Schadensfrüherkennung an Dentalkugellagern anhand einer Acoustic-Emission Analyse

  • Anton Steinmaßl

Student thesis: Master's Thesis

Abstract

In order to avoid unplanned downtimes and the resulting costs and machine failures, it is very important to detect damage to components such as ball bearings at an early stage. Various methods can be used for this purpose. One effective method is the analysis of acoustic emission signals, which can detect emerging damage at a very early stage. In addition to preventing downtimes, such damage detection can also help to reduce the test time and thus the resulting costs in endurance tests through early detection.
The aim of this thesis is to answer whether acoustic emission analysis also enables early detection of damage in miniature ball bearings such as those used in dental instruments. The following research question is posed: Is it possible to detect ball bearing damage on dental ball bearings at an early stage using acoustic emission signals?
In order to answer this question, a measurement setup was developed with which acoustic emission signals in the frequency range of 250 kHz - 800 kHz can be recorded. Subsequently, several data sets were recorded on dental turbines in which corresponding bearings are installed. This was followed by an evaluation of various features over the entire life cycle and a detailed analysis of individual significant measurements. In addition to the evaluation of the acoustic emission data, the speed curve was also recorded and microscope and computer tomography images were taken in order to be able to assign recognizable fault patterns to the signals.
The evaluation of the recorded data showed that it is not possible to detect damage to dental turbines at an early stage using acoustic emission signals. Although some structure-borne sound signals could be recorded, these can be assigned to characteristic frequencies of the bearings and therefore do not correspond to the expected acoustic emission signals. These recorded structure-borne sound signals also did not reveal any advantage over other methods such as speed analysis for the early detection of damage.
Further research could be conducted, for example, into the causes of the recorded data. Another possibility is an acoustic emission analysis of the ball bearings in a reduced model without damping elements.
Date of Award2024
Original languageGerman (Austria)
SupervisorGerald Zauner (Supervisor)

Cite this

'