Analysis of Nonrepeatable Radial Vibration of Magnetic Disk Spindles

Ono, Kyosuke; Saiki, Naoya; Sanada, Y.; Kumano, Akihiko

doi:10.1115/1.2930184

Cited by 14 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The lubricant is added at the beginning of the experiments and is kept in the clearance by the pump-in effect of the spiral grooves and the surface tension of the lubricant. In the rotating-shaft spindle, load is added by a magnet (4), which can move up and down by adjusting the micrometer (1). The magnetism between the magnet and the nut changes in proportion to the space between them.…”

Section: Experimental Set-up and Test Results: Rotating-shaft Spindlementioning

confidence: 99%

See 1 more Smart Citation

Dynamic characteristics of spiral groove bearing spindles: comparison between rotating‐shaft and fixed‐shaft designs

et al. 2005

View full text Add to dashboard Cite

In this paper, two types of spiral groove bearing (SGB) spindles, a rotatingshaft spindle and a fixed-shaft spindle, are analysed, and the dynamic characteristics of these two types of spindles are tested and compared. The effects of lubricants on the dynamic characteristics and power consumption of the spindles are considered. It is found that the dynamic characteristics of the fixed-shaft spindle are much better in terms of non-repeatable run out than those of the rotating-shaft spindle. The lubricants are found to have significant effects on both the dynamic characteristics and power consumption of the spindles.

show abstract

Section: Experimental Set-up and Test Results: Rotating-shaft Spindlementioning

confidence: 99%

“…However, ball-bearing spindles, which are widely used in modern HDDs, cannot meet these requirements. 1,2 To solve this problem, many HDD and spindle motor manufacturers have been investigating substitutes for ball bearings. One of the candidates is the hydrodynamic liquid-film bearing.…”

Section: Introductionmentioning

confidence: 99%

Dynamic characteristics of spiral groove bearing spindles: comparison between rotating‐shaft and fixed‐shaft designs

et al. 2005

View full text Add to dashboard Cite

show abstract

“…This difference can change the clearance of the bearings, the bearing characteristics and consequently the dynamics of the HDD spindle system at elevated temperature. This may result in coincidence of the natural frequencies of the HDD spindle system with bearing frequencies, excessive vibration by resonance, and eventually read/write errors (Richter and Talke 1988;Ono et al 1991;Jang et al 2001;Jang and Jeong 2002).…”

Section: Introductionmentioning

confidence: 95%

Improvement of dynamic characteristics of a HDD spindle system supported by ball bearing at elevated temperature

Jang

Kim

et al. 2005

Microsyst Technol

View full text Add to dashboard Cite

This research investigates how the design variables of ball bearing affect the bearing stiffness and the natural frequencies of a hard disk drive (HDD) spindle system at elevated temperature. It shows that any design change that increases the contact angle of ball bearing reduces the variation in the bearing stiffness and the natural frequencies at elevated temperature. This research also proposes a robust HDD spindle motor in which a wave spring maintains a constant preload minimizing the effect of temperature variation. Experimental modal testing shows that the reduction of the natural frequencies at elevated temperature is much less in the proposed HDD spindle system than in the conventional spindle system. The proposed HDD spindle motor can improve the dynamic reliability of a HDD spindle system, which contributes to the high track density of a HDD.

show abstract

“…One of its sources is the waviness of a ball bearing in a HDD spindle system, and it generates bearing frequencies and the excessive vibration especially when one of the bearing frequencies matches with one of the natural frequencies of HDD spindle system [1][2][3][4]. In HDD industry, this resonance has been avoided by designing the natural frequencies of a HDD spindle system not to coincide with bearing frequencies.…”

Section: Introductionmentioning

confidence: 99%

Analysis of dynamic characteristics of a HDD spindle system supported by ball bearing due to temperature variation

Jang¹,

Kim²,

Han³

et al. 2003

Microsystem Technologies

View full text Add to dashboard Cite

This paper presents a method to investigate the characteristics of a ball bearing and the dynamics of a HDD spindle system due to temperature variation. Finite element model is developed for the rotating and stationary parts of a HDD spindle system separately to determine their thermal deformations by using ANSYS, a finite element program. Then, the relative position of the rotating part with respect to the stationary part is determined by solving the equilibrium equation of the contact force between upper and lower ball bearings. The validity of the proposed method is verified by comparing the theoretical natural frequencies of a HDD spindle system with the experimental ones before and after temperature variation. The proposed method makes it possible to predict the characteristics of a ball bearing and the dynamics of a HDD spindle system due to temperature variation. It shows that the elevated temperature results in the increase of contact angle and the decrease of bearing deformation, contact force and bearing stiffness, which result in the decrease of the natural frequencies of a HDD spindle system. IntroductionNonrepeatable runout (NRRO) is one of the major obstacles to achieve high track density in a computer hard disk drive (HDD). One of its sources is the waviness of a ball bearing in a HDD spindle system, and it generates bearing frequencies and the excessive vibration especially when one of the bearing frequencies matches with one of the natural frequencies of HDD spindle system [1][2][3][4]. In HDD industry, this resonance has been avoided by designing the natural frequencies of a HDD spindle system not to coincide with bearing frequencies. However, the operating temperature inside a HDD has thermal cycles, starting from room temperature up to 80°C. This may result in looseness of a ball bearing, natural frequency shifts of a HDD spindle vibration, coincidence with bearing frequencies, and eventually read/write errors.Several researchers have investigated the sources of natural frequency shifts of a HDD spindle system due to temperature rise, i.e. disk media and ball bearing. Jr-Yi Shen et al. (2000) studied both experimentally and theoretically how temperature variations affect natural frequencies of disk media [5]. They pointed out that natural frequency shifts of aluminum and glass disks at elevated temperatures result primarily from residual stresses and thermal membrane stresses of the disks, respectively. Chaw-Wu Tseng et al. studied how temperature variation affects natural frequencies of rocking vibration of a rotating disk and spindle system through mathematical modeling and experimental measurement [6]. They pointed out that frequency shifts of rocking modes at elevated temperature primarily result from relaxation of bearing stiffness. In their mathematical thermal model, they only included the radial displacement of the outer race with respect to the inner race at the elevated temperature without taking account of the axial displacement. In addition to radial displacement, axial displacemen...

show abstract

Analysis of Nonrepeatable Radial Vibration of Magnetic Disk Spindles

Cited by 14 publications

References 0 publications

Dynamic characteristics of spiral groove bearing spindles: comparison between rotating‐shaft and fixed‐shaft designs

Dynamic characteristics of spiral groove bearing spindles: comparison between rotating‐shaft and fixed‐shaft designs

Improvement of dynamic characteristics of a HDD spindle system supported by ball bearing at elevated temperature

Analysis of dynamic characteristics of a HDD spindle system supported by ball bearing due to temperature variation

Contact Info

Product

Resources

About