摘要 |
PROBLEM TO BE SOLVED: To prevent a contact accident of a rotor and a moving blade with protection wire net provided on a suction opening for preventing foreign matter from flowing therein due to buckling with accompanying thermal expansion by temperature gradient. SOLUTION: In a molecular pump 1 of a structure arranging a suction opening 6a of exhaust gas close to the rotor 4, the protection wire net 6 which consists of a plurality or rectangular grids 6c, has a tip part of a wire element of a long side of a rectangle adjoining to a center part of the wire element 6a of the long side of each rectangle perpendicularly cross in a T-shape, and has a lightning shape grid pattern by alternately connecting the rectangles. The protection wire net 6 is installed on the suction opening part 5a. COPYRIGHT: (C)2006,JPO&NCIPI |