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Desmodromic
:''In general mechanical terms, the word ''desmodromic'' is used to refer to mechanisms that have different controls for their actuation in different directions.'' A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system, rather than by a more conventional spring. The valves in a typical four-stroke engine allow the air/fuel mixture into the cylinder at the beginning of the cycle and exhaust spent gases at the end of the cycle. In a conventional four-stroke engine, valves are opened by a cam and closed by return spring. An engine using desmodromic valves has two cams and two actuators, each for positive opening and closing without a return spring. Etymology The word comes from the Greek words ''desmos'' (, translated as "bond" or "knot") and ''dromos'' (, "track" or "way"). This denotes the major characteristic of the valves being continuously "bound" to the camshaft. Idea The common valve spring system is satisfactory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desmo Photo
:''In general mechanical terms, the word ''desmodromic'' is used to refer to mechanisms that have different controls for their actuation in different directions.'' A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system, rather than by a more conventional spring. The valves in a typical four-stroke engine allow the air/fuel mixture into the cylinder at the beginning of the cycle and exhaust spent gases at the end of the cycle. In a conventional four-stroke engine, valves are opened by a cam and closed by return spring. An engine using desmodromic valves has two cams and two actuators, each for positive opening and closing without a return spring. Etymology The word comes from the Greek words ''desmos'' (, translated as "bond" or "knot") and ''dromos'' (, "track" or "way"). This denotes the major characteristic of the valves being continuously "bound" to the camshaft. Idea The common valve spring system is satisfactory f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducati Motor Holding
Ducati Motor Holding S.p.A. () is the motorcycle-manufacturing division of Italian company Ducati (company), Ducati, headquartered in Bologna, Italy. The company is directly owned by Italian automotive manufacturer Lamborghini, whose German parent company is Audi, itself owned by the Volkswagen Group. History In 1926 Antonio Cavalieri Ducati and his three sons, Adriano, Marcello, and Bruno, founded ''Società Scientifica Radiobrevetti Ducati'' (SSR Ducati) in Bologna to produce vacuum tubes, Capacitor, condensers and other radio components. In 1935 they had become successful enough to enable construction of a new factory in the Borgo Panigale area of the city. Production was maintained during World War II, despite the Ducati factory being a repeated target of Allied bombing. It was finally destroyed by around 40 Consolidated B-24 Liberators on 12 October 1944 as part of the United States Army Air Forces's Operation Pancake, which involved some 700 aircraft flying from airfields ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ducati
Ducati Motor Holding S.p.A. () is the motorcycle-manufacturing division of Italian company Ducati, headquartered in Bologna, Italy. The company is directly owned by Italian automotive manufacturer Lamborghini, whose German parent company is Audi, itself owned by the Volkswagen Group. History In 1926 Antonio Cavalieri Ducati and his three sons, Adriano, Marcello, and Bruno, founded ''Società Scientifica Radiobrevetti Ducati'' (SSR Ducati) in Bologna to produce vacuum tubes, condensers and other radio components. In 1935 they had become successful enough to enable construction of a new factory in the Borgo Panigale area of the city. Production was maintained during World War II, despite the Ducati factory being a repeated target of Allied bombing. It was finally destroyed by around 40 Consolidated B-24 Liberators on 12 October 1944 as part of the United States Army Air Forces's Operation Pancake, which involved some 700 aircraft flying from airfields in the Province of Foggia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poppet Valve
A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against a corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. The poppet valve was invented in 1833 by American E.A.G. Young of the Newcastle and Frenchtown Railroad. Young had patented his idea, but the Patent Office fire of 1836 destroyed all records of it. Etymology The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poppet Valve
A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against a corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. The poppet valve was invented in 1833 by American E.A.G. Young of the Newcastle and Frenchtown Railroad. Young had patented his idea, but the Patent Office fire of 1836 destroyed all records of it. Etymology The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fabio Taglioni
Fabio Taglioni (10 September 1920 – 18 July 2001) was an Italian engineer. Born in Lugo di Romagna, he was chief designer and technical director of Ducati from 1954 until 1989. His desmodromic 90° V-twin engine design is still used in all current Ducati motorcycle engines. Among the many race victories of his early desmo twin, the 1978 legendary return of Mike Hailwood at the Isle of Man is perhaps the most memorable. After World War II, Taglioni designed engines for Ceccato motorcycles and Mondial before joining Ducati in 1954. He began by designing Ducati's OHC four-stroke singles, and in 1963 designed the prototype V4 Ducati Apollo. This led to the 1972 Ducati 750 Imola Desmo, and the 1970s and 1980s production Ducati L-twin motorcycles. He died in Bologna Bologna (, , ; egl, label= Emilian, Bulåggna ; lat, Bononia) is the capital and largest city of the Emilia-Romagna region in Northern Italy. It is the seventh most populous city in Italy with about ... [...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 vacuum pressure into the cylinder through its downward motion. The piston is moving down as air is being sucked in by the downward motion against the piston. #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 clos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, 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. __TOC__ Piston engines Internal combustion engines An internal combustion engine is acted upon by the pressure of the expanding combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the connecting rod and onto the crankshaft. The connecting rod is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, a kinetic energy is any term in a system's Lagrangian which includes a derivative with respect to time. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2. In relativistic mechanics, this is a good approximation only when ''v'' is much less than the speed of light. The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galling
Galling is a form of wear caused by adhesion between sliding surfaces. When a material galls, some of it is pulled with the contacting surface, especially if there is a large amount of force compressing the surfaces together. Galling is caused by a combination of friction and adhesion between the surfaces, followed by slipping and tearing of crystal structure beneath the surface. This will generally leave some material stuck or even friction welded to the adjacent surface, whereas the galled material may appear gouged with balled-up or torn lumps of material stuck to its surface. Galling is most commonly found in metal surfaces that are in sliding contact with each other. It is especially common where there is inadequate lubrication between the surfaces. However, certain metals will generally be more prone to galling, due to the atomic structure of their crystals. For example, aluminium is a metal that will gall very easily, whereas annealed (softened) steel is slightly mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertzian Contact Stress
Hertzian may refer to: * Hertzian antenna * Hertzian cone, the cone produced when an object passes through a solid, such as a bullet through glass * Hertzian contact stress, localized stresses that develop as two curved surfaces come in contact and deform slightly under imposed loads * Hertzian dipole In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole wi ..., defined as a finite oscillating current over an infinitesimal length at a specified position * Hertzian wave, the original name of radio waves * Hertzian wave telegraphy {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
