Abstract: The present invention provides a pump comprising a regenerative pumping mechanism. A rotor of the pump has a generally disc-shaped pump rotor mounted on an axial driveshaft for rotation relative to a stator, the pump rotor having rotor formations disposed in a surface and defining at least a portion of a flow path for pumping gas from an inlet to an outlet. The rotor formations are formed between the pump rotor and the stator of the pumping mechanism. The pump rotor and the stator comprise an axial gas bearing arrangement for controlling axial clearance between the rotor and the stator during pump operation. Thus, this configuration of pump provides a gas bearing disposed on the rotor which enables an improved control of axial clearance between the pump's rotor and stator components.

Abstract: A vacuum pump rotor suitable for use in a vacuum pump is described for a vacuum pump that comprises a regenerative pumping mechanism. The rotor has a generally disc-shaped configuration and is mounted on an axial shaft for rotation relative to a stator of a vacuum pump. The rotor has a first and second opposing surface on which a rotor formations are disposed, each rotor formation defining a portion of a pump stage formed between the pump rotor and a stator for pumping gas from an inlet to an outlet in the same radial direction along the first and second opposing surface. A conduit is provided to interconnect the portions of the pump stage and assist with pressure imbalance that might occur on opposing sides of the rotor.

Abstract: A multistage vacuum pump includes a stator housing a multistage rotor assembly, each stage having intermeshing Roots rotor components, wherein the tip radius of the rotor components at an inlet stage of the pump is larger than the tip radius of the rotor components at an exhaust stage of the pump, wherein a meshing clearance between the rotor components at the inlet stage of the pump is greater than a meshing clearance between the rotor components at the exhaust stage of the pump.

Abstract: A screw pump and pumping arrangement including a screw pump having a chamber and externally threaded rotors mounted on shafts for counter-rotation and flow paths with fluid inlets located at a common low pressure side of the chamber.

Abstract: A differentially pumped vacuum system including apparatus having at least first and second chambers; and a vacuum pump for differentially pumping fluid from the chambers to generate a first pressure above 0.1 mbar in the first chamber and a second pressure lower than the first pressure in the second chamber, the pump having at least first and second pump inlets each for receiving fluid from a respective pressure chamber and a plurality of pumping stages positioned relative to the inlets so that fluid received from the first chamber passes through fewer pumping stages than fluid from the second chamber, the inlets being attached to the apparatus such that at least 99% of the fluid mass pumped from the apparatus passes through at least one of the pumping stages of the pump.

Abstract: A method of monitoring the condition of a pump (10) or at least one component of a system that includes a pump which component or components are not a part of the pump, includes the step of generating a predetermined test condition in the pump or system component or components. During a period in which such a test condition is present, signals indicative of the pump or system component or components are obtained. Wear in the pump bearings, the build-up of deposits in the pump or in pipework forming a part of the pump system can be detected or predicted and corrective action taken before the pump or system fails. By providing a method of monitoring pump or system condition in-situ, it is possible to reduce the likelihood of pump failure in use and the need to carry out over frequent servicing of the pump.

Abstract: A vacuum pumping system comprises a vacuum pumping arrangement comprising: a drive shaft; a motor for driving said drive shaft; a molecular pumping mechanism comprising a turbomolecular pumping mechanism; and a backing pumping mechanism. The drive shaft drives said molecular pumping mechanism and said backing pumping mechanism. The system also comprises an evacuation mechanism, such as a load lock pump, for evacuating at least, said turbomolecular pumping mechanism.

Abstract: A differentially pumped mass spectrometer system comprises a mass spectrometer having a plurality of pressure chambers; a vacuum pump attached thereto and comprising at least three pump inlets, a first pumping section, a second pumping section downstream from the first pumping section, and a third pumping section downstream from the second pumping section, an outlet from a first, relatively low, pressure chamber being connected to a first pump inlet through which fluid can enter the pump from the first chamber and pass through the first, second and third pumping sections towards a pump outlet, an outlet for a second, medium pressure chamber of the spectrometer being connected to a second pump inlet through which fluid can enter the pump and pass through, of said sections, only the second and third pumping sections towards the pump outlet, and an outlet for a third, highest pressure chamber of the spectrometer being connected to a third pump inlet through which fluid can enter the pump and pass through, of sai

Abstract: A multi-stage, clam shell, vacuum pump comprises two housing components (12) which are to be sealingly connected to one another such that an array of chambers extending longitudinally from an inlet region of the pump to an outlet region of the pump is defined thereby. Sealing means (30) are provided within the vacuum pump, between the two housing components, to prevent transfer of fluid in to and out of the vacuum pump where said components are connected. An array of discrete, elongate channels (33, 34, 36, 38) is provided, located between the sealing means (30) and the array of chambers (14, 16, 18, 20, 22). The channels serve to protect the sealing means (30) from fluid that passes through the chambers during operation of the vacuum pump. Each channel is configured to receive a barrier fluid having a different pressure than a barrier fluid to be received by an adjacent channel.

