Patent ID: 7292425

Claim:
A magnetic bearing device comprising: a rotor supported in a levitating state by electromagnets; an axial position sensor for detecting an axial position of the rotor; characteristic curve adjustment means capable of adjusting a characteristic curve representing a relation between a sensor output voltage of the axial position sensor and an axial position of the rotor; digital conversion means for specifying an upper limit value of the sensor output voltage to perform digital conversion to an output of the characteristic curve adjustment means; and axial position control means for controlling the electromagnets based on an output of the digital conversion means, wherein: the characteristic curve adjustment means adjusts the characteristic curve so that a proximal position Zb 1 of the rotor when a target provided in the rotor moves the closest to the axial position sensor may become larger than a minimum value Zmin of the axial position of the rotor determined by an upper limit value of the characteristic curve and so that a distance between the proximal position Zb 1 of the rotor and the minimum value Zmin of the axial position may become the narrowest one.