ELONGATED PERMANENT RING MAGNET WITH A PLURALITY OF AXIALLY DIRECTED MAGNETIZED ZONES AND MAGNETIC BEARING WITH SUCH A RING MAGNET

摘要

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.

主权项

1. A single piece elongate permanent ring magnet for a magnetic bearing used in rotating machinery, whereby, in use said bearing has an axis of rotation parallel with, and centrally through the bore of the ring magnet, wherein the magnet comprises an even number of axially polarized zones between the axial ends of the magnet, with axially neighbouring polarized zones in mutual repulsion to each other.