The invention relates to a suction/compression assembly for aspirating/compressing gases from/in a system to/from an external environment. The assembly includes an operating machine comprising a body, which defines a chamber, within which one or more rotors are housed, rotating about a corresponding rotation axis. Such a chamber has a symmetrical transverse section evaluated on a plane with respect to at least one first reference plane on which said rotation axis lies. The assembly comprises a device for injecting gas into said chamber which comprises a manifold, connectable to an external source, and a plurality of injection pipes connected to the manifold and to the body of the machine. The body defines a plurality of injection passages, each of which is configured to make one of said injection pipes communicating with the chamber of the machine.

The present invention concerns a dry vacuum pump comprising: a drive device (1) comprising a drive shaft (3) at one end of which is fixed at least one drive wheel (4) provided to set in motion at least one belt (5); at least two parallel rotors (7, 8) each having a shaft (9, 10) provided with a rotor element (11, 12), this shaft (9, 10) being able to be driven in rotation by the belt (5) and being equipped at one of its axial ends with a toothed wheel (13, 14), this pump having the special features that: the drive wheel (4) and the belt (5) are smooth; each shaft (9, 10) of the rotor (7, 8) comprises at least one smooth section (16, 17) arranged to co-operate with the belt (5), and the toothed wheels (13, 14) of the shafts (9, 10) of the rotor (7, 8) are dimensioned and arranged to mesh with one another.

The present invention concerns a dry vacuum pump comprising: a drive device (1) comprising a drive shaft (3) at one end of which is fixed at least one drive wheel (4) provided to set in motion at least one belt (5); at least two parallel rotors (7, 8) each having a shaft (9, 10) provided with a rotor element (11, 12), this shaft (9, 10) being able to be driven in rotation by the belt (5) and being equipped at one of its axial ends with a toothed wheel (13, 14), this pump having the special features that: the drive wheel (4) and the belt (5) are smooth; each shaft (9, 10) of the rotor (7, 8) comprises at least one smooth section (16, 17) arranged to co-operate with the belt (5), and the toothed wheels (13, 14) of the shafts (9, 10) of the rotor (7, 8) are dimensioned and arranged to mesh with one another.

A positive displacement roots blower can include a housing having an inlet structured to receive an incoming flow of a fluid, an outlet structured to receive an outgoing flow of the fluid, and a passage. The positive displacement roots blower can also include a pair of intermeshed rotating members supported for complementary rotation within the housing, where the rotating members and the housing form respective operating volumes there between which rotate with the rotating members. Each of the respective operating volumes has the following regions: (1) open to inlet/closed to outlet; (2) closed to inlet/closed to outlet; and (3) closed to inlet/open to outlet. The passage includes a restriction and connects to at least one of the operating volumes when the at least one of the respective operating volumes is in region (2). The restriction can be a venturi feedback connecting to the outlet.

A compressor provided with a compressor element, a motor configured to drive said compressor element and an electronic pressure switch. The electronic pressure switch includes a pressure sensor; a current sensor; a microprocessor unit including a first input port and a second input port; a first communication unit; and a second communication unit. The electronic pressure switch includes a housing. The microprocessor unit, the pressure sensor, the current sensor, the first communication unit and the second communication unit are integrated in said housing.

A twin-shaft pump comprising: two shafts configured to rotate in synchronisation, each of the shafts comprising a gear mounted thereon, the gears each comprising gear wheels, the gear wheels being configured to intermesh to provide the synchronised rotation; an oil reservoir comprising a porous material, the reservoir being configured when supplied with oil to retain the oil within the porous material; and at least one wick extending from the oil reservoir towards a first of the two shafts and operable to supply oil by capillary action from the porous material along the wick to lubricate the gears.

A portable mechanical ventilator having a Roots blower provides a desired gas flow and pressure to a patient circuit. The mechanical ventilator includes a flow meter operative to measure gas flow produced by the Roots blower and an exhalation control module configured to operate an exhalation valve connected to the patient circuit. A bias valve connected between the Roots blower and the patient circuit is specifically configured to generate a bias pressure relative to the patient circuit pressure at the exhalation control module. The bias valve attenuates pulsating gas flow produced by the Roots blower such that gas flowing to the mass flow meter exhibits a substantially constant pressure characteristic. The bias pressure facilitates closing of the exhalation valve at the start of inspiration, regulates positive end expiratory pressure during exhalation, and purges sense lines via a pressure transducer module.

A compressor provided with a compressor element, a motor configured to drive said compressor element and an electronic pressure switch. The electronic pressure switch includes a pressure sensor; a current sensor; a microprocessor unit including a first input port and a second input port; a first communication unit; and a second communication unit. The electronic pressure switch includes a housing. The microprocessor unit, the pressure sensor, the current sensor, the first communication unit and the second communication unit are integrated in said housing.

A hydrogen circulation pump for a fuel cell includes a housing, rotary shafts, and two-lobe rotors. Each of the rotors has a configuration defined by the profile defined by an arc having a radius R and extending from apex end to a first transition point, an involute curve extending from the first transition point to a second transition point, and an envelope curve formed continuously with the involute curve from the second transition point to the bottom end based on a basic circle having a radius r. A distance between the apex ends of the lobe portions of each of the rotors is D. A distance between the axes of the pair of the rotary shafts is L. The radius R is set in {(2)/16}L<R<{(2752)/56}L, and the radius r is set in L/(22)<r<0.3(2)L, and the radius r is set in /(42)L<r<1.28/(42)L, and the distance D is set in 2{L+/(42)L}<D<2.032{L+/(42)L}.

Provided is a two-shaft rotary pump which is capable of improving reliability and operation efficiency by preventing an exhaust gas from flowing backward into a pump as much as possible, preventing the interior of the pump form being excessively compressed as much as possible, and suppressing temperature rise in the pump. A two-shaft rotary pump in which two rotating shafts (20, 20) provided with rotors (30, 30) are supported by bearings, such that the two rotors (30, 30) are rotated in a noncontact manner with a small clearance kept therebetween and the two rotors (30, 30) are rotated in a noncontact manner with a small clearance between an inner surface of a cylinder (50) and the two rotors, and a gas sucked into the cylinder (50) and compressed is discharged from the cylinder (50), wherein an escape hole capable of letting a part of the compressed gas escape is provided in at least one of end wall portions (52) constituting both ends of the cylinder (50) and opened in the axial direction of the rotating shafts (20, 20).