subclass_of two-stroke engine
Pneumatic cylinder ( s ) ( sometimes known as air cylinders ) are mechanical devices which use the ___MASK80___ of compressed ___MASK5___ to produce a force in a reciprocating linear ___MASK83___ . ___MASK14___ ( Fast ___MASK47___ User ___MASK50___ Designer ) is a graphical editor and GUI builder that is used to produce FLTK source code . ___MASK14___ edits and saves its state in text . fl files , which can be edited in a text editor for finer control over display and ___MASK55___ . A two - ___MASK58___ , or two - ___MASK73___ , engine is a type of internal ___MASK96___ which completes a power ___MASK73___ with two strokes ( up and down movements ) of the piston during only one crankshaft revolution . This is in contrast to a `` four - ___MASK58___ engine '' , which requires four strokes of the piston to complete a power ___MASK73___ . In a two - ___MASK58___ engine , the end of the combustion ___MASK58___ and the beginning of the compression ___MASK58___ happen simultaneously , with the intake and exhaust ( or scavenging ) functions occurring at the same time . Two - ___MASK58___ engines often have a high power - to - weight ratio , usually in a narrow range of rotational speeds called the `` power band '' . Compared to four - ___MASK58___ engines , two - ___MASK58___ engines have a greatly reduced number of moving parts , and so can be more compact and significantly lighter . The first commercial two - ___MASK58___ engine involving in - cylinder compression is attributed to Scottish engineer Dugald Clerk , who patented his design in 1881 . However , unlike most later two - ___MASK58___ engines , his had a separate charging cylinder . The crankcase - scavenged engine , employing the area below the piston as a charging ___MASK60___ , is generally credited to Englishman Joseph Day . The first truly practical two - ___MASK58___ engine is attributed to Yorkshireman Alfred Angas Scott , who started producing twin - cylinder water - cooled motorcycles in 1908 . Gasoline ( spark ignition ) versions are particularly useful in lightweight or portable applications such as chainsaws and motorcycles . Despite that , they are also used in diesel compression ignition engines operating in large , weight - insensitive applications , such as marine propulsion , railway locomotives and electricity generation . In a two - ___MASK58___ engine , the heat transfer from the engine to the cooling system is less than in a four - ___MASK58___ , which means that two - ___MASK58___ engines can be more efficient . However , crankcase - compression two - ___MASK58___ engines , such as the common small gasoline - powered engines , create more exhaust emissions than four - ___MASK58___ engines because their petroil lubrication mixture is also burned in the engine , due to the engine ' s total - loss oiling system . A four - ___MASK58___ engine ( also known as four ___MASK73___ ) is an internal combustion ( IC ) engine in which the piston completes four separate strokes while turning a crankshaft . A ___MASK58___ refers to the full travel of the piston along the cylinder , in either direction . The four separate strokes are termed : In a ___MASK32___ , the crankpins , also known as crank journals are the journals of the big end bearings , at the ends of the connecting rods opposite to the pistons . In a piston ___MASK33___ , a piston ___MASK44___ joins a piston to the crosshead and thus to the connecting ___MASK44___ that drives the crankshaft or ( for steam locomotives ) the driving wheels . A ___MASK5___ compressor is a mechanical device that increases the pressure of a ___MASK5___ by reducing its volume . An air compressor is a specific type of ___MASK5___ compressor . A piston ___MASK10___ is a ___MASK26___ ___MASK10___ that fits into a groove on the outer diameter of a piston in a ___MASK32___ such as an internal combustion engine or steam engine . A ___MASK32___ , also often known as a piston engine , is a heat engine ( usually , although there are also pneumatic and hydraulic reciprocating engines ) that uses one or more reciprocating pistons to convert pressure into a rotating motion . This article describes the common features of all types . The main types are : the internal combustion engine , used extensively in motor vehicles ; the steam engine , the mainstay of the Industrial Revolution ; and the niche application Stirling engine . Internal Combustion engines are further classified in two ways : either a spark - ignition ( SI ) engine , where the spark plug initiates the combustion ; or a compression - ignition ( CI ) engine , where the air within the cylinder is compressed , thus heating it , so that the heated air ignites fuel that is injected then or earlier . ___MASK5___ is one of the four fundamental states of matter ( the others ___MASK79___ ___MASK18___ , liquid , and plasma ). A pure gas may be made up of individual atoms ( e . g . a noble gas like neon ), elemental molecules made from one type of atom ( e . g . oxygen ), or compound molecules made from a variety of atoms ( e . g . carbon dioxide ). A gas mixture would contain a variety of pure gases much like the air . What distinguishes a gas from liquids and solids is the vast separation of the individual gas particles . This separation usually makes a colorless gas invisible to the human observer . The interaction of gas particles in the presence of electric and gravitational fields are considered negligible as indicated by the constant velocity vectors in the image . One type of commonly known gas is steam . A crankshaft  related to " crank " is a mechanical ___MASK29___ able to perform a conversion between reciprocating ___MASK83___ and rotational ___MASK83___ . In a ___MASK32___ , it translates reciprocating ___MASK83___ of the piston into rotational ___MASK83___ ; whereas in a reciprocating compressor , it converts the rotational ___MASK83___ into reciprocating ___MASK83___ . In order to do the conversion between two motions , the crankshaft has " crank throws " or " crankpins ", additional bearing surfaces whose axis is offset from that of the crank , to which the " big ends " of the connecting rods from each cylinder attach . A ___MASK60___ is a device that moves fluids ( liquids or gases ), or sometimes slurries , by mechanical action . Pumps can be classified into three major groups according to the method they use to move the fluid : " direct lift ", " displacement ", and " gravity " pumps . In a reciprocating piston ___MASK33___ , the connecting ___MASK44___ or conrod connects the piston to the crank or crankshaft . Together with the crank , they form a simple mechanism that converts reciprocating ___MASK83___ into rotating ___MASK83___ . A piston is a component of reciprocating engines , reciprocating pumps , ___MASK5___ compressors and pneumatic cylinders , among other similar mechanisms . It is the moving component that is contained by a cylinder and is made ___MASK5___ - tight by piston rings . In an engine , its purpose is to ___MASK86___ force from expanding ___MASK5___ in the cylinder to the crankshaft via a piston rod and / or connecting rod . In a ___MASK60___ , the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder . In some engines , the piston also acts as a valve by covering and uncovering ports in the cylinder ___MASK87___ . The petrol enters inside the cylinder and the piston moves upwards and the spark plug produces spark and the petrol is set on fire and it produces an energy that pushes the piston downwards . Reciprocating ___MASK83___ , also called reciprocation , is a repetitive up - and - down or back - and - forth linear ___MASK83___ . It is found in a wide range of mechanisms , including reciprocating engines and pumps . The two opposite motions that comprise a single reciprocation cycle are called strokes . A ___MASK3___ is a device that regulates , directs or controls the flow of a fluid ( gases , liquids , fluidized solids , or slurries ) by ___MASK90___ , closing , or partially obstructing various passageways . Valves are technically fittings , but are usually discussed as a separate category . In an open ___MASK3___ , fluid flows in a direction from higher pressure to lower pressure . The word is derived from the Latin " valva ", the moving part of a door , in turn from " volvere ", to turn , roll . A reciprocating compressor or piston compressor is a positive - displacement compressor that uses pistons driven by a crankshaft to deliver gases at high ___MASK45___ .