Magnetic Bearings and Bearingless Drives

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Mechanical dynamics

Akira Chiba

An object has six degrees of freedom, i.e., x-, y- and z-axis positions and rotational positions θ_x, θ_y, and θ_z around these three axes. In most magnetic bearing systems, one axis is assigned as the rotating shaft axis so that the rotating shaft should be suspended by active or passive regulation of the remaining five axis positions. Therefore understanding the dynamic constraints of the mechanical system is important.

In this chapter, the dynamic characteristics of a simple mechanical system are described. In the first section, the fundamental equations are described for a two-axis system including the gyroscopic effect. It is important to note that there is cross coupling between axes caused by the gyroscopic ...