Use this URL to cite or link to this record in EThOS:
Title: Reliability of automotive transmission bearings
Author: Carvajal, Gerardo
ISNI:       0000 0004 5993 5628
Awarding Body: Open University
Current Institution: Open University
Date of Award: 2016
Availability of Full Text:
Access from EThOS:
The manufacture of rolling element bearings, as high precision mechanical components, has experienced remarkable advances in the last few decades. Some of the key factors for these advances include the incorporation of computer numerical control in machining, improvements in the quality of lubricants and improvements in the cleanliness of the steel. This in turn, has led to the highest ever level of reliability not only of the rolling bearing as a unit but of the whole mechanical assembly where the rolling bearing is destined to work. However, under high performance running conditions, such as in automotive transmissions, intrinsic and/or external factors can hinder the rolling bearings from performing as expected and as a result, premature failure may occur. In this context, the present PhD thesis investigates the premature and recurrent failure of a specific type of roller bearing, identified by its model number as 30206, when used as the tail bearing of a particular automotive rear differential unit. For this, a series of theoretical and practical approaches are used first, to characterise the failure, secondly, to propose failure hypotheses and lastly, to evaluate the hypotheses. From the forensic studies carried out on in-field-used bearings, three failure hypotheses are proposed; in these, the mechanisms of fretting, static overload and corrosion are respectively regarded as precursors to surface-initiated rolling contact fatigue. For the evaluation, 'pre-damaged' bearings, representative of each failure hypothesis, are first generated via various mechanisms and then tested in a bespoke made rolling contact fatigue test rig.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available