A coaxial valve includes a valve box having an inlet opening, an outlet opening, and a common flow channel. An axially movable cylindrical valve casing has an opening for a fluid inlet port and an opening for a fluid outlet port, both of which are joined up in the flow channel. A coaxially positioned shutoff mechanism located inside the valve box closes off the inlet port or the outlet port of the valve casing. To provide for axial movement, the valve casing has at least one external circular groove. The drive casing has at least one inner circular groove, which is adapted to the outer circular groove so that the inner and outer grooves are engaged, via inside ball bearings, to create a ball planetary gear and ball rotary spindle drive. The drive casing is turnable and forced to turn by a drive motor inside of the valve box.
