Electronic Measurement and Diagnostic Technology
I²G - Integral Instrumentation of Gas Foil Bearings

In the project I²G the focus is integration of sensors in the energy-efficient and environment-friendly gas foil bearings. In the future rotational speed, temperature and friction states can be determined and relayed to the controller of the axle.

Gas foil bearing with the first version of the sensor system

Project goal

The goal of the project is to integrate a sensor system into the gas foil bearing that provides the current rotational velocity, state of friction and temperature as wireless data to an outside receiver. It is supposed to be powered from the bearing itself via energy harvesting and must not change the workings of the bearing. This also means that nothing can be attached to the rotor, which means many of the values need to be interpreted indirectly from vibrations.

Gas Foil Bearing

Gas foil bearings work similarly to hydrodynamic journal bearings, however, instead of oil they use gas (e.g. air or whatever gas the machine interacts with) as the lubricant. While this means they can only support relatively light rotors, it also means they run very efficiently up to extreme velocities and can be applied in areas where oil contamination would be problematic. This makes them a perfect fit for the air compressor for fuel cell systems or for cooling turbines for air conditioning, but they are also used in other turbo machinery.

Project structure

A key component of more efficient operation of machines is the available data about them that allows for optimisation of usage and operation. Since machine elements tend to be located close to places where such data can be collected, the DFG priority program 2305 "Sensor-Integrated Machine Elements pave the way for Widespread Digitalization" puts those in the focus. The idea is, that by integrating sensor systems into standardized machine elements it will become easier for manufacturers and users of machines to collect and use data from their machines without additional development effort, thus boosting digitalization.

The priority program is made up of ten projects located at different universities across Germany, each focusing on a different machine element. At the Department of Electronic Measurement and Diagnostic Technology, we are focusing on gas foil bearings. For that, we have joined forces with the department of Engineering Design and Product Reliability from faculty five, who are experts on this type of bearing.