page_title: Crankcase
section_title: Four-stroke engines
hierarchical_section_title: Crankcase / Four-stroke engines
caption_attribution_description: Català&#x202f;&#x3a;&#32; Motor de 4 tampon: Admisió. Compresió. Explosió. Escapament.Čeština&#x202f;&#x3a;&#32; Funkce čtyřdobého motoru: Sání - Sací ventil je otevřený a píst pohybem dolů nasává směs. Komprese - Oba ventily jsou uzavřené. Píst pohybem vzhůru zmenšuje objem směsi, tím stoupá její tlak a teplota. Těsně před horní úvratí je směs zapálena elektrickou jiskrou. Expanze - Oba ventily jsou uzavřené. Směs paliva a vzduchu zapálená elektrickou jiskrou shoří. V pracovním prostoru válce se prudce zvýší teplota i tlak vzniklých plynů. Ty expandují a během pohybu pístu směrem dolů konají práci. Výfuk - Píst se pohybuje směrem k HÚ (Horní úvrať). Výfukový ventil je otevřený. Spaliny z pracovního prostoru válce jsou vytlačovány do výfukového potrubí.Deutsch&#x3a;&#32; Animation eines Viertakt-Verbrennungsmotors, Ottomotor: Ansaugen - Der Kolben saugt das Benzin-Luft-Gemisch vom Vergaser in den Zylinder. Verdichten - Der Kolben presst das Gasgemisch zusammen. Arbeiten - Der Funke einer Zündkerze entzündet das Gasgemisch, es verbrennt explosionsartig. Der Kolben wird nach unten gedrückt, das Gas verrichtet am Kolben Arbeit. Ausstoßen - Der Kolben drückt die Verbrennungsgase aus dem Zylinder.English&#x3a;&#32; Animated scheme of a four stroke internal combustion engine, Otto principle: Intake stroke - Air and vaporised fuel are drawn in. Compression stroke - Fuel vapor and air are compressed and ignited. Power stroke - Fuel combusts and piston is pushed downwards. Exhaust stroke - Exhaust is driven out.Español&#x202f;&#x3a;&#32; Motor alternante: Tiempo de admisión - El aire y el combustible vaporizado entran. Tiempo de compresión - El vapor de combustible y el aire son comprimidos y encendidos. Tiempo de combustión - El combustible se inflama y el pistón es empujado hacia abajo. Tiempo de escape - Los gases de escape se conducen hacia afuera.Français&#x202f;&#x3a;&#32; Moteur à quatre temps: L'essence, mélangée à de l'air, fait son entrée. La vapeur d'essence et l'air sont compressés par le piston. La bougie émet une étincelle - la combustion (explosion) produit une forte poussée qui entraîne le piston vers le bas. Sortie des résidus de combustion vers le silencieux.Hrvatski&#x202f;&#x3a;&#32; Takt (usis) - usis svježeg zraka (diesel) ili usis smjese goriva i zraka (benzin). Takt (kompresija) - kompresija radnog medija u cilindru. Takt (izgaranje) - gorivo se ubrizguje u cilindar i dolazi do samozapaljenja (diesel) ili gorivu smjesu pali svjećica (benzin). Takt (ispuh) - izgorena smjesa se istiskuje iz cilindra u ispušne kanale.Italiano&#x202f;&#x3a;&#32; Ciclo Otto: Aspirazione - L'aria e il combustibile vaporizzato entrano nel cilindro. Compressione - Il vapore del combustibile e l'aria vengono compressi e scocca la scintilla. Scoppio - Il combustibile si infiamma e il pistone viene spinto verso il basso. Scarico - Il gas di scarico viene espuslo.Nederlands&#x3a;&#32; Geanimeerd schema van een viertakt verbrandingsmotor, Otto-principe: Inlaat - Lucht en verdampte brandstof worden aangezogen. Compressie - Brandstofdamp en lucht worden samengeperst en ontstoken. Expansie - Brandstofverbranding en zuiger worden naar beneden geduwd. Uitlaat - Uitlaat wordt verdreven.Português&#x202f;&#x3a;&#32; Ciclo Otto (Motor de Explosão a 4 Tempos): Tempo: Admissão - Entra no cilindro uma mistura de ar e combustível vaporizado. Tempo: Compressão - A mistura de ar e combustível é comprimida e no fim dá-se a ignição de uma vela. Tempo: Expansão - Depois da ignição da vela, a mistura gasosa sofre uma forte dilatação, empurrando o pistão. Tempo: Escape - A mistura gasosa resultante da explosão, sai do cilindro para o exterior.Türkçe&#x3a;&#32; Emme zamanı - Hava ve yakıt buharı içeri emilir. Sıkıştırma zamanı - Yakıt buharı ve hava sıkıştırılır ve tutuşturulur. Yanma zamanı - Yakıt yanar ve piston aşağı itilir. Egsoz zamanı - Yanmış gazlar dışarı atılır.Русский&#x202f;&#x3a;&#32; Цикл Отто работы 4-тактного двигателя внутреннего сгорания: Такт впуска — Впускается топливо-воздушная смесь. Такт сжатия — Смесь сжимается и поджигается. Такт расширения — Смесь сгорает и толкает поршень вниз. Такт выпуска — Продукты горения выпускаются.日本語&#xff1a; 吸入行程: ピストンが下がり混合気（燃料を含んだ空気）をシリンダ内に吸い込む行程。 圧縮行程: ピストンが上死点まで上がり混合気を圧縮する行程。 爆発行程: 着火された混合気の爆発によりピストンが下死点まで押し下げられる行程。 排気行程: 慣性によりピストンが上がり燃焼ガスをシリンダ外に押し出す行程。
context_page_description: A crankcase is the housing for the crankshaft in a reciprocating internal combustion engine. In most modern engines, the crankcase is integrated into the engine block.
  Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/air mixture passing through the crankcase before entering the cylinder. This design of the engine does not include an oil sump in the crankcase.
  Four-stroke engines typically have an oil sump at the bottom of the crankcase and the majority of the engine's oil is held within the crankcase. The fuel/air mixture does not pass through the crankcase in a four-stroke engine, however a small amount of exhaust gasses often enter as "blow-by" from the combustion chamber.
  The crankcase often forms the lower half of the main bearing journals, although in some engines the crankcase completely surrounds the main bearing journals.
  An open-crank engine has no crankcase. This design was used in early engines and remains in use in some large diesel engines, such as used in ships.
context_section_description: Most four-stroke engines use a crankcase that contains the engine's lubricating oil, as either a wet sump system or the less common dry sump system. Unlike a two-stroke (crankcase-compression) engine, the crankcase in a four-stroke engine is not used for the fuel/air mixture.
caption: Four-stroke engine- oil shown in yellow at the bottom