DC-BIASED AXIAL MAGNETIC BEARING

摘要

A DC-biased axial magnetic bearing includes a rotating member (50) (or shaft) having a radially extending tab (or support) (52) located between a pair of teeth (62, 64) of a C-shaped control member (60). A permanent magnet (68) provides a DC magnetic field (82) which travels through an overhanging arm (70) and provides a DC bias attractive force between a surface (72) of the arm (70) and an upper surface (74) of the shaft (50) which levitates the shaft (50) such that the tab (52) is equally spaced between the surfaces (62, 64). Coils are wrapped circumferentially around the shaft (50) within the C-shaped control member (60) and current through the coils provides electromagnetic trim control of the position of the tab (52) between the surfaces (62, 64) in response to changes in axial position of the shaft (50) indicated by position sensors (96). The bearing may also be used in horizontal applications, e.g., in an engine.