?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F559%2F&rft.title=A+comparison+of+bearing+life+in+new+and+refurbished+railway+axle+boxes&rft.creator=Broadbridge%2C+P.&rft.creator=Wake%2C+G.&rft.subject=Transport+and+Automotive&rft.description=A+simple+linear+dynamical+model+shows+that+at+normal+running+speeds+of+freight+wagons%2C+forced+oscillations+due+to+periodic+track+compliance+are+transferred+to+the+overlying+unsprung+mass+and+significantly+amplified.+Due+to+these+oscillations%2C+a+small+gap+opens+and+closes+between+the+collar+of+a+journal+bearing+and+the+axle+box+many+times+every+second.+The+forces+between+these+components+reach+peaks+of+over+10+tonnes.+This+is+an+environment+in+which+wear+of+the+soft+spherical+graphite+iron+of+the+axle+box+will+eventually+take+place.%0D%0A%0D%0ADue+to+repeated+unloadings+of+the+weight+on+the+bearing+during+oscillations%2C+the+bearing+collar+may+slowly+slip+against+the+axle+box+wall.+Although+our+calculations+show+that+abrasive+wear+due+to+this+slippage+is+negligible%2C+the+calculation+raises+general+principles+that+apply+to+other+possible+wear+mechanisms.+If+lifetime+is+proportional+to+hardness%2C+we+can+estimate+relative+lifetimes+of+refurbished+and+new+boxes.+Although+the+resleeve+material+is+softer+than+the+original%2C+the+cost+to+lifetime+ratio+would+favour+refurbishment+under+this+assumption.%0D%0A%0D%0AImportant+unanswered+questions+are+identified+and+a+specific+integrated+program+of+field%2C+laboratory%2C+and+theoretical+study+is+suggested.&rft.date=2001&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F559%2F1%2FA-comparison-of-bearing-life-in-new-and-refurbished-railway-axle-boxes.pdf&rft.identifier=++Broadbridge%2C+P.+and+Wake%2C+G.++(2001)+A+comparison+of+bearing+life+in+new+and+refurbished+railway+axle+boxes.++%5BStudy+Group+Report%5D+++++