Hollow filled turbocharger rotor shaft

A turbocharger comprising:

• a housing having a turbine housing section and a compressor housing section arranged along an axis of rotation;
• a rotor shaft assembly having a rotor shaft disposed along the axis of rotation and having a first end and a second end, a turbine rotor connected to the first end of the rotor shaft, and a compressor rotor connected to the second end of the rotor shaft, wherein the compressor rotor is contained in the compressor housing section, and the turbine rotor is contained in the turbine rotor housing section, the rotor shaft having an outwardly oriented surface and an interior chamber defined therein, the interior chamber having an interior chamber volume;
• and
• at least one thermal transfer material contained in the interior chamber of the rotor shaft, wherein the rotor shaft is composed of a material having a first thermal conductivity value, and the thermal transfer material is composed of a material having a second thermal conductivity value, the second thermal conductivity value being greater than the first thermal conductivity value, the at least one thermal transfer material being adapted for liquefication at an operating temperature of the turbocharger such that the at least one transfer material transitions from a solid state to a liquid state during operation of the turbocharger.