Nonlinear dynamic model of a pivot ball bearing in hard disk drive including the hertzian contact force

Abstract The key task for the spindle motor in a hard disk drive is to provide stable, reliable and consistent turning power for many years to allow the hard drive to function properly. As hard disks become more advanced, virtually every component in them is required to do more & perform better, and the spindle motor is no exception. Increasing the rotational speed at which the platters spin means that the data can be read off the disk faster, and also reduces rotational latency, the time that the heads must wait for the correct sector number to come under the head. For this reason, there has been a push to increase the speed of the spindle motor. Since the launching of hydro-dynamic bearing spindle technology for high speed application will not be in due course, current ball bearing technology will still be around for a couple of years provided the spindle speed does not exceed around 15 Krpm. Therefore optimizing the steel balls in the spindle system is an alternative to deal with the ever-increasing performance requirements of the hard disk drive. To accomplish this, we have to understand the failure phenomenon in the spindle, thereby set test requirements to overcome the failure mechanism. These test requirements will help us to understand the performance characteristic and robustness of the spindle motor. In this paper, the test requirements is set according to modal, load and vibration methods to quantify the hard disk drive ball bearing spindle motor.

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Nonlinear Dynamic Modeling and Vibration Analysis of Faulty Rolling Bearing Based on Collision Impact

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4050678 ◽

2021 ◽

Vol 16 (6) ◽

Author(s):

Longkui Zheng ◽

Yang Xiang ◽

Chenxing Sheng

Keyword(s):

Kinetic Energy ◽

Potential Energy ◽

Dynamic Model ◽

Nonlinear Dynamic ◽

Rolling Bearing ◽

Hertzian Contact ◽

Nonlinear Dynamic Model ◽

Impact System ◽

Rolling Element ◽

The Impact

Abstract This study proposes a new nonlinear dynamic model of rolling bearing faults based on a collision impact system. The dynamic model accounts for the collision impact system consisting of the rolling elements and localized faults according to the nonlinear Hertzian contact. First, considering the impact of the rolling element and fault structure, the collision impact system between rolling element and localized fault is established, and the vibration responses of the collision impact system can be obtained. Second, the overall rolling bearing is treated as a mass-spring model, and the contact between the rolling element and raceway is treated as a nonlinear spring that conforms to the Hertzian contact deformation theory. Third, according to the Lagrange equation, overall potential energy, overall kinetic energy, elastic potential energy, and kinetic energy of the collision impact system are used to describe the vibration characteristics. Considering the impact of collision impact systems, a nonlinear dynamic model of rolling bearing faults is established. The simulated acceleration results based on the nonlinear dynamic model are compared to experimental results. The comparison indicates that the numerical model can be used to predict the vibration characteristics of rolling bearings faults effectively.

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