Patent ID: 6884047

Claim:
Vacuum pumping apparatus comprising: a scroll set having an inlet and an outlet, said scroll set comprising a stationary scroll element including a stationary scroll blade extending from a single side of a stationary plate and an orbiting scroll element including an orbiting scroll blade extending from a single side of an orbiting plate to form a single-sided scroll set, wherein said stationary and orbiting scroll blades are intermeshed together to define one or more interblade pockets; a drive mechanism operatively coupled to said orbiting scroll element for producing orbiting motion of said orbiting scroll blade relative to said stationary scroll blade so as to cause said one or more interblade pockets to move toward said outlet, said drive mechanism including a motor and a crankshaft having an axis of rotation, and an orbiting bearing coupled between said crankshaft and said orbiting plate, wherein the scroll set is configured such that an imaginary plane perpendicular to the axis of rotation passes through the orbiting bearing and at least a portion of the orbiting scroll blade; and said scroll set further comprising a first pumping stage in series with a second pumping stage and wherein the imaginary plane passes through at least a portion of the first pumping stage.