Patent ID: 7993118

Claim:
A rotor assembly for a supercharger assembly comprising: at least one lobe defining at least one cavity; wherein said at least one cavity is configured to contain a fluid operable to cool said at least one lobe; a rotatable shaft member defining an axis of rotation; wherein said at least one lobe is operatively connected to said shaft member, is helically-shaped with a radially-inner wall and a radially-outer wall defining said at least one cavity such that said at least one cavity extends radially from said radially-inner wall to said radially-outer wall and fluid flows in said at least one cavity in an axial direction between said radially-inner wall and said radially-outer wall; wherein said at least one lobe extends along the axis of rotation; wherein said at least one lobe is operatively connected to said shaft member; wherein said shaft member defines a feed passage operable to communicate said fluid to said at least one cavity, and defines a return passage operable to exhaust said fluid from said at least one cavity; and wherein said at least one lobe and said shaft member cooperate to define an annular passage extending axially between said shaft member and said radially-inner wall on an opposing side of said radially-inner wall than said at least one cavity and that is operable to communicate said fluid between said at least one cavity and said return passage.