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108-603: The company began as an aircraft engine manufacturer in the early 20th century and through World War I . BMW manufactured its first motorcycle in 1923, the R32 , which featured a flat-twin boxer engine. BMW Motorrad still uses the flat-twin boxer configuration, but now manufactures motorcycles with a variety of engine configurations. With the exception of the G310 series (which is produced at TVS' plant in Hosur , Tamil Nadu , India ) and

216-443: A gas turbine engine offered. Thus was born the idea to mate a turbine engine to a traditional propeller. Because gas turbines optimally spin at high speed, a turboprop features a gearbox to lower the speed of the shaft so that the propeller tips don't reach supersonic speeds. Often the turbines that drive the propeller are separate from the rest of the rotating components so that they can rotate at their own best speed (referred to as

324-618: A better efficiency. A hybrid system as emergency back-up and for added power in take-off is offered for sale by Axter Aerospace, Madrid, Spain. Small multicopter UAVs are almost always powered by electric motors. Reaction engines generate the thrust to propel an aircraft by ejecting the exhaust gases at high velocity from the engine, the resultant reaction of forces driving the aircraft forwards. The most common reaction propulsion engines flown are turbojets, turbofans and rockets. Other types such as pulsejets , ramjets , scramjets and pulse detonation engines have also flown. In jet engines

432-531: A chain drive appears in the Polybolos , described by the Greek engineer Philon of Byzantium (3rd century BC). Two flat-linked chains were connected to a windlass , which by winding back and forth would automatically fire the machine's arrows until its magazine was empty. Although the device did not transmit power continuously since the chains "did not transmit power from shaft to shaft, and hence they were not in

540-419: A combustion section where fuel is added and ignited, one or more turbines that extract power from the expanding exhaust gases to drive the compressor, and an exhaust nozzle that accelerates the exhaust gases out the back of the engine to create thrust. When turbojets were introduced, the top speed of fighter aircraft equipped with them was at least 100 miles per hour faster than competing piston-driven aircraft. In

648-564: A common crankshaft. The vast majority of V engines are water-cooled. The V design provides a higher power-to-weight ratio than an inline engine, while still providing a small frontal area. Perhaps the most famous example of this design is the legendary Rolls-Royce Merlin engine, a 27-litre (1649 in ) 60° V12 engine used in, among others, the Spitfires that played a major role in the Battle of Britain . A horizontally opposed engine, also called

756-474: A constant pitch radius ). Chains are often narrower than belts, and this can make it easier to shift them to larger or smaller gears in order to vary the gear ratio. Multi-speed bicycles with derailleurs make use of this. Also, the more positive meshing of a chain can make it easier to build gears that can increase or shrink in diameter, again altering the gear ratio. However, some newer synchronous belts claim to have "equivalent capacity to roller chain drives in

864-490: A cooling system into the air duct of a hydrogen jet engine permits greater fuel injection at high speed and obviates the need for the duct to be made of refractory or actively cooled materials. This greatly improves the thrust/weight ratio of the engine at high speed. It is thought that this design of engine could permit sufficient performance for antipodal flight at Mach 5, or even permit a single stage to orbit vehicle to be practical. The hybrid air-breathing SABRE rocket engine

972-440: A cylinder on the other side. Opposed, air-cooled four- and six-cylinder piston engines are by far the most common engines used in small general aviation aircraft requiring up to 400 horsepower (300 kW) per engine. Aircraft that require more than 400 horsepower (300 kW) per engine tend to be powered by turbine engines . An H configuration engine is essentially a pair of horizontally opposed engines placed together, with

1080-427: A departure from BMW's naming convention. The R series are built around a horizontally opposed flat-twin (boxer) engine. As the engine is mounted with a longitudinal crankshaft, the cylinder heads protrude well beyond the sides of the frame. Originally, R series bikes had air-cooled heads but are now produced only with partial oil cooling or water cooling . The type of internal combustion engine cooling used across

1188-405: A few have been rocket powered and in recent years many small UAVs have used electric motors . In commercial aviation the major Western manufacturers of turbofan engines are Pratt & Whitney (a subsidiary of Raytheon Technologies ), General Electric , Rolls-Royce , and CFM International (a joint venture of Safran Aircraft Engines and General Electric). Russian manufacturers include

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1296-408: A flat or boxer engine, has two banks of cylinders on opposite sides of a centrally located crankcase. The engine is either air-cooled or liquid-cooled, but air-cooled versions predominate. Opposed engines are mounted with the crankshaft horizontal in airplanes , but may be mounted with the crankshaft vertical in helicopters . Due to the cylinder layout, reciprocating forces tend to cancel, resulting in

1404-572: A fraction of the cost of traditional engines. Such conversions first took place in the early 1970s; and as of 10 December 2006 the National Transportation Safety Board has only seven reports of incidents involving aircraft with Mazda engines, and none of these is of a failure due to design or manufacturing flaws. The most common combustion cycle for aero engines is the four-stroke with spark ignition. Two-stroke spark ignition has also been used for small engines, while

