ROTARY VALVE WITH SINGLE OR DOUBLE CHANNEL SPOOL

摘要

A rotary valve has cylindrical flanges and a spool which includes at least one straight cylindrical flow channel. A geometrical butt-joint is avoided in both rotary positions of the spool thereby obviating reworking of the housing and/or spool. The cross-section of the flow path is kept constant when the circumferential surface of the spool and the housing inner surface are constructed as parallel freeform surfaces having such a curvature that the mouths of the flow channel and the mouths of the flanges in the inner surface of the housing are non-overlapping (congruent) sectional planes in both rotary positions of the spool. The valve is more economically manufactured, since reworking of the housing and spool is obviated and the spool can be made as a one-piece casting.