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  UNIVERZITET U TUZLI – MAŠINSKIFAKULTET 

Rotary engine-Wankel engine

Polo!ni engleki "e#ik II

Ime i prezime:

Ner$in Ma%$&to!i' 

Brojindeksa: I – ()*+,Odsjek: ENER.ETSK/ MAŠINSTV/Datum: )*010),10

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1.ENGLISH VERSION

1.1 Basics

 The Wankel engine is a type of internal combustion engine usingan eccentric rotary design to convert pressure into rotating motion. Overthe commonly used reciprocating piston designs, the Wankel engine deliversadvantages of: simplicity, compactness, high revolutions per minute, and ahigh power-to-weight ratio. The engine is commonly referred to as a rotaryengine, although this name applies also to other completely dierentdesigns. ll parts rotate moving in one direction as opposed to thecommon piston engine which has pistons violently changing direction. The four-stroke cycle occurs in a moving combustion chamber between theinside of an oval shaped housing, and a rotor that is similar in shape toa !euleau" triangle with sides that are somewhat #atter.

 The concept of the engine was conceived by $erman engineer %eli"Wankel. Wankel received his &rst patent for the engine in '()(, begandevelopment in the early '(*+s at , and completed a workingprototype in '(*/.

 These advantages have given rotary engine applications in a variety ofvehicles and devices, including: automobiles, motorcycles, racing cars, aircraft, snowmobiles, chain saws, and au"iliary power units.

1.2 Design

0n the Wankel engine, the four strokes of a Otto cycle piston engine occurin the space between a rotor and the inside of a housing. The theoreticalshape of the rotor between the &"ed corners is the result of a minimi1ationof the volume of the geometric combustion chamber and a ma"imi1ation

of the compression ratio. The central drive shaft, called the 2eccentricshaft2 or 23-shaft2, passes through the center of the rotor and is supportedby &"ed bearings. The rotors both rotate around the eccentrics andmake orbital revolutions around the eccentric shaft. eals at the corners of the rotor seal against the periphery of the housing, dividing it into threemoving combustion chambers. The rotation of each rotor on its own a"is iscaused and controlled by a pair of synchroni1ing gears. The power outputof the engine is not transmitted through the synchroni1ing gears. The forceof gas pressure on the rotor 4to a &rst appro"imation5 goes directly to the

center of the eccentric, part of the output shaft.

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1.3 Materials

nlike a piston engine, where the cylinder is cooled by the incomingcharge after being heated by combustion, Wankel rotor housings areconstantly heated on one side and cooled on the other, leading to highlocal temperatures and une6ual thermal e"pansion. While this places highdemands on the materials used, the simplicity of the Wankel makes iteasier to use alternative materials, such as e"otic alloys and ceramics.

With water cooling in a radial or a"ial #ow direction, with the hot waterfrom the hot bow heating the cold bow, the thermal e"pansion remainstolerable.

  1.4 Adentages

7rime advantages of the Wankel engine are:

• far higher power to weight ratio than a piston engine

• 0t is appro"imately one third of the weight of a piston engine of

e6uivalent power output

• 0t is appro"imately one third of the si1e of a piston engine of

e6uivalent power output

• o reciprocating parts

•

ble to reach higher revolutions per minute than a piston engine

• Operates with almost no vibration

• 8heaper to mass-produce as the engine contains fewer parts

  1.! Disadentages

• !otor sealing.• low combustion

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• 9ad fuel economy .• 7oor emissions

2.BOSNIAN VERSION2.1 Osn"e

Wankel motor e tip motora koi koristi ekscentri;ni di1an 1a pretvorbupritiska u rotaciono kretane. <a ra1liku od obi;no kori=tenog di1ana saklipovima koi se kre>u nai1meni;no, Wankel motor ima slede>e prednosti: ednostavnost, kompaktnost,veliki bro obrtaa u minuti, i visok omersnage i te?ine. 7od ovim motorom se obi;no misli na rotaciski motor iakopod ovim imenom imamo mnogo motora potpuno ra1li;itih di1ana.vi dielovi rotirau kre>u>i se u ednom smeru =to e suprotno obi;nomklipnom motoru gde klipovi nasilno mienau smer kretana. @etverotaktniproces se obavla u komori 1a sagorievane koa se kre>e i1meAuunutra=nosti ku>i=ta ovalnog oblika, i rotora koi ima oblik sli;an !euleau"-ovom trouglu ali su mu strane ne=to ravnie.Boncept motora e smi=len od nema;kog in?enera %eliksaWankela.Wankel e prvi patent primio '()(. godine,a negov ra1vo e1apo;eo '(*+. god. na i 1avr=io prvi prototip '(*/. god.7rednosti ovog motora omugu>ile su negovu primenu u ra1nim vo1ilima iureAaima uklu;uu>i: automobile, motocikle, trkau>e automobile, avione,motorne sanke, motorne pile, i sli;no.

2.2 Di#a$n

Wankel motoru, C takta Otto ciklusa klipnog motora se de=avau uprostoru i1meAu unutra=nosti ku>i=ta i rotora. Teoretski , oblik rotorai1meAu &ksiranih kraeva 1a re1ultat ima minimi1irane 1apremine komore1a sagorievane i maksimi1irane kompresionog odnosa.8entralno pogonsko vratilo,koe se 1ove ekscentri;no vratilo ili 3vratilo,prola1i kro1 centar rotora i nala1i se na &ksiranim le?aevima. Obarotora rotirau oko ekscentra i prave kru?ne obrtae oko ekscentri;nogvratila. <aptiva;i na kraevima rotora 1aptivau i1meAu ku>i=ta i rotorastvarau>i tako D komore 1a sagorievane. !otacia svakog od tri rotora eu1rokovana i kotrolirana od strane para sinhroni1ovanih 1up;anika. 01la1na

D

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snaga motora ne prenosi se preko sinhroni1iranih 1up;anika. ila pritiskana rotor ide direknto na centar ekscentra, diela i1la1nog vratila.

2.3 Materi$ali

<a ra1liku od klipnog motora, gde e cilindar hlaAen ula1nim punenemnakon =to se 1agrie usled sagorievana, ku>i=te rotora Wankel motora sekontantno grie na edno strani i hladi na drugo strani, vode>i do visokihlokalnih temperatura i neuedna;enog rasporeda temperatura. <bog ovogaimamo visoke 1ahteve 1a i1bor materiala ali sa druge strane Wankelmotor nam 1bog svoe ednostavnosti dopu=ta kori=tene alternativnihmateriala kao =to su eg1oti;ne legure i keramika. a vodenim hlaAenem uradialnom ili aksialnom smeru,sa vrelom vodom i1 vrelog luka griemohladni luk,raspored temperatura ostae tolerantan.

2.4 %redn"sti

$lavne prednosti Wankel motora su :

• Enogo ve>i omer snage i te?ine nego kod klipnog motora• On e te?ak otprilike ednu tre>inu te?ine klipnog motora iste snage• egove dimen1ie su edna tre>ina dimen1ia klipnog motora iste

snage• 9e1 dielova 1a nai1meni;no kretane

• Eo?e dosti>i ve>i bro obrtaa u minuti od klipnog motora• !adi gotovo be1 vibracia•  eftinii 1a masovnu proi1vodnu er motor ima mane dielova

2.! Ned"statci

• <aptivane rotora• poro sagorievane• laba ekonomi;nost goriva• Felike emisie

C