System, method and apparatus for disk drive fluid dynamic bearing

A disk drive, comprising:

• an enclosure having a base with a nest extending therefrom, and a top cover coupled to the base;
• a plurality of media disks rotatably mounted to the enclosure, each media disk having a form factor of at least about 3.5 inches;
• and
• a fluid dynamic bearing (FDB) mounted between the enclosure and the plurality of media disks, the FDB comprises an integrally formed shaft and lower thrust bush, the shaft and lower thrust bush are seated in and make contact with the nest, and the FDB comprises a top thrust bearing formed from a material that is softer than the shaft and lower thrust bearing, and the top thrust bearing comprises bronze, brass or a combination thereof.

A disk drive, comprising:

• an enclosure having a nest extending therefrom;
• a media disk rotatably mounted to the enclosure, the media disk having a form factor of at least about 3.5 inches to about 15 inches;
• a fluid dynamic bearing (FDB) mounted between the enclosure and the media disk, the FDB comprising an integrally formed shaft and lower thrust bush formed together from a single material, such that the shaft and lower thrust bush are not separate parts that are joined together, and they are not formed from different materials, and the single material comprises a material having a Young's modulus of at least about 2 E8 N/m2;
• the shaft and lower thrust bush are seated in and make contact with the nest on axial and radial sides thereof, and axial and radial abutting surfaces of the nest, shaft and lower thrust bearing are substantially perpendicular;
• the FDB further comprises a top thrust bearing formed from a second material that is softer than the single material, and the second material comprises bronze, brass or a combination thereof;
• and
• a perpendicularity between the shaft and the lower thrust bush comprises a runout of a few micrometers from the outer diameter to the inner diameter of a thrust plate.