Ispitivanje utjecaja temperature na dinamiku trošenja tarnog materijala suhe spojke

master's thesis

• Title (english): Characterization of influence of temperature on the dynamics of wear of an automotive dry friction material
• Author: Alen Miklik
• Mentor: Matija Hoić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2020-01-24, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)

Abstract

Suha tarna spojka je važan mehanički sklop koji se široko koristi u automobilskoj primjeni. Spojke se koriste za upravljanje prijenosa okretnog momenta između motora s unutarnjim izgaranjem i transmisije. To se postiže isključivanjem i uključivanjem spojke koja predstavlja razdvojivu vezu između koljenastog vratila i ulaznog vratila transmisije. Toplina generirana trenjem klizanja nastaje prilikom uključivanja spojke. Kao rezultat tome temperatura dodirnih površina se brzo povećava zbog razlike u brzini vrtnje između pogonskih i gonjenih elemenata spojke. Zbog sve većih energijskih zahtjeva u pogledu okretnog momenta i temperature koji se postavljaju na sustave spojke, postalo je potrebno steći veću kontrolu nad njihovim tribološkim karakteristikama (koeficijent trenja i stupanj trošenja) kako bi se poboljšao razvoj učinkovitijih spojki. U ovom radu provedeno je ispitivanje utjecaja temperature na dinamiku trošenja tarnog materijala automobilske suhe tarne spojke. Kroz teorijska poglavalja dan je opći pregled automobilskih suhih spojki i pripadajućih tarnih materijala. Također su objašnjene vrste mehanizama trošenja koji se javljaju tijekom rada suhe tarne spojke, kao i utjecaj temperature na trenje i trošenje tarnog materijala. Ispitivanja su provedena na tribometru sa CNC karakteristikama koji koristi čitave tarne ploče kao ispitne uzorke i koji omogućava precizno upravljanje radnim parametrima kao što su normalna sila, brzina klizanja i temperatura. Provedena su dva seta ispitivanja: u jednom je radna temperatura mijenjana u očekivanom rasponu radnih temperatura spojke (do 240°C), dok je u drugom radna temperatura postepeno povećavana do pojave efekta temperaturnog zamora materijala (eng. fading). Na kraju, rezultati provedenih ispitivanja i njihova interpretacija zaključuju rad.

Abstract (english)

Dry friction clutch is an essential mechanical assembly which is widely used in the automotive application. Clutches are used to control the torque flow between internal combustion engine and transmission. This is achieved by separating and coupling the clutch which represent a detachable link between crankshaft and transmission input shaft. Frictional heat is generated when the clutch starts to engage. As a result of this operation the contact surfaces temperature is increased rapidly due to the difference in speed between the driving and driven parts of the clutch. Due to the increasing energy demands (torque and temperature) over the clutch systems, it has become necessary to gain more control over their tribological characteristics (friction coefficient and wear rate) to improve the development of more efficient clutches. In this Thesis characterization of influence of temperature on the dynamics of wear of an automotive dry friction material is conducted. Through the theoretical chapters, a general overview of automotive dry clutches and associated friction materials is given. Types of wear mechanisms that occur during the operation of a dry friction clutch as well as the temperature influence on friction and wear of friction material are also explained. The experiments were performed on a CNC disc-on-disc tribometer that allows precise control of operating parameters such as normal force, slip speed, and temperature. Two sets of experiments were performed: in one the operating temperature was changed within the expected range of clutch operating temperatures (to 240°C), while in the other, the operating temperature was gradually increased until the effect of the temperature fatigue of the material known as fading occurred. At the end, the results of conducted experiments and their interpretation conclude the thesis.

• Keywords: automobilska suha spojka; disc-on-disc tribometar; tarni materijal; temperatura; trenje; trošenje; fading
• Keywords (english): automotive dry clutch; disc-on-disc tribometer; friction material; temperature; friction; wear; fading
• Language: croatian
• URN:NBN: urn:nbn:hr:235:120257
• 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; Embargo expiration date: 2022-01-16
• Created on: 2020-01-15 21:25:32