Abstract: A scroll pump includes an inlet and an outlet, a fixed scroll and an orbiting scroll intermeshed with each other, wherein the fixed scroll and orbiting scroll define a space therebetween. The scroll pump further includes a biasing apparatus configured to bias the orbiting scroll against the fixed scroll, a fluid recirculation channel which extends from the space to the inlet through either the fixed scroll or the orbiting scroll, and a fluid recirculation valve disposed in the fluid recirculation channel. The fluid recirculation valve is configured to permit flow of fluid from the space to the inlet through the fluid recirculation channel or to block flow of fluid through the fluid recirculation channel. The fluid recirculation valve is configured to switch from a closed state to an open state when a pressure differential across the fluid recirculation valve is equal to or exceeds a certain threshold value.

Abstract: 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.

Abstract: A set of seals for sealing between two half shells defining at least one pumping chamber and two head plates to be mounted at either end of the two half shells. The set of seals includes: at least one annular seal for sealing between at least one of the head plates and the two half shells; two longitudinal seals for sealing between longitudinal contact faces of the two half shell stators on either side of the at least one pumping chamber, the longitudinal seals being configured to have end portions that abut against the at least one annular seal when mounted in the pump. Each of the seals within the set of seals are made of a material having at least one of: a hardness between 73-83, on the Shore A hardness scale; and a stiffness of between 2.4 and 4.2 N/mm per mm length.

Abstract: A scroll vacuum pump has an axially extending drive shaft with an eccentric shaft portion, such that rotation of the drive shaft imparts an orbiting motion to an orbiting scroll relative to a fixed scroll. An axial adjustment mechanism has a plurality of adjustment members angularly spaced around the drive shaft and extending through the pump housing towards the orbiting scroll, the plurality of adjustment members each being configured to provide an independently adjustable axial position of the orbiting scroll. A plurality of sealing means isolate the plurality of adjustment members from a pump chamber, the plurality of sealing means extending around each of the plurality of adjustment members and comprising at least one flexible portion such that one end of the sealing means may orbit relative to a fixed other end of the sealing means.

Abstract: 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.

Abstract: A scroll pump (100, 200) comprising a first scroll comprising a first spiral wall (124, 224); a second scroll comprising a second spiral wall (134, 234), the second spiral wall being intermeshed with the first spiral wall; and a pad (180, 280) formed from a different material to the first and second scrolls, the pad being located between the first and second scrolls radially inwards or outwards of the first and second spiral walls.

Abstract: The invention provides a scroll pump comprising an orbiting scroll and a fixed scroll, wherein the orbital axis of the orbiting scroll is movable in a radial direction relative to the fixed scroll while the orbiting scroll is orbiting about its orbital axis, or wherein the fixed scroll is movable relative to the orbiting scroll in a radial direction while the orbiting scroll is orbiting about its orbital axis.

Abstract: 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.

Abstract: The invention provides a crank sleeve for a scroll pump. The crank sleeve has a longitudinal axis and is configured to provide a radially extending crank offset for imparting an orbital path on an orbital scroll of the scroll pump. The crank sleeve further comprises an integrally formed counterbalance for reducing pump vibration extending radially in a direction substantially opposite to the crank offset.

Abstract: A pump includes a first housing part defining a first portion of a bore extending within the first housing part and shaped to receive a rotor; and a second housing part defining a second portion of the bore extending within the second housing part and shaped to receive the rotor. The first housing part has a first face abutable against an opposing second face of the second housing part to position the first portion of the bore with the second portion of the bore to receive the rotor. The first portion of the bore has a first circular cross-section portion centered along the first face and the second portion of the bore having a second circular cross-section portion centered, within the second housing part, at a distance from the second face.

Abstract: A dry vacuum pump may include a stator which defines an internal chamber in which a rotor is rotationally mounted. A sensor is mounted to the stator and has an output connected to a processing circuit arranged to analyse the output of the sensor to determine the absolute distance between a point on the surface of the rotor and internal stator surface. The rotor to stator clearance can thus be accurately determined in real time during operation of the pump, so that the pump performance can be optimised over its serviceable life.

