| 摘要 |
PURPOSE: A multi-stage dry vacuum pump is provided to cool the heat of process gas inside a gas path where the process gas flows and the heat generated in a pump cylinder, thereby evenly cooling the pump cylinder and rotors throughout an axial direction. CONSTITUTION: A multi-stage dry vacuum pump comprises multi-stage cylinders(1, 2, 3, 4), a pair of rotors(10, 11, 12, 13, 14, 10a, 11a, 12a, 13a, 14a), two pump spindles, a motor, a pair of gears, a gas path, an inner cooling path, and a cooling fan. A compression ratio of the multi-stage cylinders is designed to be increased to a rear end. The rotors received inside receiving spaces of the cylinders are synchronized by being mutually engaged and rotated. Each rotor is mounted in the pump spindles. The motor rotates one of the pump spindles. The gear is installed on the pump spindle so that the two spindles are rotated by being interlocked. The gas path is connected to the inner receiving spaces of the multi-stage cylinders, thereby guiding the discharge of gas, which is transferred by being successively compressed through the multi-state cylinders. [Reference numerals] (AA) Cross section A-A |
