Mechanically driven centrifugal air compressor with integral plastic pulley and internal helical ring gear

Claim 1

A centrifugal air compressor adapted to be mechanically driven by an internal combustion engine and deliver air thereto for combustion, said compressor comprising a housing, an impeller shaft having an impeller with helical vanes at one end and a helical pinion gear at an opposite end, plain journal bearings supporting said impeller shaft at axially spaced locations in said housing, a plastic input member, a support shaft rotatably supporting said plastic input member on said housing in parallel relationship with said impeller shaft, said plastic input member including an integral internal helical ring gear meshing with said helical pinion gear, said plastic input member further including an integral compressor pulley adapted to be driven by the crankshaft of an engine at increased speed by a belt driven by a pulley of larger diameter fixed to the engine crankshaft, a thrust bearing extending about said impeller shaft and mounted in said housing between said impeller and one of said plain journal bearings, a thrust ring mounted on said impeller shaft and sandwiched on one side by a thrust face of said thrust bearing and sandwiched on an opposite side by both said housing and said one plain journal bearing to axially locate said impeller shaft in said housing and wherein air pressure from impeller operation acting on said impeller imposes an axial tension load on said impeller shaft that is borne by said thrust face, and said helical pinion gear and the vanes of said impeller having the same lead so that said internal helical ring gear and helical pinion gear impose a substantial axial tension load on said impeller shaft in opposition to that imposed by air pressure from impeller operation to thereby effect a net axial thrust load borne by said thrust face that is substantially less than that imposed by the air pressure from impeller operation.