Patent ID: 7828533
Filing Date: 2010-11-09
Classification: F04C

Abstract:
1. A stator comprising: an inner surface including a plurality of lobes, wherein the plurality of lobes define a major diameter circumscribing the plurality of lobes and a minor diameter inscribing the plurality of lobes; wherein a stator ratio is equal to the major diameter divided by the minor diameter; and wherein the stator ratio is selected from the group consisting of 1.350 or less for a stator with two lobes, 1.263 or less for a stator with three lobes, 1.300 or less for a stator with four lobes, 1.250 or less for a stator with five lobes, 1.180 or less for a stator with six lobes, 1.175 or less for a stator with seven lobes, 1.150 or less for a stator with eight lobes, 1.125 or less for a stator with nine lobes, and 1.120 or less for a stator with ten lobes.