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Camshafts
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 into r ... [...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] |
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] |
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] |
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] |
Reciprocating Motion
Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth linear motion. 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 crank can be used to convert into reciprocating motion, or conversely turn reciprocating motion into circular motion. For example, inside an internal combustion engine (a type of reciprocating engine), the expansion of burning fuel in the cylinders periodically pushes the piston down, which, through the connecting rod, turns the crankshaft. The continuing rotation of the crankshaft drives the piston back up, ready for the next cycle. The piston moves in a reciprocating motion, which is converted into the circular motion of the crankshaft, which ultimately propels the vehicle or does other useful work. The reciprocating motion of a pump piston is close to but different from, sinusoidal A ... [...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] |
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] |
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] |
Hydroforming
Hydroforming is a means of shaping ductile metals such as aluminium, brass, low alloy steel, and stainless steel into lightweight, structurally stiff and strong pieces. One of the largest applications of cost-effective hydroforming is the automotive industry, which makes use of the complex shapes made possible by hydroforming to produce stronger, lighter, and more rigid unibody structures for vehicles. This technique is particularly popular with the high-end sports car industry and is also frequently employed in the shaping of aluminium tubes for bicycle frames. Hydroforming is a specialized type of die forming that uses a high pressure hydraulic fluid to press room temperature working material into a die. To hydroform aluminium into a vehicle's frame rail, a hollow tube of aluminium is placed inside a negative mold that has the shape of the desired result. High pressure hydraulic pumps then inject fluid at very high pressure inside the aluminium tube which causes it to expand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casting
Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various time setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Heavy equipment like machine tool beds, ships' propellers, etc. can be cast easily in the required size, rather than fabricating by joining several small pieces. Casting is a 7,000-year-old process. The oldest surviving casting is a copper frog from 3200 BC. History Throughout history, metal casting has been used to make tools, weapons, and religious objects. Metal casting history and develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machining
Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which utilizes machine tools, in contrast to ''additive manufacturing'' (e.g. 3D printing processes, 3D printing), which uses controlled addition of material. Machining is a major process of the manufacture of many metal products, but it can also be used on other materials such as wood, plastic, ceramic, and composite material, composites. A person who specializes in machining is called a machinist. As a commercial venture, machining is generally performed in a machine shop, which consists of one or more workrooms containing primary machine tools. Although a machine shop can be a standalone operation, many businesses maintain internal machine shops or tool rooms that support their specialized needs. Much modern-day machining uses Numerical control, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forging
Forging is a manufacturing process involving the shaping of metal using localized compression (physics), compressive forces. The blows are delivered with a hammer (often a power hammer) or a die (manufacturing), die. Forging is often classified according to the temperature at which it is performed: cold forging (a type of cold working), warm forging, or hot forging (a type of hot working). For the latter two, the metal is heated, usually in a forge. Forged parts can range in weight from less than a kilogram to hundreds of metric tons.Degarmo, p. 389 Forging has been done by metalsmith, smiths for millennia; the traditional products were kitchenware, household hardware, hardware, hand tools, edged weapons, cymbals, and jewellery. Since the Industrial Revolution, forged parts are widely used in mechanism (engineering), mechanisms and machines wherever a component requires high strength of materials, strength; such forgings usually require further processing (such as machining) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
