Industrial robot

1. An industrial robot comprising:

a first hand and a second hand, each of which is provided with a first hand portion comprising:

one substrate-mounting portion to mount a sheet of substrate and a second hand portion having multiple substrate-mounting portions arranged to overlap with each other in the up-down direction at a predetermined pitch;

a first arm which said first hand portion and said second hand portion of said first hand are rotatably joined to a front end thereof;

a second arm which said first hand portion and said second hand portion of said second hand are rotatably joined to a front end thereof;

an arm support portion to which a base end of said first arm and a base end of said second arm are rotatably joined;

a column portion for holding said arm support portion movable in an up-down direction;

a first hand portion-rotating mechanism for rotating said first hand portion of said first hand with respect to said first arm;

a second hand portion-rotating mechanism structured to rotate said second hand portion of said first hand with respect to said first arm;

a third hand portion-rotating mechanism structured to rotate said first hand portion of said second hand with respect to said second arm;

a fourth hand portion-rotating mechanism structured to rotate said second hand portion of said second hand with respect to said second arm;

a first arm-rotating mechanism structured to rotate said first arm with respect to said arm support portion;

a second arm-rotating mechanism structured to rotate said second arm with respect to said arm support portion; and

wherein said first hand portion and said second hand portion of said first hand are arranged such that they overlap with each other in the up-down direction and a center of rotation of said first hand portion of said first hand aligns with a center of rotation of said second hand portion of said first hand;

said first hand portion and said second hand portion of said second hand are arranged such that they overlap with each other in the up-down direction and a center of rotation of said first hand portion of said second hand aligns with a center of rotation of said second hand portion of said second hand;

said first arm is attached to a top surface of said arm support portion;

said second arm is attached to a bottom surface of said arm support portion;

said first arm and said second arm are arranged such that a center of rotation of said first arm aligns with the center of rotation of said second arm;

wherein the first hand portion-rotating mechanism comprises a first hand portion-driving motor;

the second hand portion-rotating mechanism comprises a second hand portion-driving motor;

the first hand portion-rotating driving motor and the second hand portion-rotating driving motor are arranged inside the first arm;

the third hand portion-rotating mechanism comprises a third hand portion-driving motor;

the fourth hand portion-rotating mechanism comprises a fourth hand portion-driving motor;

the third hand portion-rotating driving motor and the fourth hand portion-rotating driving motor are arranged inside the second arm;

in a direction perpendicular to the up-down direction, a center of a connecting portion of the arm support portion is disposed to a first side of a center of the column portion; and

when the first arm, the first hand portion, and the second hand portion are in a retracted position, the center of rotation of the first hand portion and the center of rotation of the second hand portion are disposed to a second side of the center of the column portion in the direction perpendicular to the up-down direction.

2. The industrial robot as set forth in claim 1 wherein

the first hand portion-rotating mechanism comprises a first hand portion-driving motor;

the second hand portion-rotating mechanism comprises a second hand portion-driving motor;

the first hand portion-rotating driving motor and the second hand portion-rotating driving motor are arranged inside the arm support portion.

3. The industrial robot as set forth in claim 1 wherein

the first hand portion-rotating mechanism comprises a first hand portion-driving motor;

the second hand portion-rotating mechanism comprises a second hand portion-driving motor;

the first hand portion-rotating driving motor and the second hand portion-rotating driving motor are arranged inside the arm support portion.

4. The industrial robot as set forth in claim 1 wherein said pre-processed substrates are mounted on said first hand portion and said second hand portion of said first hand, and the processed substrates are mounted on said first hand portion and said second hand portion of said second hand.

5. The industrial robot as set forth in claim 4 wherein said process is a cleaning process which cleans said substrates.

6. The industrial robot as set forth in claim 1 further comprising a horizontally-moving mechanism for moving said column portion in a horizontal direction.

7. The industrial robot as set forth in claim 6 wherein

said arm support portion extends, when viewed from a vertical direction, from said column portion in a direction inclined with respect to a direction orthogonal to a moving direction of said column portion moved by said horizontally-moving mechanism.

8. The industrial robot as set forth in claim 1 wherein

the first hand portion-rotating mechanism comprises a first pulley fixed to the output shaft of the first hand portion-driving motor;

the second hand portion-rotating mechanism comprises a second pulley fixed to the output shaft of the second hand portion-driving motor;

the third hand portion-rotating mechanism comprises a third pulley fixed to the output shaft of the third hand portion-driving motor;

the fourth hand portion-rotating mechanism comprises a fourth pulley fixed to the output shaft of the fourth hand portion-driving motor;

wherein the first pulley is positioned above the second pulley, and the third pulley is positioned below the forth pulley.