Patent ID: 7146971

Claim:
A supercharger impeller comprising; a central hub; an outer shroud; an inlet at a center of said central hub; an exit at a peripheral portion of said hub; a plurality of primary and secondary vanes being between said central hub and said outer shroud including a plurality of passages for fluid accelerating from said inlet at the center of said central hub to said exit at the peripheral portion of said hub to rotate said plurality of vanes about a central axis of the supercharger impeller; each of said plurality of primary and secondary vanes further characterizing: an inverted profile starting with a zero rake angle at the outer periphery and continuing to a middle section of said supercharger impeller; and at a point of the middle section of said supercharger impeller; and at a point of a middle section each of said plurality of vanes curving five to ten degrees to a negative rake angle that proceeds the central axis of said supercharger impeller; and said supercharger impeller being casting aluminum alloy of 354T6, 201T7, and A/B206.