1512-407: A free-turbine engine). A turboprop is very efficient when operated within the realm of cruise speeds it was designed for, which is typically 200 to 400 mph (320 to 640 km/h). Turboshaft engines are used primarily for helicopters and auxiliary power units . A turboshaft engine is similar to a turboprop in principle, but in a turboprop the propeller is supported by the engine and the engine

1620-456: A handful of types are still in production. The last airliner that used turbojets was the Concorde , whose Mach 2 airspeed permitted the engine to be highly efficient. A turbofan engine is much the same as a turbojet, but with an enlarged fan at the front that provides thrust in much the same way as a ducted propeller , resulting in improved fuel efficiency . Though the fan creates thrust like

1728-569: A peak pressure of 30 MPa (300 bar). Although engine weight increases by 30%, aircraft fuel consumption is reduced by 15%. Sponsored by the European Commission under Framework 7 project LEMCOTEC , Bauhaus Luftfahrt, MTU Aero Engines and GKN Aerospace presented the concept in 2015, raising the overall engine pressure ratio to over 100 for a 15.2% fuel burn reduction compared to 2025 engines. On multi-engine aircraft, engine positions are numbered from left to right from

1836-478: A piston-engine with two 10 piston banks without a high-pressure turbine, increasing efficiency with non-stationary isochoric - isobaric combustion for higher peak pressures and temperatures. The 11,200 lb (49.7 kN) engine could power a 50-seat regional jet . Its cruise TSFC would be 11.5 g/kN/s (0.406 lb/lbf/hr) for an overall engine efficiency of 48.2%, for a burner temperature of 1,700 K (1,430 °C), an overall pressure ratio of 38 and

1944-424: A propeller, the surrounding duct frees it from many of the restrictions that limit propeller performance. This operation is a more efficient way to provide thrust than simply using the jet nozzle alone, and turbofans are more efficient than propellers in the transsonic range of aircraft speeds and can operate in the supersonic realm. A turbofan typically has extra turbine stages to turn the fan. Turbofans were among

2052-425: A search for replacement fuels for general aviation aircraft a priority for pilots’ organizations. Turbine engines and aircraft diesel engines burn various grades of jet fuel . Jet fuel is a relatively less volatile petroleum derivative based on kerosene , but certified to strict aviation standards, with additional additives. Model aircraft typically use nitro engines (also known as "glow engines" due to

2160-785: A single camshaft in the crankcase (variously above or below the crankshaft), the Oilhead has a camshaft in each head. (It is still technically an overhead valve engine rather than a true overhead camshaft unit, as the camshaft bears onto very short pushrods which operate valve rockers). In 2013, BMW introduced water-cooling to its boxer range. The engine is still used in the BMW R nineT line of motorcycles. In April 2020 BMW launched its cruiser BMW R18 with BMW's largest boxer engine featuring 1,802 cc (110.0 cu in), 90 hp (67 kW) and 158 N⋅m (117 lbf⋅ft). From 2013 (R1200GS), some BMW bikes have water-cooled heads, but (like

2268-463: A single row of cylinders, as used in automotive language, but in aviation terms, the phrase "inline engine" also covers V-type and opposed engines (as described below), and is not limited to engines with a single row of cylinders. This is typically to differentiate them from radial engines . A straight engine typically has an even number of cylinders, but there are instances of three- and five-cylinder engines. The greatest advantage of an inline engine

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2376-404: A smooth running engine. Opposed-type engines have high power-to-weight ratios because they have a comparatively small, lightweight crankcase. In addition, the compact cylinder arrangement reduces the engine's frontal area and allows a streamlined installation that minimizes aerodynamic drag. These engines always have an even number of cylinders, since a cylinder on one side of the crankcase "opposes"

2484-432: A three-segment nomenclature for motorcycles. The first segment indicates the engine type, the second indicates the approximate engine displacement in cubic centimeters (with one notable exception: the F 650 GS, which has an engine displacement of 798cc), while the third indicates the class of motorcycle (e.g., sport, sport touring, dual-sport, etc.). The three segments are separated by blanks. A similar 3-segment nomenclature

2592-507: A wet clutch and a unitary construction gearbox. It was at this time also that the K bike shaft drive moved from the right side to the left. Despite this new engine, the traditional flying brick K engine continued in service with the giant K1200LT luxury touring bike until 2009, at which point the flying brick bowed out along with the K1200LT. This was the event that presaged the development of the ultimate K engine in terms of size and complexity,

2700-533: Is a pre-cooled engine under development. At the April 2018 ILA Berlin Air Show , Munich -based research institute de:Bauhaus Luftfahrt presented a high-efficiency composite cycle engine for 2050, combining a geared turbofan with a piston engine core. The 2.87 m diameter, 16-blade fan gives a 33.7 ultra-high bypass ratio , driven by a geared low-pressure turbine but the high-pressure compressor drive comes from

2808-449: Is a twin-spool engine, allowing only two different speeds for the turbines. Pulsejets are mechanically simple devices that—in a repeating cycle—draw air through a no-return valve at the front of the engine into a combustion chamber and ignite it. The combustion forces the exhaust gases out the back of the engine. It produces power as a series of pulses rather than as a steady output, hence the name. The only application of this type of engine

