PURPOSE: To provide a dynamic pressure fluid bearing which has a long life and can be run under ultra-high speed rotation without allowing a thrust lubri cant having a high viscosity to mix into the radial side reducing its loss, and to embody a rotor capable of withstanding a high-speed rotation by preventing the shaking caused by a rotor yoke and rotor boss at the time of high-speed rotation.
CONSTITUTION: The bearing is obtd. by arranging a sealing member 13 having a conical taper and arranging a thrust receiving material 11 having an inverted conical taper. Further, a revolving shaft 1 facing this sealing member 13 is provided with spiral shallow grooves 14 and an oil repelling agent is applied between the sealing member 13 and the revolving shaft 1, thereby, the dynamic pressure fluid bearing rotatable at a ultra-high speed is obtd. The contact area of the rotor is decreased by reducing the outside diameter of the contact surface of the rotor boss 3 and the rotor yoke 5 to about ≤1/2, thereby, the rotor capable of withstanding a high-speed rotation without the occurrence of the shaking is obtd.
SAEKI YASUO
FUJII SHIGEKI
