SPOOL VALVE FOR FLUID CONTROL

摘要

A spool valve is provided with a stem portion that defines a fluid passageway formed by a pair of sidewalls with, preferably, interior surfaces that are shaped hydrodynamically and exterior surfaces that include a pressure-balancing channel. This stem passageway, which is designed to facilitate the flow of high--speed/high-pressure fluids controlled by the valve, is maintained in a predetermined orientation relative to the ports of the valve cylinders by a mechanism preferably including (a) a cam-following roller supported in a tang fixed to each spool and (b) a two-element cam that captures the roller within two of the parallel sides of a cam-track groove formed in the respective interior surfaces of each cam element.