INDUSTRIAL ROBOT

• US 20150258693A1
• Filed: 07/25/2013
• Published: 09/17/2015
• Est. Priority Date: 08/09/2012
• Status: Active Grant

• Current Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Original Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Inventors: Yazawa, Takayuki, Masuzawa, Yoshihisa, Watanabe, Hirokazu, Tanabe, Tomoki
• Granted Patent: US 9,764,461 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B25J 11/0095 Manipulators transporting wafers
• CPC Class Codes: B25J 19/002 using counterweights
• CPC Class Codes: B25J 19/0054 Cooling means
• CPC Class Codes: B25J 21/005 Clean rooms
• CPC Class Codes: B25J 9/042 comprising an articulated arm
• CPC Class Codes: B25J 9/126 Rotary actuators
• CPC Class Codes: H01L 21/67742 Mechanical parts of transfer devices robots in general in B25J
• CPC Class Codes: Y10S 901/23 Electric motor
• CPC Class Codes: Y10S 901/25 Gearing
• CPC Class Codes: Y10S 901/48 Counterbalance
• CPC Class Codes: Y10T 74/20317 including electric motor

Abstract

The present invention is to provide an industrial robot, which is placed in vacuum for use, capable of efficiently cooling down hand- or arm-driving motors which are arranged inside the arm in air. The industrial robot is provided with a motor for rotating a second arm unit with respect to a first arm unit, a motor for rotating a hand with respect to the second arm unit, a reduction gear for reducing the rotation of the motor and transmitting it to the second arm unit, and a reduction gear for reducing the rotation of the motor and transmitting it to the hand; the hand and the arm are placed in vacuum. The reduction gears and are coaxially arranged so that the center of rotation of the second arm unit with respect to the first arm unit coincides with the axial centers of the reduction gears. The interior space of the hollow first arm unit is kept at atmospheric pressure in which the motors and the reduction gears are arranged.

Claims

1. An industrial robot comprising:

a main body unit;

an arm having a first arm unit, which is rotatably linked to said main body unit with a base end thereof, and a second arm unit which is rotatably linked to the front end of said first arm section with the base end thereof;

a hand which is rotatably linked to the front end of said second arm unit;

a first motor structured to rotate said second arm unit with respect to said first arm unit;

a second motor structured to rotate said hand with respect to said second arm unit;

a first reduction gear structured to reduce the rotation of said first motor and transmitting it to said second arm unit; and

a second reduction gear structured to reduce the rotation of said second motor and transmitting it to said hand;

wherein said hand and said arm are arranged in vacuum;

said first reduction gear and said second reduction gear are hollow reduction gears in which a through hole is formed in the centers thereof in the radial direction;

said first reduction gear and said second reduction gear are arranged coaxially on top of the other so that the center of rotation of said arm unit with respect to said first arm or the center of rotation of said hand with respect to said second arm unit agrees with the axial centers of said first reduction gear and said second reduction gear, and they configure part of a first joint section connecting said first arm unit and said second arm unit or a second joint section connecting said second arm unit and said hand;

said first motor, said second motor, said first reduction gear and said second reduction gear are arranged an interior space of said first arm unit or said second arm unit which is formed hollow; and

said interior space is at atmospheric pressure.

2. The industrial robot as set forth in claim 1 wherein, when said object-to-be-handled is taken out of a storage unit, in which objects-to-be-handled to be mounted on said hand are stored, or into said storage unit, said first arm unit and said hand rotate such that the angle of rotation of said first arm unit with respect to said main body unit is the same as the angle of rotation of said hand with respect to said second arm unit and the direction of rotation of said first arm unit with respect to said main body unit is opposite the direction of rotation of said hand with respect to said second arm unit.

3. The industrial robot as set forth in claim 1 wherein said first arm unit is attached to said main body unit to extend from said main body unit to one side in the horizontal direction;

and

a counter weight which extends from said main body unit to the other side in the horizontal direction is attached to said first arm unit.

