| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of suppressing loss of torque, and reducing a radial dimension of a pumping groove row, in a bearing device using a lubrication oil.SOLUTION: An almost annular upper annular portion 23A is projected to a radial outer side from a static shaft 22A. A first pumping groove raw to distribute a lubrication oil to a radial inner side, is disposed on an upper face of a sleeve 311A or a lower face of the upper annular portion. Further the sleeve has a second inner peripheral face positioned at a radial outer side of the upper annular portion. A lower face of a cap, an upper face of the upper annular portion, a second inner peripheral face, or an outer peripheral face of the upper annular portion is provided with a second pumping groove raw to distribute the lubrication oil to a radial outer side or an axial lower side. Thus a radial dimension of the first pumping groove raw 831A and the second pumping groove raw as a whole can be reduced. Further a radial dimension of the upper annular portion can be reduced. Accordingly, a loss of torque can be suppressed. |
