Actuator for a spool valve

Abstract

A valve positioner (10) for controlling a valve closure element is provided. The positioner includes a positioner housing with a plurality of fluid flow passageways in fluid communication with a fluid supply source and the valve closure element. The positioner housing is configured to receive a detachable spool manifold assembly (14). The spool manifold assembly is positioned adjacent the plurality of fluid flow passageways. The spool manifold assembly includes a reciprocally moveable spool (34) configured to selectively port fluid flow from the plurality of fluid flow passageways. The spool manifold assembly includes a diaphragm (48) connected to the spool via a flexible shaft (50). The diaphragm is in fluid communication with a transducer for receiving a fluid causing the diaphragm to expand or contract and thereby displacing the spool. The flexible shaft is radially elastic in order to minimize axial backlash between the diaphragm and the spool. The flexible shaft configuration minimizes the spool stroke.

Description

[0001] Cross References to Related Applications [0002] This application claims priority from US Provisional Patent Application No. 61 / 011035, filed January 14, 2008, the contents of which are incorporated herein by reference. [0003] Statement Regarding: Federally Funded Research / Development [0004] Not applicable technical field [0005] The present invention relates generally to fluid flow control, and more particularly to a high flow positioner for regulating fluid flow in a fluid circuit. Background technique [0006] Control valves regulate flowing fluids such as gases, steam, water or chemical compounds. Actuators can be used to regulate fluid flow within a control valve. The actuator provides the power to open or close the valve and thereby regulate fluid flow within the valve. [0007] A valve positioner is an actuator-mounted device that implements a control strategy determined by the output of a controller in electrical communication with the valve posit...

AI Technical Summary

Problems solved by technology

Therefore, high amplification ratios cause instability, while lower amplification ratios usually cannot meet the dynamic performance requirements

Adding an intensifier also includes adding tubing and fittings, resulting in increased cost and parts

Additional parts make maintenance more difficult and potentially increase the risk of failure and / or leaks

Also, intensifiers must be calibrated and tuned, which costs time and money

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