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 can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The first side coupling assembly can have a first side coupling body and a first side elastomeric insert. The second side coupling assembly can have a second side coupling body and a second side elastomeric insert. The central hub can define central hub bores therein. The plurality of coupler pins can be received in the central hub bores. The first and second side elastomeric inserts provide dampening between (i) the first side coupling body and the central hub and (ii) the second side coupling body and the central hub.

An inter-stage coupling for a multi-stage vacuum booster pump may include a first coupling face configured to be received by a first adjacent stage of the multi-stage vacuum pump; a second coupling face configured to be received by a second adjacent stage of the multi-stage vacuum pump; and a recirculator comprising a recirculation inlet aperture formed in the first coupling face, a recirculation outlet aperture formed in the first coupling face, and a recirculation conduit having a recirculation valve configured to selectively fluidly couple the recirculation inlet aperture with the recirculation outlet aperture. In this way, the pressure in a stage can be relieved by fluidly coupling the outlet aperture with the inlet aperture in order to recirculate built-up gas from one part of the first stage pump to another part of the first stage pump in order to reduce the strain on the rotor.

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.

An arrangement (100) for specifying the pressure (64), produced by a pump (30) driven by an electric motor (31), includes a processor (116) which derives a target pressure value (62, 118) from an internal torque value (114) and a loss torque (108). The arrangement (100) further derives (112) the internal torque value (114) from a motor current value (110) and a motor constant k.sub.e.

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.

The disclosure describes a flow conditioning device for dampening pulses and improving performance of a compressor. In one approach, a diffuser device includes a housing member having a first end and a second end, the housing member coupled to an outlet of a compressor, and a diffuser member disposed within the housing member. The diffuser member is in fluid communication with a working fluid delivered from the compressor, and includes a core member extending along a longitudinal axis of the diffuser member, and a plurality of flutes extending radially from the core member. In some approaches, the plurality of flutes and an inner surface of the housing define a plurality of fluid channels for delivering the working fluid from the first end to the second end of the housing member. In some approaches, the diffuser member is rotatably coupled to the housing member.

A vacuum pump system for evacuating a chamber, in particular a lock or a process chamber, is provided that includes a main vacuum pump preferably configured as a screw pump. An inlet of the main vacuum pump is connected with the chamber to be evacuated. As seen in the feeding direction of the main vacuum pump an auxiliary vacuum pump is arranged which is in particular a Roots pump. An outlet area of the main vacuum pump is connected with a main outlet on the one hand and an inlet of the auxiliary vacuum pump on the other hand. Further, an outlet of the auxiliary vacuum pump is connected with the main outlet.

A vacuum pump system for evacuating a chamber, in particular a lock or a process chamber, is provided that includes a main vacuum pump preferably configured as a screw pump. An inlet of the main vacuum pump is connected with the chamber to be evacuated. As seen in the feeding direction of the main vacuum pump an auxiliary vacuum pump is arranged which is in particular a Roots pump. An outlet area of the main vacuum pump is connected with a main outlet on the one hand and an inlet of the auxiliary vacuum pump on the other hand. Further, an outlet of the auxiliary vacuum pump is connected with the main outlet.

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 can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The first side coupling assembly can have a first side coupling body and a first side elastomeric insert. The second side coupling assembly can have a second side coupling body and a second side elastomeric insert. The central hub can define central hub bores therein. The plurality of coupler pins can be received in the central hub bores. The first and second side elastomeric inserts provide dampening between (i) the first side coupling body and the central hub and (ii) the second side coupling body and the central hub.

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.