Abstract: The present invention is directed to a magnet for a magnetic bearing arrangement, a bearing arrangement comprising said magnet, and a vacuum pump comprising said bearing arrangement. In particular the invention can be particularly useful in a magnetic bearing arrangement that reduces stray magnetic fields for a turbomolecular vacuum pump, although it is understood that the invention is not limited to this field and other applications will be understood by the skilled person.

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: The present invention is directed to a magnet for a magnetic bearing arrangement, a bearing arrangement comprising said magnet, and a vacuum pump comprising said bearing arrangement. In particular the invention can be particularly useful in a magnetic bearing arrangement that reduces stray magnetic fields for a turbomolecular vacuum pump, although it is understood that the invention is not limited to this field and other applications will be understood by the skilled person.

Abstract: Stray magnetic fields created by non-symmetrical magnetisation of the permanent magnets in a rotating magnet array of a magnetic bearing assembly, when used in turbo molecular pumps, can cause significant problems to devices such as scanning electron microscopes. In order to minimise the stray fields, at least the dipole and quadrupole moments of each magnet in the array is first measured. The magnets in the array are then arranged relative to one another such that both the dipole and quadrupole moments are minimised, thus minimising the stray magnetic field when the magnet array rotates in the turbomolecular pump.

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 vacuum pump (50) comprises a casing and a rotor located in the casing, the rotor comprising a shaft (52) supported by a bearing arrangement (64, 66) for rotation relative to the casing. A lubricant reservoir (82) is provided for storing lubricant for lubricating a rolling bearing (64) of the bearing arrangement, and a brush (84) comprising a set of bristles (86) held by the reservoir transfers lubricant from the reservoir to the rotor.

Abstract: Stray magnetic fields created by non-symmetrical magnetisation of the permanent magnets in a rotating magnet array of a magnetic bearing assembly, when used in turbo molecular pumps, can cause significant problems to devices such as scanning electron microscopes. In order to minimise the stray fields, at least the dipole and quadrupole moments of each magnet in the array is first measured. The magnets in the array are then arranged relative to one another such that both the dipole and quadrupole moments are minimised, thus minimising the stray magnetic field when the magnet array rotates in the turbomolecular pump.

Abstract: A vacuum pump having a vacuum pumping mechanism mounted for rotation by a shaft and a brushless motor for rotating the shaft where the vacuum pumping mechanism comprises a turbo pumping mechanism comprising pumping stages, and a molecular drag pumping mechanism comprising at least one pumping stage, and a shaft supported for rotation by bearings, and where the motor comprises a permanent magnet rotor fixed relative to the shaft and the rotor has four poles and a stator has non-overlapping stator coils.

Abstract: A vibration isolator is described for inhibiting transfer of vibration to an apparatus during evacuation thereof by a pump. The isolator comprising a bellows for isolating from the ambient atmosphere fluid drawn from the apparatus by the pump. A first flange is connected to one end of the bellows for mounting the isolators the apparatus, and a second flange is connected to the other end of the bellows for mounting the isolator to the pump. The bellows surrounds a resilient element, preferably a helical tension spring, which is substantially co-axial with the bellows. The resilient element has a first end located proximate to the first flange and connected to the second flange, and a second end located proximate to the second flange and connected to the first flange.

Abstract: A vacuum pump (50) comprises a casing and a rotor located in the casing, the rotor comprising a shaft (52) supported by a bearing arrangement (64, 66) for rotation relative to the casing. A lubricant reservoir (82) is provided for storing lubricant for lubricating a rolling bearing (64) of the bearing arrangement, and a brush (84) comprising a set of bristles (86) held by the reservoir transfers lubricant from the reservoir to the rotor.

Abstract: A vibration isolator is described for inhibiting transfer of vibration to an apparatus during evacuation thereof by a pump. The isolator comprising a bellows for isolating from the ambient atmosphere fluid drawn from the apparatus by the pump. A first flange is connected to one end of the bellows for mounting the isolators the apparatus, and a second flange is connected to the other end of the bellows for mounting the isolator to the pump. The bellows surrounds a resilient element, preferably a helical tension spring, which is substantially co-axial with the bellows. The resilient element has a first end located proximate to the first flange and connected to the second flange, and a second end located proximate to the second flange and connected to the first flange.

Abstract: A vacuum pump having a vacuum pumping mechanism mounted for rotation by a shaft and a brushless motor for rotating the shaft where the vacuum pumping mechanism comprises a turbo pumping mechanism comprising pumping stages, and a molecular drag pumping mechanism comprising at least one pumping stage, and a shaft supported for rotation by bearings, and where the motor comprises a permanent magnet rotor fixed relative to the shaft and the rotor has four poles and a stator has non-overlapping stator coils.