Abstract: The present invention relates to a turbo-molecular vacuum pump comprising bearings for supporting the drive shaft and/or the rotor in relation to a pump body, wherein a first bearing is coupled to the rotor and disposed on supporting mount at the high vacuum side of the rotor and radial struts extend from the supporting mount and form an integral part of the body; the invention is characterised in that the radial struts comprise a hinge portion that can flex to allow relative movement of the inlet flange with respect to the supporting mount to reduce distortion effects.

Abstract: In situations where a vacuum system is suddenly overloaded, there is a risk of mechanical damage being sustained, for example, bearing damage, gear slippage or rotor and/or stator collisions. Sudden overloads can also lead to electrical damage, for example, over-currents or power surges. Therefore a pressure regulating apparatus is provided for use in a vacuum pumping system having an inlet, an outlet and a conduit interposed between, and in fluid communication with, the inlet and the outlet, wherein the cross-sectional area of the conduit is greater than that required to meet the conductance requirements of the inlet and the outlet.

Abstract: A pump includes a first housing part defining a first portion of a bore extending within the first housing part and shaped to receive a rotor; and a second housing part defining a second portion of the bore extending within the second housing part and shaped to receive the rotor. The first housing part has a first face abutable against an opposing second face of the second housing part to position the first portion of the bore with the second portion of the bore to receive the rotor. The first portion of the bore has a first circular cross-section portion centered along the first face and the second portion of the bore having a second circular cross-section portion centered, within the second housing part, at a distance from the second face.

Abstract: 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.

Abstract: The present invention relates to a turbo-molecular vacuum pump comprising bearings for supporting the drive shaft and/or the rotor in relation to a pump body, wherein a first bearing is coupled to the rotor and disposed on supporting mount at the high vacuum side of the rotor and radial struts extend from the supporting mount and form an integral part of the body; the invention is characterised in that the radial struts comprise a hinge portion that can flex to allow relative movement of the inlet flange with respect to the supporting mount to reduce distortion effects.

Abstract: A dry vacuum pump may include a stator which defines an internal chamber in which a rotor is rotationally mounted. A sensor is mounted to the stator and has an output connected to a processing circuit arranged to analyse the output of the sensor to determine the absolute distance between a point on the surface of the rotor and internal stator surface. The rotor to stator clearance can thus be accurately determined in real time during operation of the pump, so that the pump performance can be optimised over its serviceable life.

Abstract: A multi-stage vacuum pump comprising: first and second half-shell stator components defining a plurality of pumping chambers and for assembly together along respective longitudinally extending faces; first and second end stator components for assembly at respective longitudinal end faces of the first and second half-shell stator components; gaskets for sealing between the first and second half-shell stator components when assembled together at the longitudinally extending faces; and O-rings for sealing between the first and second end stator components and the first and second half-shell stator components when assembled; wherein annular channels intersect longitudinal recesses and each longitudinal recess comprises a stop fixed relative to the intersection, and the gasket and the longitudinal recess are configured that when the gasket is located in the recess during assembly the gasket is biased against the stop for locating an end portion of the gasket relative to the intersection.

Abstract: A multi-stage vacuum pump may include a sealing arrangement for sealing between the stator components of the pump. The end seals of the arrangement comprise an annular portion for sealing between end stator components and shell components and axial portions which extend from the annular portion and together with separate axial seals seal between the shell components.

Abstract: The present invention relates to a multi-stage vacuum pump comprising: first and second half-shell stator components and first and second end stator components which when assembled define a plurality of pumping chambers. The half-shell components are assembled together along respective pairs of mutual engaging longitudinal faces and the end stator components are assembled at the ends of the half-shell components at respective pairs of mutual engaging end faces. A longitudinal channel is counter-sunk in at least one longitudinal face of each pair of mutual engaging longitudinal faces for receiving respective longitudinal sealing members for sealing between the half-shell components.