What should be paid attention to in the design of turbomachinery bearings?

A turbomachinery bearing carries a rotating shaft that passes between the turbine and compressor. Its radial design allows it to be situated at a lower temperature than the conventional radial bearings. This type of bearing also allows for better cooling and longer life. In addition, this design also allows for improved control over the axial positioning of the compressor.

Modern oil-free turbomachinery requires a low-maintenance, reliable, and low-power loss bearings. Because of the extreme temperature and power density of these high-speed machines, conventional liquid-lubricated bearings are unsuitable. A modern oil-free foil bearing meets these needs while providing low power loss and high load capacity, even in supercritical operations. These features make oil-free foil bearings an ideal choice for turbomachinery applications.

Prior art turbomachines use journal and thrust bearings located between the turbine and the compressor. This arrangement prevents them from being exposed to the excessive heat generated in the combustion chamber. The heat generated by the turbine and the compressor also affects the life of the thrust bearings and journal bearings. However, modern materials technology allows for more efficient and cost-effective designs for metal bearings.

These materials can sustain a large amount of pressure and weight. Current designs support a pound of load per square inch of bearing projected area and 1000-shaft-rpm. The design of these bearings is highly complex and requires special design considerations. Moreover, this design also improves weight-supporting properties.

Another important factor affecting the life of a turbomachinery bearing is its dynamic behavior. Its behavior is often nonlinear and often displays unexpected patterns. Because of this, the design of turbomachinery bearings should account for such behaviors and take this into consideration. It is essential to develop proper models for the bearings to ensure optimal operation and performance.