Analysis of Friction-Induced Self-Excited Vibration of a Contact Recording Head Slider Using a Two-Degrees-of-Freedom Model.

Abstract

We present a theoretical analysis of the friction-induced self-excited vibration of a contact head slider that has been studied for future high-density recording disk storage. In order to understand the fundamental destabilizing mechanism of the contact slider, a simple two-degrees-of-freedom slider model for a single contact pad slider was used for first analysis. The instability of this system was caused by the asymmetry of the stiffness matrix due to the friction force. The unstable condition of this system is discussed in terms of the suspension position, the normal and pitch natural frequencies and the key parameters that are related to the frictional coefficient and the contact and suspension stiffnesses. The destabilizing mechanism of friction force is explained using the complex mode shape. From this analysis it is found that the system always becomes stable if the contact position is located on the trailing side away from the slider's center of mass. The stability characteristics of more extended models of a contact slider, including a tripad slider, are also discussed based on the analytical results obtained from the basic model.