Patent ID: 8820073

Claim:
An apparatus comprising: a compressor assembly comprising: a compressor housing defining an inlet and an outlet; a compressor impeller wheel having a plurality of vanes and mounted in the housing between said inlet and outlet, the wheel being rotatable about an axis; the housing having an inner wall defining a surface located in close proximity to radially outer edges of the impeller vanes which sweep across said surface as the impeller wheel rotates about its axis; the inlet comprising a tubular wall extending away from the impeller wheel in an upstream direction; the housing further comprising an enclosed chamber defined between said inner wall and an outer wall and in communication with at least one opening in said inner wall; the outer wall being penetrated by a plurality of ventilation apertures spaced around the outer wall of the chamber; wherein there is provided a ventilation conduit connected to each of the plurality of ventilation apertures and the second end of each of the ventilation conduits is connected to an intake conduit that is connected to the housing inlet.