Abstract: A multistage vacuum pump comprises a stator housing a multistage rotor assembly, each stage comprising inter-meshing Roots rotor components, wherein the tip radius of the rotor components at an inlet stage of the pump is larger than the tip radius of the rotor components at an exhaust stage of the pump.

Abstract: A vacuum pump housing comprises first (12) and second half-shell stator components (14) defining a plurality of pumping chambers separated by partition members (26, 28, 30, 32). Each pumping chamber comprises an inlet port (42, 44, 46, 48, 50) for receiving fluid and an outlet port (54, 56, 58, 60, 62) through which pumped fluid is exhausted from the chamber. The inlet ports are open on an external surface of the first stator component, and the outlet ports are open on an opposing external surface of the second stator component. The stator components further define transfer channels (66, 68, 70, 72) for conveying fluid between the pumping chambers. Each transfer channel preferably comprises first and second portions located on opposite sides of the housing.

Abstract: A Roots vacuum pump stator is arranged to house a pair of intermeshing rotors, said stator being characterised in that it comprises a director or deflector arranged to direct solid material entrained in a gas pumped through the pump towards the outlet. In other words, the stator according to the present invention has a means for directing or deflecting powder or solid material entrained in a gas being pumped directly towards an outlet of the pump or out of the pump. The directing means can comprise a channel disposed between the arcuate surface and the outlet, said channel comprising a portion that engages the arcuate surface prior to the bottom-dead-centre position and which extends away from the rotor's axis of rotation towards the pump outlet.

Abstract: A regenerative pumping mechanism comprises a rotor having a series of blades positioned in an annular array on one side of the rotor, and a stator having an annular channel within which the blades rotate. In order to control the axial clearance between the rotor and the stator, an axial magnetic bearing actively controls relative axial movement between the rotor and the stator. This can allow the pumping mechanism to provide controllable axial sealing between the rotor and the stator, as opposed to radial sealing.

Abstract: A dry pump comprises a stator housing a rotor assembly comprising intermeshing rotor components defining a running clearance with a surface of the stator, means for applying a transient magnetic force to at least one magnetic member of the rotor assembly to move the rotor components away from the stator surface and increase the size of the running clearance to reduce a frictional force applied to the rotor components by particulates accumulated within the running clearance, and means for moving the rotor components back towards the stator surface upon reduction of the magnetic force.

Abstract: A vacuum pumping arrangement for evacuating an enclosure is provided. The arrangement comprises a turbomolecular vacuum pump having an inlet which is connectable using fixing members to an outlet of an enclosure to be evacuated. Each of the fixing members passes through a first aperture in the inlet and through a second aperture in the outlet. An elongate, circumferentially extending cavity is provided extending from or adjacent to one of these apertures to accommodate a crushable insert. Energy transmitted to the fixing members by the turbomolecular vacuum pump during a failure thereof is thus absorbed by the deformation of the inserts. By absorbing a proportion of the energy in this way separation of the inlet from the outlet is thus inhibited.

Abstract: Scroll-type pumping apparatus comprises a stator (104) comprising a fixed scroll member (106) having an end plate with a first spiral wrap (110) extending therefrom; an orbital scroll member (108) having an end plate with a second spiral wrap (112) extending therefrom to intermesh with the first spiral wrap; a plurality of flexible supports (118) each having one end connected to the orbital scroll member and another end connected to the stator to support the orbital scroll member relative to the stator, and a linear drive system (120) for driving the orbital scroll member to orbit relative to the fixed scroll member. The use of a linear drive system in combination with the flexible supports can provide apparatus having no rotational or rubbing parts.

Abstract: The invention provides a dual inlet screw pump, in which a chamber 18 defines with first and second externally threaded rotors 30, 32 respective fluid flow paths within the chamber 18. This can enable fluid entering the pump via a first inlet 20 to be pumped substantially in isolation from fluid entering the pump via the second inlet 22.

Abstract: A vacuum pump comprises a molecular drag pumping mechanism and a regenerative pumping mechanism. A rotor element of the molecular drag pumping mechanism surrounds rotor elements of the regenerative pumping mechanism.

Abstract: Scroll-type pumping apparatus comprises a stator (104) comprising a fixed scroll member (106) having an end plate with a first spiral wrap (118) extending therefrom, and an orbital scroll member (108) having an end plate with a second spiral wrap (120) extending therefrom to intermesh with the first spiral wrap (118). A motor drives a drive shaft for generating orbital movement of the orbital scroll member relative to the fixed scroll member (106). The apparatus comprises a plurality of flexible rods (122) arranged about the drive shaft and each having one end connected to the orbital scroll member (108) and another end connected to the stator (104) to support the orbital scroll member (108) relative to the stator and to inhibit rotation of the orbital scroll member.

Abstract: A multi-stage vacuum pump comprises a first piston in a first cylinder defining a first stage pumping chamber and a second piston in a second cylinder defining a second stage pumping chamber. The pump has a spool valve between the first and second cylinders for controlling flow from the first stage pumping chamber to the second stage pumping chamber. Either the first cylinder and the first piston or the second cylinder and the second piston being stepped so as to define a third stage pumping chamber. The spool valve is arranged to control the flow from the second stage pumping chamber to the third stage pumping chamber.