Vol 8, No 3 (2022)

The diagnostic indicators of defects in aircraft gas turbine engines based on the vibration intensity have several draw-backs. Quite significant is the error in estimating such intensity. Moving an engine from the test bench to the facility leads to an increase in vibration intensity, which cannot be taken into account when developing diagnostic methods in the conditions of the engine manufacturer's plant. The known dimensionless discriminants have generally a fairly complex structure. This study reveals the possibility of using structural diagnostic indicators as a simple ratio of two parameters. Based on the example of tooth flank wear and the side clearance value in the turboprop engine gearbox, we have demonstrated the possibility to assess its technical condition by the vibration parameters and signals from standard tachometric sensors of the input and output shaft rotation speeds.

The paper describes a mobile laser system based on a noise-proof digital speckle pattern interferometer for studying the coupled vibrations of the bladed wheels during engine development stage. The mechanical properties influence of the optical scheme elements of the speckle interferometer when recording information without vibration isolation is studied. It is noted an improvement in the quality of the obtained speckle interferograms with an increase in the construction rigidity of the diffusely scattering element of the speckle pattern interferometer.

The most effective way of non-destructive control of the technical condition of a complex hydro mechanical system such as a steering drive is diagnostics by dynamic characteristics. The diagnostic signs considered in this article are: dynamic values of the pressure and flow rate of the working fluid, as well as the speed of the spool movement and the shift of the rod under disturbing influences. On the example of the steering drive KAU-30B, the possibility of diagnosing the wear of elements of hydro mechanical systems based on the analysis of transients is shown.