A hydrodynamic bearing device with high reliability, with which reductions
in size, weight, and thickness can be achieved, as well as a motor and a
disk driving apparatus that make use of this hydrodynamic bearing device.
The hydrodynamic bearing device comprises a shaft, a thrust flange, a
sleeve, a seal plate, and a retaining plate. A radial dynamic pressure
bearing is formed in the radial direction gap between the shaft and the
sleeve, and a thrust dynamic pressure bearing is formed in the thrust
dynamic bearing gap between the sleeve and the thrust flange. A
communicating hole is formed for communicating between the gap between
the sleeve and the seal plate and the thrust direction gap between the
sleeve and the thrust flange. The radial dynamic pressure bearing and/or
the thrust dynamic pressure bearing are formed such that a lubricating
oil circulates in the gap between the sleeve and the seal plate from the
inner peripheral side of the sleeve toward the outer peripheral side.