| 摘要 |
<p>An improved drill head and spool therefor, the spool having one annular aerodynamic bearing arrangement mounted onto the rotor, preferably at the distal end thereof. Typically, the rotor also enables the selective mounting and dismounting of a distal dental tool via a chuck that is actuable from a proximal end of the head, as in conventional heads. Preferably, the rotor shaft also comprises a second aerodynamic bearing arrangement at the proximal end thereof, but may include other types of bearing arrangements instead. In the improved drill head of the present invention, the magnitudes and frequencies of the noise generated thereby are substantially reduced with respect to other types of rotor bearings, and does not suffer from the problems of jewel bearings or static air bearings.</p> |
