Clarification of Contact Dynamic Characteristics and Perfect Contact Sliding Condition of Tri-pad Contact Slider with Air Bearing System

点击翻译按钮获取中文摘要

1. Contact Dynamics Characteristics and Design Condition of a Slider and Disk Surface (Single-DOF Model)We theoretically derived the perfect contact sliding condition of a single-DOF slider over random wavy disk surface and verified its validity by numerical simulations and experiments. Then, we derived the design conditions of slider and disk surface both for perfect contact sliding and wear durability.2. Design Conditions of Tri-pad Slider (2-DOF Model)We numerically simulated the contact sliding ability of tri-pad sliders, changing design parameters. As a result, it was found that if we make the slider be in perfect contact sliding with disk surface waviness whose standard deviation is 1nm, the contact pressure becomes several MPa. Since the current allowable contact pressure is several kPa for the life time of 5 years, it is almost impossible to satisfy both perfect contact sliding and wear durability condition. Thus, it is the remained subject to expand the calculation range to near contact regime, in which the slider contacts with disk surface intermittently.3. 3-DOF Numerical Simulation of Tri-pad SlidersWe numerically analyzed the effects of roll vibration of the slider on the spacing variation and found that the effect of roll vibration can be neglected even if the ratio of right and left air bearing stiffness is 0.8 (the worst case).4. Experimental Study of Tri-pad SlidersWe manufactured experimental set up which can measure slider dynamic behavior in near contact and contact regimes by reducing ambient pressure to less than 0.1 atmospheric pressure. We observed multiple peak resonance phenomena and decrease of the main resonance frequency from near contact to contact regime.