Abstract: Under uniform and uniformly accelerated circular centrifugal environments, characteristics of the electro hydraulic servo valves(EHSV) with its spool perpendiculars the centrifugal angular velocity vector in a same plane, in different planes and parallels to each other are analyzed. Based on mechanical analysis of the spool and the armature-flapper assembly according to kinetic theory of rotational transport motion, mathematical models of the EHSV under the three-dimensional centrifugal environment are obtained. Influence of centrifugal environment affected on displacements of armature, flapper and spool are got. Capability of acceleration resistance of the EHSV under three typical spatial proposals is gained: the EHSV with its spool parallels the centrifugal angular velocity vector has the strongest resistance to acceleration, the medium one is the EHSV with its spool perpendiculars the centrifugal angular velocity vector in different planes, and the weakest is the EHSV with its spool perpendiculars the centrifugal angular velocity vector in a same planes. Validation test is carried out using a servo valve. Spool displacement is calculated from the no-load flow when the control current is zero. And mathematical relationship between spool displacement and centrifugal acceleration is obtained. The theoretical results are in good agreement with the experimental results.

Key words: acceleration resistance, hydraulic, mathematical model, servo valve, three-dimensional centrifugal environment