Patent ID: 6194800
Filing Date: 2001-02-27
Classification: F04D,F16C

Abstract:
A magnetic bearing comprising:a rotatable rotor portion; anda stationary stator portion having a plurality of north magnetic poles and a plurality of south magnetic poles arranged in a circumferential direction of said stator portion, each of said magnetic poles spanning a circumferential angle W with respect to a center of the magnetic bearing, said rotatable rotor portion being arranged within said stator such that an outer surface of said rotatable rotor portion faces an inner surface of each of said magnetic poles, each of said magnetic poles being formed into a shape having a flux-increasing portion at an end of each of said magnetic poles with respect to said circumferential direction of said stator portion, said flux-increasing portion spanning a circumferential angle a with respect to said center ofthe magnetic bearing wherein a magnetic flux between said rotatable rotor portion and said inner surface of each of said magnetic poles at said flux- increasing portion has a density distribution increasing from said end of said each of said magnetic poles toward a center of said each of said magnetic poles with respect to said circumferential direction of said stator portion, and wherein a ration of .alpha./.psi. is greater than 0.15.