Abstract: A pumping system has a motor (32) for driving a pumping mechanism (30). A variable frequency drive unit (36) has an input for receiving electrical energy of relatively high power and first, fixed frequency from a power supply, and an output coupled to an input (46) of the motor for supplying electrical energy of relatively low power and second, variable frequency to the motor. This second frequency preferably has a maximum value greater than the first frequency. A control circuit (50) is provided for selectively coupling the motor input (46) directly to the power supply for the supply of the relatively high power energy to the motor to maximize the torque that can be produced by the pumping mechanism. After a period of time the control circuit terminates the direct coupling of the motor input to the power supply for the supply of the relatively low power energy to the motor.

Abstract: A pump includes a plurality of pumping stages comprising a respective plurality of pumping mechanisms driven by one or more drive shafts for pumping fluid through the pumping stages from a pump inlet at a high vacuum stage to a pump outlet at a low vacuum stage; a lubrication chamber housing a bearing assembly for supporting the drive shaft for rotational movement, the drive shaft extending from the high vacuum stage to the lubrication chamber through an opening of a head plate of the lubrication chamber; an inter-stage purge port through which gas can enter the pump at an inter-stage location downstream of the high vacuum; a lubrication chamber purge port located in the lubrication chamber through which purge gas can flow from a source of purge gas; wherein the inter-stage port is connected to the lubrication chamber for controlling the pressure of purge gas in the lubrication chamber.

Abstract: A plasma abatement device comprises a gas chamber having a gas inlet for receiving a gas to be treated by the device and a gas outlet, at least part of the inner surface of the gas chamber being formed from, or coated with, an electrically conductive material that is resistant to corrosion during treatment of a gas containing a halocompound and water vapor.

Abstract: A pump comprising a regenerative pumping mechanism having a generally disc-shaped rotor mounted on an axial shaft for rotation relative to a stator. The rotor has first and second surfaces each having a series of shaped recesses formed in concentric circles thereon, and a stator channel formed in a surface of the stator which faces one of the rotor's first or second surfaces. The rotor divides the a gas flow path into sub-flow paths such that gas can flow towards the outlet simultaneously along both the first surface and the second surface of the rotor.

Abstract: The present invention provides a vacuum pump (10) which comprises a turbo-molecular pumping mechanism (12) in series with a Siegbahn pumping mechanism (14). A first pump inlet (16) is provided through which gas can pass through both the turbo-molecular pumping mechanism and the Siegbahn pumping mechanism. Additionally, an inter-stage (inlet 18) is provided through which gas can enter the pump at a location between the turbo-molecular pumping mechanism and the Siegbahn pumping mechanism and pass only through the Siegbahn pumping mechanism. There are flow channels (52, 62) in a first plurality of stages (32, 34) of the Siegbahn pumping mechanism which are in fluid communication with the inter-stage inlet (18) and gas entering the pump through the inter-stage inlet is pumped in parallel along said flow channels.

Abstract: The present disclosure relates to a vacuum pump including a bearing and a lubricant supply system for lubricating the bearing. The lubricant supply system includes: a lubricant reservoir comprising a reservoir matrix for receiving a lubricant; a lubricant transfer arrangement in contact with the reservoir matrix for transferring lubricant from the reservoir matrix to the bearing, the lubricant reservoir including a reservoir enclosure for locating the reservoir matrix in position relative to the lubricant transfer arrangement; wherein the lubricant reservoir includes a plurality of contact regions at which the reservoir matrix is in contact with the reservoir enclosure for locating the reservoir matrix in position relative to the lubricant transfer arrangement and a plurality of spacing regions between respective contact regions at which the reservoir matrix is spaced apart from the reservoir enclosure for receiving gas and lubricant foam caused by outgassing in the lubricant in the reservoir matrix.

Abstract: A scroll compressor (10) comprising a scroll pumping mechanism having two co-operating scrolls (14,16) mounted within a pump housing (18) so that on relative orbital movement of the scrolls fluid is pumped from a pump inlet (20) in the pump housing to a pump outlet (22) in the pump housing. The scroll compressor (10) further comprises a filter (24) located within the pump housing (18) along a fluid flow path (26) between the pump inlet (20) and the scroll pumping mechanism (12) for resisting the passage of particulates (28) upstream of the compressor.

