OIL DYNAMIC PRESSURE BEARING DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent oil from leaking in operating, in an oil dynamic pressure bearing device. SOLUTION: An oil dynamic pressure bearing device is provided with a shaft and a sleeve to be rotatably fitted to the shaft, a herringbone groove for generating dynamic pressure is provided on either the shaft or the sleeve, and oil is filled in a clearance between the shaft and the sleeve. The surface roughness of the inner peripheral part facing the shaft of an oil sump part provided on the upper side of the sleeve is improved.