Patent ID: 8128369

Claim:
An impeller comprising: a hub; a plurality of blades attached to and radially disposed about the hub, each blade having a trailing edge that runs parallel to an axis of rotation of the hub; a ring to which all of the blades are attached, the ring comprising a single annular member having an inlet side and an outlet side, the inlet side of the ring being disposed in coplanar relation with an inlet side of the impeller, the ring having a concave profile wherein a diameter at the inlet side thereof is smaller than a diameter at the outlet side thereof, wherein a portion of the trailing edge of each of the blades proximate the inlet side of the impeller extends through first and second opposing major surfaces of the ring, wherein a height of the ring is less than a height of each blade, wherein the ring blocks a low-momentum flow zone toward the inlet side of the impeller, wherein an outer circumference of the ring is substantially co-extensive with trailing edges of the blades.