Abstract: The present invention is a scroll pump comprising two intermeshing scrolls arranged so that on relative orbital movement of the scrolls gas is pumped from an inlet to an outlet. The scrolls have a plurality of successive scroll wraps I, II, II, IV, V, VI between the inlet and the outlet. There is a single-start condition in which fluid is pumped from the inlet to the outlet along a single flow path extending through each of the scroll wraps in succession and a multi-start condition in which fluid is pumped from the inlet along a plurality of flow paths which extend in parallel through radially adjacent scroll wraps and converge to a single flow path prior to the outlet. A valve arrangement is operable for switching the scroll pump between the single-start and the multi-start conditions.

Abstract: The present invention relates to a scroll pump with two scrolls that are co-operable for pumping fluid from an inlet to an outlet on relative orbiting motion of the scrolls. Each scroll comprises a scroll base from which a scroll wall extends generally axially towards the base of the opposing scroll. A gas conduit having an inlet at a first location of the pumping channel and an outlet at a second location of the pumping channel allows over-compression at the first location of the pumping channel to be exhausted to the second location of the pumping channel. A one-way valve located in the gas conduit allows the passage of gas through the conduit from the conduit inlet to the conduit outlet when a predetermined pressure differential between the first and second locations of the pumping channel is generated during roughing when the scroll inlet is at or close to atmosphere.

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: To lengthen the service period on DC plasma abatement devices a modified DC plasma torch is provided with an electrically conductive cathode and an electrically conductive anode spaced apart from one another to form a gap therebetween; a metal swirl bush at least partially located within the gap and comprising a channel adapted to permit, in use, a gas to flow through the gap; and a ceramic element interposed between any one or more of: the cathode and the swirl bush; and the anode and the swirl bush.

Abstract: Vacuum pump for pumping gas from a process chamber, the pump comprising: a rotor supported for rotation in a pumping chamber by a drive shaft, the shaft extending through a shaft bore in a wall of the pumping chamber extending transversely to the drive shaft, and a seal arrangement provided between the shaft and the transverse wall for resisting the passage of gas through the shaft bore, wherein on rotation of the rotor gas is pumped from a low pressure region at an inlet of the pumping chamber to a high pressure region at an outlet of the pumping chamber, and wherein the rotor and the transverse wall are spaced apart by an axial clearance along which back leakage of gas can flow from the high pressure region to the low pressure region, and an additional leakage path for back leakage is formed spaced away from the seal arrangement along which gas can flow without contact with the seal arrangement so that the amount of gas which contacts the seal arrangement during use of the pump is reduced.

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: Chemical vapor deposition apparatus comprises a process chamber, a bubbler for supplying a volatile precursor to the chamber, a vacuum pump for drawing an exhaust gas from the process chamber, an abatement device for treating the exhaust gas, and a bypass line for conveying the precursor from the bubbler to the abatement device, the bypass line bypassing both the process chamber and the vacuum pump.

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: The present invention relates to a vacuum pump 10 comprising a turbo molecular pumping mechanism 14 wherein an operative characteristic of the turbomolecular pumping mechanism is dependent on the orientation of the vacuum pump and the pump comprises an orientation sensor 28 for sensing the orientation.

Abstract: The present invention relates to a vacuum pumping system (18) for evacuating gas from a plurality of chambers (12, 14, 16) at different pressures. The pumping system comprises a plurality of compound vacuum pumps (20, 22), wherein each compound pump comprises a plurality of pumping mechanisms (24,26,28) connected in series between a pump inlet (30) and a pump exhaust (32) and an interstage port (34, 36) between pumping mechanisms in the series. The system is configured such that gas evacuated from one of said chambers is pumped through the interstage ports of at least two of said compound pumps.

Abstract: A vacuum pumping system comprises a primary foreline for receiving a gas stream from an outlet of a chamber, a first vacuum pump for evacuating the chamber, a second vacuum pump for evacuating the chamber, a first secondary foreline for conveying gas from the primary foreline to the first vacuum pump, a second secondary foreline for conveying gas from the primary foreline to the second vacuum pump, and valve means for selectively connecting a chosen one of the first and second secondary forelines to the primary foreline. The condition of the vacuum pumps is monitored during use. When both vacuum pumps are operating normally, the valve means is controlled to divert a first reactant-rich gas from the primary foreline into the first secondary foreline, and to divert a second reactant-rich gas from the primary foreline to the second secondary foreline, thereby inhibiting mixing of the first and second reactants within the vacuum pumps.

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: 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.