Abstract: A rotary positive displacement pump for fluids, in particular for the lubrication oil of a motor vehicle engine (60), has a displacement that can be regulated by means of the rotation of a stator ring (12) having an eccentric cavity (13) in which the rotor (15) of the pump (1) rotates. The stator ring (12) is configured as a multistage rotary piston for displacement regulation and is arranged to be directly driven by a fluid under pressure, in particular oil taken from a delivery side (19) of the pump or from a point of the lubrication circuit located downstream the oil filter (62). The invention also concerns a method of regulating the displacement of the pump (1) and a lubrication system for a motor vehicle engine in which the pump (1) is used.

Abstract: The present document describes a rotating and reciprocating piston device comprising: chambers disposed about a chamber axis, the chambers having two ends and a port for passage of a fluid at each one of the ends of the chambers; pistons having two ends, each one of the pistons slidably positioned within a respective one of the chambers thereby determining a space at either end of each piston within its respective chamber; and a track forming a closed circuit through which the chamber axis passes, the track for determining a position of a piston within its respective chamber and hence the space on either side thereof.

Abstract: A process for making a metal tool having controlled porosity is disclosed. The process includes the step of preparing metal powder by gas atomization. The metal powder is filled into a metal container. The powder-filled container is placed in a metal vessel and surrounded with glass frit. The metal vessel is then heated to a temperature sufficient to melt the glass frit. The metal vessel is then compacted under sufficient pressure to partially consolidate the metal powder so as to retain porosity therein in an amount sufficient to permit air to vent through the metal tool.

Abstract: An object is to provide a high inner pressure type multistage compression rotary compressor capable of avoiding beforehand generation of vane fly of a second rotary compression element and realizing a stabilized operation, the rotary compressor includes a communication path which connects an intermediate pressure region to a region having a low pressure as a suction pressure of a first rotary compression element; and a valve device which opens or closes this communication path, the rotary compressor applies a high pressure as a back pressure of an upper vane, and this valve device opens the communication path in a case where a pressure difference between the intermediate pressure and the low pressure increases a predetermined upper limit value before the intermediate pressure reaches the high pressure.

Abstract: A vacuum pump, comprising at least one pump chamber (7, 8, 23 to 26) and at least one chamber (3, 5, 27) adjoining the pump chamber. The vacuum pump is fitted with a gas ballast device to avoid damage being caused in the adjoining chambers by the gases being pumped, the ballast gas being delivered via the chamber adjoining the pump chamber.

Abstract: A lobed rotor-type pump has a drive shaft, a pump housing, an eccentric rotor journal, a rotor, three working-fluid chambers, intake and discharge ports, and a communication passage. The pump housing has a circumferentially-extending peri-trochoidal curved surface in its inner periphery. The eccentric rotor journal is fixedly connected to the drive shaft. The rotor is slideably fitted to the eccentric rotor journal. The rotor has three lobes equi-distantly spaced circumferentially around its outer periphery so that the rotor rotates eccentrically while keeping the lobes in sliding contact with the peri-trochoidal curved surface. The three working-fluid chambers, which are defined between respective three lobes and the peri-trochoidal curved surface, rotate in synchronism with the rotor. The intake and discharge ports are provided in the housing to input low-pressure incompressible fluid and to output high-pressure fluid.

Abstract: A rotor-type pump comprises a housing having a trochoidal curved surface and an intake port and a discharge port. A drive shaft is mounted rotatably about a first axis in the housing. A rotor having a second axis eccentric to the first axis is rotatably mounted to the drive shaft. The rotor cooperates with the trochoidal curved surface. A plurality of working-fluid chambers are defined by the trochoidal curved surface and an outer peripheral surface of the rotor and variable in volume as the rotor rotates. The intake port is open into one chamber of the chambers and the discharge port is open into another chamber thereof. A communication passage fluidly interconnects at least adjacent two of the chambers. A rotor control mechanism is provided for controlling the rotor to move along the trochoidal curved surface with a predetermined clearance therebetween upon rotation of the rotor.

Abstract: A multistage discharge type rotary vacuum pump comprises a rotor rotably mounted within a cylinder chamber and dividing the cylinder chamber into first stage and second stage working chambers. A plurality of radially extending vanes are slidably mounted in the rotor in angularly spaced relation, and the vanes undergo radial sliding movement during rotation of the rotor such that the vane tips maintain sliding contact with the cylinder chamber. Each working chamber has an inlet port at the upstream side thereof for admitting exhaust gas evacuated from a confined space during use of the pump, and an outlet port at the downstream side thereof for discharging the exhaust gas which has been compressed in the working chamber in response to rotation of the rotor. The outlet port of the first stage working chamber communicates through a discharge valve with a storage chamber, and the storage chamber communicates through a pressure-responsive discharge valve with the inlet port of the second stage working chamber.

Abstract: The rotary piston machine contains a rotor (22) having a plurality of sector-shaped chambers (30). Each chamber (30) houses a flap piston being swivelingly mounted and reciprocated synchroneously with the rotation of the rotor (22). By each of the double acting flap pistons (32) two working compartments are confined, and always two adjacent flap pistons (32) are driven in counterphase to one another. The adjoining working compartments of adjacent piston chambers (30) are commonly connected to inlet and outlet aperture slots (44) in the periphery of the rotor (22). The inlet and outlet ports (42) and ducts (A,B,C,D,E) are provided in the stator (21) around the periphery of the rotor (22).

Abstract: A rotary pump which comprises a cylinder having two walls which cover both ends thereof to form a compressing chamber, each of the walls includes a bearing at its center and holes around the bearing to form an inlet or an outlet of the fluid, a shaft supported by the bearings and driven by a motor, a piston having two connected arc surfaces rotatably mounted within the cylinder, each surface of the piston including a groove, an outlet port and an inlet port, a separating plate mounted in the hole of the piston and dividing the hole into two parts and separating the outlet ports and inlet ports on each part, a plunger which may be moved back and forth in the piston hole to open or close the inlet ports. The present invention can pump the fluid in periodic high pressure or stable middle pressure by controlling the movement of the plunger in piston.

Abstract: A compressor-expander for use in air conditioning including a chamber of generally elliptical cross section having a compressor side and an expander side each with inlet and outlet ports. Rotatable in the chamber is a vaned rotor defining enclosed compartments in which the air is positively compressed accompanied by an increase in temperature in the compressor side and is positively expanded with a decrease in temperature in the expander side, the elliptical eccentricity of the compressor side being less than 0.62 and the eccentricity on the expander side being less than the eccentricity of the compressor side in a ratio lying between 0.68 and 0.95. Pressure in the compartment at the point of discharge is substantially at atmospheric level, and the expander outlet port is so located that when a compartment on the expander side is centered on the major axis, the leading vane is at the threshold of discharge.

Abstract: A rotary positive displacement, hot gas regenerative engine having at least two cylindrical rotors, each of which is disposed within an elliptical stator. The longitudinal axis of one rotor is in registration with the longitudinal axis of the other rotor. The longitudinal axis of one stator is offset from and is in spaced parallel relationship with the longitudinal axis of the other stator. The longitudinal axes of the rotors are in spaced parallel relationship with the longitudinal axes of the stators. The rotors, which are mounted on a common shaft, are provided with a plurality of radially extending slidable vanes that form a plurality of expansion chambers and a plurality of compression chambers in each rotor-stator pair. The longitudinal axis of the rotor in each rotor-stator pair is offset from the longitudinal axis of the stator of that rotor-stator pair so that the volume of the expansion chambers is greater than the volume of the compression chambers.