| 摘要 |
A dental angle handpiece head has a rotor shaft mounted in ball bearings which are lubricated through respective holes at opposite ends of the head, the holes opening externally and leading to annular spaces between the inner and outer races of the bearings. The holes have two portions of different diameter to form a step therebetween the outer hole portion being of larger diameter. The inner hole portion is inclined towards the axis of rotation of the rotor shaft in a direction away from the head and also in the direction of rotation of the shaft from the outside to the inside of the housing. |
