| 摘要 |
PURPOSE:To prevent penetration and closed compression by setting the number of turns of a vane to 1-1.5 turns and allowing the range of the direction of the normal line to the vane surface in the range from the turn starting point of the vane to the point turned back by 0.5 turn from the turn end point to cover at least 360 deg.. CONSTITUTION:The number N of turns of a vane is set within a range of 1-1.5 turns. The range of the direction of the normal line f1 with respect to the vane surface of the points starting from the turn starting point D1 of the vane of the point E1 turned back by 0.5 turn from the turn end point C1 covers at least 360 deg., when the both ranges of the direction of the normal line with respect to a pair of vanes 1 and 1' which are rectilinearly symmetrical are added, i.e., when 0-180 deg. in the direction of the normal line on the vane in the range between D1 E1 and 180-360 deg. in the direction of the normal line on the vane in the range between E'1 D'1 are added. Therefore, in the phase where the contact of the sipral surface is cut-off, the spiral surface of a fixed vane 1' and the spiral surface of a transferring vane 2' are attached, and generation of penetration phenomenon is prevented. |
