An object of the present invention is to provide a hydrodynamic bearing
type rotary device which can improve rotation performance, suppress a
friction torque, and reduce power consumption of motor, and a recording
and reproducing apparatus including the same. A shaft having a flange on
one end and a hub on the other end is provided with a bearing of a sleeve
so as to be rotatable. The sleeve includes a communication hole. A third
gap between the hub and the sleeve end surface is a flow path, and is
connected to the communication hole. Provided that a first gap between a
thrust plate 4 and the flange 3 is S1, a second gap between the flange 3
and a lower end surface of the sleeve 1 is S2, and a third gap between
the upper end surface of the sleeve 1 and the hub 7 is S3, widths of the
gaps satisfy the relational expression, S3>(S1+S2).