| 摘要 |
1,018,300. Dental handpieces. MICRO TURBINES Ltd. March 6, 1964, [March 12, 1963], No. 9731/63. Heading A5R. [Also in Divisions F1 and F2]. An air driven dental turbine comprises a rotor 2 carrying blades 10 in an eccentric chamber 11 and mounted in air bearings 16,17 within a housing 1. Each bearing 16,17 comprises inner and outer sleeves 22, 23 with internal annular passages 26, annular rubber "0" rings 25 of 45 degrees Shore Hardness in grooves 24 supporting the bearings so as to effect vibration damping of the rotor and associated dental tool mounted in bore 3a. The "0" rings 25 also prevent axial leakage of air between the outer surface of the bearings 16, 17 and the inner wall of the housing 1. Air is supplied to the turbine through a passage 12 in the stem 13, part flowing through port 14 to drive the rotor and the remainder flowing through passages 18,19 to bearings 16,17. The bearing air flows through radial and axial passages 27a, 27, respectively, to the annular passages 26 within the bearings 16, 17 and thence through holes 31, 32 to the bearing surfaces 29. Thrust bearing air flows through holes 28. Exhaust air leaves the turbine through a passage 15 in stem 13. |
