Patent ID: 6290477
Filing Date: 2001-09-18
Classification: F01C,F04C

Abstract:
Scroll vacuum pump comprising at leasta fixed portion made up of two half-shells each including a substantially flat wall disposed perpendicularly to a longitudinal axis of the pump, a spiraling wall being disposed projecting perpendicularly on each of said substantially flat walls,a mobile portion including at least a disk parallel to said substantially flat walls and mounted pivotingly on a shaft bearing surface eccentric relative to a drive shaft parallel to said longitudinal axis, guide means imparting to said disk an orbital movement about the said eccentric bearing surface during rotation of the drive shaft, a spiraling wall being disposed projecting perpendicularly on each of the substantially flat opposite faces of said disk,the spiraling wall of each of the two half-shells of the fixed portion being directed toward the substantially flat face facing it of said disk and the spiraling wall of each of the faces of the mobile portion being directed toward the said substantially flat wall of the half-shell facing it of the fixed portion, each pair of two corresponding spiraling walls being made up of two spiraling walls having substantially the same shape and being interleaved one on the other,each spiraling wall including an upper non-deformable ridge close to the substantially flat wall or face facing it, a slight play being provided between each of the said upper ridges and the substantially flat wall or face facing it,characterized in thatthe beginnings of the spirals of the pair of spiraling walls disposed on one side of the central disk arc offset by one hundred eighty degrees relative to the beginnings of the spirals of the pair of spiraling walls disposed on the other side of the central disk, and a distance provided between each of the said upper ridges and the substantially flat wall or face facing it ranges between 0 and 5 hundredths of a mm.