Abstract: A system of modular electrohydraulic servovalves is centrally controlled may be used to control the operation of critical hydraulic actuators. A programmable controller operates a group of modular servovalves which each deliver a portion of the total actuator fluid requirements. The flow rate, valve position, and valve pressure of each servovalve is monitored by the controller and compared to expected values in memory to determine whether a servovalve malfunction exists. If so, the controller maintains the required flow rate to the actuator by closing the malfunctioning valve and either activating a spare or proportionally increasing the flow rates of the remaining servovalves to compensate for the loss.

Abstract: The present invention is an improvement upon conventional single-screw menisms in that the gaterotor housing is substantially isolated from both the inlet and outlet port areas by a window opening path through the casing whereby the gaterotor teeth pass for engagement with the mainrotor. The window path has been extended and has close clearances provided on both sides of the entering gaterotor teeth creating two barriers to internal leakage thereby reducing window path losses, increasing volumetric efficiency and allowing higher pressure capability.

Abstract: The teeth of a gaterotor in a single screw mechanism has flanks in contact ith the mainrotor thread which are relieved only on diagonally opposite sides above and below the gaterotor sealing plane at the leading inner and trailing outer tooth edges. When properly arranged in a mechanism capable of having multiple teeth engaged in a single screw thread, the blowhole leakage paths at the mainrotor thread crest-gaterotor tooth root-housing interface are interconnected between opposite chambers which are at equal pressure. This eliminates blowhole leakage and removes the primary limitation on gaterotor thickness and strength.

Abstract: A single screw mechanism with a reduced differential pressure applied to gaterotor teeth. This is accomplished by providing multiple tooth engagement of gaterotor teeth in a particular mainrotor compression chamber. Multiple tooth engagement makes possible the use of metallic gaterotor teeth and the elimination of gaterotor supports used to prevent the disengagement of gaterotor teeth due to high differential pressure.

Abstract: The present invention overcomes performance losses of positive displacement compressors due to internal liquid recirculation. This is achieved by removing or scavenging liquid that leaks out of the compression pocket before it is captured by another lower-pressure compression pocket of the compressor. The scavenged liquid is collected in the bottom of the compressor pressure vessel and cooled before it is reinjected into the compressor to complete the cycle.