Influence of transverse vibrations on the tribological performance of rolling-sliding contacts
File(s)
Author(s)
Uribe Saenz de Camara, David
Type
Thesis
Abstract
Rolling-element bearings are one of the most abundant machine components found in mechanical systems. There is a rising demand for a higher efficiency and longer service lives of mechanical components. The reliability of rolling bearings has increased considerably over the last decades, and yet there are circumstances when they fail prematurely, well short of their rated life. In certain applications, the rolling bearings are subjected to external vibrations, and there is anecdotal evidence that these vibrations can lead to premature bearing failure. Dynamic vibrations are difficult to predict, have the potential to disrupt the steady-state operating conditions, and their effect on tribological contact conditions remains unclear. Some authors have even suggested that their impact might be negligible, but there is no systematic investigation under controlled conditions of the effect of transverse vibrations on the tribological performance of rolling-sliding contacts. This thesis addresses this by studying its effect on contact damage, friction and lubrication condition under conditions relevant to bearing field operation.
A novel setup combining a triple-disc contact fatigue rig and an electrodynamic modal shaker has been developed to facilitate the systematic study of a wide range of transverse vibrations prevalent in real-world applications, covering frequencies up to 1,000 Hz, displacement amplitudes up to 500 um, velocities up to 200 mm/s, and accelerations up to 13 g. The devised methodology enables the generation of surface damage as well as the measurement of contact friction in two orthogonal directions, the meticulous control over both tribological and vibration parameters, so that the influence of single parameters of interest can be isolated. The new setup was conceived with a notable emphasis on flexibility, facilitating the simulation of diverse operating conditions found in various applications, such as those pertinent to large-scale wind turbine bearings or those prevalent in smaller-scale railway bearings.
A novel setup combining a triple-disc contact fatigue rig and an electrodynamic modal shaker has been developed to facilitate the systematic study of a wide range of transverse vibrations prevalent in real-world applications, covering frequencies up to 1,000 Hz, displacement amplitudes up to 500 um, velocities up to 200 mm/s, and accelerations up to 13 g. The devised methodology enables the generation of surface damage as well as the measurement of contact friction in two orthogonal directions, the meticulous control over both tribological and vibration parameters, so that the influence of single parameters of interest can be isolated. The new setup was conceived with a notable emphasis on flexibility, facilitating the simulation of diverse operating conditions found in various applications, such as those pertinent to large-scale wind turbine bearings or those prevalent in smaller-scale railway bearings.
Version
Open Access
Date Issued
2024-03
Date Awarded
2024-07
Copyright Statement
Creative Commons Attribution NonCommercial NoDerivatives Licence
Advisor
Kadiric, Amir
Sponsor
SKF (Firm)
Publisher Department
Mechanical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)