2916-490: Is above and behind. In the Cessna 337 Skymaster , a push-pull twin-engine airplane, engine No. 1 is the one at the front of the fuselage, while engine No. 2 is aft of the cabin. Aircraft reciprocating (piston) engines are typically designed to run on aviation gasoline . Avgas has a higher octane rating than automotive gasoline to allow higher compression ratios , power output, and efficiency at higher altitudes. Currently

3024-453: Is bolted to the airframe : in a turboshaft, the engine does not provide any direct physical support to the helicopter's rotors. The rotor is connected to a transmission which is bolted to the airframe, and the turboshaft engine drives the transmission. The distinction is seen by some as slim, as in some cases aircraft companies make both turboprop and turboshaft engines based on the same design. A number of electrically powered aircraft, such as

3132-720: Is more common because it is difficult to get enough air-flow to cool the rear cylinders directly. Inline engines were common in early aircraft; one was used in the Wright Flyer , the aircraft that made the first controlled powered flight. However, the inherent disadvantages of the design soon became apparent, and the inline design was abandoned, becoming a rarity in modern aviation. For other configurations of aviation inline engine, such as X-engines , U-engines , H-engines , etc., see Inline engine (aeronautics) . Cylinders in this engine are arranged in two in-line banks, typically tilted 60–90 degrees apart from each other and driving

3240-430: Is of lesser concern, rocket engines can be useful because they produce very large amounts of thrust and weigh very little. A rocket turbine engine is a combination of two types of propulsion engines: a liquid-propellant rocket and a turbine jet engine. Its power-to-weight ratio is a little higher than a regular jet engine, and works at higher altitudes. For very high supersonic/low hypersonic flight speeds, inserting

3348-413: Is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles . It is also used in a wide variety of machines besides vehicles. Most often, the power is conveyed by a roller chain , known as the drive chain or transmission chain , passing over a sprocket , with the teeth of the gear meshing with the holes in the links of the chain. The gear is turned, and this pulls

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3456-504: Is sometimes evaluated in comparison to chain drive; in particular belt drive vs chain drive vs shaft drive is a key design decision for most motorcycles. Drive shafts tend to be tougher and more reliable than chain drive, but the bevel gears have far more friction than a chain. For this reason virtually all high-performance motorcycles use chain drive, with shaft-driven arrangements generally used for non-sporting machines. Toothed-belt drives are used for some (non-sporting) models. Chain drive

3564-460: Is still the R 1200 GS with 23,681 units sold in 2015. BMW have a long history in motorsports with many successes in a wide range of disciplines including Isle of Man TT, Dakar Rally, and Superbikes. There are four lines of BMW motorcycles: The series differ primarily in the class of engine that each uses. The F Series of single-cylinder BMW motorcycles was first launched in 1994, as the F650 , and

3672-513: Is that it allows the aircraft to be designed with a low frontal area to minimize drag. If the engine crankshaft is located above the cylinders, it is called an inverted inline engine: this allows the propeller to be mounted high up to increase ground clearance, enabling shorter landing gear. The disadvantages of an inline engine include a poor power-to-weight ratio , because the crankcase and crankshaft are long and thus heavy. An in-line engine may be either air-cooled or liquid-cooled, but liquid-cooling

3780-530: Is the R1200GS and its sibling R1200GS Adventure, which sold 24,467 units – accounting for 28% of BMW's annual production. Current production includes a variety of shaft and chain driven models, with engines from 310 cc to 1,802 cc; and models designed for off-road , dual-purpose , sport , and touring activities. In 2008, BMW introduced the DOHC Boxer HP2 Sport, and entered

3888-427: Is used for BMW automobiles. However, there is significantly less consistency across the range with respect to the second segment (engine displacement/100). Engine type: Engine displacement in cc: Styling suffix designations: Additionally, a bike may have the following modifiers in its name: Examples: K 1200 S, R 1200 RT, F 650 GS, R 1150 RSL, K 1200 LT, K 1200 LT-C, R 1200 RT-P, R 1200 RSA, S 1000 RR. Prior to

3996-648: The Duolever . As of 2018, the Duolever has been used on all K1300 and K1600 models. The official BMW Motorrad explanation of the duolever includes this: The advantage of this front wheel suspension on the motorcycle market at present is its torsional rigidity. The BMW Motorrad Duolever front wheel suspension is not influenced by negative forces in the same manner as a conventional telefork whose fixed and take-off tubes twist laterally as well as longitudinally during jounce/rebound and steering. Its two trailing links absorb

4104-527: The QinetiQ Zephyr , have been designed since the 1960s. Some are used as military drones . In France in late 2007, a conventional light aircraft powered by an 18 kW electric motor using lithium polymer batteries was flown, covering more than 50 kilometers (31 mi), the first electric airplane to receive a certificate of airworthiness . On 18 May 2020, the Pipistrel E-811 was

4212-650: The R1100S BoxerCup Replika (a model with its own race series) shows that the Telelever fork provides responsive and predictable handling. The term "Telelever" is a portmanteau word from "Telescopic fork" and "Lever"; the "lever" being the wishbone arm. In 2004, BMW announced the K1200S, incorporating a new front suspension based upon a design by Norman Hossack . BMW recognised this fact but paid Hossack no royalties. BMW named its new front suspension

4320-525: The R90S used the 247 engine; and its successor, the R100RS, was fitted with an oil cooler. An "Oilhead" is a name to describe BMW flat-twin motorcycle engines with partial oil-cooling, and to distinguish these engines from the earlier air-cooled "Airhead" models. The Oilhead's finned cylinders have conventional air-cooling, but the four-valve cylinder-heads are oil-cooled. Unlike earlier BMW boxers which had

4428-684: The Rutan Quickie . The single-rotor engine was put into a Chevvron motor glider and into the Schleicher ASH motor-gliders. After the demise of MidWest, all rights were sold to Diamond of Austria, who have since developed a MkII version of the engine. As a cost-effective alternative to certified aircraft engines some Wankel engines, removed from automobiles and converted to aviation use, have been fitted in homebuilt experimental aircraft . Mazda units with outputs ranging from 100 horsepower (75 kW) to 300 horsepower (220 kW) can be

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4536-530: The Système Panhard . A common design was using a differential located near the centre of the car, which then transferred drive to the rear axle via roller chains. This system allowed for a relatively simple design which could accommodate the vertical axle movement associated with the rear suspension system. Frazer Nash were strong proponents of this system using one chain per gear selected by dog clutches . Their chain drive system, (designed for

4644-484: The United Engine Corporation , Aviadvigatel and Klimov . Aeroengine Corporation of China was formed in 2016 with the merger of several smaller companies. The largest manufacturer of turboprop engines for general aviation is Pratt & Whitney. General Electric announced in 2015 entrance into the market. In this section, for clarity, the term "inline engine" refers only to engines with

4752-424: The gyroscopic effects of the heavy rotating engine produced handling problems in aircraft and the engines also consumed large amounts of oil since they used total loss lubrication, the oil being mixed with the fuel and ejected with the exhaust gases. Castor oil was used for lubrication, since it is not soluble in petrol, and the resultant fumes were nauseating to the pilots. Engine designers had always been aware of

4860-424: The oxygen necessary for fuel combustion comes from the air, while rockets carry an oxidizer (usually oxygen in some form) as part of the fuel load, permitting their use in space. A turbojet is a type of gas turbine engine that was originally developed for military fighters during World War II . A turbojet is the simplest of all aircraft gas turbines. It consists of a compressor to draw air in and compress it,

4968-463: The "hexhead", BMW inverted the Paralever and moved the torque arm from the bottom to the top of the drive shaft housing (photo right). This reduces underhang of components and tends to increase ground clearance in right lean. The term "Paralever" is a portmanteau word from "Parallelogram" and "Lever". The "lever is the swinging arm; and the "parallelogram" is the shape between the four elements of

5076-475: The 2005 K1200S. The new engine generates 123 kW (165 hp) and is tilted forwards 55 degrees. It is 43 cm (17 in) wide, giving the bikes a very low center of mass without reducing maximum lean angles. In October 2008, BMW announced the new K1300GT, K1300S and K1300R models, all of which feature a larger capacity 1293 cc engine producing up to 175 hp (130 kW). The new engine produces maximum power output 1,000 RPM lower than

5184-713: The C400 series (which is produced at Loncin's plant in Chongqing , China ), all BMW Motorrad's motorcycle production takes place at its plant in Berlin , Germany . Some engines are manufactured in Austria, China, and Taiwan. Most of the current motorcycles in BMW Motorrad's range were designed by David Robb , who was the company's chief designer from 1993 to 2012 when he was replaced by Edgar Heinrich . The most popular model

5292-817: The Clerget 14F Diesel radial engine (1939) has the same power to weight ratio as a gasoline radial. Improvements in Diesel technology in automobiles (leading to much better power-weight ratios), the Diesel's much better fuel efficiency and the high relative taxation of AVGAS compared to Jet A1 in Europe have all seen a revival of interest in the use of diesels for aircraft. Thielert Aircraft Engines converted Mercedes Diesel automotive engines, certified them for aircraft use, and became an OEM provider to Diamond Aviation for their light twin. Financial problems have plagued Thielert, so Diamond's affiliate — Austro Engine — developed

5400-565: The Japanese off-road racing motorcycles but the most unusual and significant was the use of a single pivot point for the drive sprocket and the swing arm. This unusual configuration allowed for a very tense drive chain with no slop and eliminated acceleration squat. The former benefit saves on chain and sprocket wear and the latter allows for a more consistent drive geometry and fully available rear suspension travel during heavy acceleration. In mid-2006, The F Series added two new motorcycles to

5508-399: The K & R Series. Paralever is a further advance in BMW's single-sided rear suspension technology (photo right). It decouples torque reaction as the suspension compresses and extends, avoiding the tendency to squat or rise under acceleration and reducing tyre chatter on the road surface. It was introduced in 1988 R 80 GS and R 100 GS motorcycles. In 2005, along with the introduction of

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5616-451: The Telelever and the Duolever front suspensions for several years, has partly returned to telescopic forks in the 2015 model year with the introduction of the R 1200 R and R 1200 RS. Englishman Ernest Earles designed a unique triangulated fork that, unlike telescopic forks, resists the side-forces introduced by sidecars. BMW fitted the Earles fork to all its models for 14 years from 1955. In