4. An industrial robot comprising:

a main body unit;

an arm comprising a first arm unit which is rotatably linked to said main body unit with the base end thereof, a second arm unit which is rotatably linked to the front end of said first arm with the base end thereof, and a third arm unit which is rotatably linked to the front end of said second arm unit with the base end thereof;

a hand which is rotatably linked to the front end of said second arm unit;

a first motor structured to rotate said second arm unit with respect to said first arm unit;

a second motor structured to rotate said third arm unit with respect to said second arm unit;

a third motor structured to rotate said hand with respect to said third arm unit;

a first reduction gear for reducingstructured to reduce the rotation of said first motor and transmitting it to said second arm unit;

a second reduction gear structured to reduce the rotation of said second motor and transmitting it to said third arm unit; and

a third reduction gear structured to reduce the rotation of said second motor and transmitting it to said hand;

wherein said hand and said arm are arranged in vacuum;

said first reduction gear, said second reduction gear and said third reduction gear are hollow reduction gears in which a through hole is formed in the centers thereof in the radial direction;

at least two reduction gears out of said first reduction gear, said second reduction gear and said third reduction gear are arranged coaxially on top of the other so that the axial centers thereof coincide with the center of rotation of said second arm unit with respect to said first arm unit, the center of rotation of third arm unit with respect to said second arm unit, or the center of rotation of said hand with respect to said third arm unit and they configure part of a first joint section connecting said first arm unit and said second arm unit, a second joint section connecting said second arm unit and said third arm unit or a third join section connecting said third arm unit and said hand;

at least two reduction gears, which are arranged coaxially on top of the other, and at least two motors out of said first motor, said second motor, and said third motor which are connected with said at least two reduction gears are arranged in an interior space of said first arm unit, said second arm unit or said third arm unit which are formed hollow; and

said interior space is kept at atmospheric pressure.

5. An industrial robot comprising:

a main body unit;

an arm comprising a first arm unit which is rotatably linked to said main body unit with the base end thereof, a second arm unit which is rotatably linked to the front end of said first am with the base end thereof, and a third arm unit which is rotatably linked to the front end of said second arm unit with the base end thereof;

a hand which is rotatably linked to the front end of said third arm unit;

a first motor structured to outstretch said arm;

a second motor structured to rotate said hand with respect to said third arm unit;

a first reduction gear structured to reduce the rotation of said first motor and transmitting it to said arm; and

a second reduction gear structured to reduce the rotation of said second motor and transmitting it to said hand;

wherein said hand and said arm are arranged in vacuum;

said first reduction gear and said second reduction gear are hollow reduction gears in which a through hole is formed in the centers thereof in the radial direction;

said first reduction gear and said second reduction gear are arranged coaxially on top of the other so that the axial centers thereof coincide with the center of rotation of said second arm unit with respect to said first arm unit, the center of rotation of said third arm unit with respect to said second arm unit, or the center of rotation of said hand with respect to said third arm unit and they configure at least part of a first joint section connecting said first arm unit and said second arm unit, a second joint section connecting said second arm unit and said third arm unit or a third joint section connecting said third arm unit and said hand;

said first motor, said second motor, said first reduction gear and said second reduction gear are arranged in an interior space of said first arm unit, said second arm unit or said third arm unit which are formed hollow; and

said interior space is kept at atmospheric pressure.

6. An industrial robot comprising:

a main body unit;

an arm comprising a first arm unit which is rotatably linked to said main body unit with the base end thereof, a second arm unit which is rotatably linked to the front end of said first arm unit with the base end thereof, a third arm unit which is rotatably linked to the front end of said second arm unit with the base end thereof, and a fourth arm unit which is linked to the front end of said third arm unit with the base end thereof;

a hand which is rotatably linked to the front end of said fourth arm unit;

a first motor structured to rotate said second arm unit with respect to said first arm unit;

a second motor structured to rotate said third arm unit with respect to said second arm unit;

a third motor structured to rotate said fourth arm unit with respect to said third arm unit;

a fourth motor structured to rotate said hand with respect to said fourth arm unit;

a first reduction gear structured to reduce the rotation of said first motor and transmitting it to said second arm unit;

a second reduction gear structured to reduce the rotation of said second motor and transmitting it to said third arm unit;

a third reduction gear structured to reduce the rotation of said third motor and transmitting it to said fourth arm unit;

a fourth reduction gear structured to reduce the rotation of said fourth motor and transmitting it to said hand;

wherein said hand and said arm are arranged in vacuum;

said first reduction gear, said second reduction gear, said third reduction gear and said fourth reduction gear are hollow reduction gears in which a through hole is formed in the centers thereof in the radial direction;

