A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A screw compressor includes a first rotor and a second rotor, and each rotor is provided with a synchronisation gear. The screw compressor is further provided with an electric motor and one or two driving gears for driving the first rotor or second rotor. At least one of the synchronisation gears or driving gears is provided with spokes between a rim supporting a gear mesh and a corresponding gear hub.

A screw compressor includes a first rotor and a second rotor, and each rotor is provided with a synchronisation gear. The screw compressor is further provided with an electric motor and one or two driving gears for driving the first rotor or second rotor. At least one of the synchronisation gears or driving gears is provided with spokes between a rim supporting a gear mesh and a corresponding gear hub.

A rotary positive displacement pump comprises a housing rotationally supporting first and second parallel and axially extending drive shafts having constantly meshing gears such that the drive shafts rotate in opposite directions. A rotor casing is connected to a front side of the housing and has axial rear and front walls and a circumferential side wall jointly defining a pumping cavity. The casing houses first and second rotors drivingly connected to the first and second drive shafts respectively. The rotors rotate in opposite directions and mutually interact to provide a positive pumping effect on fluid product entering the cavity. First and second sealing arrangements prevent leakage of fluid product from the cavity towards the rear side of the casing along the first/second drive shafts. A heating device is detachably fastened to the rear casing wall to heat the casing, the first/second sealing arrangements and/or any fluid product within the casing.

A rotary positive displacement pump comprises a transmission housing having front and rear walls and rotationally supporting first and second drive shafts having constantly meshing gears such that the drive shafts rotate in opposite directions. A rotor casing connected to a front side of the housing has rear and front walls and a circumferential side wall defining an interior pumping cavity. The casing houses first and second rotors drivingly connected to the first and second drive shafts to provide a positive pumping effect on fluid product entering the cavity. The front and rear walls of the housing define an intermediate space through which the drive shafts extend. A first guard is located in the intermediate space and surrounds the drive shafts, or first and second guards are located in the intermediate space and surround the first and second drive shafts respectively, for protecting a person from contacting the drive shafts.

A rotary positive displacement pump comprises a transmission housing having front and rear walls and rotationally supporting first and second drive shafts having constantly meshing gears such that the drive shafts rotate in opposite directions. A rotor casing connected to a front side of the housing has rear and front walls and a circumferential side wall defining an interior pumping cavity. The casing houses first and second rotors drivingly connected to the first and second drive shafts to provide a positive pumping effect on fluid product entering the cavity. The front and rear walls of the housing define an intermediate space through which the drive shafts extend. A first guard is located in the intermediate space and surrounds the drive shafts, or first and second guards are located in the intermediate space and surround the first and second drive shafts respectively, for protecting a person from contacting the drive shafts.

A dry rotary pump for recirculating an at least partially gaseous composition containing hydrogen. The dry rotary pump comprising a first rotating shaft and a second rotating shaft. The first rotating shaft and the second rotating shaft are driven in rotation by a drive system in a gear chamber. The dry rotary pump comprises a first pair of seals and a second pair of seals, each comprising a first shaft seal and a second shaft seal. The dry rotary pump comprises a pressure equalization chamber in fluid connection with a gap between the first shaft seal and the second shaft seal to regulate pressure in the gap. The gear chamber is in fluid connection with the gap, and the pumping chamber is in fluid connection with the first shaft seal and the first shaft seal by a pulsation attenuation chamber.

An internal combustion heat engine, of which the architecture of one elementary cylinder includes 4 identical mobile couplings distributed about the Z axis of the engine, consisting of a segmented piston driven by the crank pin of a crankshaft and guided by a roller rolling in a slide. The crankshafts, which are parallel and synchronized by a gear mechanism, perform one revolution per cycle. Each piston includes a sliding surface that nearly touches the cylinder face of the adjacent piston, but on which the segmentation slides in sealed contact. The concave shape of the 4 overlapping faces encloses a chamber volume that changes cyclically: at a minimum, having a quasi-spherical shape during combustion, reducing the heat losses at the walls, and at a maximum, uncovering the ports allowing intake and exhaust via transfer units and manifolds with the possibility of more economical Miller/Atkinson distribution, via rotary plates.

An internal combustion heat engine, of which the architecture of one elementary cylinder includes 4 identical mobile couplings distributed about the Z axis of the engine, consisting of a segmented piston driven by the crank pin of a crankshaft and guided by a roller rolling in a slide. The crankshafts, which are parallel and synchronized by a gear mechanism, perform one revolution per cycle. Each piston includes a sliding surface that nearly touches the cylinder face of the adjacent piston, but on which the segmentation slides in sealed contact. The concave shape of the 4 overlapping faces encloses a chamber volume that changes cyclically: at a minimum, having a quasi-spherical shape during combustion, reducing the heat losses at the walls, and at a maximum, uncovering the ports allowing intake and exhaust via transfer units and manifolds with the possibility of more economical Miller/Atkinson distribution, via rotary plates.