A Durability Assessment of Rolling Element Bearings in a Camshaft Application, Considering Sensitivity to Installation and Operating Parameters Mahle Powertrain, Limited

Format:

Conference/Event

Author/Creator:

Bleach, Bleach, author.

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

Concerns over greenhouse gas emissions are driving governmentsand the automotive industry to seek out ways of reducing vehicleCO₂ emissions. Engine friction reduction is one means of reducingCO₂ emissions, through fuel consumption improvements. One areawhere it is felt that friction reduction is possible is inconnection with the camshaft bearings.Mahle has conducted experimental evaluation of rolling elementbearings used to support camshafts, replacing the standard plainjournal bearings. The aim of the testing was to gain anunderstanding of the durability of rolling element bearings, testedin a range of different operating conditions. The controlled testconditions included variations to: - Camshaft speed, - Oiltemperature, - Oil age/specification, - Oil supply method/flowrate,- Bearing journal line bore misalignment tolerance, and - Bearingjournal diametrical tolerance.A Design of Experiments software package was used to generate areduced test matrix, with the aim of allowing a full understandingof the effects of each of the test variables, whilst vastlyreducing the number of tests required. The testing required thecreation of a rig that could test multiple bearings simultaneouslyin all of the different operating conditions required. This enableda large number of tests to be accomplished within the requiredtimescale.The bearings were measured in a number of ways before and aftertesting to ascertain wear mechanisms attributable to each of thetest variables. The results indicated that although there was ameasurable reduction in bearing assembly weight for all bearings,there was very little measurable wear on any of the bearing contactsurfaces, and therefore no operating condition can be outlined asdetrimental to the bearing life. The conclusion therefore is thatrolling element bearings would be suitable to support camshafts inproduction engines. This paper details the approach to the testing,and discussion of the results

Notes:

Vendor supplied data

Publisher Number:

2012-01-1331

Access Restriction:

Restricted for use by site license