at least two reduction gears out of said first reduction gear, said second reduction gear, said third reduction gear and said fourth reduction gear are arranged coaxially on top of the other so that the axial centers thereof coincide with the center of rotation of said second arm unit with respect to said first arm unit, the center of rotation of said third arm unit with respect to said second arm unit, the rotation of center of said fourth arm unit with respect to said third arm unit or the center of rotation of said hand with respect to said fourth arm unit and they configure part of a first joint section connecting said first arm unit and said second arm unit, a second joint section connecting said second arm unit and said third arm unit, a third join section connecting said third arm unit and said fourth arm unit or a fourth joint section connecting sad fourth arm unit and said hand;

two or more reduction gears, which are arranged coaxially with each other, and at least two motors out of said first motor, said second motor, and said third motor which are connected with said two or more reduction gears are arranged in an interior space of said first arm unit, said second arm unit, said third arm unit or said fourth arm unit which are formed hollow; and

said interior space is at atmospheric pressure.

7. A method for returning an industrial robot to an original position, comprising:

setting coordinates of a temporary current position of said industrial robot which has stopped with its coordinates lost;

moving said industrial robot to a predetermined position; and

returning said industrial robot is automatically said original position.

8. The method for returning an industrial robot to an original position as set forth in claim 7, wherein

said industrial robot is provided with a hand on which an object-to-be-handled is mounted, an arm comprising multiple arm units rotatably linked to each other and the front end of which said hand is rotatably linked to, multiple arm-driving motors for rotating said multiple arm units, and a hand-driving motor for rotating said hand;

in the setting coordinates of a temporary current position, the coordinates representing a temporary current position of the center of rotation of said hand with respect to said arm are set;

in the moving said industrial robot, said industrial robot is moved to a position at which a storage unit storing said objects-to-be-handled and said hand with said object-to-be-handled do not interfere with each other when said industrial robot is being returned.

9. The method for returning an industrial robot to an original position as set forth in claim 8,

wherein a portable teaching operation terminal is connected with said industrial robot to teach said industrial robot the operation position;

and

in the setting coordinates of a temporary current position, the coordinates representing a temporary current position of said center of rotation of said hand which an operator has visually confirmed and determined are input to said teaching operation terminal to set the temporary current position of the center of rotation of said hand.

10. The method for returning an industrial robot to an original position as set forth in claim 8,

wherein, when viewed in the top-bottom direction which is the axial direction of the rotation of said hand, said hand moves in a straight line to take said object-to-be-handled into said storage unit or to take said object-to-be-handled out of said storage unit;

in the moving said industrial robot, said industrial robot is made to perform a linear interpolation move so that said hand is moved in the direction, in which said hand was moving during the time of taking said object-to-be-handled in and out, as viewed in the top-bottom direction.

11. The method for returning an industrial robot to an original position as set forth in claim 8,

wherein, in the setting coordinates of a temporary current position, the coordinates representing a temporary current position of the center of rotation of said hand viewed in the top-bottom direction can be set by either coordinates of a cylindrical coordinate system or coordinates of a rectangular coordinate system, which are specified in a plane orthogonal to the top-bottom direction which is the axial direction of the rotation of said hand, and the coordinates representing a temporary current position of the center of rotation of said hand viewed in the top-bottom direction are set by the coordinates of said cylindrical coordinate system or the coordinates of said rectangular coordinate system.

12. The method for returning an industrial robot to an original position as set forth in claim 8,

wherein said industrial robot is provided with an operation member to operate said industrial robot in said moving step;

and

in the moving said industrial robot, said industrial robot is operated by a jogging operation by which said industrial robot moves while an operator of said industrial robot is operating said operation member and stops when said operator stops operating said operation member.

13. An industrial robot comprising:

a hand on which an object-to-be-handled is mounted;

an arm comprising multiple arm units which are rotatably linked to each other and also linked to said hand with the front end thereof;

multiple arm motors structured to rotate said multiple arm units; and

a hand-driving motor structured to rotate said hand;

wherein a temporary current position setting means is provided to set the coordinates representing a temporary current position of said center of rotation of said hand of said industrial robot which has stopped, having lost the coordinates of the current position of the center of rotation of said hand with respect to said arm.

14. An industrial robot having an arm comprising multiple arm units which are linked to be relatively rotatable, comprising:

multiple motors structured to rotate said multiple arm units;

multiple motor drivers structured to drive said multiple motors;

a power source structured to supply a power to said multiple motor drivers;

a charge-discharge unit which is connected to said multiple motor drivers and chargeable with regenerative power generated by said multiple motors; and

a control execution unit structured to control said multiple motor drivers;

wherein, when said industrial robot makes an emergency stop, said power is turned off and said control execution unit stops said multiple motors while controlling said multiple motor drivers by using the power supplied from said charge-discharge unit.

