# US 11,440,181 B2 · Planetary gear train, gearbox and industrial robot > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,181 B2 - Document ID: US11440181B2 - Status: Granted - Kind: B2 - Application number: 17/291,866 - Filed: 2018-11-19 - Published: 2022-01-13 - Granted: 2022-09-13 - Earliest claimed: 2018-11-19 - Assignees: ABB Schweiz AG - Applicants: ABB Schweiz AG - Inventors: Per Lindblom - Web page: https://patentgrep.com/patent/US11440181B2 ## CPC - B25J 9/103: {with backlash-preventing means} - F16H 1/2854: {involving conical gears} - F16H 1/2827: {by allowing limited movement of the planet carrier, e.g. relative to its shaft} - F16H 1/2863: {Arrangements for adjusting or for taking-up backlash} - F16H 1/32: in which the central axis of the gearing lies inside the periphery of an orbital gear - F16H 2001/327: {with the orbital gear having internal gear teeth} - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - F16H: GEARING ## Abstract A planetary gear train including a ring gear defining a central axis; a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction; a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being axially displaceable along the central axis; and a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction. A gearbox for an industrial robot, the gearbox including a planetary gear train, and an industrial robot including a planetary gear train or a gearbox, are also provided. ## Claims ### Claim 1 A planetary gear train comprising: a ring gear defining a central axis; a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction; a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being allowed to move along the central axis; and a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction. ### Claim 2 (depends on 1) The planetary gear train according to claim 1, wherein the planet gear toothing has a helix angle of 0.5 to 8 degrees. ### Claim 3 (depends on 2) The planetary gear train according to claim 2, wherein the carrier forcing device includes a spring. ### Claim 4 (depends on 2) The planetary gear train according to claim 2, further comprising a stationary part, and wherein the carrier forcing device is arranged between the stationary part and the planet carrier. ### Claim 5 (depends on 2) The planetary gear train according to claim 2, wherein the helix angle of the planet gear toothing is 1 to 5 degrees. ### Claim 6 (depends on 1) The planetary gear train according to claim 1, wherein the carrier forcing device includes a spring. ### Claim 7 (depends on 6) The planetary gear train according to claim 6, wherein the spring encircles the central axis. ### Claim 8 (depends on 7) The planetary gear train according to claim 7, wherein the spring is a disc spring. ### Claim 9 (depends on 7) The planetary gear train according to claim 7, wherein the spring is preloaded. ### Claim 10 (depends on 6) The planetary gear train according to claim 6, wherein the spring is a disc spring. ### Claim 11 (depends on 6) The planetary gear train according to claim 6, wherein the spring is preloaded. ### Claim 12 (depends on 1) The planetary gear train according to claim 1, further comprising a stationary part, and wherein the carrier forcing device is arranged between the stationary part and the planet carrier. ### Claim 13 (depends on 1) The planetary gear train according to claim 1, wherein at least one of the planet gears is axially displaceable along its planet axis relative to the planet carrier, and wherein the planetary gear train further comprises at least one planet forcing device arranged to force the at least one axially displaceable planet gear along the planet axis in the conical direction. ### Claim 14 (depends on 1) The planetary gear train according to claim 1, wherein the ring gear is rotatable about the central axis. ### Claim 15 (depends on 1) The planetary gear train according to claim 1, further comprising a sun gear meshing with the planet gears. ### Claim 16 (depends on 1) The planetary gear train according to claim 1, wherein the planetary gear train comprises a first planetary gear stage and a second planetary gear stage. ### Claim 17 (depends on 16) The planetary gear train according to claim 16, wherein the second planetary gear stage comprises the sun gear, and wherein the sun gear is fixed with a planet carrier of the first planetary gear stage. ### Claim 18 (depends on 16) The planetary gear train according to claim 16, wherein the planet gears comprising the conical and helical planet gear toothing are provided in the second planetary gear stage. ### Claim 19 A gearbox for an industrial robot, the gearbox comprising a planetary gear which includes: a ring gear defining a central axis; a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction; a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being allowed to move along the central axis; and a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction. ### Claim 20 An industrial robot comprising a planetary gear train or a gearbox, including: a ring gear defining a central axis; a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction; a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being allowed to move along the central axis; and a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction.