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Camshaft
A camshaft is a shaft that contains a row of pointed cams in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems and early electric motor speed controllers. Camshafts in piston engines are usually made from steel or cast iron, and the shape of the cams greatly affects the engine's characteristics. History Trip hammers are one of the early uses of a form of cam to convert rotating motion, e.g. from a waterwheel, into the reciprocating motion of a hammer used in forging or to pound grain. Evidence for these exists back to the Han dynasty in China, and they were widespread by the medieval period. Camshafts were first described by Ismail al-Jazari in 1206. Once the rotative version of the steam engine was developed in the late 18th century, the operation of the valve gear was usually by an eccentric, which turned the rotation of the crankshaft i ... [...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] |
Poppet Valve
A poppet valve (also sometimes called mushroom valve) is a valve typically used to control the timing and quantity of petrol (gas) or vapour flow into or out of an engine, but with many other applications. 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. Etymology The word poppet shares etymology with "puppet": it is from the Middle English ''popet'' ("youth" or "doll"), from Middle French ''poupette'', whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uniflow Steam Engine
The uniflow type of steam engine uses steam that flows in one direction only in each half of the cylinder. Thermal efficiency is increased by having a temperature gradient along the cylinder. Steam always enters at the hot ends of the cylinder and exhausts through ports at the cooler centre. By this means, the relative heating and cooling of the cylinder walls is reduced. Design details Steam entry is usually controlled by poppet valves (which act similarly to those used in internal combustion engines) that are operated by a camshaft. The inlet valves open to admit steam when minimum expansion volume has been reached at the start of the stroke. For a period of the crank cycle, steam is admitted, and the poppet inlet is then closed, allowing continued expansion of the steam during the stroke, driving the piston. Near the end of the stroke, the piston will uncover a ring of exhaust ports mounted radially around the centre of the cylinder. These ports are connected by a manifold a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IOE Engine
The intake/inlet over exhaust, or "IOE" engine, known in the US as F-head, is a four-stroke internal combustion engine whose valvetrain comprises OHV inlet valves within the cylinder head and exhaust side-valves within the engine block.V.A.W Hillier: ''Fundamentals of Motor Vehicle Technology'', 4th edition, Standly Thornes, Cheltenham 1991, , p. 39+40 IOE engines were widely used in early motorcycles, initially with the inlet valve being operated by engine suction instead of a cam-activated valvetrain. When the suction-operated inlet valves reached their limits as engine speeds increased, the manufacturers modified the designs by adding a mechanical valvetrain for the inlet valve. A few automobile manufacturers, including Willys, Rolls-Royce and Humber also made IOE engines for both cars and military vehicles. Rover manufactured inline four and six cylinder engines with a particularly efficient version of the IOE induction system. A few designs with the reverse system, exhaus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cam (mechanism)
A cam is a rotating or sliding piece in a linkage (mechanical), mechanical linkage used especially in transforming rotary motion into linear motion. It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an Eccentric (mechanism), eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the ''Cam follower, follower'', which is a lever making contact with the cam. A cam timer is similar, and these were widely used for electric machine control (an electromechanical timer in a washing machine being a common example) before the advent of inexpensive electronics, microcontrollers, integrated circuits, programmable logic controllers and digital control. Camshaft The cam can be seen as a device that converts rotational mot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flathead Engine
A flathead engine, also known as a sidevalve engine''American Rodder'', 6/94, pp.45 & 93. or valve-in-block engine, is an internal combustion engine with its poppet valves contained within the engine block, instead of in the cylinder head, as in an overhead valve engine. Flatheads were widely used internationally by automobile manufacturers from the late 1890s until the mid-1960s but were replaced by more efficient overhead valve and overhead camshaft engines. They are currently experiencing a revival in low-revving aero-engines such as the D-Motor. The side-valve design The valve gear comprises a camshaft sited low in the cylinder block which operates the poppet valves via tappets and short pushrods (or sometimes with no pushrods at all). The flathead system obviates the need for further valvetrain components such as lengthy pushrods, rocker arms, overhead valves or overhead camshafts. The sidevalves are typically adjacent, sited on one side of the cylinder(s), though ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Engine
A reciprocating engine, more often known as a piston engine, is a heat engine that uses one or more Reciprocating motion, reciprocating pistons to convert high temperature and high pressure into a Circular motion, 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 Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition engine, spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition engine, compression-ignition (CI) engine, where the air within the cylinder is compressed, Adiabatic process, thus heating it, so that the heated air ignites fuel that is injected diesel engine, then or hot-bulb engine, earlier.''Thermodynamics: An Engineering Approach'' by Yunus A. Cengal and Michael A. Boles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ismail Al-Jazari
Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, , ) was a Muslim polymath: a scholar, inventor, mechanical engineer, artisan and artist from the Artuqid Dynasty of Jazira in Mesopotamia. He is best known for writing ''The Book of Knowledge of Ingenious Mechanical Devices'' (, also known as ''Automata'') in 1206, where he described 50 mechanical devices, along with instructions on how to construct them. One of his more famous inventions is the elephant clock. He has been described as the "father of robotics" and modern day engineering. Biography Al-Jazari was born in the area of Upper Mesopotamia in 1136. Sources state his exact location is unknown, but they speculate he could have been born in Jazirat ibn Umar, where he got the name Jazari from or Al-Jazira which was used to denote Upper Mesopotamia. The only biographical information known about him is contained in his ''Book of Knowledge of Ingenious Mechanical Devices''. Like his father ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder Bank
The engine configuration describes the fundamental operating principles by which internal combustion engines are categorized. Piston engines are often categorized by their cylinder layout, valves and camshafts. Wankel engines are often categorized by the number of rotors present. Gas turbine engines are often categorized into turbojets, turbofans, turboprops and turboshafts. Piston engines Any design of motor/engine, be it a V or a boxer can be called an "in-line" if it's mounted in-line with the frame/chassis and in-line with the direction of travel of the vehicle. When the motor/engine is across the frame/chassis this is called a TRANSVERSE motor. Cylinder arrangement is not in the description of how the motor/engine is oriented. Therefore a V4 motor/engine can be a transverse or an in-line. Where the cylinders are arranged in two or more lines (such as in V engines or flat engines), each line of cylinders is referred to as a 'cylinder bank'. The angle between cylinder b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Lorenzo Marr
Walter Lorenzo Marr (1865-1941) was an automotive pioneer and engineer who worked with David Dunbar Buick perfecting the first Buick production automobiles. He worked with Buick a number of times around the turn of the century, building Buick's first two one-off vehicles. He was the Buick Motor Company's first chief engineer from 1904 through 1918, staying on as consulting engineer until 1923. He was also the founder of the Marr Auto Car Company in 1903 which produced the Marr Auto Car. The Marr Auto Car was one of the world's first automobiles with an overhead camshaft (OHC) engine. Possibly his most important achievement was building one of the first overhead valve engines (OHV). This he did in 1898 when he built a trike that weighed 118 pounds, and whose single cylinder had a bore and stroke of 3 inches each. He brought the concept of the overhead valve engine with him to Buick in 1901, where the invention was patented to Buick's chief engineer Eugene Richard in 1904 (applied ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marr (automobile)
The Marr Auto-Car was an automobile built in Elgin, Illinois by the Marr Auto-Car Company from 1902 to 1904. History The car was designed by early automobile pioneer Walter L. Marr who had worked as an engine designer for Buick in 1901 and went on to be Chief Engineer there from 1904 to 1918. The Marr was a two-seat runabout with a single-cylinder 1.7L engine that was mounted under the seat. The engine is one of the first known to have featured an overhead camshaft (OHC). The vehicle had the first tilt steering wheel, changeable speed gears on a planetary transmission and a revolutionary new carburetor A carburetor (also spelled carburettor or carburetter) is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Ventu .... Factory price was $600, (). The plant burned to the ground in August 1904 with 14 cars inside. Only one Marr Auto-Car is extan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-head Engine
A T-head engine is an early type of internal combustion engine that became obsolete after World War I. It is a sidevalve engine distinguished from the more common L-head by its valve placement. In T-head engines, the intake valves are located on one side of the engine block and the exhaust valves on the other. When viewed from the end of the crankshaft, especially in a cutaway view, the cylinder and combustion chamber resemble a 'T', leading to the name "T-head". In contrast, an L-head engine has all valves on the same side. Overview The T-head engine was an early form of crossflow cylinder head. It was relatively complex for its time, requiring separate camshafts for the intake and exhaust valves. T-heads were typically intricate castings, necessitating blind bores for the cylinders and valve chambers. This complexity made T-head engines more expensive to produce compared to the simpler L-head (flathead) engines. Moreover, T-head engines were heavy and inefficient for their di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