5724-574: The Wankel engine has been used in motor gliders where the compactness, light weight, and smoothness are crucially important. The now-defunct Staverton-based firm MidWest designed and produced single- and twin-rotor aero engines, the MidWest AE series . These engines were developed from the motor in the Norton Classic motorcycle . The twin-rotor version was fitted into ARV Super2s and

5832-399: The braking and suspension functions. Braking forces are taken back via the wishbone, thereby eliminating brake dive . During braking, the trail and castor angle ( rake ) increases instead of decreasing as with traditional telescopic forks. Some riders used to conventional forks reported that the Telelever can initially lack "feel", and that the absence of dive is initially disconcerting; but

5940-489: The chain moves at constant speed, then the shafts must accelerate and decelerate constantly. If one sprocket rotates at a constant speed, then the chain (and probably all other sprockets that it drives) must accelerate and decelerate constantly. This is usually not an issue with many drive systems; however, most motorcycles are fitted with a rubber bushed rear wheel hub to virtually eliminate this vibration issue. Toothed belt drives are designed to limit this issue by operating at

6048-660: The chain putting mechanical force into the system. Another type of drive chain is the Morse chain, invented by the Morse Chain Company of Ithaca, New York , United States. This has inverted teeth. Sometimes the power is output by simply rotating the chain, which can be used to lift or drag objects. In other situations, a second gear is placed and the power is recovered by attaching shafts or hubs to this gear. Though drive chains are often simple oval loops, they can also go around corners by placing more than two gears along

6156-546: The chain; gears that do not put power into the system or transmit it out are generally known as idler-wheels . By varying the diameter of the input and output gears with respect to each other, the gear ratio can be altered. For example, when the bicycle pedals' gear rotates once, it causes the gear that drives the wheels to rotate more than one revolution. Duplex chains are another type of chain which are essentially two chains joined side by side which allow for more power and torque to be transmitted. The oldest known application of

6264-500: The compression-ignition diesel engine is seldom used. Starting in the 1930s attempts were made to produce a practical aircraft diesel engine . In general, Diesel engines are more reliable and much better suited to running for long periods of time at medium power settings. The lightweight alloys of the 1930s were not up to the task of handling the much higher compression ratios of diesel engines, so they generally had poor power-to-weight ratios and were uncommon for that reason, although

6372-593: The cylinders arranged evenly around the crankshaft, although some early engines, sometimes called semi-radials or fan configuration engines, had an uneven arrangement. The best known engine of this type is the Anzani engine, which was fitted to the Bleriot XI used for the first flight across the English Channel in 1909. This arrangement had the drawback of needing a heavy counterbalance for the crankshaft, but

6480-486: The cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks. The first practical rotary engine

6588-466: The direct line of ancestry of the chain-drive proper", the Greek design marks the beginning of the history of the chain drive since "no earlier instance of such a cam is known, and none as complex is known until the 16th century." It is here that the flat-link chain, often attributed to Leonardo da Vinci , actually made its first appearance." The first continuous as well as the first endless chain drive

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6696-508: The discontinuation of the R27 in 1967, BMW made motorcycles with single-cylinder engines. These were similar in design to their larger flat-twin motorcycles, including the use of shaft drive, but the engine was mounted vertically within the frame. The K series BMWs have water-cooled engines of three ( K75 ), or four (K100, K1100, K1200, K1300 ), or six (K1600) cylinders. Up until 2004, all K series engines, whether three or four cylinders were that of

6804-421: The drive chain is heavier than an equivalent drive belt, the system will have a higher inertia . Theoretically, this can lead to a greater flywheel effect, however in practice the belt or chain inertia often makes up a small proportion of the overall drivetrain inertia. One problem with roller chains is the variation in speed, or surging, caused by the acceleration and deceleration of the chain as it goes around

6912-581: The engine core is the bypass ratio. Low-bypass engines are preferred for military applications such as fighters due to high thrust-to-weight ratio, while high-bypass engines are preferred for civil use for good fuel efficiency and low noise. High-bypass turbofans are usually most efficient when the aircraft is traveling at 500 to 550 miles per hour (800 to 890 kilometres per hour), the cruise speed of most large airliners. Low-bypass turbofans can reach supersonic speeds, though normally only when fitted with afterburners . The term advanced technology engine refers to

7020-438: The engine works by having a coiled pipe in the combustion chamber that superheats the fuel (propane) before being injected into the air-fuel inlet. In the combustion chamber, the fuel/air mixture ignites and burns, creating thrust as it leaves through the exhaust pipe. Induction and compression of the fuel/air mixture is done both by the pressure of propane as it is injected, along with the sound waves created by combustion acting on

7128-415: The engine's heat-radiating surfaces to the air and tends to cancel reciprocating forces, radials tend to cool evenly and run smoothly. The lower cylinders, which are under the crankcase, may collect oil when the engine has been stopped for an extended period. If this oil is not cleared from the cylinders prior to starting the engine, serious damage due to hydrostatic lock may occur. Most radial engines have

