| 摘要 |
PURPOSE:To enable production cost to be reduced while maintaining compatibility between the application of light weight and the maintenance of rigidity, and make easy the proper maintenance of the cross sectional area of an oil passage and the continuity thereof. CONSTITUTION:A stator shaft 4 formed out of an iron metal element and having external surface for supporting the inner side of the internal cylindrical section of a drum formed out of an iron metal element, and an annular flange 3a formed out of a light metal element and integrated with the internal surface of a housing 3, are press coupled and jointed to each other, until a flange edge 3b and a stepped surface 4j come in contact with each other, while a serrated coupling section 8 is formed with serrations engaged under pressure between the external surface of the stator shaft 4 and the internal surface of the flange 3a. |
