S112032 流体動圧軸受端部に設けられたテーパーシールに関するメカニズムの解明 : 衝撃を受けたときのテーパーシールにおける流体表面の挙動([S11203]機械要素の設計・製造・応用技術(3))

Abstract

To clarify the mechanism of the taper seal at the end of the fluid dynamic bearing used in the spindle motor of a hard disk drive, the behavior of the fluid surface in the seal when subjected to a shock is analyzed and solved. As a multi-phase flow, the behavior of the fluid surface in the seal is analyzed and numerically solved by using VOF method in consideration of the response of the rotor, the inertia force and the surface tension acting on the fluid, and the influence of the pressure from the bearing. The influences of the eccentricity of the rotor, the oil barrier film coated on the seal wall, the shock strength and the taper seal shapes on the behavior of the fluid surface are discussed. As a result, it is clarified that decreasing the eccentricity of the rotor, decreasing the mass of the rotor, increasing the stiffness and damping of the bearing, making a suitable seal shape are effective countermeasures against lubricant leakage from the seal.