Magnetic circuit device for magnetic bearing

Abstract

In a magnetic circuit device for a magnetic bearing that includes a permanent magnet ring constituted by a plurality of permanent magnets and a soft magnetic material ring, the circumferential uniformity of the magnetic field near an axial end surface of the permanent magnet ring is enhanced. A magnetic circuit device for a magnetic bearing includes: a permanent magnet ring that is formed by disposing a plurality of anisotropic permanent magnets in a circumferential direction; a first soft magnetic material ring that contacts an outer circumferential surface of the permanent magnet ring; and a second soft magnetic material ring that contacts an inner circumferential surface of the permanent magnet ring. Each of the plurality of anisotropic permanent magnets is magnetized parallel to a straight line that passes through a center of the anisotropic permanent magnet and that extends in a radial direction. The entirety of the outer circumferential surface of the permanent magnet ring has homopolarity, and the entirety of the inner circumferential surface of the permanent magnet ring has homopolarity and has a reverse polarity of the outer circumferential surface of the permanent magnet ring. Grooves in an axial direction are formed on at least one of the first soft magnetic material ring and the second soft magnetic material ring.

Dependencies are inferred from the claim text.