| 摘要 |
<p>An electro-hydraulic servo-distributor comprising a primary or pilot stage having a drive means constituted by a magnetic circuit which comprises two parallel polar cores, and two rectilinear magnets parallel to the cores and connected magnetically to one end of the cores by at least one metal plate. Two control coils are wound around the cores and a movable plate assembly is arranged opposite the other ends of the polar cores, forming therewith equal air gaps. The arrangement of the different components of the magnetic circuit is such that the flux produced by the control coils and the flux of one of the magnets pass across the corresponding air gap in the same direction, while the flux produced by the other magnet pass across the other air gap in the opposite directions. A support member is provided with a central part on which the movable plate assembly is fixed, and two lateral torsion rods which are each terminated by a lateral portion are engaged in the fixed structure of the servo-distributor. The support member also carries in its central part a hydraulic closure member which is substantially perpendicular to the plate assembly and which is intended to close according to the direction of magnetic turning moment to which the movable plate assembly is subjected, one or the other of two jets which are supplied with a hydraulic fluid, by a secondary or hydraulic stage controlling flow or controlling pressure.</p> |
