A Comparison Study on the Performance of Four Types of Oil Lubricated Hydrodynamic Thrust Bearings for Hard Disk Spindles

Abstract

In this paper, the static and dynamic performance of herringbone, step-pocket, taper-pocket, and taper-flat thrust bearings were numerically analyzed. Optimal values for the design parameters of each type of bearing were analyzed in terms of both maximum axial stiffness (kzz) and maximum ratio of axial stiffness to friction torque (kzz/T) and bearing performance for both cases was calculated. The optimal performance characteristics of these bearings were compared in terms of application to hard disk spindles. Step-pocket and taper-pocket thrust bearings are superior to herringbone and taper-flat thrust bearings with respect to both the maximum kkk and the maximum kzz/T conditions. It was found that the dams of thrust bearings with pockets play an important part in improving the hearing performance. It was made clear that the taper-pocket and the taper-flat thrust bearings have a much larger load capacity than the other two types of thrust bearings in the proximity of zero clearance.

Optimum Design of Oil Lubricated Thrust Bearing for Hard Disk Drive with High Speed Spindle Motor

“…Currently, groove geometries that are being widely used in HDD thrust bearings are mainly a spiral or a herringbone grooved geometries. Several investigators have conducted numerical analysis predictions of these grooves for HDD bearing performance [1][2][3][4][5]. There were also some attempts at improving the dynamic stiffness and damping of HDD spindle by introducing permanent magnetic thrust plates into the bearing spindle structure [6] or introducing magnetic fluid as lubricants [7].…”

Stability analysis of a disk-spindle supported by a plain journal bearing and pivot bearing

“…A ball bearing is low in cost but has weak points in terms of non-repeatable run out, vibration, noise and poor durability to external shocks compared with a hydrodynamic bearing. Therefore hydrodynamic bearings such as spiral or herringbone groove type Hatch 1995, 1996;Ku 1996Ku , 1997, three-lobe type (Yoshida et al 1996) and others (Ono et al 1998;Zhu and Ono 1999) have been studied for application in hard disk drives. Since the reliability of lubricant sealing has been improved, a fluid bearing is now being widely used for hard disk drives not only in mobile computers but also in high-end computers.…”

Herringbone‐grooved bearing with non‐uniform grooves for high‐speed spindle

“…[1][2][3][4] Owing to their high stiffness and high damping characteristics, grooved bearings show good run-out characteristics even for smaller equipment. The basic characteristics of herringbone-grooved bearings have been fully investigated in previous studies by applying 'narrow groove theory' 5 or another theory.…”

“…(2) The displacement of the rotor is only of parallel mode to the shaft without tilting. (3) The lubricant in the bearing clearance is incompressible, and cavitation does not occur.…”