Hydrodynamic bearing assembly, motor provided with hydrodynamic bearing assembly and recording disc driving device equipped with motor

Abstract

There is provided a hydrodynamic bearing assembly that includes: a sleeve with an axial hole into which a shaft is inserted; a radial dynamic pressure unit formed on at least one of an outer diameter of the shaft and an inner diameter of the sleeve; and a sub-radial dynamic pressure unit formed on at least one of the outer diameter of the shaft and the inner diameter of the sleeve in an upper part in an axial direction of the radial dynamic pressure unit, wherein an oil interface formed in an axial hole between the radial dynamic pressure unit and the sub-radial dynamic pressure unit moves up toward the sub-radial dynamic pressure unit as the temperature of a motor rises due to driving of the motor.

Dependencies are inferred from the claim text.