15. The industrial robot as set forth in claim 14, further comprising:

a hand which is rotatably linked to the front end of said arm;

a hand-driving motor structured to rotate said hand with respect to said arm; and

a hand-driving motor driver structured to drive said hand motor;

wherein said control execution unit is structured to stop said hand motor while controlling said hand motor driver by using the power supplied from said charge-discharge unit.

16. The industrial robot as set forth in claim 15,

wherein a main body unit to which the base end of said arm is rotatably linked;

said arm comprises a first arm unit which is rotatably linked to said main body unit with the base end thereof and a second arm unit which is rotatably linked to the front end of said first arm with the base end thereof and which said hand is rotatably linked to the front end thereof;

as said motor, a first motor structured to rotate said first arm with respect to said main body unit and a second motor for rotating said second arm unit with respect to said first arm unit are provided; and

as said motor driver, a first motor driver structured to drive said first motor and a second motor driver for driving said second motor are provided.

17. The industrial robot as set forth in claim 14, further comprising:

an elevation motor structured to elevate said arm;

an elevation motor driver structured to drive said elevation motor;

a first brake structured to stop said elevation motor; and

a second brake structured to stop said elevation motor with a braking force larger than that of said first brake;

wherein said control execution unit is is structured to control said elevation motor driver, said first brake and said second brake and also, at the time of said emergency stop, operate said first brake and then operate said second brake to stop said elevation motor.

18. robot comprising

an arm configured by relatively-rotatably linked multiple arm units,

multiple motors for rotating said multiple arm units,

multiple motor drivers for driving said multiple motors respectively,

a power source for supplying power to said multiple motor drivers, and

a charge-discharge unit which is connected to said multiple motor drivers and is chargeable with regenerative power generated by said multiple motors, the method comprising:

when said industrial robot makes an emergency stop, turning off said power and stopping said motors said multiple motors while said multiple motor drivers are being controlled by a use of the power supplied from said charge-discharge unit.

19. An industrial robot comprising:

an arm comprising relatively-rotatably linked multiple arm units;

multiple motors structured to rotate said multiple arm units; and

a main body unit to which the base end of said arm is rotatably linked;

wherein based on the position and the moving direction of said, a control unit for controlling said industrial robot switches the control between whether controlling said industrial robot by a cylindrical coordinate system using the center of rotation of said arm with respect to said main body unit as the original position or by a rectangular coordinate system using the center of rotation of said arm as the original position.

20. The industrial robot as set forth in claim 19 further comprising:

a hand which is rotatably linked to the front end of said arm;

a hand-driving motor structured to rotate said hand; and

as said arm, a first arm unit which is rotatably linked to said main body unit with the base end thereof and a second arm unit which is rotatably linked to the front end of said first arm unit with the base end thereof and to the front end of which said hand is rotatably linked;

wherein said control unit is structured to control said industrial robot by said cylindrical coordinate system when the center of rotation of said hand with respect to said second arm unit moves in a straight line on an imaginary line passing through the center of rotation of said arm when viewed from the top-bottom direction which is the axial direction of rotation of said first arm unit and said second arm unit, or by said rectangular coordinate system when the center of rotation of said hand moves in the straight line in a position not along said imaginary line when viewed from the top-bottom direction.

21. The industrial robot as set forth in claim 20 wherein said control unit is structured to control said industrial robot in said cylindrical coordinate system when said hand is rotated with respect to said second arm unit while said first arm is not rotated with respect to said main body unit and said second arm unit is not rotated with respect to said first arm unit.

22. The industrial robot as set forth in claim 20 wherein said control unit is structured to control said industrial robot by said cylindrical coordinate system when said first arm unit is rotated with respect to said main body unit while said second arm unit is not rotated with respect to said first arm unit and said hand is not rotated with respect to said second arm unit.

23. A method of controlling an industrial robot comprising

an arm configured by relatively-rotatably linked multiple arm units,

multiple motors for rotating said multiple arm units, and

a main body unit to which the base end of said arm is rotatably linked, the method comprising:

based on the position and the moving direction of said arm, switching control of said industrial robot between a cylindrical coordinate system using the center of rotation of said arm with respect to said main body unit and a rectangular coordinate system using the center of rotation of said arm.