Patent ID: 6767181
Filing Date: 2004-07-27
Classification: F04D,F05B

Abstract:
A pump comprising:a pump casing having an axis and comprising a cover having a face surface and a body positioned about the axis, with an arcuate channel defined in the face surface of the cover and extending at least partially circumferentially about the axis; an inlet opening extending through the cover and coupled to the arcuate channel; and an impeller positioned between the face surface of the cover and the body, wherein the arcuate channel has a first section and a second section, with the first section extending from the inlet opening and being continually sloped relative to the face surface of the cover, said first section having a length of about 40 to about 90 degrees, as measured circumferentially on the face surface of the cover about the axis, said first section including an inlet ramp, a main ramp, and a secondary ramp, with the secondary ramp being positioned between the main ramp and the inlet ramp, and the inlet ramp being positioned adjacent the inlet opening, wherein each ramp has a depth and a slope, with the depth of the inlet ramp being greater than the depth of the secondary ramp, and the depth of the secondary ramp being greater than the depth of the main ramp, and the slope of each ramp is different from the slope of the other ramps.