Engineering Design and Product Reliability

KuP - Conical Gas Foil Bearings

Figure 1: Pressure distribution of the conical gas foil bearing

Figure 2: Production of the conical gas foil bearing

  • Project: Conical Gas Foil Bearings
  • Funding: KuP
  • Project duration:  01.11.2019 - 31.10.2024
  • Project description:  Gas foil bearings (GFBs) are innovative machine elements used to support high-speed rotors without contact on an aerodynamic air film. This results in very low bearing friction and thus very little wear and losses. Due to a compliant film structure in the air gap, GFBs exhibit advantageous vibration behavior and lower requirements for manufacturing and alignment accuracies compared to conventional aerodynamic bearings.  By using air as the lubricating medium, GFBs function without contamination from lubricating oil. This property makes GFBs predestined for use in the air supply of fuel cells. As a result, the topic of GFBs is becoming increasingly important and gaining general interest in the current energy transition. A conical design of GFBs pursues the idea that both axial and radial forces can be absorbed by only one bearing. Compared to conventional bearing arrangements using two radial and two axial GFBs, this has the potential to halve the number of bearings required in a rotor system. This not only results in advantages in terms of cost and installation space, but also allows increased design freedom. Despite this potential, conical GFBs have remained virtually unexplored to date. The nonlinear properties of the air film and film structure result in complex vibration behavior for rotors supported by GFBs. A wide variety of nonlinear effects such as subsynchronous vibrations and instabilities occur. Since these effects can severely limit the functionality of the bearings, it is essential to understand them fundamentally. For this purpose, we carry out numerical simulation methods as well as experimental investigations.
  • Project objective: 
    • Numerical description of the dynamic and static behavior of conical gas foil bearings
    • Production and geometric measurement of bearing prototypes
    • Experimental rotordynamic examination of the bearing
    • Validation of the numerical model through experimental findings
  • Publications:

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