaces of the rotor relative to the rotation axis at least one second electromagnet arranged to act on a central zone of the one of the two surfaces of the rotor relative to the rotation axis and at least one third electromagnet arranged between the at least one first electromagnet and the at least one second electromagnet, wherein the rotor is configured to be magnetically coupled to the at least two sets of electromagnets and the at least two sets of electromagnets are arranged in proximity of the rotor in order to induce eddy currents on the two surfaces of the rotor and apply a torque to the rotor to rotate the shaft of the turbomachine. ### Claim 2 (depends on 1) The turning device according to claim 1, wherein the electromagnets are configured to apply the torque along a predefined direction of rotation of the main shaft in order to accelerate the main shaft. ### Claim 3 (depends on 1) The turning device according to claim 1, wherein the electromagnets are configured to apply the torque opposite to a predefined direction of rotation of the main shaft in order to slow down the main shaft. ### Claim 4 (depends on 1) The turning device according to claim 1, wherein each of the at least two sets of electromagnets is configured to be powered by a respective phase of an input electric current, the respective phases being different relative to each other. ### Claim 5 (depends on 1) The turning device according to claim 1, wherein the rotor is shaped as a disc. ### Claim 6 (depends on 1) The turning device according to claim 1, wherein the rotor is provided with holes to optimize both the rotor weight and cooling. ### Claim 7 (depends on 1) The turning device according to claim 1, wherein the rotor is configured to be directly jointed to the main shaft. ### Claim 8 (depends on 1) The turning device according to claim 1, wherein the rotor is configured to be connected to the main shaft via transmission coupling. ### Claim 9 (depends on 1) The turning device according to claim 1, wherein the rotor is made of an electrically conductive material. ### Claim 10 (depends on 1) The turning device according to claim 1, wherein the at least one first electromagnet, the at least one second electromagnet and the at least one third electromagnet are radially spaced evenly along a common radial direction of the rotor. ### Claim 11 A turbomachine comprising: a shaft; and a turning device comprising: a rotor connectable to the shaft and having a rotation axis and two surfaces forming opposite sides of the rotor; and at least two sets of electromagnets connectable to an electric power source, at least one of the at least two sets of electromagnets acts on one of the two surfaces of the rotor and at least another of the at least two sets of electromagnets acts on the other of the two surfaces of the rotor, and at least one of the at least two sets of electromagnets comprises at least one first electromagnet arranged to act on a peripheral zone of one of the two surfaces of the rotor relative to the rotation axis, at least one second electromagnet arranged to act on a central zone of the one of the two surfaces of the rotor relative to the rotation axis and at least one third electromagnet arranged between the at least one first electromagnet and the at least one second electromagnet, wherein the rotor is configured to be magnetically coupled to the at least two sets of electromagnets and the at least two sets of electromagnets are arranged in proximity of the rotor in order to induce eddy currents on the two surfaces of the rotor and apply a torque to the rotor to rotate the shaft. ### Claim 12 (depends on 11) The turbomachine according to claim 11, wherein the electromagnets are configured to apply the torque along a predefined direction of rotation of the main shaft in order to accelerate the main shaft. ### Claim 13 (depends on 11) The turbomachine according to claim 11, wherein the electromagnets are configured to apply the torque opposite to a predefined direction of rotation of the main shaft in order to slow down the main shaft. ### Claim 14 (depends on 11) The turbomachine according to claim 11, wherein the rotor is shaped as a disc. ### Claim 15 (depends on 11) The turbomachine according to claim 11, wherein the rotor is provided with holes to optimize both the rotor weight and cooling. ### Claim 16 (depends on 11) The turbomachine according to claim 11, wherein the rotor is configured to be at least one of directly jointed to the main shaft or connected to the main shaft via a transmission coupling.