in a computer storage drive the hub 124 typically features a constant diameter outer mounting surface 136 to securely locate the storage disks not shown in a radial direction the retaining clamp groove 128 is adapted to receive a retainer not shown to securely hold the disk stack not shown against the flange 132 the rotating oil filled bearing 116 generally comprises an upper bearing plate 140 a lower bearing plate 144 and a spacer 148 the upper 140 and lower 144 bearing plates are generally annular in shape and are fixed to the hub 124 annular spacer 148 is interposed between the upper 140 and lower 144 bearing plates to maintain space 152 between the bearing plates 140 and 144 a number of bearing components are fixed or interconnected to the base plate 156 these include a spindle 160 an air bearing element 164 an oil filled bearing thrust plate 168 and a stator assembly 172 the spindle 160 is affixed to the base 156 at a first end and may also be secured to the top of the disk drive enclosure not shown at a second end using a fastener not shown inserted into a threaded hole 176 or by other means of attachment known in the art support of the shaft 160 on both ends is desirable because it increases the overall stiffness of the disk drive assembly the stationary air bearing element 164 is concentric to the spindle 160 and may be formed from a separate piece of material or may be integral to the spindle 160 the air bearing.