Patent ID: 6034454
Filing Date: 2000-03-07
Classification: F16C,H02K

Abstract:
A motor comprising:a shaft body;a generally disk-like thrust plate extending outwardly in a radial direction from an outer peripheral surface of the shaft body;a cylindrical sleeve structure which forms a fine clearance between itself on one hand and the shaft body and the thrust plate on the other, an amount of lubricant fluid being maintained in at least a part of the fine clearance;a hydrodynamic bearing means capable of holding the shaft body and the sleeve structure so as to effect a relative rotation between the shaft body and the sleeve structure, any one of the shaft body and the sleeve structure being secured on a rotor equipped with a rotor magnet, the other one of the shaft body and the sleeve structure being adapted to act as a stationary member cooperative with a stator;a radial bearing section capable of holding said lubricant fluid between said shaft body and an internal vertical surface of the sleeve structure;a thrust bearing section capable of holding said lubricant fluid between one side of said thrust plate and an internal horizontal surface of the sleeve structure; anda thrust gas-interposing section communicated to the outside atmosphere formed on the other side of the thrust plate;wherein said rotor is under an action of a magnetic bias in a manner such that the one side of the thrust plate is urged in an axial direction of the sleeve structure.