7236-537: The event, this was the year that use of sidecars peaked and quickly fell off in most European markets (e.g. the UK) but the Earles fork system was well liked by solo riders too. It causes the front end of the motorcycle to rise under braking — the reverse of the action of a telescopic fork. The mechanical strength of this design sometimes proved to be a weakness to the rest of the motorcycle, since it transfers impact pressure to

7344-465: The final drive housing, potentially reducing drive train losses. All of the original format K engines were also mated to a dry automotive-type clutch. The uniform use of the traditional K engine ceased with the K1200 models in 2005, with a new 1200 series engine that was radically different from the flying brick in that it was a conventional transversely 55-degree slant-mounted four-cylinder engine coupled to

7452-606: The first electric aircraft engine to be awarded a type certificate by EASA for use in general aviation . The E-811 powers the Pipistrel Velis Electro . Limited experiments with solar electric propulsion have been performed, notably the manned Solar Challenger and Solar Impulse and the unmanned NASA Pathfinder aircraft. Many big companies, such as Siemens, are developing high performance electric engines for aircraft use, also, SAE shows new developments in elements as pure Copper core electric motors with

7560-399: The first engines to use multiple spools —concentric shafts that are free to rotate at their own speed—to let the engine react more quickly to changing power requirements. Turbofans are coarsely split into low-bypass and high-bypass categories. Bypass air flows through the fan, but around the jet core, not mixing with fuel and burning. The ratio of this air to the amount of air flowing through

7668-598: The forces resulting from the jounce/rebound and keep the wheel carrier stable. Thus, any torsioning is excluded and the front wheel suspension is very precise. The steering commands of the rider are converted directly and the feedback from the front wheel is transparent in all driving conditions. Aircraft engine An aircraft engine , often referred to as an aero engine , is the power component of an aircraft propulsion system . Aircraft using power components are referred to as powered flight . Most aircraft engines are either piston engines or gas turbines , although

7776-553: The frame where damage is more difficult and expensive to correct. Developed by Saxon-Motodd in Britain in the early 1980s, the Telelever fork aims to improve handling stability during cornering and braking. The Telelever uses conventional telescopic forks , but the stanchions contain only lubricating oil. Springing and damping functions are dealt with by a monoshock attached to a "Telelever" wishbone . The wishbone pivots on

7884-420: The front of the engine block, and the wishbone's forward end is attached via a rose-joint to a brace connecting the fork sliders. As there is no lower triple clamp, the fork sliders are longer and lighter than on a conventional telescopic fork, and the greater slider/tube overlap reduces both torsional flex and unsprung weight . The Telelever system's main benefit is that it separates the steering function from

7992-497: The intake stacks. It was intended as a power plant for personal helicopters and compact aircraft such as Microlights. A few aircraft have used rocket engines for main thrust or attitude control, notably the Bell X-1 and North American X-15 . Rocket engines are not used for most aircraft as the energy and propellant efficiency is very poor, but have been employed for short bursts of speed and takeoff. Where fuel/propellant efficiency

8100-425: The introduction of the K 100 series and the R 1100 series motorcycles, the letter prefix was always the same, and the numbers were either based on displacement, as mentioned above, or were just model numbers. The first BMW monolever suspensions appeared in 1980 on the then-new R80G/S range. It had a single universal joint immediately behind the engine/gear-box unit. This system was later included on updated versions of

8208-514: The line up. The Scarver was different from the F650GS variants in that it utilized a belt drive system opposed to a chain, had a much lower seat height, and was intended for on-road use. All F650 motorcycles produced from 2000 to 2007 used a 652 cc engine built in Austria by Rotax and were built by BMW in Berlin. In late 2006, the G series of offroad biased bikes motorcycles was launched using

8316-572: The lineup, the F800S sports bike and F800ST sports tourer, both which use a 798 cc parallel-twin engine built by Rotax . Both motorcycles also feature a belt drive system similar to what was in use on the F650CS. In 2007 the single-cylinder F650GS was replaced with the twin-cylinder F800GS and F650GS models. The latter uses a de-tuned version of the 798 cc engine fitted to the F800GS, marking

8424-430: The many limitations of the rotary engine so when the static style engines became more reliable and gave better specific weights and fuel consumption, the days of the rotary engine were numbered. The Wankel is a type of rotary engine. The Wankel engine is about one half the weight and size of a traditional four-stroke cycle piston engine of equal power output, and much lower in complexity. In an aircraft application,

8532-608: The model designation became the K1100. The K1100LT was the first with the new engine displacement. In 1998 BMW increased the size again to 1,170 cc. This upgraded flat-four engine appeared in the K1200RS. This engine continued in production for the K1200LT range, with a power-boosting update in 2004, until the end of the LT production run. The later K1200 engine is a 1,157 cc transverse inline-four, announced in 2003 and first seen in

8640-433: The modern generation of jet engines. The principle is that a turbine engine will function more efficiently if the various sets of turbines can revolve at their individual optimum speeds, instead of at the same speed. The true advanced technology engine has a triple spool, meaning that instead of having a single drive shaft, there are three, in order that the three sets of blades may revolve at different speeds. An interim state

