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Kristoffer Berg

Kristoffer Berg
Condition monitoring of rolling element bearings
Fakultet for teknologi og realfag
10. desember 2018

Condition monitoring of rolling element bearings

Operation of a test rig for axial rolling element bearings subject to abrasive wear and data collection using vibration and acoustic emission acquisition systems. 

The project was carried out the autumn of 2018, to assist PhD student Martin Hemmer with his research project on condition monitoring of rolling element bearings. The work involved operation of a test rig for axial rolling element bearings subject to abrasive wear and data collection using vibration and acoustic emission acquisition systems.  

The majority of test rigs for roller bearings are designed to investigate fatigue damage through run-to-failure experiments. However, this axial bearing test rig is designed to allow a hardened needle to be brought in contact with the roller end, applying controlled damage of the roller end. This failure mode has been observed in industrial applications but is rarely considered in the literature. The purpose of testing is twofold:

·         Identify fault signature as scratches form on roller ends

·         Identify the effect of accumulated scratches

Description of the tests

The first test performed during the project was to use the test rig with the hardened needle and applying controlled damage of the roller ends. The test was performed during a variable range of rotational speed of the bearing, and with a fixed axial force of 5000kg. For each test, data was collected using vibration and acoustic emission acquisition systems.

During the second test, the inflicted damage was construct with sand paper with variable grits of P80, P320, P400, P500 and P1200. Each time the test was performed, the bearing with the rollers were disassembled and sorted. Started off with the finest sand paper grit, the sandpaper was used to damage the end-surface of the rollers before it was assembled again. The last step dealt with running a series with different rotational speed for a certain time interval together with a fixed axial force of 5000kg. This test-sequence was then performed 8 times where the coarsest sand paper grit of P320 and P80 was used several times just with different level of damage. 

Results for the project

The outcome of this project forms a foundation for identifying different fault signatures caused by scratches on the roller ends, and also how to identify the effect and outcome of scratches found at the roller ends from a bearing used in the industry.