Abstract
This paper describes the static characteristics of water-lubricated high speed conical bearings. This type of bearing is intended to be applied to spindles for drilling small holes on printed circuit-boards. Pressurized water is first fed to the inside of the rotating shaft and supplied to recesses on the shaft surface through feeding holes. Water pressure is therefore greatly increased at the outlets of feeding holes due to the centrifugal force by shaft rotation. In addition, water pressure also increases by hydrodynamic effect of shallow recesses. The static characteristics are theoretically predicted and calculated results are compared with experimental ones. It was found that the proposed conical bearings can achieve both low power consumption and large load capacity.
