Abstract

A method and apparatus for a supercharger wherein pressurized air originating from the compressor side is fed into its gear box for draining the oil therein due to the reduced size of the gear box. The supercharger includes a gear case encompassing the drive gear and the driven gear. The gear case has at least one oil inlet in the gear case to receive oil, and at least one oil outlet on the gear case. An air passage has a first end connected to the compressor end down stream in relation to the compressor wheel, and a second end connected to the gear box, whereby pressurized air at the compressor end is disposed to be channeled toward the inside of the gear box for draining lubricating fluid therein.