摘要 |
A fluid-driven motor has a manifold with an arcuate seal including first and second valve openings and a sealing surface. A cylinder pivotally mounted on the manifold has a facing surface cooperating with the arcuate seal. The arcuate seal and the facing surface define a position-responsive valve configuration such that, when the cylinder assumes a neutral position, an aperture of the facing surface faces the sealing surface, and when the cylinder is angularly displaced in either direction, the aperture overlaps one or other of the valve openings, thereby connecting to the correspond fluid flow channel in the manifold. A pressure compensation volume underlies the sealing surface and receives fluid pressure from the fluid flow channels through valves, or from the internal volume of the cylinder, so that a pressure within the pressure compensation volume approaches a value no less than a current pressure within the internal volume. |