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Five-stroke Engine
The five-stroke engine is a compound internal combustion engine patented by Gerhard Schmitz in 2000. Concept The goal of the five-stroke engine is to achieve higher efficiency than a four-stroke engine. In order to increase efficiency, a secondary cylinder is added as an expansion processor to extract more energy from the fuel. Schmitz's concept engine uses two primary "high pressure" cylinders with standard four-stroke power cycles, in addition to a larger secondary "low pressure" expansion cylinder. The hot exhaust gas from the two primary cylinders is fed into the secondary cylinder, halving the volume of gases in the primary cylinders after combustion. This concept is similar to that of compound steam engines, which expand steam in high pressure cylinders before exhausting it into low-pressure cylinders in order to extract more energy from the steam. In 1879, Nicolaus Otto built a 5-stroke engine which was commercially produced, but suffered from poor performance. Two Span ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compound Internal Combustion Engine
A compound internal combustion engine is a type of internal combustion engine (ICE) where gasses of combustion are expanded in two or more stages. A typical arrangement for a compound ICE is that the fuel/air is first combusted and expanded in one of two alternating 4-stroke combustion high-pressure (HP) cylinders, then having given up heat and losing pressure, it exhausts directly into a larger-volume low-pressure (LP) cylinder, where it is re-expanded extracting more work from it. The crankshaft is arranged so the two high-pressure cylinders have synchronized reciprocating motion, while the low-pressure cylinder throw is positioned at a 180-degree phase difference from the high-pressure throws causing opposing reciprocating motion between the high-pressure and low-pressure cylinders. History Compound ICEs have been around for nearly as long as standard ICEs with the first patent being issued to Nicolaus Otto's Deutz company in 1879. This design was likely created by then Deu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Camshaft
An overhead camshaft (OHC) engine is a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion chamber in the engine block. ''Single overhead camshaft'' (SOHC) engines have one camshaft per cylinder bank, bank of cylinders. ''Dual overhead camshaft'' (DOHC, also known as "twin-cam") engines have two camshafts per bank. The first production car to use a DOHC engine was built in 1910. Use of DOHC engines slowly increased from the 1940s, leading to many automobiles by the early 2000s using DOHC engines. Design In an OHC engine, the camshaft is located at the top of the engine, above the combustion chamber. This contrasts the earlier overhead valve engine (OHV) and flathead engine configurations, where the camshaft is located down in the engine block. The valves in both OHC and OHV engines are located above the combustion chamber; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atkinson Cycle
The Atkinson-cycle engine is a type of internal combustion engine invented by James Atkinson (inventor), James Atkinson in 1882. The Atkinson cycle is designed to provide Energy conversion efficiency, efficiency at the expense of power density. A variation of this approach is used in some modern automobile engines. While originally seen exclusively in hybrid electric applications such as the earlier-generation Toyota Prius, later hybrids and some non-hybrid vehicles now feature engines with variable valve timing, which can run in the Atkinson cycle as a part-time operating regimen, giving good economy while running in Atkinson cycle, and conventional power density when running as a conventional, Otto cycle engine. Design Atkinson produced three different designs that had a short compression stroke and a longer expansion stroke. The first Atkinson-cycle engine, the ''differential engine'', used opposed pistons. The second and best-known design was the ''cycle engine'', which used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermodynamic Cycle
A thermodynamic cycle consists of linked sequences of thermodynamic processes that involve heat transfer, transfer of heat and work (physics), work into and out of the system, while varying pressure, temperature, and other state variables within the system, and that eventually returns the thermodynamic system, system to its initial state. In the process of passing through a cycle, the working fluid (system) may convert heat from a warm source into useful work, and dispose of the remaining heat to a cold sink, thereby acting as a heat engine. Conversely, the cycle may be reversed and use work to move heat from a cold source and transfer it to a warm sink thereby acting as a heat pump. If at every point in the cycle the system is in thermodynamic equilibrium, the cycle is reversible. Whether carried out reversible or irreversibly, the net entropy change of the system is zero, as entropy is a state function. During a closed cycle, the system returns to its original thermodynamic stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Six-stroke Engine
