LUBRICANT, HYDRODYNAMIC BEARING, SPINDLE MOTOR AND ROTATOR

摘要

PROBLEM TO BE SOLVED: To provide a hydrodynamic bearing improved in starting characteristics at low temperature, capable of favorably keeping bearing characteristics in wide operating temperature range, having long life and suffi ciently exhibiting earthing function without providing a specific earthing mecha nism. SOLUTION: In this hydrodynamic bearing constituted of a shaft 1 having a flange and formed of a cylindrical member 2 and a ring member 3, a sleeve 4, a cyclic lid member 5 and a lubricant F packed in minute spaces R1 to R6 containing a bearing space formed among these constituent members, a lubricant comprising >=18C and <=24C phosphate ester or containing >=18C and <=24C phosphate ester as a base oil and having <=1.0×1011Ωcm volume resistivity is adopted as the above lubricant F.