A pump assembly may include a rotor having a rotor shaft portion; a stator having a bore portion defining a bore for receiving the rotor shaft portion; and a circumferential protrusion extending radially into the bore between the bore portion and the rotor shaft portion, wherein at least one of the protrusion and a corresponding surface of the rotor shaft portion or the bore portion is configured to be abraded by the other upon experiencing contact therewith. In this way, the gap between the bore portion and the rotor shaft portion may be at least partially filled by the circumferential protrusion in order to provide a seal. The protrusion and one of the bore portion and the rotor shaft portion may be formed from different hardness materials.

A rotary piston compressor/pump/blower includes a housing spatially limiting a working chamber, an intake connection for guiding fluid into the working chamber, a pressure connection for guiding the fluid out of the working chamber, and a rotor assembly having a first rotor rotatably arranged in a first working sub-chamber and a second rotor cooperating with the first rotor and rotatably arranged in a second working sub-chamber. The rotary piston compressor/pump/blower also includes a ventilation channel, formed in the housing and connected to the working chamber via a ventilation channel opening, for the temporally limited introducing of air into the working chamber, wherein the ventilation channel opening is open at least in sections, in particular completely open, in a compression phase.

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.

A compressor or vacuum pump including: a casing having a cooling gas inlet and a cooling gas outlet for allowing a cooling gas to flow therethrough; a fan mounted at the cooling gas inlet, including a fan housing and configured to blow said cooling gas into said casing; a compression or vacuum chamber including a first housing, a process gas inlet and outlet for allowing a process gas to flow therethrough and at least one rotating element; a driving module including a second housing and at least one bearing for supporting said at least one rotating element; a silencer including a cover and configured to attenuate noise generated by the compressor or vacuum pump. The silencer includes a recess structure on its cover, configured to deflect the cooling gas flow from the fan towards the driving module.

A stator of a dry vacuum pump is provided, the pump having at least two rotors to rotate in a synchronised manner in opposite directions in a central housing to drive a gas to be pumped between a suction inlet and a delivery outlet, the stator including an outer part made of cast iron containing less than 5% nickel, and a stator insert wherein is arranged the central housing configured to receive the at least two rotors, the stator insert containing at least 10% nickel, the outer part of the stator having been cast on the stator insert. There is also provided a rotary shaft configured to bear and drive in rotation at least one rotor of a vacuum pump, a dry vacuum pump having at least one such stator and/or at least one such shaft, and a method for manufacturing such a stator and/or such a rotary shaft.

A vacuum pump rotor comprises at least one displacement element arranged on a rotor shaft. The rotor shaft comprises at least one shaft end for a bearing element to be arranged thereon. The rotor element, the at least one displacement element and the at least one shaft end are made from aluminum or an aluminum alloy.

A rotor unit assembly includes a rotor unit having a chamber and a rotor located within the chamber. The rotor has a piston which extends radially outward from the main body of the rotor; and a valve flange with an aperture. The rotor unit further comprises a rotatable hub, with a cavity configured to receive the piston. The rotor unit further comprises a first low pressure port provided in a path described by the piston; a first high pressure port positioned in a path described by the valve flange aperture around the clearance volume; and a second high pressure port positioned in a path described by the cavity around the hub axis.

A vacuum pump comprises rotor elements arranged in a suction chamber. An outlet duct is connected to an exhaust pipe. For the purpose of silencing, sound expansion spaces are provided in the outlet duct, which are integrated into the pump housing. Alternatively or in addition to these sound expansion spaces, sound expansion spaces may be provided in an inlet duct which is used for the inlet of gas ballast, said sound expansion spaces being preferably likewise integrated into the pump housing.

A supercharger rotor with reduced rotational inertia may result in increased performance of a supercharger. The rotor may include composite material and may be extrusion molded, injection molded, or otherwise molded or laid-up. In certain embodiments, the rotor may include a core with a central portion and one or more radially extending portions. The core may be extruded or formed of stacked sheets. A molded portion of the rotor, including one or more lobes, may be molded over a corresponding one of the radially extending portions. In other embodiments, a main portion of the rotor includes one or more lobes but no central hole nor a corresponding shaft extending between ends of the main portion. Instead, stub shafts are attached to the ends of the main portion. The increased performance may include decreased noise, decreased cost, increased reliability and/or durability, increased thermal efficiency, an increased power-to-weight ratio, etc.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.