Abstract: A pump system includes pump having a control feature which, responsive to a supply of pressurized working fluid, reduces the pressure of the working fluid pressurized by the pump. The control feature is connected to the output of the pump by a regulating valve. The control feature receives pressurized working fluid to decrease the output of the pump in response to the pressure of the supplied working fluid. A regulating valve selectively connects the pressurized working fluid to the control feature. The regulating valve has a control port to receive pressurized working fluid from the pump to urge the valve to a closed position against a biasing force. A controllable valve is operable to interrupt the supply of pressurized working fluid to control port to alter the output pressure of the pump.

Abstract: A pump including a pump chamber 18, formed in a pump body 11, between a cam ring 17 and a rotor 15. The cam ring is formed so as to move in a direction whereby the pump capacity of the pump chamber increases and decreases. First and second fluid pressure chambers 33 and 34 are formed at opposite sides of the cam ring 17. The pump has a spool that is axially moved by a difference in fluid pressure between upper and lower stream sides of a metering throttle 50 connected to a discharge side passage 27 of the pump chamber. The spool is part of a control valve 30 that controls fluid pressure in at least the first fluid pressure chamber. An electronic driving unit, for example, a solenoid 60, applies axial thrust to the spool of the control valve.

Abstract: A high pressure pump suitable for use in devices such as pressure washers or the like is disclosed wherein the pump's head assembly includes an integral start valve for allowing the fluid through the head assembly so the engine may be more easily started. When the pump reaches a predetermined rate of flow of the fluid, the start valve assembly closes to circulate the fluid through said pump assembly.

Abstract: A pump chamber 18 is formed between a cam ring 17 and a rotor 15 in a pump body 11. The cam ring is formed so as to move to direction that pump capacity of the pump chamber increases and decreases. A first and second fluid pressure chambers 33 and 34 are formed at both sides of moving direction of the cam ring 17. The pump has a spool operates to axis direction by difference in fluid pressure of upper and lower stream sides of a metering throttle 50 formed on a way of a discharge side passage 27 of the pump chamber and provides at least a control valve 30 controlling fluid pressure in the first fluid pressure chamber. An electronic driving unit applying thrust to axis direction to the spool of the control valve, for example, a solenoid 60 is provided.

Abstract: A variable displacement vane pump is disclosed which includes a pump housing having a cylindrical interior chamber, a cylindrical rotor member mounted for rotational movement within the interior chamber of the pump housing, a cam member mounted for pivotal movement within the interior chamber of the pump housing about a fulcrum aligned with the vertical centerline of the interior chamber, the cam member defining a cam body having a circular bore extending therethrough for receiving the rotor member, the cam body having lateral sealing lands formed thereon, the sealing lands having arcuate sealing surfaces defining segments of a cam arc through which the cam member pivots, and static cam seals supported within the interior chamber of the pump housing and oriented on each end of a chord of the cam arc, each cam seal biased into a continuous contact position with an adjacent sealing surface of the cam member.

Abstract: A process for controlling a system for generating electricity which contains at least two compressors and two microturbines. Compressed gas from a pressure vessel is supplied to the first microturbine, and thereafter the pressure within the pressure vessel is measured. If the pressure is below a specified value, a first compressor is caused to operate to feed compressed gas to the pressure vessel. Thereafter, as the system needs require, a second compressor and, optionally, a third compressor is caused to furnish compressed gas to the pressure vessel. If the system pressure within the pressure vessel is too high, the third compressor is shut down and, if necessary, the second compressor and the first compressor are then sequentially shut down.

Abstract: Fore many applications it is desirable to determine the operating level, i.e. the current flow rate V and the total pressure difference &Dgr;pt of a fan in the installed state without external measuring points and calibration. The invention should develop a suitable method and a corresponding fan. In the method of the invention, from a measured effective pressure difference &Dgr;pMw a flow rate V is determined and from that, via an operational characteristic curve a target value for the total pressure difference &Dgr;pst is found. By comparing the target value &Dgr;pst determined this way with its measured value &Dgr;pMt the operating level and its accuracy are determined. For this purpose on the fan of the invention measuring points are provided for measuring one or more effective pressure differences &Dgr;pMw and the total pressure difference &Dgr;pMt.

Abstract: An overspeed detection circuit for producing an overspeed trip signal for shutting off a supply of motive fluid to a prime mover upon the prime mover exceeding an overspeed trip limit includes a differentiating circuit effective to differentiate a speed signal to produce an acceleration signal related to the rate of change in the speed signal. The acceleration signal is summed with the speed signal to produce an effective speed signal which anticipates the crossing of an overspeed threshold when a fault permits a constant speed increase to occur but does not force the summed signal to cross the overspeed threshold when normal speed control is exercised.