US Patent 9790953 Filter device

A multi or single-stage turbocompressor with at least one compressor wheel fastened to a shaft. The shaft is mounted in a turbocompressor housing which, behind the hub disc of the compressor wheel, includes an interior housing region as well as in front of the hub disc of the compressor wheel a front interior housing region. The driven compressor wheel delivers a fluid from an inlet channel to an outlet channel. The front interior housing region includes a wheel lateral space from which an extraction channel for the extraction of fluid is provided.