| 摘要 |
PROBLEM TO BE SOLVED: To provide a screw vacuum pump capable of restraining the leakage of the fluid to the minimum during operation, and capable of achieving sufficient vacuum condition compared to the conventional product used for the similar purposes. SOLUTION: A male screw shaft body 2 having a ridge shape almost coinciding with a bottom shape of a female screw groove of a female screw cylinder body 1, a same pitch and a same twisting direction, and having a smaller nominal diameter than the female screw cylinder body is fitted into the female screw cylinder body 1 in such a manner of being completely engaged to each other. An outlet port 8 is formed on a lead direction side of the female screw cylinder body and the male screw shaft body, and an inlet port 7 is formed on an opposite side thereof. The female screw cylinder body and the male screw shaft body are formed to have the same rotational direction an the number of rotations of the male screw is set to be higher so that they are rotated with the respective predetermined number of rotations. COPYRIGHT: (C)2004,JPO
|
