abstract |
A dental handpiece ( 10 ) has a supporting rotor assembly ( 15 ) and ball bearings ( 13, 14 ) supporting the rotor. Each ball bearing ( 13, 14 ) has a plurality of balls ( 22 ). Each bearing ( 13, 14 ) has an inner race ( 20 ) and an outer race ( 21 ) and at least the outer race ( 21 ) has an increased outer diameter. |