A six-stroke engine is one of several alternative internal combustion engine designs that attempt to improve on traditional two-stroke and four-stroke engines. Claimed advantages may include increased fuel efficiency, reduced mechanical complexity, and/or reduced emissions. These engines can be divided into two groups based on the number of pistons that contribute to the six strokes. In the single-piston designs, the engine captures the heat lost from the four-stroke Otto cycle or Diesel cycle and uses it to drive an additional power and exhaust stroke of the piston in the same cylinder in an attempt to improve fuel efficiency and assist with engine cooling. The pistons in this type of six-stroke engine go up and down three times for each injection of fuel. These designs use either steam or air as the working fluid for the additional power stroke. The designs in which the six strokes are determined by the interactions between two pistons are more diverse. The pistons may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-stroke Engine
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed: #Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing a partial vacuum (negative pressure) in the cylinder through its downward motion. #Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are closed during this stage. #Combustion: Also known as power or ignition. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-stroke Engine
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which requires four strokes of the piston in two crankshaft revolutions to complete a power cycle. During the stroke from bottom dead center to top dead center, the end of the exhaust/intake (or Scavenging (automotive), scavenging) is completed along with the compression of the mixture. The second stroke encompasses the combustion of the mixture, the expansion of the burnt mixture and, near bottom dead center, the beginning of the scavenging flows. Two-stroke engines often have a higher power-to-weight ratio than a four-stroke engine, since their power stroke occurs twice as often. Two-stroke engines can also have fewer moving parts, and thus be cheaper to manufacture and weigh less. In countries and regions with stringe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroke (engine)
In the context of an internal combustion engine, the term stroke has the following related meanings: * A phase of the engine's cycle (e.g. compression stroke, exhaust stroke), during which the piston travels from top to bottom or vice versa. * The type of power cycle used by a piston engine (e.g. two-stroke engine, four-stroke engine). * "Stroke length", the distance travelled by the piston during each cycle. The stroke length, along with bore diameter, determines the engine's displacement. Phases in the power cycle Commonly used engine phases or strokes (i.e. those used in a four-stroke engine) are described below. Other types of engines can have very different phases. Induction-intake stroke The induction stroke is the first phase in a four-stroke (e.g. Otto cycle or Diesel cycle) engine. It involves the downward movement of the piston, creating a partial vacuum that draws an air-fuel mixture (or air alone, in the case of a direct injection engine) into the combustion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stirling Engine
A Stirling engine is a heat engine that is operated by the cyclic expansion and contraction of air or other gas (the ''working fluid'') by exposing it to different temperatures, resulting in a net conversion of heat energy to mechanical Work (physics), work. More specifically, the Stirling engine is a closed-cycle regenerative heat engine, with a permanent gaseous working fluid. ''Closed-cycle'', in this context, means a thermodynamic system in which the working fluid is permanently contained within the system. ''Regenerative'' describes the use of a specific type of internal heat exchanger and thermal store, known as the Regenerative heat exchanger, ''regenerator''. Strictly speaking, the inclusion of the regenerator is what differentiates a Stirling engine from other closed-cycle hot air engines. In the Stirling engine, a working fluid (e.g. air) is heated by energy supplied from outside the engine's interior space (cylinder). As the fluid expands, mechanical work is extrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pistonless Rotary Engine
A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does. Designs vary widely but typically involve one or more wikt:rotor, rotors, sometimes called rotary pistons, as described in QT-Wankel: Two Concepts 100 Years Apart. Although many different designs have been constructed, only the Wankel engine has achieved widespread adoption. The term rotary combustion engine has been used as a name for these engines to distinguish them from early (generally up to the early 1920s) aircraft engines and motorcycle engines also known as ''rotary engines''. However, both continue to be called ''rotary engines'' and only the context determines which type is meant, whereas the "pistonless" prefix is less ambiguous. Pistonless rotary engines A pistonless rotary engine replaces the linear reciprocating motion of a piston with more complex compression/expansion motions with the objective of improving some aspect of the engine's op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbocharger
In an internal combustion engine, a turbocharger (also known as a turbo or a turbosupercharger) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake air, forcing more air into the engine in order to produce more power for a given displacement. Turbochargers are distinguished from superchargers in that a turbocharger is powered by the kinetic energy of the exhaust gases, whereas a is mechanically powered (usually by a belt from the engine's crankshaft). However, up until the mid-20th century, a turbocharger was called a "turbosupercharger" and was considered a type of supercharger. History Prior to the inv ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
