| 摘要 |
A dental handpiece includes a head, a tubular chuck having an open-ended axial bore for receiving the shank of a dental bur and a tubular bur tube having an outer surface and an axial bore therethrough for receiving the chuck therein. The bur tube has at least one inner raceway formed integrally along its outer surface. An outer race having an outer raceway is associated with the inner raceway. A plurality of ball bearings are mounted between the raceways. A rotor may be formed integrally with the outer surface of the bur tube. <IMAGE> |
