| 摘要 |
<p>The purpose of the present invention is to provide a screw-type vacuum pump capable of increasing a precision of screw blades, and being easily manufactured by identically forming pitches of the screw blades in a longitudinal direction. According to the present invention, the vacuum pump comprises an inlet and an outlet discharging a gas received through the inlet to the outlet by a driving screw member and a driven screw member. A driving screw member is formed into a tapered shape where a diameter is gradually increased from the inlet to the outlet, and an outer circumference of the driving screw blade is formed into a tapered shape where the diameter is gradually decreased. A driven screw member is formed into a tapered shape where the diameter is gradually increased from the inlet to the outlet, and the outer circumference of the driven screw blade is formed into a tapered shape where the diameter is gradually decreased. An internal space of the casing includes a tapered inner surface to decrease a cross sectional area of a driving screw member receiving space wherein the driving screw member is received and rotated while being adhered to a surface of the driving screw member receiving space and a driven screw member receiving space, wherein the driven screw member is received and rotated by being adhered to the surface of the driven screw member receiving space from the inlet to the outlet.</p> |
