Patent ID: 6020664
Filing Date: 2000-02-01
Classification: F16C,H02K

Abstract:
An electric spindle motor, comprising:a base plate;a stationary sleeve extending substantially perpendicular from said base plate along a rotational axis;a shaft extending within said sleeve along said rotational axis and spaced apart therefrom to define a first clearance gap;a liquid fluid situated within said first clearance gap for providing at least radial stiffness for said shaft;a rotatable housing situated in a manner that forms a cavity between said housing and said base plate, said shaft and said sleeve being situated within said cavity;a stator situated within said cavity and coaxially around said shaft and stationary sleeve;a plate situated within said cavity and extending radially outward from said stationary sleeve;a rotatable sleeve situated within said cavity and extending radially inward from said housing, said rotating sleeve including upper and lower surfaces that are complementary shaped with upper and lower surfaces of said plate and spaced apart therefrom to form a second clearance gap; anda gas fluid situated within said second clearance gap for providing at least axial stiffness for said shaft.