A Novel Bi-Directional Proportional Hydraulic Valve Actuator

摘要

This paper presents a novel solenoid design which generates a bi-directional force proportional to the magnitude and direction of the applied current, and largely independent of the armature position. The new design employs a traditional arrangement comprising a pressure tube with a removable coil. The bi-directional force characteristic is achieved using a novel armature design incorporating permanent magnets in conjunction with a new pressure tube design. The pressure tube utilizes standard in-fill brazing processes, making this actuator suitable for high-pressure applications. The coil assembly is standard, though in contrast to traditional single acting solenoids, the polarity of the applied current must be reversible. The new bi-directional actuator achieves similar force and stroke compared to a standard single acting solenoid of the same size. This enables a traditional 3-position proportional valve function to be achieved using a more compact actuator package. In addition, not only is the inductance of the new actuator substantially lower, but the variation of the inductance over the working stroke is less. This makes it especially attractive for use in high-speed valve applications.