| 摘要 |
PROBLEM TO BE SOLVED: To surely hold the oil in a dynamic pressure bearing and to obtain a rotation effect stable over a long time by providing the maximum opening clearance in a wedge shape with a wall of a narrow angle with respect to a rotating direction, thereby suppressing the leaking out and splashing of lubricant fluid, such as oil, at the time of high-speed rotation of a revolving member. SOLUTION: The opening clearance 41 disposed on a sleeve rotation part side has the wedge shape having gradually widening parts in the cross section perpendicular to an axis in a rotating direction. The maximum opening clearance 44 is provided with the wall of the angle narrow in the rotating angle direction. Since the clearance is provided with the wall, a revolving shaft 3 can surely bring the excess oil 12a adhered to the sleeve aperture during its rotation into abutment on the wall of the narrow angle. The oil 12a imparted with kinetic energy by the rotation of the revolving shaft 3 is changed in a moving direction to a downward direction from the rotating direction. Consequently, since the oil can be surely dropped into an oil sump part, the excess oil 12a adhered to the sleeve aperture may be surely removed. |
