| 摘要 |
<p>Kobelt 28 C.W FLUID ACTUATED POSITIONER A fluid actuated positioner for producing a mechanical output signal proportional to a fluid input signal. Input signal acts on input rod of input cylinder to control a main valve which controls flow between chambers of a hydraulic power cylinder. Power cylinder has output piston rod connected to device to be controlled, and fluid forces on output rod are determined by pressure differences across faces of output piston, which differences are determined by amount of metering of main valve. Valve can be simple clearance passage maintained open to permit steady flow therethrough in non-changing signal, or can be spool valve which stops flow during non-changing. Both devices do not require exceptionally close tolerance manufacture, and creep problems are reduced.</p> |