8748-463: The most common Avgas is 100LL. This refers to the octane rating (100 octane) and the lead content (LL = low lead, relative to the historic levels of lead in pre-regulation Avgas). Refineries blend Avgas with tetraethyllead (TEL) to achieve these high octane ratings, a practice that governments no longer permit for gasoline intended for road vehicles. The shrinking supply of TEL and the possibility of environmental legislation banning its use have made

8856-404: The new AE300 turbodiesel , also based on a Mercedes engine. Competing new Diesel engines may bring fuel efficiency and lead-free emissions to small aircraft, representing the biggest change in light aircraft engines in decades. While military fighters require very high speeds, many civil airplanes do not. Yet, civil aircraft designers wanted to benefit from the high power and low maintenance that

8964-458: The oilheads), the new engines still use air-cooling for the cylinders. Approximately 34% of the cooling is attributed to the water-cooling which is concentrated in the highest heat-generating areas such as around the exhaust-valve seats, etc. The inlets are now on top of the cylinder (not behind as before) and the exhausts are below (no longer in front). Between the introduction of the R39 in 1925 and

9072-410: The original "flying brick" layout, so called due to the external appearance of the engine. The layout of these original K engines is unique within motorcycling in that the engine is mounted lying on its side, with the crank on the right side of the bike and the cylinder heads and valve gear on the left. This format had the advantage of allowing the drive system to have only one 90-degree translation within

9180-483: The point of view of the pilot looking forward, so for example on a four-engine aircraft such as the Boeing 747 , engine No. 1 is on the left side, farthest from the fuselage, while engine No. 3 is on the right side nearest to the fuselage. In the case of the twin-engine English Electric Lightning , which has two fuselage-mounted jet engines one above the other, engine No. 1 is below and to the front of engine No. 2, which

9288-432: The power-to-weight ratio is very important, making the Wankel engine a good choice. Because the engine is typically constructed with an aluminium housing and a steel rotor, and aluminium expands more than steel when heated, a Wankel engine does not seize when overheated, unlike a piston engine. This is an important safety factor for aeronautical use. Considerable development of these designs started after World War II , but at

9396-576: The previous engine, producing more torque due in part from a butterfly flap fitted in the exhaust. In 2011, BMW launched the K1600 range—the K1600GT and K1600GTL—featuring a new 1,649 cc (100.6 cu in) straight-six engine , which is mounted transversely across the chassis. The engine is angled forward by 50°. The engine was originally used on the Concept 6, a concept bike that

9504-518: The rear suspension (rear drive, drive shaft, transmission, and lower or upper brace). Other motorcycle manufacturers have patented similar designs, including Arturo Magni for MV Agusta and Magni-Moto Guzzi machines, and Moto Guzzi 's Compact Reactive Shaft Drive. In 1935, BMW fitted the first mass-produced hydraulically damped telescopic fork to its R12 and R17 motorcycles. BMW still uses telescopic forks today on its F-series, G-series, HP, and S1000RR motorcycles. The R-series, which had used only

9612-530: The same 652 cc engine fitted to the F650GS, although that engine is no longer manufactured by Rotax. The latest version of the 652 cc single engine fitted in the new G650GS is now produced in Berlin after 2 years production in Loncin, China. In November 2007, the G450X sport enduro motorcycle was launched using a 450 cc single-cylinder engine. The G450X contained several technological improvements over

9720-529: The same width". Both can be used to move objects by attaching pockets, buckets, or frames to them; chains are often used to move things vertically by holding them in frames, as in industrial toasters, while belts are good at moving things horizontally in the form of conveyor belts . It is not unusual for the systems to be used in combination; for example the rollers that drive conveyor belts are themselves often driven by drive chains. Drive shafts are another common method used to move mechanical power around that

9828-526: The serious off-road competition motorcycle market with the release of the BMW G450X motorcycle. BMW Motorrad motorcycles are categorized into product families, and each family is assigned a different letter prefix. The current families are: BMW Motorrad achieved record sales for the fifth time in succession in 2015. With a total of 136,963 vehicles sold in 2015, BMW registered a 10.9% increase in sales in comparison with 2014. The biggest single market in 2015

9936-664: The six-cylinder K1600 series fitted to the K1600GT and GTL models. The first K-series production bike was the K100 , which was introduced in 1983. In 1988, BMW introduced the K1 which had the Bosch Motronic fuel injection system. From 1985 to 1996, the K75 740 cc three-cylinder engine was produced. In 1991, BMW increased the displacement of the K100 from 987 cc to 1,097 cc and

10044-431: The sprocket link by link. It starts as soon as the pitch line of the chain contacts the first tooth of the sprocket. This contact occurs at a point below the pitch circle of the sprocket. As the sprocket rotates, the chain is raised up to the pitch circle and is then dropped down again as sprocket rotation continues. Because of the fixed pitch length, the pitch line of the link cuts across the chord between two pitch points on

10152-412: The sprocket, remaining in this position relative to the sprocket until the link exits the sprocket. This rising and falling of the pitch line is what causes chordal effect or speed variation. In other words, conventional roller chain drives suffer the potential for vibration, as the effective radius of action in a chain and sprocket combination constantly changes during revolution ("Chordal action" ). If

