Twin-shaft vacuum pump

摘要

Each flat metal sheet (6) is dumbbell-shaped and has a large central hole (7) to accommodate a support shaft (8). Each flat sheet is set at a small angle with respect to the adjacent sheet so that the assembly forms a coarse two-start screw thread. Small holes (9) surrounding the central large hole assist in setting the sheets at the correct angle to each other. There are two shafts side-by-side with oppositely-handed intermeshing screw threads.