Abstract: A compact housing 10 and disk stack subassembly for use in a data recording disk file permit the disk stack subassembly to be located entirely within and axially secured to the parallel interior walls 12, 14 of the housing 10. The disk stack subassembly includes an in-hub motor having a stator assembly 60 which is secured to a lower bearing support 42. The lower bearing support 42 is axially movable with respect to the outer race 33 of the lower bearing assembly 24. The inner race 27 of lower bearing assembly 24 is attached to the rotatable shaft 20 of the disk stack subassembly. The lower bearing support 42 and the attached stator assembly 60 are biased axially by means of disk spring 52 in the direction of the cavity 35 where the in-hub motor is located. Thus, the overall axial length of the disk stack subassembly is less than the axial distance between the parallel interior walls 12, 14 of the single piece half shell housing 10.

Abstract: A disk drive assembly includes a baseplate housing joined with front and rear covers to enclose a spindle that supports ball bearings and a hub for rotating a stack of magnetic disks. Voice coil actuators are disposed diametrically opposed but offset on each side of a plane bisecting the stack. Pressurizing ports, annular seals and a sealing cap prevent air contamination. Thermally conductive rings contacting the bearings and the housing compensate for temperature differential. Symmetry of the assembly in at least two planes ensures minimal vibration and resonance effects.