| 摘要 |
PURPOSE:To enable an area of the scroll member in the caption which requires machine-finishing through cutting process to be reduced, by leaving as bare skin of cast the outer wall of an area of a scroll element which lies at most one round of a periphery from the outmost end of the scroll line of the scroll element. CONSTITUTION:A fixed scroll member 15 is made of cast material on which machine-finishing is applied through cutting process. A scroll element 152 is formed to shape a scroll line around an axis. An end plate 151 is a circular disc having a diameter by which it is closely fitted to the inner wall of a housing 10 as an integral part of said scroll element 152 at one end thereof. Here, an area of the outer wall of said scroll element 152, which lies from the outmost point A of the scroll line by nearly a half of the periphery toward the center, e.g. point B, is left as bare skin of cast. Besides, an area of the surface of said end plate 151, namely the area surrounded by the points A, B, C, and D, is also left as bare skin of cast. Thus, the area to be cutting process being reduced, necessary machining time can be saved. |
