A dry vacuum pump has a stator (2) and two rotors (5) that are accommodated in at least one compression chamber (3) of the stator (2), the rotors (5) being configured to rotate synchronously in opposite directions so as to drive a gas to be pumped between an intake and a delivery of the vacuum pump. The rotors (5) and the compression chamber (3) of the stator (2) are coated with a nickel-phosphorus coating (11) comprising between 9% and 14% phosphorus and having a thickness greater than 20 μm, the nickel-phosphorus coating (11) having undergone a hardening heat treatment comprising a step of heating to a treatment temperature greater than 250° C. for a treatment duration greater than one hour, so as to have a hardness greater than 700 HV.

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 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 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 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 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.

An apparatus for applying a vacuum during a surgical procedure can include a vacuum pump assembly having a port, a first housing, a second housing, a first silencer or tubular magnet and a second silencer. The first housing can define a first cavity receiving the vacuum pump assembly therein. A portion of the first housing can be formed by a portion of the port. The second housing can define a second cavity receiving the first housing therein. A portion of the second housing can be formed by a second portion of the port. The first silencer or tubular magnet can be coupled to the first housing and can have a longitudinal extent along a longitudinal axis. The first silencer or tubular magnet can extend from the first housing within the second cavity. The second silencer can be coupled to the second housing and can have a longitudinal extent along a longitudinal axis. The second silencer can extend from the second housing within second cavity.

A rotary piston engine comprises a housing (1) spatially limiting a working chamber (2), an intake connection (4) for guiding gas into the working chamber (2), a pressure connection (6) for guiding the gas out of the working chamber (2), and a rotor assembly (4) having a first rotor (14) rotatably arranged in a first working sub-chamber (12) and a second rotor (21) cooperating with the first rotor (14) and rotatably arranged in a second working sub-chamber (13). The rotary piston engine also comprises a ventilation channel (8), formed in the housing (1) and connected to the working chamber (2) via a ventilation channel opening (9), for the temporally limited introducing of air into the working chamber (2), wherein the ventilation channel opening (9) is open at least in sections, in particular completely open, in a compression phase.

A roots rotor for removing dust coagulum and droplets comprises a rotor body, which rotates inside the roots pump case. Both ends of the rotor body are sealing surfaces, which are meshed with the inner wall of the roots pump case. The rotor slot scraping cavities are arranged on both sides of the sealing surface. The side of the rotor slot scraping cavity close to the sealing surface is set as the scraper surface, which forms a sharp edge with the sealing surface. A guide surface is arranged on the surface of the rotor body, and the guide surface is located on the side of the rotor slot scraping cavity away from the sealing surface. The utility model overcomes the disadvantages of the prior art, and the attachment can be scraped off and gathered into the rotor slot scraping groove through the action of the scraper surface; and with the rotation of the rotor body, the particles and dust can be easily dropped outside the exhaust port of the pump; thus to achieve to avoid the accumulation of dust, coagulum and other incompressible medium in the process gas on the wall of the pump case.

A rotor unit assembly (10) having a rotor unit (90). The rotor unit (90) comprises a chamber (104) and a rotor (200) located within the chamber (104). The rotor (200) has a piston (214) which extends radially outward from the main body (202) of the rotor (200); and a valve flange (240) with an aperture (242). The rotor unit further comprises a rotatable hub (300), with a cavity (314) configured to receive the piston (214). The rotor unit (90) further comprises a first low pressure port (130) provided in the path described the piston (214); a first high pressure port (120) positioned in the path described the valve flange aperture (242) around the clearance volume (210); and a second high pressure port (122) positioned in the path described by the cavity (314) around the hub axis (306).