Air start/assist for turbochargers

The compressor for a turbocharger includes an assist system to provide a power stream of a driving fluid such as air to act on the impeller of the compressor until the driving power of the exhaust gases from an internal combustion engine are sufficient to drive the impeller. The compressor includes a housing forming a compression chamber in which the impeller is rotatably disposed. The impeller has a floor with a plurality of blades projecting from the floor. A plenum surrounds the housing and is connected to a source of pressurized air for supplying air to the compression chamber to drive the impeller. An aperture is provided through the housing for each blade and communicates the air from the plenum to the compression chamber and against the blades. The axis of the aperture is coincident with a line extending from the lower outer radial edge of the blade adjacent the floor to the point at which the air jet from the aperture impinges upon the next successive blade