# US 12,191,749 B2 · Galvanometer drive with zero-backlash mounting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,749 B2 - Document ID: US12191749B2 - Status: Granted - Kind: B2 - Application number: 17/798,971 - Filed: 2021-02-01 - Published: 2023-10-26 - Granted: 2025-01-07 - Earliest claimed: 2020-02-17 - Assignees: SCANLAB GmbH - Applicants: SCANLAB GmbH - Inventors: Norbert Kirr; Tobias Edlboeck; Thomas Lares; Hans-Joachim Muenzer - Web page: https://patentgrep.com/patent/US12191749B2 ## CPC - H02K 7/08: Structural association with bearings - F16C 23/08: self-adjusting - H02K 7/083: {radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence)} - H02K 7/088: {radially supporting the rotor directly} - F16C 19/54: Systems consisting of a plurality of bearings with rolling friction (spindle bearings F16C35/08) - F16C 25/083: {with resilient means acting axially on a race ring to preload the bearing} - F16C 35/077: between housing and outer race ring - F16C 2229/00: Setting preload - F16C 2380/26: Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract A galvanometer drive with a rotor that is rotatable about an axis of rotation and includes a magnet, and a stator unit that surrounds the rotor and includes a coil, the rotor being supported by two bearings, at least one of which is a floating bearing, such that the rotor can perform a rotational movement relative to the stator unit about the axis of rotation. A radial movement limiting device is adapted to limit the radial movement of the floating bearing with respect to the stator unit. ## Claims ### Claim 1 A galvanometer drive comprising: a rotor which is rotatable about an axis of rotation and which comprises a magnet, and a stator unit which surrounds the rotor and which comprises a coil, the rotor being supported by two bearings, at least one of which is a floating bearing, in such a way that it can perform a rotational movement about the axis of rotation relative to the stator unit, characterized by a radial movement limiting device, which is adapted to limit the radial movement of the floating bearing with respect to the stator unit, wherein a ratio of radial stiffness to axial stiffness at the floating bearing is greater than 10. ### Claim 2 (depends on 1) The galvanometer drive according to claim 1, wherein the floating bearing comprises an outer ring, an inner ring and a plurality of rolling elements between the inner ring and the outer ring and the inner ring is rigidly attached to the rotor and the outer ring is displaceable in the direction of the axis of rotation, wherein the radial movement limiting device limits the radial movement of the outer ring with respect to the stator unit. ### Claim 3 (depends on 1) The galvanometer drive according to claim 1, wherein the radial movement limiting device is a spring element attached to the floating bearing by which the floating bearing is axially subjected to pressure, wherein the spring element has a portion rigidly attached to the floating bearing and another portion rigidly attached to the stator unit. ### Claim 4 (depends on 3) The galvanometer drive according to claim 3, wherein the spring element comprises a rotationally symmetrical, star-shaped arrangement of n leaf spring elements, n being a natural number greater than or equal to 3. ### Claim 5 (depends on 4) The galvanometer drive according to claim 4, wherein the number n of leaf spring elements is less than or equal to 100. ### Claim 6 (depends on 3) The galvanometer drive according to claim 3, wherein the spring element is designed as a disc spring or diaphragm spring. ### Claim 7 (depends on 3) The galvanometer drive according to claim 3, wherein the spring element has a displacement stiffness in the radial direction which is greater than the spring stiffness in the axial direction by at least a factor of 50. ### Claim 8 (depends on 3) The galvanometer drive according to claim 3, wherein the displacement stiffness in the radial direction has a value above 4 kN/mm, and below 1000 kN/mm. ### Claim 9 (depends on 1) The galvanometer drive according to claim 1, wherein the radial movement limiting device is a rolling guide mounted between the floating bearing and the stator unit and rigidly attached both to the floating bearing and to the stator unit. ### Claim 10 (depends on 9) The galvanometer drive according to claim 9, wherein the rolling guide consists of a guide inner element, a guide outer element and a plurality of rolling elements arranged therebetween. ### Claim 11 (depends on 10) The galvanometer drive according to claim 10, wherein the guide inner element is formed in one piece with the floating bearing and/or the guide outer element is formed in one piece with the stator unit. ### Claim 12 (depends on 9) The galvanometer drive according to claim 9, wherein the rolling guide is preloaded. ### Claim 13 (depends on 1) The galvanometer drive according to claim 1, wherein the radial movement limiting device applies a force to the floating bearing in the radial direction. ### Claim 14 (depends on 13) The galvanometer drive according to claim 13, wherein the radial movement limiting device comprises a spring element which is mounted between the stator unit and the rotor in such a way that the spring element exerts a force on the rotor in the radial direction. ### Claim 15 (depends on 13) The galvanometer drive according to claim 13, wherein the radial movement limiting device has a weight which generates the force on the floating bearing in the radial direction as a result of the action of gravity. ### Claim 16 (depends on 13) The galvanometer drive according to claim 13, wherein the radial movement limiting device applies a force to the floating bearing in the radial direction via electromagnetic interaction. ### Claim 17 (depends on 13) The galvanometer drive according to claim 13, wherein a force on the rotor in the radial direction is generated by generating a radially asymmetric magnetic field between the rotor and the stator unit. ### Claim 18 (depends on 17) The galvanometer drive according to claim 17, wherein a radially asymmetric magnetic field is generated by the presence of at least one region in the rotor or in the stator unit, which region has a different magnetic susceptibility than the rest of the rotor or the stator unit, respectively.