A control valve in an intermittent air-generating device has a five-port valve, the inlet port of which is connected to a fluid supply source and the outlet port is connected to an air-spraying device. As a result of pilot air being supplied to a pilot input port, a valve element moves, and as a result of the inlet port and the outlet port being put in an ON state in which the two are in communication with each other, compressed air is sprayed from the air-spraying device. Meanwhile, as a result of the pilot air being discharged from the pilot input port by way of a discharge port, the valve element moves in the opposite direction and the inlet port and the outlet port are put in an OFF state in which the state of communication between the two is blocked. The ON state and OFF state alternate intermittently.

A control valve in an intermittent air-generating device has a five-port valve, the inlet port of which is connected to a fluid supply source and the outlet port is connected to an air-spraying device. As a result of pilot air being supplied to a pilot input port, a valve element moves, and as a result of the inlet port and the outlet port being put in an ON state in which the two are in communication with each other, compressed air is sprayed from the air-spraying device. Meanwhile, as a result of the pilot air being discharged from the pilot input port by way of a discharge port, the valve element moves in the opposite direction and the inlet port and the outlet port are put in an OFF state in which the state of communication between the two is blocked. The ON state and OFF state alternate intermittently.

An improved servovalve for a seismic vibrator or vibration machine which includes a left additional passageway conducting a portion of sampled pressure from a left cylinder pressure chamber to only a portion of the right end drive surface of the spool, wherein the portion of the right end drive surface is less that of the entirety of the right end drive surface; and a right additional passageway conducting a portion of sampled pressure from a right cylinder pressure chamber to only a portion of the left end drive surface of the spool, wherein the portion of the left end drive surface is less that the entirety of the left end drive surface; thereby providing at least two additional passageways configured to provide linear proportional pressure feedback in spool movement control.

An active separation control system, comprising a fluidic oscillatory actuator having an ejector member, an oscillator member, and a joining channel between said oscillator member and said ejector member, all mounted on at least one flexible member, said fluidic oscillatory actuator being mountable on a rotatable door of a vehicle such that said flexible member assumes a different shape when said door is closed than when said door is open, wherein said joining channel is also flexible to assume a shape of said flexible member.

An active separation control system, comprising a fluidic oscillatory actuator having an ejector member, an oscillator member, and a joining channel between said oscillator member and said ejector member, all mounted on at least one flexible member, said fluidic oscillatory actuator being mountable on a rotatable door of a vehicle such that said flexible member assumes a different shape when said door is closed than when said door is open, wherein said joining channel is also flexible to assume a shape of said flexible member.

A hydraulic propulsion system converts heat or thermal energy into hydraulic energy, and such hydraulic energy into mechanical work. The hydraulic propulsion system includes a thermal unit, a hydraulic cylinder with pistons and springs mounted therein, one or more hydraulic motors, one or more hydraulic accumulators, and one or more electrical energy generators, as well as a plurality of flow control valves to control the flow of hydraulic fluid between the various components. The hydraulic propulsion system may be enhanced by an energy transmission unit including a wave generator.

A hydraulic propulsion system converts heat or thermal energy into hydraulic energy, and such hydraulic energy into mechanical work. The hydraulic propulsion system includes a thermal unit, a hydraulic cylinder with pistons and springs mounted therein, one or more hydraulic motors, one or more hydraulic accumulators, and one or more electrical energy generators, as well as a plurality of flow control valves to control the flow of hydraulic fluid between the various components. The hydraulic propulsion system may be enhanced by an energy transmission unit including a wave generator.

A method and apparatus are presented. An active flow control system comprises a flow control valve, a manifold, and a temperature control system. The flow control valve is configured to control a flow of air into the manifold. The manifold is operatively connected to a number of actuators. The temperature control system is configured to heat at least a portion of the flow of air.

A method and apparatus are presented. An active flow control system comprises a flow control valve, a manifold, and a temperature control system. The flow control valve is configured to control a flow of air into the manifold. The manifold is operatively connected to a number of actuators. The temperature control system is configured to heat at least a portion of the flow of air.

A method and apparatus for dithering hydraulic valves to mitigate static friction (“stiction”) associated with the hydraulic valves. A first hydraulic valve and a second hydraulic valve are dithered to mitigate stiction associated with those valves. The dithering of the first and second hydraulic valves also cause dithering of a main hydraulic valve associated with the first and second hydraulic valves. Accordingly, stiction of three hydraulic valves of a hydraulic system is mitigated.