| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device for a motor capable of reducing an abrasion between a pillow part and a rotating axis and a precipitation of a sludge and improving a life and exactness of the motor by respectively supporting both an end face of the rotating axis by a pivot bearing and the rotating axis in the radial direction by a dynamic pressure-type fluid bearing, and using a specific lubricant composition for both the bearings. SOLUTION: This bearing device for a motor is the one supporting both an end face of a rotating axis by a pivot bearing and the rotating axis in the radial direction by a dynamic pressure-type fluid bearing and using a lubricant composition obtained by blending a base oil comprising a compound of formula I R and R' are each an alkyl group of formula II [(m) is 0-6; (n) is 13-15] with the proviso that combinations of carbon numbers of R and R' consist essentially of (13, 14), (14, 14), (14, 15) and (15, 15)} with 0.5-1.5 pts.wt. linear organic polymer compound e.g. a polymer of formula III [R is a 1-18C alkyl; (n) is a polymerization degree]} having 350,000-1,000,000 molecular weight and 3-7 pts.wt. compound of formula IV (R is an alkyl) for the bearing device for the motor. |
