| 摘要 |
PROBLEM TO BE SOLVED: To increase a bearing loading ability and seizure resistance by positioning the carvature center of the arc shape inner surface of a lower member to a more upper side than the combination surface on a line perpendicular to the combination surface of upper/lower members and the carvature center of the arc shape inner surface of an upper member to a downside. SOLUTION: A carvature center 21 of the fitting periphery surface 7a of the lower metal 8b of a cap 7 is displaced by a prescribed amount B1 to the more upper side than the combination surfaces 11a, 11b on the line 23 perpendicular to the combination surfaces 11a, 11b of a large end part 1 with the cap 7. The carvature center 22 of the fitting periphery surface 1b of the upper metal 8a of the large end part 1 is displaced by a prescribed amount B2 to the more lower side than the combination surfaces 11a, 11b of the line 23. Thereby, a clearance C on the combination surfaces 11a, 11b or the direction parallel with this is enlarged and even if a bearing load F is exerted to the direction of the cap 7 with a low rigidity, the upper metal 8a or lower metal 8b is not contacted with a crank pin 2 and the degree of close in N can be minified by the elastic deformation of the bearing part and a sufficient oil film thickness can be ensured at the lower parts of the combination surfaces 11a, 11b.
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