Abstract: A device streamlines air flow inside a hard disk drive with a stationary afterbody that is located adjacent to each of the disks. A diverter portion of the device enhances the volumetric flow of air through the diffuser. The overall function of the device effectively expands the air flow so that the speed of the air flow gradually decreases while pressure increases. This design reduces losses in system momentum due to sudden expansion of the air in the drive. In addition, air flow moving toward the disk pack may be contracted to allow efficient energy conversion from pressure energy to kinetic energy prior to merging of the bypass air flow with the air flow among the disks.

Abstract: A disk clamp for securing data storage disks to the hub of a spindle motor in a hard disk drive has a circumferential rib protruding from a lower surface of the disk clamp. A complementary recess is formed in the hub of the spindle motor for closely receiving the rib on the disk clamp. The inner diameter of the rib and the outer diameter of the recess are closely toleranced to provide a very precise centering feature for mounting and aligning the disk clamp with respect to the hub and spindle motor. This design reduces the complexity of the tooling and fixtures required to complete the assembly and the overall part cost is reduced.

Abstract: A method is disclosed for analyzing the vibrational characteristics of rotating devices, such as hard disk drives and jet engines, that are coupled through bearings to flexible supports. In the method, the rotating device is discretized, for example, using a mesh suitable for finite element analysis. The support is also discretized. The natural frequency of elastic vibration modes for the rotating device is calculated and the natural frequency of vibration modes for the support is calculated. The mode shapes are then calculated and a set of modal basis corresponding to the mode shapes is utilized. Bearing stiffness and damping matrices are input, and the Lagrangian equations of motion are integrated numerically in the modal space, to calculate the vibrational response of the rotating device and support. The modal space results are then transformed into ordinary space. The vibrational analysis may be used to design devices having desired vibrational characteristics.

Abstract: A disk clamp for securing disks to the hub of a spindle motor in a disk drive has symmetrically spaced apart countersunk apertures in the top surface of the disk clamp. The apertures enable the disk clamp to maintain a proper orientation before the fasteners are attached. This design overcomes issues related to rotation and displacement of the clamp while it is being fastened to the hub, and reduces the complexity of the tooling and fixtures required to complete the assembly. Less tooling complexity also allows multi-fastener driver systems to be employed so that all of the fasteners required to complete the assembly may be simultaneously attached and driven into the disk clamp. The countersunk apertures on the disk clamp are designed to couple with tapered sleeves on the installation tool to quickly and precisely center the fasteners in the disk clamp while providing anti-rotation torque for the disk clamp.