Robot with belt-drive system

• US 20080121064A1
• Filed: 06/28/2006
• Published: 05/29/2008
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Genmark Automation Incorporated (Nidec Corporation)
• Original Assignee: Genmark Automation Incorporated (Nidec Corporation)
• Inventors: Todorov, Alexander
• Granted Patent: US 8,701,519 B2
• Time in Patent Office: Days
• US Class Current: 74/490.04
• CPC Class Codes: B25J 18/04 rotatable
• CPC Class Codes: B25J 9/0021 All motors in base
• CPC Class Codes: B25J 9/042 comprising an articulated arm
• CPC Class Codes: B25J 9/104 with cables, chains or ribbons
• CPC Class Codes: H01L 21/67742 Mechanical parts of transfer devices robots in general in B25J
• CPC Class Codes: H01L 21/67766 Mechanical parts of transfer devices robots in general in B25J
• CPC Class Codes: Y10T 74/20305 Robotic arm
• CPC Class Codes: Y10T 74/20323 including flaccid drive element
• CPC Class Codes: Y10T 74/20329 Joint between elements
• CPC Class Codes: Y10T 74/20341 Power elements as controlling elements

Abstract

A substrate handling robot having a robot body and a robot arm with an end effector is configured to exhibit angular (θ), radial (R) and Z motion. A pair of coaxial shafts link the robot arm to respective motors dedicated to angular (θ) and radial (R) motions. The motors are stationarily mounted with respect to the robot body. The shafts are rotatably supported by a floating platform which is motivated in the Z direction by a third motor also stationarily mounted with respect to the robot body. The third motor is coupled to the platform by a Z motion linkage. The first and second motors are coupled to the coaxial shafts by angular and radial motion linkages each of which includes primary and secondary timing belts whose relative motions are synchronized with the Z motion linkage to achieve controllable independent angular (θ), radial (R) and Z motions in a simple, light-weight package.

Claims

1. A robot comprising:

a robot arm;

a robot body;

a floating Z platform mounted for motion in a Z direction in the robot body;

a shaft coupled to the robot arm and to the floating Z platform, the shaft being rotatable about a primary axis and movable with the floating Z platform;

a first motor configured to impart Z motion to the floating Z platform and to the shaft coupled thereto;

a primary timing belt stationarily mounted in the robot body;

a second motor configured to rotate the primary timing belt; and

a secondary timing belt coupled to the primary timing belt and to the shaft to thereby transfer motion of the primary timing belt to the robot arm by way of said shaft.

2. The robot of claim 1, wherein the motion transferred to the robot arm is angular (θ

) motion.

3. The robot of claim 2, wherein the robot arm includes a plurality of pivotably coupled links, the proximalmost of said links being mounted for rotation about the primary axis to thereby provide said angular (θ

) motion.

4. The robot of claim 1, wherein the motion transferred to the robot arm is radial (R) motion.

5. The robot of claim 4, wherein the robot arm includes a plurality of pivotably coupled links and an arm radial motion linkage configured to transfer rotation of said shaft to the distalmost link to thereby provide said radial (R) motion.

6. The robot of claim 1, wherein the shaft is a first shaft, the primary timing belt is a first primary timing belt, and the secondary timing belt is a first secondary timing belt, the robot further comprising:

a second shaft coaxial with the first shaft, the second shaft coupled to the robot arm and to the floating Z platform, the second shaft being rotatable about the primary axis independently of the first shaft and movable with the floating Z platform;

a second primary timing belt stationarily mounted in the robot body;

a third motor configured to rotate the second primary timing belt; and

a second secondary timing belt coupled to the second primary timing belt and to the second shaft to thereby transfer motion of the second primary timing belt to the robot arm by way of said second shaft.

7. The robot of claim 1, wherein the first motor is coupled to the floating Z platform by way of a timing belt to which the floating Z platform is clamped.

8. The robot of claim 1, wherein the first motor is coupled to the floating Z platform by way of a rotating threaded rod that engages a threaded nut which is fixed with respect to the floating Z platform.

9. The robot of claim 1, wherein the first motor is coupled to the floating Z platform by way of a rack and pinion.

10. An assembly for providing a robot having a robot arm and a robot body with Z motion and at least one of R and θ

motions, the assembly comprising;

a floating platform configured for translation relative to said robot body in a first direction;

a shaft coupled to said robot arm and said floating platform, said shaft being translatable with the floating platform in said first direction and being axially rotatable about a primary axis extending in said first direction;

a first motor mounted stationarily relative to said robot body such that translation of said floating platform and shaft occurs relative to said first motor;

a second motor mounted stationarily relative to said body such that translation of said floating platform and shaft occurs relative to said second motor;

a first linkage coupling said first motor to said floating platform such that said first motor is capable of motivating said translation of said floating platform and said shaft; and

a second linkage coupling said second motor to said shaft such that said second motor is capable of motivating said axial rotation of said shaft, said second linkage including;

a primary timing belt stationarily mounted relative to said robot body; and

a motion conversion assembly translatable with said floating platform and said shaft, said motion conversion assembly including a secondary timing belt coupled to the primary timing belt.

