Switchable single-start or multi-start scroll pump

摘要

The present invention is a scroll pump comprising two intermeshing scrolls arranged so that on relative orbital movement of the scrolls gas is pumped from an inlet to an outlet. The scrolls have a plurality of successive scroll wraps I, II, II, IV, V, VI between the inlet and the outlet. There is a single-start condition in which fluid is pumped from the inlet to the outlet along a single flow path extending through each of the scroll wraps in succession and a multi-start condition in which fluid is pumped from the inlet along a plurality of flow paths which extend in parallel through radially adjacent scroll wraps and converge to a single flow path prior to the outlet. A valve arrangement is operable for switching the scroll pump between the single-start and the multi-start conditions.

主权项

1. A vacuum scroll pump comprising:
a first scroll intermeshing with a second scroll and arranged so that, on relative orbital movement of the scrolls, fluid is pumped from an inlet of the scroll pump to an outlet of the scroll pump, wherein each of the first and second scrolls comprises a respective plurality of successive scroll wraps between the inlet and the outlet; a single-start condition in which fluid is pumped from the inlet to the outlet along a single flow path extending through each of the scroll wraps of the first scroll in succession; a multi-start condition in which fluid is pumped from the inlet along a plurality of flow paths which extend in parallel through radially adjacent scroll wraps of the first scroll and converge to a single flow path prior to the outlet; and a valve arrangement operable for switching the scroll pump between the single-start and the multi-start conditions.