Dental drill with magnetic air turbine having magnetic bearings

A magnetic bearing unit comprising in combination:

• a support structure;
• at least two spaced-apart magnets in the form of first and second annuluses coaxially aligned and both mounted fixedly onto said support structure, the magnets of said first and second annuluses having unlike magnetic poles facing one-another for annulus faces in juxta-position spaced-apart relationship, as a first annulus face of said first annulus and as a second annulus face of said second annulus;
• and a third magnet in the form of a third annulus mounted around and fixedly onto an elongated shaft, the third annulus being coaxially aligned with said first and second annuluses and positioned between said first and second annuluses in spaced-away relationship from both the first and second annuluses with said shaft extending through a least an aperature of one of said first and second annuluses axially thereof and in spaced-away relationship from the annulus inner wall, said third magnet having like-magnetic poles adjacent in relationship to adjacent said first and second annulus faces such that each of said first and second annuluses are repelled magnetically by the magnetic forces of said third annulus;
• said third magnet having a third face in opposing magnetic relationship to said first annulus face and having a fourth face in opposing magnetic relationship to said second annulus face in said relationship of magnetically repelling said first and second annuluses;
• at least one set of (1) said first and second annuluses faces, and (2) said third and fourth faces, being substantially concavely-angled, and the remainder of (1) said first and second annuluses faces, and (2) said third and fourth faces being substantially convexly-angled such that said third and fourth faces as opposite end-faces of said third annulus are substantially seated one within the other of said first and second annulus faces as opposing faces in juxtaposition spaced-away relationship exerting both axially-directed and transversely extending repelling forces relative to a longitudinal axis of said elongated shaft whereby said elongated shaft is forcefully suspended against both axial and lateral movement, by outside forces acting on said shaft.