Electrical drive for an industrial robot

{
  "publication_number": "US10516351B2",
  "country": "US",
  "kind": "B2",
  "title": "Electrical drive for an industrial robot",
  "abstract": "Provided is an electrical drive for an industrial robot, wherein each driver circuit for the associated power switches of the first half-bridge is designed, in the case of a voltage-free or current-free state of the associated control input, to put the power switch associated with the control input into a non-conductive state, each driver circuit for the associated power switches of the second half-bridge is designed, in the case of a voltage-free or current-free state of the associated control input, to put the power switch associated with the control input into a conductive state, and a switching device is provided, which is designed, with the safety signal for the forced switch-off of the rotating-field voltage, to simultaneously switch the control inputs of the driver circuits for all power switches of the inverter into a voltage-free and/or current-free state.",
  "claims": [
    "1. An electrical drive for an industrial robot, wherein the drive comprises an inverter having a first half bridge and a second half bridge for generating a rotating field voltage from a direct voltage intermediate circuit, control electronics for generating control signals for activating all power switches of the first half bridge and all power switches of the second half bridge, and a rotating field motor fed by the inverter via a motor circuit, wherein the inverter comprises a first connection device for providing activation signals for influencing a mode of operation of the drive by a functional controller of the robot and an interface device for supplying at least one safety signal for forced switching-off of the rotating field voltage by a safety controller of the robot, wherein each power switch is allocated a driver circuit having a double-pole control input galvanically separated from the motor circuit, wherein a respective driver circuit for the power switches of the first half bridge is designed, in the case of a voltage-free or current-free state of the control input, to put the power switch, which is allocated in each case to the control input, into a non-conductive state, a respective driver circuit for the power switches of the second half bridge is designed, in the case of a voltage-free or current-free state of the control input, to put the power switch, which is allocated in each case to the control input, into a conductive state, and a switching device is provided which is designed to simultaneously switch the control inputs of the driver circuits for all of the power switches of the inverter into a voltage-free and/or current-free state by the safety signal for the forced switching-off of the rotating field voltage.",
    "2. The electrical drive as claimed in claim 1, wherein the safety signal is designed having two circuits, wherein the switching device is designed to simultaneously switch the control inputs of the driver circuits to a voltage-free and/or current-free state independently of both the first circuit and the second circuit.",
    "3. The electrical drive as claimed in claim 1, wherein the driver circuit comprises an optocoupler.",
    "4. The electrical drive as claimed in claim 3, wherein the interface device has a first interface and a second interface for receiving a first safety signal and a second safety signal, which is redundant with respect to the first safety signal, from the safety controller of the robot, wherein a first switch of the switching device is actuated by the first safety signal for disconnecting the diodes of the optocouplers from earth and Wherein a second switch of the switching device is actuated by the second safety signal for disconnecting the control electronics for driving the optocouplers from the supply voltage.",
    "5. The electrical drive as claimed in claim 1, wherein the switching device is designed, in the case of a current-free or voltage-free state of the safety signal with respect to a fixed reference potential, to simultaneously switch the control inputs of the driver circuits of all of the power switches to a voltage-free and/or current-free state.",
    "6. The electrical drive as claimed in claim 1, wherein the rotating field motor fed by the inverter is a permanently excited synchronous motor.",
    "7. The electrical drive as claimed in claim 1, wherein an electronically accessible data memory is provided which is structurally coupled to the rotating field motor, wherein the control electronics of the inverter and/or the safety controller and/or the functional controller is designed to read-out the data memory as soon as the rotating field motor is connected ready for operation to the inverter, wherein the control electronics of the inverter and/or the safety controller and/or the functional controller is designed to derive the suitability of the rotating field motor in combination with the inverter for damage-free short-circuit braking from information stored in the data memory.",
    "8. The electrical drive as claimed in claim 1, wherein a rotation angle sender which is structurally coupled to the rotating field motor is provided, for detecting, by sensors, the absolute and/or relative angle change of a motor shaft of the rotating field motor, which is coupled via a communications connection to the control electronics of the inverter and/or the safety controller and/or to the functional controller for determining an actual position of a motor axle of the rotating field motor and/or a robot axle of the robot, wherein the electronically accessible data memory is combined with the rotation angle sender structurally and in terms of signal technology."
  ],
  "description_excerpt": "The present invention relates to an electrical drive for an industrial robot, an industrial robot comprising such an electrical drive and to a method for operating such an electrical drive for an industrial robot. Furthermore, the present invention relates to a computer program product for carrying out such a method for operating an electrical drive of an industrial robot.\n\nAn electrical drive for an industrial robot can comprise an inverter having a first half bridge and a second half bridge for generating a rotating field voltage. Furthermore, such an electrical drive comprises control electronics for generating control signals for activating the power switches of the first and second half bridges and comprises a rotating field motor which is fed by the inverter via a motor circuit. A functional controller of the robot can provide activation signals for influencing the mode of operation of the electrical drive. Furthermore, the electrical drive can comprise an interface device for supplying a safety signal for the forced switching-off of the rotating field voltage.\n\nFor example, the document EP 0 742 637 A1 describes a method and a device for safely braking an electrical drive. In this case, the document EP 0 742 637 A1 describes that in the controller there is provided a way of producing an integrated armature short-circuit in order to effect emergency braking in the event of a fault. In order to produce the integrated armature short-circuit, one inverter bridge is blocked, while the other inverter bridge effects a short-circuit of the phases of the electrical drive by means of synchronized activation.",
  "cpc": [
    "H02P 3/22",
    "B25J 19/0004",
    "B25J 9/0009",
    "H02M 7/53871",
    "H02P 27/08",
    "H02P 29/0241"
  ],
  "ipc": [
    "B25J 19/00",
    "B25J 9/00",
    "H02M 7/5387",
    "H02P 27/08",
    "H02P 29/024",
    "H02P 3/22"
  ],
  "assignees": [
    "Keba AG"
  ],
  "inventors": [
    "Franz Mayr"
  ],
  "filing_date": "2016-09-20",
  "publication_date": "2019-12-24",
  "grant_date": "2019-12-24",
  "priority_date": "2015-11-19",
  "application_number": "US-201615775344-A",
  "family_id": "56985611",
  "cited_by_count": 0,
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}