Turbocharger having controlled heat transfer for bearing protection

Turbocharger apparatus comprising a center housing means for spacing apart respective compressor housing portions and journaling an elongate shaft extending between said housing portions, a compressor rotor and a turbine rotor each drivingly connected to said shaft at opposite ends thereof and rotatable within respective ones of said housing portions, an axially elongate bearing carred by said center housing means proximate to said turbine housing portion and rotatably supporting said shaft, said shaft defining a first conductive heat transfer path extending from said turbine rotor to said bearing, said housing including means for defining a singular second U-shaped conductive heat transfer path extending from said turbine housing portion to said bearing, said second heat transfer path including a radially outer wall portion of said center housing means which at a transverse radial plane disposed axially within the axial dimension of said bearing defines a first radially outer annular leg of said second heat transfer path wherein conductive heat transfer extends axially away from said turbine housing portion through said radial plane, and said second heat transfer path also including a radially inner wall portion of said center housing means defining a second radially inner annular leg of said second heat transfer path wherein conductive heat transfer extends axially from said radial plane toward said turbine housing portion and said bearing, said second leg being defined in part by a material selected to undergo a molecular change of phase at a determined temperature with attendant absorption of heat.

Turbocharger apparatus comprising:

• a housing defining a center housing porton axially spacing apart respective turbine housing and compressor housing portions, said center housing carrying a bearing member disposed adjacent to said turbine housing portion, each of said turbine housing portion and said compressor housing portion defining a respective inlet and outlet communicating via a respective flow path for flow therethrough of combustion products and charge air, respectively;
• an elongate shaft rotatably received in said bearing member and extending axially between said compressor housing portion and said turbine housing portion;
• means for providing a flow of liquid lubricant to said bearing;
• a compressor rotor rotatably received in said flow path of said compressor housing portion and drivingly connecting with said shaft;
• a turbine rotor also drivingly connecting with said shaft and rotatable in the respective flow path of said turbine housing portion;
• said housing further defining a radially extending wall between said bearing member and said turbine rotor, said wall having an axially disposed face confronting said bearing member, said radially extending wall including an aperture rotatably receiving said shaft, and said shaft and said radially extending wall defining cooperating sealing means for impeding fluid flow therebetween;
• said housing further defining a circumferentially continuous annular recess between said bearing member and said axially disposed face of said wall, and means for draining from said recess liquid lubricant escaping axially from said bearing along said shaft and which is flung radially outwardly into said recess by spinning motion of said shaft, whereby said axially disposed face of said radially extending wall is maintained substantially dry of liquid lubricant during operation of said turbocharger.

Turbocharger apparatus comprising a housing rotatably receiving both a shaft and a turbine rotor which is drivingly connected on said shaft;

• said housing defining an exhaust gas inlet, an exhaust gas outlet, and a flow path extending between said inlet and said outlet traversing said turbine rotor;
• a bearing member carried by said housing and journaling said shaft most proximate to but spaced axially from said turbine rotor;
• said housing defining a radially extending transverse wall interposed between said bearing and said turbine rotor;
• sealing means cooperating with said shaft and said radially extending wall to inhibit fluid flow therebetween;
• means for providing a flow of liquid lubricant to said bearing member for axial outward flow therefrom;
• and
• said housing defining a radially extending annular recess circumscribing said shaft and opening radially inwardly theretoward and being disposed immediately adjacent said bearing member between the latter and said radially extending wall to receive liquid lubricant exiting said bearing member axially which is flung radially outwardly by rotary motion of said shaft.