Magnetic bearing device

Abstract

A magnetic bearing device has a rotating shaft (3) and a bearing structure (5) for supporting the rotating shaft by a magnetic force. The bearing structure (5) has magnetic pole portions (7) facing an outer circumferential surface of the rotating shaft (3) and surrounding the rotating shaft (3), and supports the rotating shaft (3) in a non-contact manner by a magnetic force generated between the magnetic pole portions (7) and the rotating shaft (3). A depression (9) is formed in the surface of the rotating shaft. At least one of a shape, a position, and the number of the depressions (9) is set so as to suppress an eddy current on the surface of the rotating shaft (3) that is generated by rotation of the rotating shaft (3) and by a magnetic field caused by the magnetic pole portions (7).

Dependencies are inferred from the claim text.