Friction and wear of spindle motor hydrodynamic bearings for information storage systems during startup and shutdown

Abstract

This paper investigates the friction and wear characteristics of two typical hydrodynamic bearings for hard disk drive (HDD) spindle motors (SPM), i.e., the herringbone groove and multi-taper bearings, during start-up and shut-down transient operation. The friction characteristics are calculated by a lubricated friction model which is an extension of Kogut and Etsion's dry friction model (a modified version of the CEB model), while the wear characteristics are qualitatively evaluated in non-dimensional form by the semi-analytical wear model proposed by Holm-Archard. The average flow Reynolds equation and the pressure-compliance relationship of elasticplastic roughness contact are used together to consider the combined effects of partial lubrication and asperity contact occurring during start-up and shut-down. Then, the friction and wear characteristics of the herringbone groove and multi-taper bearings are calculated and compared under the condition of HDD application.

A Comparative Study of Turning and Stationary Groove Journal Bearings for HDD Spindle Motors Under Transient Contact Conditions

“…Thus, the rough contact pressure is given as follows [10]: Based on the assumptions made in Section II, the real contact area and shear stress of the boundary lubrication regime are both equal to zero.…”

“…Considering elastic-plastic deformation [8], the rough contact pressure, , is given by (7) with (8) where is the interference of asperities. The ratio of the real contact area to nominal contact area in elastic-plastic contacts can be written as [9] (9) where (10) If the resistant force induced by damage to adhered asperities up to elastic-plastic contact is introduced, the friction shear stress can be calculated by (11) where (12) It should be noted that determining the critical interference of the adsorbed surface film contact, , is not easy. For simplicity, is assumed to be 0 in the present analysis, although this remains an issue that must be investigated further.…”

“…The present authors have proposed an algorithm which allows the CEB (or KE) model to be applied to lubricated situations so that the effect of adsorbed surface films can be considered at the same time with rough contact and partial lubrication, and successfully applied it to analyzing the stationary groove configuration [10]. In this paper, we analyze the friction and wear characteristics of the turning groove configuration and compare the results with those of the stationary groove configuration for both herringbone groove and multi-taper bearings.…”

A miniature spindle motor with fluid dynamic bearings for portable storage device applications

“…Many researchers have investigated the performance of the FDB in the spindle motors of data storage drives (Osman et al 2003;Chao and Huang 2005;Feng and Kenjo 2007;Jang et al 2007;Nada and Osman 2007). None of the aforementioned works, however, put effort toward the case of the FDB designed for miniature spindle motor.…”

An Integrated System Modeling and Analysis of Hard Disk Drive Spindle Motors

“…Based on [3] and [4], which dealt with the SPM mechanical system in the submicro/nanometer scale, we present a simulation model that integrates micromechanical and electronic components and allows examination of submicrometer SPM mechatronics behavior. The drive circuit equations and the rotor's equations of motion are simultaneously solved, incorporating the average flow-Reynolds equation and the pressure-compliance relationship of elastic-plastic roughness contact.…”