Gas dynamic bearing for spindle motor

A spindle motor comprising a stator including a support shaft stood on a base, a cap-shaped rotor rotatably and concentrically disposed around said support shaft, thrust and radial bearings disposed between said stator and said rotor, a stator coil secured to said stator, and a rotor magnet member secured to said rotor in opposing relation to said stator coil,

• wherein said thrust and radial bearings are hydrodynamic bearings, said thrust bearing comprising movable and fixed pieces, said movable piece being secured to the lower end of a cylindrical portion of said rotor and extended outwardly from said cylindrical portion, said fixed piece being secured to said base in opposing relation to said movable piece, said stator coil being secured to the outer peripheral portion of said support shaft above said radial bearing, and said rotor magnet member being secured to the under side of a top of the cap-shaped rotor so that an axial gap is provided between said stator coil and said rotor magnet member.

A spindle motor comprising a stator including a support shaft stood on a base, a cap-shaped rotor rotatably and concentrically disposed around said support shaft, thrust and radial bearings disposed between said stator and said rotor, a stator coil secured to said stator, and a rotor magnet member secured to said rotor in opposing relation to said stator coil,

• wherein said thrust and radial bearings are hydrodynamic bearings, said thrust bearing comprising movable and fixed pieces, said movable piece being secured to the lower end of a cylindrical portion of said rotor and extended inwardly from said cylindrical portion, said fixed piece being secured to said base in opposing relation to said movable piece, and both said stator coil and said rotor magnet member being disposed above said radial bearing.

A spindle motor comprising a stator including a support shaft positioned on a base, a cap-shaped rotor rotatably and concentrically disposed around said support shaft, thrust and radial bearings disposed between said stator and said rotor, a stator coil secured to said stator, and a rotor magnet member secured to said rotor in opposing relation to said stator coil,

• wherein said thrust and radial bearings are hydrodynamic bearings, said thrust bearing comprising movable and fixed pieces, said movable piece being secured to the lower end of a cylindrical portion of said rotor and extended outwardly from said cylindrical portion, said fixed piece being secured to said base in opposing relation to said movable piece, and said rotor magnet member being secured to said rotor at a position which is inward of said movable piece of said thrust bearing.

A spindle motor comprising a stator including a support shaft positioned on a base, a cap-shaped rotor rotatably and concentrically disposed around said support shaft, thrust and radial bearings disposed between said stator and said rotor, a stator coil secured to said stator, and a rotor magnet member secured to said rotor in opposing relation to said stator coil,

• wherein said thrust and radial bearings are hydrodynamic bearings, said thrust bearing being disposed above said radial bearing, and both said stator coil and said rotor magnet member being disposed below said radial bearing.