磁头/硬盘超薄膜气体润滑动态性能分析

Dynamic Character of Ultra Thin Film Gas lubrication for Magnetic Head/Disk

考虑速度滑移效应,利用雷诺方程和动力学方程组建立了磁头/硬盘薄膜气体润滑动力学分析模型,采用摄动法对纳米飞行高度以下的磁头动态特性进行了数值分析。结果表明,外界扰动频率靠近或超过磁头特征振动频率时,外界振动对磁头飞行姿态有明显影响,使得飞行高度振幅和气膜刚度明显增加,磁头的顺从性变差;当外界扰动频率远低于磁头特征振动频率时,随着磁头飞行高度的降低,气膜刚度和飞行高度的调制量迅速增加。通过磁头/磁盘系统的合理设计,使得磁头特征频率远大于主要的扰动频率,增加磁头对磁盘振动的顺从性,可以控制磁头的飞行高度振幅。

Frequency-amplitude character for magnetic head/disk was investigated when flying height of slider is below 10 nm. Mathematical model was derived based on Reynolds equation and dynamic ones for gas lubrication with consideration of velocity-slip effect. Then, numerical analysis was carried out with perturbation method. It is found that the perturbation has significant influence on the slider attitude, the dynamic flying-height amplitude and film rigidity increase greatly, when the perturbation frequency approaches to or gets higher than that of the slider. And the height amplitude and rigidity increase with the decreasing flying height, when the perturbation frequency is close to that of the slider. So the dynamic flying-height amplitude can be under control by the means of increasing the slider characteristic frequency much higher than that of the perturbation in slider design.