10260-439: The time the aircraft industry favored the use of turbine engines. It was believed that turbojet or turboprop engines could power all aircraft, from the largest to smallest designs. The Wankel engine did not find many applications in aircraft, but was used by Mazda in a popular line of sports cars . The French company Citroën had developed Wankel powered RE-2  [ fr ] helicopter in 1970's. In modern times

10368-414: The two crankshafts geared together. This type of engine has one or more rows of cylinders arranged around a centrally located crankcase . Each row generally has an odd number of cylinders to produce smooth operation. A radial engine has only one crank throw per row and a relatively small crankcase, resulting in a favorable power-to-weight ratio . Because the cylinder arrangement exposes a large amount of

10476-435: The use of a glow plug ) powered by glow fuel , a mixture of methanol , nitromethane , and lubricant. Electrically powered model airplanes and helicopters are also commercially available. Small multicopter UAVs are almost always powered by electricity, but larger gasoline-powered designs are under development. Chain drive Chain drive is a way of transmitting mechanical power from one place to another. It

10584-474: The various R series engines leads to the use of the distinguishing names airhead and oilhead. Airheads are BMW motorcycles with an air-cooled vertical-single or horozintally-opposed twin engine that were built from 1923 to 1995. Most airheads made from 1969 to 1995 used the BMW 247 engine , although 248/1 engines were used on mid-sized R-series motorcycles from 1978 to 1993. Even high-performance motorcycles, such as

10692-399: The years after the war, the drawbacks of the turbojet gradually became apparent. Below about Mach 2, turbojets are very fuel inefficient and create tremendous amounts of noise. Early designs also respond very slowly to power changes, a fact that killed many experienced pilots when they attempted the transition to jets. These drawbacks eventually led to the downfall of the pure turbojet, and only

10800-616: Was built by Aprilia around a carbureted 650 cc four-stroke, four-valve, single-piston engine, and chain drive. The mission for the F ;650 was to provide an entry-level BMW motorcycle. In 2000, the F650 was redesigned, now with fuel injection, and labeled the F650GS . An off-road focused F650 Dakar model was also launched that year. 2002 saw the addition of the F650CS 'Scarver' motorcycle to

10908-555: Was given power via the hydraulic works of Su's water clock tank and waterwheel, the latter which acted as a large gear . Most chain drive systems use teeth to transfer motion between the chain and the rollers. This results in lower frictional losses than belt drive systems, which often rely on friction to transfer motion. Although chains can be made stronger than belts, their greater mass increases drive train inertia . Drive chains are most often made of metal, while belts are often rubber, plastic, urethane, or other substances. If

11016-526: Was once again Germany (23,823 units), followed by the United States (16,501 units), France (12,550 units), Italy (11,150 units), United Kingdom (8,200 units) and Spain (7,976 units). With an aim for 2020 to supply 200,000 vehicles to customers, BMW Motorrad is targeting an increase of its dealership from around 1,100 to 1,500 in the future. As it was the case until now, BMW's most successful motorcycle

11124-512: Was originally depicted in the written horological treatise of the Song dynasty by the medieval Chinese polymath mathematician and astronomer Su Song (1020–1101 AD), who used it to operate the armillary sphere of his astronomical clock tower , which is the first astronomical clock, as well as the clock jack figurines presenting the time of day by mechanically banging gongs and drums. The chain drive itself converted rotary to reclinear motion and

11232-610: Was shown at the 2009 EICMA Milan Motor Show . BMW claims that the engine at 560 mm (22 in) wide, just 67 mm (2.6 in) wider than the K1300 engine, is the narrowest six-cylinder engine ever produced. Cylinder bore is 72.0 mm (2.83 in) and the distance between cylinder centres 77 mm (3.0 in). The camshaft is hollow, with cam lobes pressed on, which saves around 2 lb (0.91 kg). The engine has electronic throttle control and multiple drive modes which can be set according to road conditions. BMW uses

11340-572: Was the Gnome Omega designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically. Before the first World War most speed records were gained using Gnome-engined aircraft, and in the early years of the war rotary engines were dominant in aircraft types for which speed and agility were paramount. To increase power, engines with two rows of cylinders were built. However,

11448-479: Was the German unmanned V1 flying bomb of World War II . Though the same engines were also used experimentally for ersatz fighter aircraft, the extremely loud noise generated by the engines caused mechanical damage to the airframe that was sufficient to make the idea unworkable. The Gluhareff Pressure Jet (or tip jet) is a type of jet engine that, like a valveless pulsejet, has no moving parts. Having no moving parts,

11556-423: Was the main feature which differentiated the safety bicycle introduced in 1885, with its two equal-sized wheels, from the direct-drive penny-farthing or "high wheeler" type of bicycle. The popularity of the chain-driven safety bicycle brought about the demise of the penny-farthing, and is still a basic feature of bicycle design today. Many early cars used a chain drive system, which was a popular alternative to

11664-487: Was used to avoid the spark plugs oiling up. In military aircraft designs, the large frontal area of the engine acted as an extra layer of armor for the pilot. Also air-cooled engines, without vulnerable radiators, are slightly less prone to battle damage, and on occasion would continue running even with one or more cylinders shot away. However, the large frontal area also resulted in an aircraft with an aerodynamically inefficient increased frontal area. Rotary engines have

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