Prototype

There have been completed several technological steps to create the described technical solution, including preparation of the sensing top foil, construction of tricuspid bushing shell and the bearing’s housing as well as final test bed assembly. Below, main components of the test rig are briefly characterized.
Figure below presents a multifunctional 0.1mm-thick top foil made of superalloy Inconel. It is held by the two 3D-printed side components to keep the nominal curvature of the top foil until it is mounted in the bearing’s bushing. The sets of platinum wires (0.1mm in diameter) are used to build thermocouples. Similarly, pairs of copper connections enable current flow through the strain gauges.

Top foil dedicated for temperature and strain field measurements. There are visible: 1) sets of single wires soldered to the foil to build thermocouples, 2) pairs of thicker insulated wires to provide electrical connection to the strain gauges. A magnified view on the left shows a single-carrier two-grid strain gauge used to identify strains along the two transversely oriented directions.

The top foil, after being equipped with strain gauges and thermocouples, is mounted in the GFB’s tricuspid bushing together with the three bump foils.

Prototype top foil before sensor integration - covered with a protective layer made of a polymer
Prototype bump foils before installation in the bearing's bushing
Complete bushing assembly is shown in figure below. It should be noted that the relevant free space for a common electrode for all thermocouples should be assured to make all required electrical connections.
Complete assembly of a tricuspid bushing shell with mounted top and bump foils: 1-common electrode for all thermocouples, 2-a single spot of a thermocouple, 3-strain gauge

A complete assembly of the prototype bearing’s housing with installed bushing is shown below.

Prototype installation of a GFB with mounted bushing shell which is equipped with multifunctional top foil and the three bump foils
Top view of the GFB prototype. The installed bushing and foils with wiring are visible through the inspection hole