| 摘要 |
PURPOSE:To facilitate cutting and grinding by forming the outside curve in an involute curve and also forming the inside curve in an involute curve having the radius of a same basic circle to that of the outside curve and a circular arc having a nearly equal diameter to the groove width of a spiral body. CONSTITUTION:A scroll member 24 is formed while it is equipped with a spiral body 242 whose outside curve 550 is constituted in an involute curve, and inside curve 551 is constituted in an involute curve having the radius of the same basic circle as that of the outside curve 550 and a circular arc having a nearly equal diameter to the groove width TG of the spiral body 242. Therefore, the outside curve 550 and the inside curve 551 can be worked at the same time by means of the same cutter. |
