A dry vacuum pump includes: at least one oil sump; at least one pumping stage; two rotary shafts respectively supporting at least one rotor extending into the at least one pumping stage, the rotors being configured to rotate in a synchronized manner in the reverse direction in order to convey a gas to be pumped between an intake and an outlet of the vacuum pump, the shafts being supported by bearings lubricated by a lubricant contained in the at least one oil sump; at least one lubricant sealing device interposed between the at least one oil sump and a pumping stage at the shaft passage; and at least one expansion device configured to reduce the pressure variations between a pumping side volume and the at least one oil sump.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

Positive displacement machine such as a compressor, expander, pump or the like, for displacing a gaseous or liquid medium, the machine containing an element with at least one inlet and at least one outlet for the medium and at least two cooperating driven moving parts. The mutual periodic movement of the moving parts displaces the medium from the inlet to the outlet. Each of the at least two driven cooperating moving parts is provided with its own individual drive. The element is provided with a kinematic synchronisation coupling between the at least two cooperating moving parts for the mutual kinematic synchronisation of their movements.

Positive displacement machine such as a compressor, expander, pump or the like, for displacing a gaseous or liquid medium, the machine containing an element with at least one inlet and at least one outlet for the medium and at least two cooperating driven moving parts. The mutual periodic movement of the moving parts displaces the medium from the inlet to the outlet. Each of the at least two driven cooperating moving parts is provided with its own individual drive. The element is provided with a kinematic synchronisation coupling between the at least two cooperating moving parts for the mutual kinematic synchronisation of their movements.

A dry vacuum pump includes an elastic outer seal and at least one elastic inner seal respectively including a first and a second end annular parts parallel to one another and inserted between a respective end piece and the half-shells, and two side rails connecting the end annular parts and which are at right angles thereto, the side rails being inserted between the half-shells, the at least one inner seal being arranged inside the outer seal so that the at least one inner seal and the outer seal form at least two successive sealing barriers for the gases.

A vacuum system having a condenser and a root vacuum pump set includes an independent inlet condenser set having an inlet end for receiving vapor inputted from an output of an air cooling power generator condenser of a generator; air in the vapor being condensed, and the surplus air is outputted; a root vacuum pump set including at least one root vacuum pump; the root vacuum pump set further including an input end and an output end; the input end being connected to the independent inlet condenser set; air outputted from the independent inlet condenser set being inputted to the at least one root vacuum pump for compression and then the compressed air being outputted from the output end; and a backing pump connected to the output end of the root vacuum pump set by using an output pipe; the backing pump serving to receive air outputted from the root vacuum pump set.

A fluid working system such as a pump for displacing a working fluid such as hydraulic fluid or a motor using a working fluid is provided. The system may have a positive displacement machine which includes one or more working chamber with displacement means such as a cylinder with a reciprocating piston. There are also two or more fluid ports to allow the working fluid to flow into and out of the working chamber. The working fluid flows from one fluid port means to another either being forced to do so when pumped or moving the piston when functioning as an engine. The fluid working system has associated therewith a non-dead compliance volume of a material such as syntactic foam. This compliance volume acts to smooth any pressure fluctuations within the working fluid system.

Provided are a vacuum pump and an adapter used in the vacuum pump that are capable of responding to various changes in specifications at low cost. A turbo-molecular pump includes a base, a stator blade that is provided above the base in an axial direction of a rotor, a rotor blade that is integrally attached to the rotor, a housing that is formed in a cylindrical shape, and accommodates the stator blade and is integrally attached to the base, and an adapter that is replaceable depending on a type of the stator blade, the rotor blade, or the housing, and that is detachably mounted on the base and is configured to support the stator blade in the axial direction.

A multi-stage vacuum pump comprising a stator defining multiple pumping chambers is discussed. The stator comprises a plurality of transfer channels for providing a fluid passage from an outlet port of one of the plurality of pumping chambers to an inlet port of a subsequent pumping chamber. Some of the transfer channels comprise two side channel sections on opposing sides of the stator. One of the transfer channels comprises a single side channel section on one side of the stator. The vacuum pump further comprises a gas ballast inlet channel arranged on an other side of the stator to the one side of the stator.

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.