Running-in of gears from a surfacetransformation and efficiency point of view
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Requirements today for machines have moved beyond functionality intoefficiency and reliability, gears are no exception. The presented work focuseson the analysis of the measurement, evolution and effect of running-in on geardrives from a surface roughness and efficiency point of view. With no consen-sus on a definition or observation of running-in of gear drives, measurementsof both efficiency and surface transformation during the predefined running-inis explored. A verified methodology on how to separate form, waviness androughness is presented. Two finishing methods, namely generation groundand superfinished, are analyzed in terms of efficiency and surface characteris-tics as manufactured, after running-in and after efficiency testing in order todetermine the effects of load level during running-in.Results show that separation of form can be achieved with a carefullychosen polynomial, while waviness is more subject to how the user definesa cut-off wavelength for the surface roughness. Ground gears show distinctsmoothening in terms of surface roughness at high running-in load, and nogeneral trend for low load. This behavior is also reflected in the efficiencysince higher loads gave overall lower efficiency after running-in when com-pared to lower loads. Superfinished gears in contrast show no running-in ef-fects in terms of efficiency. Additionally, ground gears exhibit general changein friction and surface roughness during the first cycles of running-in whenanalyzing high load. Overall gains in efficiency can be obtained from running-in; however, at most speeds improvements from polishing a surface, in thiscase superfinishing, proved to lead to higher efficiency.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , xi, 53 p.
TRITA-MMK, ISSN 1400-1179 ; 2015:06
running-in, surface transformation, efficiency, gears, ground, su- perfinished
Research subject Energy Technology; Machine Design
IdentifiersURN: urn:nbn:se:kth:diva-173828ISBN: 978-91-7595-688-6OAI: oai:DiVA.org:kth-173828DiVA: diva2:855121
2015-10-16, Sal Gladan, Brinellvägen 85, KTH, Stockholm, 13:00 (English)
Mattsson, Lars, Professor
Olofsson, Ulf, Professor
FunderSwedish Energy Agency, 35557-1
QC 201509222015-09-222015-09-182015-09-22Bibliographically approved
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