Analiza dotrajalosti bregaste osovine četverotaktnog motora s unutarnjim izgaranjem

master's thesis

• Title (english): Failure of camshaft of four-stroke internal combustion engine
• Author: Nada Šućur
• Mentor: Suzana Jakovljević (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2015-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U radu je analizirana dotrajalost i oštećenje bregaste osovine četverotaktnog motora s unutarnjim izgaranjem, koji su doveli do nepravilnog rada motora. Bregasta osovina je jedan od najvažnijih dijelova motora, a naziv joj dolazi od brijegova, uzduž cijele površine, koji otvaraju i zatvaraju ventile. Trajanje otvorenosti, brzine otvaranja i zatvaranja, te hod ventila određeni su oblikom brijegova. U modernim konstrukcijama motora, bregasta osovina je najčešće smještena u glavi motora, iznad cilindara. Pogon bregaste osovine uglavnom se prenosi zupčastim remenom. Nepravilan rad bregaste osovine može dovesti do ozbiljnih kvarova i nepravilnog rada motora, što je bio slučaj na konkretnom primjeru koji se analizira. Analizom elemenata i oštećenja tribosustava, pokušat će se dati odgovor na pitanje što je dovelo do oštećenja bregaste osovine (brijegovi i rukavci ležajeva), te koji mehanizam trošenja je prisutan. U sklopu eksperimentalnog dijela ispitana je tvrdoća pripremljenih uzoraka, te je provedena elektronska mikroskopija i analiza kemijskog sastava uzoraka.

Abstract (english)

The main theme of this research is damage and failure of camshaft of four-stroke internal combustion engine. The damage of camshaft has caused problems that occurred while engine was working. Camshaft is one of the most important parts of the engine and the name comes from “cam” or “cams”, which are designed to open and close valves. The shape of cams determine speed and duration for opening and closing valves. In modern engine designs camshaft is placed in head of engine, above the cylinders. The propulsion of camshaft is transferred with timing belt. Failure of camshaft can cause malfunction and damage of engine, which was exactly case in analysed example. The main problem is to detect what has caused the damage of camshaft (triboelements) and which wear mechanisam was present (in this tribosystem). Hardness examination, SEM analysis of the wear marks and chemical composition analysis were performed within experimental part.

• Keywords: bregasta osovina; četverotaktni motor; brijegovi; glava motora; tribosustav; mehanizmi trošenja
• Keywords (english): camshaft; four-stroke engine; cams; head of engine; tribosystem; wear mechanism
• Language: croatian
• URN:NBN: urn:nbn:hr:235:699199
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 13:30:17