Substrate transport apparatus

1. A transfer apparatus comprising:

a frame;

multiple arms connected to the frame, each arm having an end effector and an independent drive axis for extension and retraction of the respective arm with respect to other ones of the multiple arms;

a linear rail defining a degree of freedom for the independent drive axis effecting extension and retraction of at least one arm; and

a common drive axis forming a common degree of freedom of but one common motor shared by each arm so that each arm is commonly dependent from the but one common motor, and the but one common motor outputs a common torque defining the common drive axis and the common degree of freedom that is common to each arm, and independent of each independent drive axis and corresponding independent degree of freedom of each arm, so that the but one common motor is configured to pivot the multiple arms commonly dependent therefrom under the common torque, as a unit, about a common pivot axis;

wherein at least one of the multiple arms having another drive axis at a base of the linear rail independent of each drive axis and common drive axis of each arm and defining another independent degree of freedom of the at least one of the multiple arms, independent with respect to each independent degree of freedom and the common degree of freedom of each other one of the multiple arms, and effected by movement of the linear rail of the at least one arm relative to the frame.

2. The transfer apparatus of claim 1 , wherein the other drive axis defining the independent degree of freedom is angled with respect to the axis for extension and retraction.

3. The transfer apparatus of claim 1 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is coplanar with a seating plane of the end effector.

4. The transfer apparatus of claim 1 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is angled with respect to other independent degrees of freedom.

5. The transfer apparatus of claim 1 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is parallel with respect to other independent degrees of freedom.

6. The transfer apparatus of claim 1 , further comprising a second common drive axis configured to move the multiple arms in unison about a common axis.

7. The transfer apparatus of claim 1 , wherein the other drive axis effects automatic workpiece centering.

8. The transfer apparatus of claim 1 , wherein the other drive axis effects independent workpiece placement adjustment for workpiece holding station location variations.

9. The transfer apparatus of claim 1 , wherein the multiple arms are telescoping arms.

10. A transfer apparatus comprising:

a frame;

multiple arms connected to the frame, each arm having an end effector and an independent drive axis defining an independent degree of freedom effecting extension and retraction of the respective arm to transport a workpiece into and out of a transport chamber;

a linear drive axis defining another independent degree of freedom, for at least one arm, that is coplanar with a seating plane of the end effector; and

a common drive axis forming a common degree of freedom of but one common motor shared by each arm so that each arm is commonly dependent from the but one common motor, and the butt one common motor outputs a common torque defining the common drive axis and the common degree of freedom that is common to each arm, and independent of each independent drive axis and corresponding independent degree of freedom of each arm, that the but one common motor is configured to pivot the multiple arms commonly dependent therefrom under the common torque, as a unit, about a common pivot axis;

wherein at least one of the multiple arms having another drive axis at a base of the linear drive axis independent of each of drive axis of each arm and defining another different independent degree of freedom of the at least one of the multiple arms, the another different independent degree of freedom being different and independent with respect to each independent degree of freedom and the common degree of freedom of each other of the multiple arms.

11. The transfer apparatus of claim 10 , wherein the other drive axis defining the independent degree of freedom is angled with respect to the axis for extension and retraction.

12. The transfer apparatus of claim 10 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is coplanar with a seating plane of the end effector.

13. The transfer apparatus of claim 10 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is angled with respect to other independent degrees of freedom.

14. The transfer apparatus of claim 10 , wherein the other drive axis defining the independent degree of freedom is arranged so that the independent degree of freedom is parallel with respect to other independent degrees of freedom.

15. The transfer apparatus of claim 10 , further comprising a second common drive axis configured to move the multiple arms in unison about a common axis.

16. The transfer apparatus of claim 10 , wherein the independent degree of freedom effects automatic workpiece centering.

17. The transfer apparatus of claim 10 , wherein the independent degree of freedom effects independent workpiece placement adjustment for workpiece holding station location variations.

18. The transfer apparatus of claim 10 , wherein the multiple arms are telescoping arms.