| 摘要 |
PROBLEM TO BE SOLVED: To improve durability of a bearing device by preventing generation of an excessively abraded portion caused by eccentric frictional force generated in the bearing device for a crankshaft using a halved rolling bearing. SOLUTION: A recessed portion 38 is formed in the upper journal support wall 34 of an upper crankcase 32b, and a bearing support body 12 made of low-carbon steel is fitted to the recessed portion 38, fastened and fixed thereto by a bolt 26. Next, a cylindrical retaining surface 17 is opened in the bearing supporting body 12, and the bering support body 12 is taken out. After the retaining surface 17 is carburized, the bearing support body 12 is divided into two by a natural split process, thereby forming a bearing stand 14 and a journal cap 16. A needle bearing 20 is stored in the cylindrical retaining surface 17 formed in such a manner that the recessed surface 14a of the bearing stand 14 is oppositely brought into contact with the recessed surface 16a of the journal cap 16. Then, the bearing stand 14 and journal portion 36 are fastened and fixed to the upper journal support wall 34 by the bolt 26. COPYRIGHT: (C)2011,JPO&INPIT
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