11. The assembly of claim 10, wherein axial rotation of the shaft imparts angular (θ

) motion to the robot arm.

12. The assembly of claim 11, wherein the robot arm includes a plurality of pivotably coupled links, the proximalmost of said links being coupled to said shaft for rotation about the primary axis to thereby provide said angular (θ

) motion.

13. The assembly of claim 10, wherein axial rotation of the shaft imparts angular radial (R) motion to the robot arm.

14. The assembly of claim 13, wherein the robot arm includes a plurality of pivotably coupled links and an arm radial motion linkage configured to transfer axial rotation of said shaft to the distalmost link to thereby provide said radial (R) motion.

15. The assembly of claim 10, wherein the shaft is a first shaft, the primary timing belt is a first primary timing belt, and the secondary timing belt is a first secondary timing belt, the motion conversion assembly is a first motion conversion assembly, further comprising:

a second shaft coaxial with the first shaft, the second coupled to said robot arm and said floating platform, the second shaft being translatable with the floating platform in said first direction and being axially rotatable about the primary axis;

a third motor mounted stationarily relative to said robot body such that translation of said floating platform and first and second shafts occurs relative to said third motor; and

a third linkage coupling said third motor to said second shaft such that said third motor is capable of motivating said axial rotation of said second shaft, said third linkage including;

a second primary timing belt stationarily mounted relative to said robot body; and

a second motion conversion assembly translatable with said floating platform and said first and second shafts, said second motion conversion assembly including a second secondary timing belt coupled to the second primary timing belt.

16. The assembly of claim 10, wherein the first linkage includes an additional timing belt to which the floating platform is connected.

17. The assembly of claim 10, wherein the first linkage includes a rotating threaded rod that engages a threaded nut which is fixed relative to the floating platform.

18. A method for enabling a robot having a robot arm and a robot body to undergo Z motion and at least one of radial (R) and angular (θ

) motions, the method comprising;

coupling motion of a first motor that is stationarily mounted with respect to the robot body to the robot arm by way of a shaft that is mounted for axial translation along a primary axis in response to said first motor motion; and

coupling motion of a second motor that is stationarily mounted with respect to the robot body to the robot arm by way of said shaft, said shaft being mounted for rotation about said primary axis in response to said second motor motion,

said coupling of motion of a second motor including;

in response to rotation of said second motor, rotating a primary timing belt that is stationarily mounted with respect to said robot body, and

converting the rotation of the primary timing belt to said rotation of said shaft about said primary axis using a motion conversion assembly that is configured to translate axially with said shaft.

19. An apparatus for enabling a robot having a robot arm and a robot body to undergo Z motion and at least one of radial (R) and angular (θ

) motions, the apparatus comprising;

means for coupling motion of a first motor that is stationarily mounted with respect to the robot body to the robot arm by way of a shaft that is mounted for axial translation along a primary axis in response to said first motor motion; and

means for coupling motion of a second motor that is stationarily mounted with respect to the robot body to the robot arm by way of said shaft, said shaft being mounted for rotation about said primary axis in response to said second motor motion,

said means for coupling motion of a second motor being operative to;

in response to rotation of said second motor, rotate a primary timing belt that is stationarily mounted with respect to said robot body, and

convert the rotation of the primary timing belt to said rotation of said shaft about said primary axis using a motion conversion assembly that is configured to translate axially with said shaft.

20. In a robot having a Z motion linkage capable of imparting Z motion to a robot arm, a robot body angular (θ

) motion linkage capable of imparting angular motion to the robot arm, and a robot body radial (R) motion linkage capable of imparting radial motion to the robot arm, a method for providing motion to the robot arm comprising;

actuating a first motor coupled to the robot arm by way of the Z motion linkage;

actuating a second motor coupled to the robot arm by way of the robot body angular (θ

) motion linkage;

actuating a third motor coupled to the robot arm by way of the robot body radial (R) motion linkage; and

synchronizing the first, second and third motors such that the robot arm undergoes Z motion while maintaining fixed angular (θ

) and radial (R) positions.

21. A computer readable medium containing a program that causes a robot having a Z motion linkage capable of imparting Z motion to a robot arm, a robot body angular (θ

) motion linkage capable of imparting angular motion to the robot arm, and a robot body radial (R) motion linkage capable of imparting radial motion to the robot arm to undergo motion based on the following procedure;

actuation of a first motor coupled to the robot arm by way of the Z motion linkage;

actuation of a second motor coupled to the robot arm by way of the robot body angular (θ

) motion linkage;

actuation of a third motor coupled to the robot arm by way of the robot body radial (R) motion linkage; and

synchronization of the first, second and third motors such that the robot arm undergoes Z motion while maintaining fixed angular (θ

) and radial (R) positions.