Air-cooled turbocharger with optional internal pressure relief valve

An air-cooled turbocharger for an internal combustion engine, comprising:

• an exhaust-driven turbine for driving a rotatable shaft,
• a compressor with a compressor wheel, driven by the rotatable shaft for generating a flow of compressed air for delivery to the cylinders of an internal combustion engine,
• a bearing housing enclosing a bearing carrier that carries the rotatable shaft, said bearing housing also forming a cooling jacket,
• means for forming a conduit for a flow of compressed air from behind the compressor wheel to the bearing housing, and
• a pressure-operated valve for controlling the flow of compressed air to the cooling jacket.

A self-cooled turbocharger for an internal combustion engine, comprising:

• a turbine section including a turbine wheel and a turbine housing for connection with a flow of exhaust gas from an internal combustion engine,
• a rotatable shaft driven by the turbine wheel,
• a compressor section including a compressor wheel driven by the rotatable shaft,
• a compressor wheel housing operatively associated with the compressor wheel to supply cylinder charge air to the cylinders of the internal combustion engine,
• a bearing housing between, and connected with, the turbine housing and the compressor housing and including bearings that rotatably carry the rotatable shaft,
• said compressor housing forming an air inlet to the compressor wheel and a compressed air outlet for connection with the cylinders of the internal combustion engine,
• said compressor housing including a back plate located between the compressor wheel and the bearing housing,
• said back plate and bearing housing forming a conduit for a flow of compressed air from behind the compressor wheel into a cooling jacket within the bearing housing around the bearings,
• said conduit including a pressure-operated valve carried by the bearing housing and including a hole in communication with the hole formed in the backplate, and
• said bearing housing also forming an opening to ambient pressure so the expansion and flow of compressed air through the cooling jacket cools the internal components of the turbocharger.

An internal combustion engine turbocharger, comprising:

• an exhaust gas-driven turbine for driving a rotatable shaft,
• a compressor with an engine intake air compressor wheel, said engine intake air compressor wheel being driven by the rotatable shaft driven by the exhaust gas-driven turbine,
• a bearing housing carrying bearings for the rotatable shaft, an interior of said bearing housing having a cooling jacket for said bearings and said rotatable shaft,
• means within the turbocharger for directing a flow of compressed cooling air from the compressor to the interior of the cooling jacket of said bearing housing, and
• said bearing housing having an opening in communication with ambient atmosphere, said opening having a non-return valve engaged between said bearing housing and said ambient atmosphere.