| 摘要 |
PURPOSE:To smoothly perform relative rotation between the first and the second rotary member by insertedly fitting a spacer between an inner wall surface of a working chamber and the first or the second resistance plate. CONSTITUTION:A nearly disc-shaped spacer 20 is arrangedly provided between an inner wall surface 12b of a left wall part 12 and the first resistance plate 18 as the spacer 20 is connected to an outside cylinder 11 through a spline. A wall surface on the side of the first resistance plate 18 of the spacer 20 is smoothly ground using a grindstone, and has excellent flatness to the first resistance plate 18. The inner wall surface 12b of the left wall part 12 therefore requires no usual rising of a smooth surface, and when the inner wall surface 12a of the left wall part 12 is ground using the grindstone, a basic end surface 13a on the outer periphery of the cylindrical part 13 can be also smoothly ground. Thus, since the cylindrical part 13 is smoothly ground up to the basic end surface 13a, even when a member 10 is extended to the basic end surface 13a, relative rotation between the hub member 10 and the cylindrical part 13 can be smoothly performed. |
