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Tachometer
A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a axle, shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes . Essentially the words tachometer and speedometer have identical meaning: a device that measures speed. It is by arbitrary convention that in the automotive world one is used for engine revolutions and the other for vehicle speed. In formal engineering nomenclature, more precise terms are used to distinguish the two. History The first tachometer was described by Bryan Donkin in a paper to the Royal Society of Arts in 1810 for which he was awarded the Gold medal of the society. This consisted of a bowl of mercury constructed in such a way that centrifugal force caused the level in a central tube to fall when it rotated and brought down the level in a narrower t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rev Limiter
A rev limiter is a device fitted in modern vehicles that have internal combustion engines. They are intended to protect an engine by restricting its maximum rotational speed, measured in revolutions per minute (RPM). Rev limiters are Engine control unit, pre-set by the engine manufacturer. There are also aftermarket units where a separate controller is installed using a custom RPM setting. A limiter prevents a vehicle's engine from being pushed beyond the manufacturer's limit, known as the ''redline'' (literally the red line marked on the tachometer). At some point beyond the redline, engine damage may occur. Operation Limiters usually work by shutting off a component necessary for the combustion processes to occur, whether it be fuel, air or spark. Internal combustion engine#Compression ignition process, Compression-ignition engines use mechanical Governor (device), governors or limiters to shut off electronic fuel injectors. A Internal combustion engine#Spark ignition process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redline
The redline is the maximum engine speed at which an internal combustion engine or traction motor and its components are designed to operate without causing damage to the components themselves or other parts of the engine. The redline of an engine depends on various factors such as stroke, mass of the components, displacement, composition of components, and balance of components. Redlining is riding or driving an automotive vehicle above the redline. The actual term ''redline'' comes from the red bars that are displayed on tachometers in cars starting at the rpm that denotes the redline for the specific engine. Straying into this area usually does not mean instant engine failure, but may increase the chances of damaging the engine. Variation of redline The acceleration, or rate of change in piston velocity, is the limiting factor. The piston acceleration is directly proportional to the magnitude of the G-forces experienced by the piston-connecting rod assembly. As long as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachograph
A tachograph is a device fitted to a vehicle that automatically records its speed and distance, together with the driver's activity selected from a choice of modes. The drive mode is activated automatically when the vehicle is in motion, and modern tachograph heads usually default to the other work mode upon coming to rest. The rest and availability modes can be manually selected by the driver whilst stationary. A tachograph system comprises a sender unit mounted to the vehicle gearbox, the tachograph head and a recording medium. Tachograph heads are of either analogue or digital tachograph, digital types. All relevant vehicles manufactured in the European Union, EU since 1 May 2006 must be fitted with digital tachograph heads. The recording medium for analogue heads are wax coated paper discs, and for digital heads there are two recording mediums: internal memory (which can be read out with one of a variety of download devices into a so-called .ddd file) and digital driver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 defines a physical quantity called ''rotation'' (or ''number of revolutions''), dimensionless, whose instantaneous rate of change is called ''rotational frequency'' (or ''rate of rotation''), with units of reciprocal seconds (s−1). A related but distinct quantity for describing rotation is ''angular frequency'' (or ''angular speed'', the magnitude of angular velocity), for which the SI unit is the radian per second (rad/s). Although they have the same dimensions (reciprocal time) and base unit (s−1), the hertz (Hz) and radians per second (rad/s) are special names used to express two different but proportional ISQ quantities: frequency and angular frequency, respectively. The conversions between a frequency and an angular frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diedrich Uhlhorn
