US 2003/0201683 A1Published application

Electric spindle motor and method having magnetic starting/stopping device

AssigneeData Storage Institute

InventorsShixin Chen, Qide Zhang

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Abstract

A high precision spindle suitable for hard disk drives, optical disk drives, such as DVDs, CD drives, and other applications includes a hub, a hybrid hydrodynamic an aerodynamic bearing system, a brushless motor, a starting/stopping assistant device and a base. The hybrid fluid film bearing system ensures that the spindle works at high precision, low acoustic noise and low power consumption. The starting/stopping assistant device lifts the rotating portion of the spindle and its load by means of magnetic force, hence, reduces the friction between the contacted surfaces of thrust air bearing. It reduces the starting/stopping time and lessens the wear of bearing, therefore, effectively suppresses the contamination caused by wear particles. Magnetic seals are also provide to prevent journal bearing fluid from leaking.

Claims23

Dependent claims

An electric spindle motor, comprising:

a base plate;
a rotatable assembly including a rotatable sleeve extending substantially perpendicular from said base plate along a rotational axis, wherein said rotatable assembly is supported by said base plate;
a stationary shaft securely coupled to said base plate, and extending within said sleeve along said rotational axis and spaced therefrom to define a first clearance gap;
a liquid fluid situated within said first clearance gap for providing at least radial stiffness for said rotatable sleeve;
a thrust plate securely coupled to said base plate;
a thrust bearing securely coupled to said rotating assembly, wherein said thrust bearing is shaped complementary with said thrust plate and spaced apart therefrom to form a second clearance gap;
a gas fluid situated within said second clearance gap for providing at least axial stiffness for said rotatable assembly;
a stator for causing the rotation of said rotatable assembly;
and
a magnetic device for moving said rotatable assembly away from said base plate substantially along said rotational axis so that said rotatable assembly is less supported by said base plate during rotation of said rotating assembly.

7 more elements

Dependencies are inferred from the claim text.