Patent ID: 6064130
Filing Date: 2000-05-16
Classification: F16C,G02B,H02K

Abstract:
A motor having a dynamic pressure bearing, the motor comprising: a supporting body; a stator coil mounted to the supporting body; a rotor having opposing upper and lower surfaces defining a thickness therebetween, and having an inner peripheral surface; a rotor magnet for generating a rotational force in cooperation with the stator coil, the rotor magnet being attached to one of the upper and lower surfaces of the rotor so as to oppose the stator; a dynamic pressure bearing rotatably supporting the rotor with respect to the supporting body; a fixed shaft forming the dynamic pressure bearing mounted to the supporting body; a cylindrical body to which the rotor is attached, the cylindrical body having opposing upper and lower surfaces defining a thickness therebetween and having an inner peripheral surface defining a central penetration hole into which the fixed shaft is inserted and an outer peripheral surface which is attached to the inner peripheral surface of the rotor, the thickness of the cylindrical body being larger than that of the rotor; and a disc shaped lower thrust cap member attached at the supporting body proximate the lower surface of the cylindrical body; wherein the upper and lower surfaces of the cylindrical body, the inner peripheral surface of the cylindrical body, and an upper surface of the lower thrust cap member are formed without any dynamic pressure generating grooves, and a groove is formed at an outer circumferential surface of the fixed shaft.