Diedrich Uhlhorn (3 June 1764 – 1837) was a German engineer, mechanic and inventor. Life Uhlhorn was an engineer, mechanic and inventor, who invented in 1817 the first mechanical tachometer. Between 1817 and 1830 he was inventor of the Presse Monétaire (level coin press known as Uhlhorn Press) which bears his name. He was married. Awards * Order of the Red Eagle The Order of the Red Eagle () was an order of chivalry of the Kingdom of Prussia. It was awarded to both military personnel and civilians, to recognize valor in combat, excellence in military leadership, long and faithful service to the kingdom, o ... References Further reading * Volker Benard-Wagenhoff, Konrad Schneider: ''Dieser unerschöpfliche, seltene Mann – Diedrich Uhlhorn und die moderne Münztechnik''. Grevenbroich 2009 * Otto Albert Bormann: Dietrich Uhlhorn (1764–1837). In: Rheinisch-Westfälische Wirtschaftsbiographien, Band I. Aschendorff, Münster 1931, pages 177-195. * Egbert Ritter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engine Control Unit
An engine control unit (ECU), also called an engine control module (ECM), is a device that controls various subsystems of an internal combustion engine. Systems commonly controlled by an ECU include the fuel injection and ignition systems. The earliest ECUs (used by aircraft engines in the late 1930s) were mechanical-hydraulic units; however, most 21st-century ECUs operate using digital electronics. Functions The main functions of the ECU are typically: * Fuel injection system * Ignition system * Idle speed control (typically either via an idle air control valve or the electronic throttle system) * Variable valve timing and/or variable valve lift systems The sensors used by the ECU include: * accelerator pedal position sensor * camshaft position sensor * coolant temperature sensor * crankshaft position sensor * knock sensors * inlet manifold pressure sensor ( MAP sensor) * intake air temperature * intake air mass flow rate sensor ( MAF sensor) * oxygen (lambda) s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Alternator (auto)
An alternator is a type of electric generator used in modern automobiles to charge the battery and to power the electrical system when its engine is running. Until the 1960s, automobiles used DC dynamo generators with commutators. As silicon-diode rectifiers became widely available and affordable, the alternator gradually replaced the dynamo. This was encouraged by the increasing electrical power required for cars in this period, with increasing loads from larger headlamps, electric wipers, heated rear windows, and other accessories. History The modern type of vehicle alternators were first used in military applications during World War II, to power radio equipment on specialist vehicles. After the war, other vehicles with high electrical demands — such as ambulances and radio taxis — could also be fitted with optional alternators. Alternators were first introduced as standard equipment on a production car by the Chrysler Corporation on the Valiant in 1960, several year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compression (physics), compression; thus, the diesel engine is called a compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Introduction Diesel engines work by compressing only air, or air combined with residual combustion gases from the exhaust (known as exhaust gas recirculation, "EGR"). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases air temperature inside the Cylinder (engine), cylinder so that atomised diesel fuel injected into the combustion chamber ignites. The torque a dies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignition Coil
An ignition coil is used in the ignition system of a spark-ignition engine to transform the battery voltage to the much higher voltages required to operate the spark plug(s). The spark plugs then use this burst of high-voltage electricity to ignite the air-fuel mixture. The ignition coil is constructed of two sets of coils wound around an iron core. Older engines often use a single ignition coil which has its output directed to each cylinder by a distributor, a design which is still used by various small engines (such as lawnmower engines). Modern car engines often use a distributor-less system (such as ''coil-on-plug''), whereby every cylinder has its own ignition coil. Diesel engines use compression ignition and therefore do not have ignition coils. Design An ignition coil consists of an iron core surrounded by two coils (''windings'') made from copper wire. The primary winding has relatively few turns of heavy wire, while the secondary winding consists of thousands o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Breaker
A contact breaker (or "points") is a type of electrical switch, found in the ignition systems of spark-ignition internal combustion engines. The switch is automatically operated by a cam driven by the engine. The timing of operation of the switch is set so that a spark is produced at the right time to ignite the compressed air/fuel mixture in the cylinder of the engine. A mechanism may be provided to slightly adjust timing to allow for varying load on the engine. Since these contacts operate frequently, they are subject to wear, causing erratic ignition of the engine. More recent engines use electronic means to trigger the spark, which eliminated contact wear and allows computer control of ignition timing. Purpose The purpose of the contact breaker is to interrupt the current flowing in the primary winding of the ignition coil. When the current stops flowing, the resulting collapse of the magnetic field in the primary winding induces a high voltage in the secondary winding. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
