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The Global ETD Search service is a free service for researchers
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Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 1 to 5 of 5 (0.02 seconds)Spelling suggestions: "subject:"sheaves""
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Drinfeld-Moduln und elliptische Garben / Drinfeld modules and elliptic sheavesWiedmann, Stefan 28 October 2004 (has links)
No description available.
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An Investigation of Improving Wear of 390 Die-cast Aluminum Through Hardcoat AnodizingWhiting, Michael J. 26 August 2005 (has links) (PDF)
The objectives of this research were to investigate the wear that occurs on the surface of a Hardcoat anodized die-cast aluminum surface, which was sliding against a composite rubber belt. This research investigated known wear theories and the results for previous testing to understand the mechanisms that were likely occurring in this application. These theories indicated that the wear occurring may be reduced by changing the hardness of the materials involved. Archard's equation gave tangible evidence of this fact, but related to the base material and not a surface coating. It was hypothesized that Hardcoat anodizing would follow the theory of Archard's equation and increase the wear resistance of 390 die-cast aluminum when sliding against a composite rubber belt. Standardized wear tests were implemented in order to test this theory. The results of the wear tests indicated that the wear resistance of the Hardcoat anodized coating did not follow the wear theories and wore at a higher rate than the base material surfaces. This is likely due to the phenomenon seen by Jiang and Arnell where the surface roughness influenced the wear rate of DLC coatings. They found that there existed a transition point where the wear rate of the surface increased with an increase of surface roughness. The Hardcoat anodized surface was rougher than the surface of the base material due to alloy materials and the processing characteristics of 390 Aluminum die-casting material. Subsequently the Hardcoat anodized surface wore at a higher rate than did the base surface. A case study was conducted on an ATV to investigate the accuracy of the results from the laboratory testing. This case study showed a significant localized wear groove in the stock CVT drive sheave with little wear occurring elsewhere. The Hardcoat anodized CVT drive sheave did not show evidence of a significant localized wear groove as the stock sheave but indicates that wear occurred more evenly across the surface. This wear is evident due to visible aluminum through the Hardcoat layer. In addition, there was a ridge at the outer diameter of the sheave where the belt could not wear the surface. Both of these items indicated that significant wear occurred on the surface, but the presence of a localized wear groove is non-existent.
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Konstrukční návrh jednoúčelového stroje na lisování valivých ložisek do kladkovnic / Design of single-purpose machine for pressing bearings in pulleysRoupec, Michal January 2013 (has links)
Purpose of this thesis is to make constructional modification of single-purpose pressing machine for Huisman Konstrukce, s.r.o. company. Present machine is non-operational and not enough powerful for present requests of workshop. Intended modifications are to describe present condition of machine, find present requirements and design simple modifications. All modifications are checked by calculations and sketched in shop drawings. There were also made alternative options of modification to show machine more versatile and automatic.
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Modellierung und Simulation der Beanspruchung von Zugsträngen aus Stahllitze für Zahnriemen / Load modelling and simulation of steelcords for timing beltsWitt, Robert 11 September 2008 (has links) (PDF)
In dieser Arbeit wird das Verhalten von gewickelten Seilen aus Stahllitze unter Zug- und Biegebelastung mit Hilfe der Methode der Finiten Elemente untersucht. Ausgehend von dem Modell einer einfachen Litze mit einem Kern- und sechs Außendrähten erfolgt eine ausführliche Analyse der Spannungsverteilung sowohl bei rein axialer Belastung als auch bei Biegung über eine Seilscheibe. Darauf aufbauend wird das Simulationsmodell schrittweise um komplexere Seilkonstruktionen bis hin zu zweifachen Verseilungen erweitert. Daran schließt sich die Untersuchung der inneren Belastungen bei Einbettung in ein Elastomer an, wie dies bei Zugsträngen in Riemengetrieben der Fall ist, sowie der spezifischen Einflüsse der Verzahnung auf die Seilbeanspruchung bei Zahnriemengetrieben. Des weiteren wird eine Möglichkeit der Validierung der Modelle vorgestellt, die ein experimentelles Ermitteln der Relativverschiebungen der Filamente auch im Inneren des Seils zulässt. Abschließend folgen Richtlinien zur Auslegung von Zugsträngen in Zahnriemen sowie Vorschläge, die in dieser Arbeit gewonnenen Ergebnisse in eine zukünftige Verschleißtheorie einfließen zu lassen. / This work examines the behaviour of steel cords under tensile loading and bending by the Method of Finite Elements (FEM). Beginning with a simple strand consisting of one centre and six outer wires a detailed analysis of the stress distribution is made for pure strain as well as for bending over a sheave. Based on this examination the model is extended step by step towards complex cord constructions. The investigation of cables embedded in an elastomer follows, especially the influence of a tooth profile of timing belts on the load inside the cable. Furthermore, a possible validation method for the model is presented. In conclusion directives are given for steel cord design in timing belts and suggestions are made to use the results in a wear model in the future.
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Modellierung und Simulation der Beanspruchung von Zugsträngen aus Stahllitze für ZahnriemenWitt, Robert 16 November 2007 (has links)
In dieser Arbeit wird das Verhalten von gewickelten Seilen aus Stahllitze unter Zug- und Biegebelastung mit Hilfe der Methode der Finiten Elemente untersucht. Ausgehend von dem Modell einer einfachen Litze mit einem Kern- und sechs Außendrähten erfolgt eine ausführliche Analyse der Spannungsverteilung sowohl bei rein axialer Belastung als auch bei Biegung über eine Seilscheibe. Darauf aufbauend wird das Simulationsmodell schrittweise um komplexere Seilkonstruktionen bis hin zu zweifachen Verseilungen erweitert. Daran schließt sich die Untersuchung der inneren Belastungen bei Einbettung in ein Elastomer an, wie dies bei Zugsträngen in Riemengetrieben der Fall ist, sowie der spezifischen Einflüsse der Verzahnung auf die Seilbeanspruchung bei Zahnriemengetrieben. Des weiteren wird eine Möglichkeit der Validierung der Modelle vorgestellt, die ein experimentelles Ermitteln der Relativverschiebungen der Filamente auch im Inneren des Seils zulässt. Abschließend folgen Richtlinien zur Auslegung von Zugsträngen in Zahnriemen sowie Vorschläge, die in dieser Arbeit gewonnenen Ergebnisse in eine zukünftige Verschleißtheorie einfließen zu lassen. / This work examines the behaviour of steel cords under tensile loading and bending by the Method of Finite Elements (FEM). Beginning with a simple strand consisting of one centre and six outer wires a detailed analysis of the stress distribution is made for pure strain as well as for bending over a sheave. Based on this examination the model is extended step by step towards complex cord constructions. The investigation of cables embedded in an elastomer follows, especially the influence of a tooth profile of timing belts on the load inside the cable. Furthermore, a possible validation method for the model is presented. In conclusion directives are given for steel cord design in timing belts and suggestions are made to use the results in a wear model in the future.
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