Substrate transport apparatus with multiple independently movable articulated arms
A substrate transport apparatus including a drive section having at least one drive shaft and at least two scara arms operably coupled to the at least one drive shaft, the at least one drive shaft being a common drive shaft for the at least two scara arms effecting extension and retraction of the at least two scara arms, wherein the at least two scara arms are coupled to each other so that, with the at least one drive shaft coupled to the at least two scara arms, rotation of the drive shaft effects extension and retraction of one of the at least two scara arms substantially independent of motion of another of the at least two scara arms.
1. A substrate transport apparatus comprising:
a drive section with a drive motor, the drive motor having a common drive shaft;
two articulated arms, each being operably connected to the common drive shaft of the drive motor for extension and retraction of each arm, and each arm having an end effector adapted for holding and transporting a substrate; and
a coupling system having a lost motion system operably coupling both articulated arms to the common drive shaft of the drive motor, the lost motion system including a rotating member coupled to the common drive shaft to rotate about an axis of rotation of the common drive shaft and coupling members movably joined to the rotating member and coupled to a respective one of the two articulated arms through pivotally released joints, the lost motion system being arranged so that the lost motion system operates, when the common drive shaft of the drive motor imparts a torque to the coupling system, to effect extension and retraction of one of the two articulated arms substantially independent of movement of another of the two articulated arms along a substantially common linear path with no more than the common drive shaft effecting extension and retraction of one of the two articulated arms.
2. The apparatus of claim 1 , wherein the coupling members comprise substantially rigid coupling elements movably joined to each other and to each of the at least two articulated arms.
3. The apparatus of claim 2 , wherein the drive motor is engaged to the common drive shaft and at least one of the coupling elements is movably coupled to the common drive shaft and is driven by the common drive shaft.
4. The apparatus of claim 3 , wherein the at least one coupling element is pivotally mounted to the drive shaft and drive shaft rotation pivots the at least one coupling element relative to the drive section.
5. The apparatus of claim 3 , wherein drive shaft rotation causes the at least one coupling element to pivot relative to the drive section about two axes of rotation, the two axes are offset and substantially parallel with each other, and wherein the drive section has another axis of rotation offset from at least one of the two axes of rotation.
6. The apparatus of claim 1 , wherein the two articulated arms are scara arms and the relationship between scara arm motion and drive motor position is variable over the extension and retraction of each scara arm.
7. The apparatus of claim 6 , wherein the apparatus further comprises a controller programmed to control motion of the two scara arms to maintain substantially steady state motion during extension and retraction.
8. The apparatus of claim 1 , wherein each pivotally released joint is configured so that a relative position of a respective coupling member with the rotating member is constrained during rotation of the rotating member from a neutral position in a predetermined direction and is pivotally released with respect to the rotating member during rotation of the rotating member from the neutral position in a second predetermined direction.
9. A substrate transport apparatus comprising:
a drive section with a common drive shaft;
multiple articulated arms connected to the drive section, each of the arms having an end effector for holding a substrate, and being capable of extension and retraction for linearly transporting the substrate; and
a coupling system having a substantially rigid base member coupled to the common drive shaft to rotate about an axis of rotation of the common drive shaft and coupling members coupling each arm to the common drive shaft, the base member being movable relative to the drive section and being movably connected to the multiple articulated arms by the coupling members through pivotally released joints allowing relative movement between each arm and the base member;
wherein the movable joints are arranged so that movement of the base member relative to the drive section generates relative movement between the base member and the multiple articulated arms at each of the movable joints causing extension and retraction of at least one of the multiple articulated arms substantially independent of movement of at least another of the multiple articulated arms along a substantially common linear path with no more than the common drive shaft causing extension and retraction of at least one of the multiple articulated arms.
10. The apparatus of claim 1 , wherein each pivotally released joint is configured to provide an axis of rotation of the rotating member and pivot about an upper arm axis of rotation of a respective one of the two articulated arms.