US 2019/0376531 A1 · DUAL VALVE FLUID ACTUATOR ASSEMBLY

Abstract

A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B).

Claims22

Dependent claims

A stage assembly for positioning a workpiece along a movement axis, the stage assembly comprising:

a stage that is adapted to couple to the workpiece;
a base;
a fluid actuator assembly that is coupled to and moves the stage along the movement axis relative to the base, the fluid actuator assembly including (i) a piston housing that defines a piston chamber;
(ii) a piston that is positioned within and moves relative to the piston chamber along a piston axis, the piston separating the piston chamber into a first chamber and a second chamber that are on opposite sides of the piston;
and (iii) a first valve sub-assembly that includes a first supply valve that controls the flow of the working fluid into the first chamber, and a first exhaust valve that controls the flow of the working fluid out of the first chamber;
wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area;
wherein the first supply orifice area is different from the first exhaust orifice area;
and
a control system that controls the valve assembly to control the flow of the working fluid into and out of the first chamber.

6 more elements

A method for positioning a workpiece along a movement axis, the method comprising:

providing a base;
coupling the workpiece to a stage;
moving the stage along the movement axis relative to the base with a fluid actuator assembly that includes (i) a piston housing that defines a piston chamber;
(ii) a piston that is positioned within and moves relative to the piston chamber along a piston axis, the piston separating the piston chamber into a first chamber and a second chamber that are on opposite sides of the piston;
and (iii) a first valve sub-assembly that controls the flow of a working fluid into the first chamber, the first valve sub-assembly including a first supply valve that controls the flow of the working fluid into the first chamber, and a first exhaust valve that controls the flow of the working fluid out of the first chamber;
wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area;
wherein the first supply orifice area is different from the first exhaust orifice area;
and
controlling the valve assembly with a control system to control the flow of the working fluid into and out of the first chamber.

6 more elements

Dependencies are inferred from the claim text.

Dual valve fluid actuator assembly

Life of this patent

Dual valve fluid actuator assembly

Life of this patent

Abstract

Claims22