| 摘要 |
The purpose of the present invention is to extend the period until accumulated products come into contact with a rotation part or a fixed part. In a rotary vane tubular part or fixed part in which a screw groove is formed, the projection surface (screw groove projection surface), which is the ridge part of the screw groove, is shaved by a desired amount around the entire periphery (the circumferential direction of the screw groove) for only a certain range in the axial direction. In a case where the screw groove is formed in the fixed part, within the space (clearance) between the outer peripheral surface of the rotary vane tubular part and the inner peripheral surface formed by the screw groove projection part of the fixed part facing the outer peripheral surface, the lower side (exhaust port side) screw groove projection surface is shaved by a desired amount. In a case where the screw groove is formed in the rotary vane tubular part, within the space between the outer peripheral surface formed by the screw groove projection surface of the rotary vane tubular part and the fixed part facing the outer peripheral surface, the screw groove projection surface on the lower side of the rotary vane tubular part is shaved by a desired amount. In this manner, the screw groove projection surface is shaved by a desired amount, and as a result the space on the lower side of the screw groove part can be partially widened. |
