Two-dimensional pressure control valve

The two-dimensional pressure control valve is a piloted control valve which functions by using both linear and rotary motions of a single spool. A gro ove on the spool land, incorporating a sensing channel, forms the pilot sta ge to control the pressure of a spool chamber, while the load pressure is f ed to the other spool chamber. To sustain the balance of the force across t he spool, the load pressure must follow the change of pressure variation al ong the groove while the spool is in rotary motion. The geometric parameter s of the groove and the spool-to-sleeve clearance have significant effects on both the static and dynamic characteristics of the valve. Increasing the sectional size of the groove results in a large Reynolds number and the st atic property of the valve thus changes from that of linearity owing to the entrance effect. The linearity of the static property is also affected by the leakage through the spool-to-sleeve clearance. The dynamic characterist ics of the valve are dependent upon both the structural parameters and the time constant of the load. The stability and dynamic response were investig ated under different structural parameters and time constants of the load u sing both linear theory and simulation methods. Experiments were designed t o obtain the static and dynamic characteristics of the valve and the leakag e through the pilot. A balance should be made between the linearity of the static property and the response speed; it was found that both fairly linea r static and desired dynamic characteristics could be simultaneously mainta ined for the two-dimensional pressure control valve.