Patent ID: 7608958

Claim:
A motor mounted with an improved dynamic pressure fluid bearing mechanism comprising a rotor rotatable freely with respect to a stator through the improved dynamic pressure fluid bearing mechanism, wherein the rotor includes: (1) a shaft, and (2) a hub in a cup shape fixed with the shaft, and wherein the stator includes: (1) a motor base, and (2) a sleeve fixed to the motor base; and wherein the improved dynamic pressure fluid bearing includes: (1) a first thrust dynamic pressure fluid bearing constituted by a surface of the rotor, a surface of the stator confronting with the surface of the rotor with having a first gap between them and lubrication fluid filled in the first gap, (2) a second thrust dynamic pressure fluid bearing constituted by another surface of the stator confronting with the other surface of the rotor with having a second gap between them and the lubrication fluid filled in the second gap, (3) a radial dynamic pressure fluid bearing constituted by an inner circumferential surface of the sleeve, an outer circumferential surface of the shaft confronting with the inner circumferential surface of the sleeve with having a third gap between them and the lubrication fluid filled in the third gap, and (4) a taper seal section in which an interface between the lubrication fluid and ambient air remains in a middle of the taper seal section, and further wherein the rotor is supported in a thrust direction by forces generated in the first thrust dynamic pressure fluid bearing and the second thrust dynamic pressure fluid bearing and directed reversely in the axial direction of the shaft, and further supported in a radial direction by the radial dynamic pressure fluid bearing, the motor further comprising: (a) a main lubrication route linking in series the taper seal section, the second gap, the first gap and the third gap in a sequential order; and (b) a bypass route linking an end of the third gap and an intermediate point between the second gap and the first gap in the main lubrication route; wherein the main lubrication route and the bypass route are filled with the lubrication fluid.