Control of balance drift in turbocharger rotating assembly

A turbocharger for an internal combustion engine, the turbocharger comprising:

• a bearing housing having a bearing bore and a thrust wall;
• a journal bearing disposed within the bore;
• a shaft having a first end and a second end, the shaft being supported by the journal bearing for rotation about an axis within the bore;
• a turbine wheel fixed to the shaft proximate to the first end and configured to be rotated about the axis by post-combustion gasses emitted by the engine;
• a compressor wheel fixed to the shaft proximate to the second end and configured to pressurize an airflow being received from the ambient for delivery to the engine;
• and
• a thrust bearing assembly pressed onto the shaft and configured to transmit thrust forces developed by the turbine wheel to the thrust wall;
• wherein pressing the thrust bearing assembly onto the shaft minimizes radial motion between the thrust bearing assembly and the shaft during operation of the turbocharger.

A turbocharger for an internal combustion engine, the turbocharger comprising:

• a bearing housing having a bearing bore and a thrust wall;
• a journal bearing disposed within the bore;
• a shaft having a first end and a second end, the shaft being supported by the journal bearing for rotation about an axis within the bore;
• a turbine wheel fixed to the shaft proximate to the first end and configured to be rotated about the axis by post-combustion gasses emitted by the engine;
• a compressor wheel pressed onto the shaft proximate to the second end and configured to pressurize an airflow being received from the ambient for delivery to the engine;
• and
• a thrust collar and a thrust washer each pressed onto the shaft and together configured to transmit thrust forces developed by the turbine wheel to the thrust wall;
• wherein:
• the thrust collar is configured to urge the thrust washer against the shoulder as the fastener is tightened;
• and
• the compressor wheel, the thrust collar, and the thrust washer pressed onto the shaft minimizes radial motion between the thrust collar, the thrust washer, and the shaft.