| 摘要 |
<p>A rotary valve having a valve body with a rotatable valve member in the form of a port plate rotatably positioned therein for causing free flow from pump to reservoir in a neutral position and having other operative positions for directing fluid to and from the valve. Passage means in the valve body have check valves providing free flow from a control port to an operative member, such as a cylinder, and for holding of pressure on the cylinder when the valve is returned to neutral position. The valve includes seat seal members positioned within flow passages in the valve body and engageable with the valve member and which are formed with opposed surfaces having a differential area whereby forces resulting from fluid pressure urge the seat seal members against the valve member.</p> |
