Dual Clutch
   HOME

TheInfoList



OR:

A dual-clutch transmission (DCT) (sometimes referred to as a twin-clutch transmission) is a type of multi-speed
vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...
transmission system In telecommunications, a transmission system is a communication system that transmits a signal from one place to another. The signal can be an signal (electrical engineering), electrical, fiber-optic communication, optical or radio wave, radio s ...
, that uses two separate
clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...
es for odd and even gear sets. The design is often similar to two separate
manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canadian English, Canada, British English, the United Kingdom and American English, the United States), or stick shift (in the United States), is a multi-speed ...
s with their respective clutches contained within one housing, and working as one unit. In car and truck applications, the DCT functions as an
automatic transmission An automatic transmission (AT) or automatic gearbox is a multi-speed transmission (mechanics), transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions. The 1904 ...
, requiring no driver input to change gears. The first DCT to reach production was the ''Easidrive'' automatic transmission introduced on the 1961 Hillman Minx mid-size car. This was followed by various eastern European tractors through the 1970s (using manual operation via a single clutch pedal), then the Porsche 962 C racing car in 1985. The first DCT of the modern era was used in the 2003 Volkswagen Golf R32. Since the late 2000s, DCTs have become increasingly widespread, and have supplanted hydraulic automatic transmissions in various models of cars. More generally, a transmission with several clutches can be called a multi clutch transmission. For example, the Koenigsegg Jesko has a transmission with one clutch per gear, making for a total of 7 clutches.


Design

The fundamental principle of a DCT is that one clutch drives a gear-set for the even-numbered gears, while the other clutch drives the odd-numbered gears. Since the DCT can pre-select an odd gear while the vehicle is being propelled in an even gear (or vice versa), DCTs can shift several times faster than is possible with a manual transmission. By timing the operation of one clutch to engage at the precise moment that the other is disengaging, a DCT can shift gears without interrupting the torque supply to the wheels. A DCT uses clutch packs (as per a manual transmission), rather than the
torque converter A torque converter is a device, usually implemented as a type of fluid coupling, that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the ...
used by traditional (hydraulic) automatic transmissions. The DCT clutches are either "wet" or "dry" and are similar to the clutches used in most motorcycles. Wet-clutches are bathed in oil to provide cooling for the clutch surface, therefore wet-clutches are often used in applications with higher torque loads, such as the engine in the
Bugatti Veyron The Bugatti Veyron EB 16.4 is a mid-engine sports car designed and developed in Germany by the Volkswagen Group and Bugatti, and manufactured in Molsheim, France by French automobile manufacturer Bugatti. It was named after the racing driver Pi ...
. Several arrangements for the two clutches are possible, and are outlined below: * Most automotive DCTs use two
concentric In geometry, two or more objects are said to be ''concentric'' when they share the same center. Any pair of (possibly unalike) objects with well-defined centers can be concentric, including circles, spheres, regular polygons, regular polyh ...
clutch packs located on the same axis as the
flywheel A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, a ...
. Therefore, the outer clutch pack has a larger diameter than the inner clutch pack. * Many DCTs for tractors (such as the Fortschritt ZT 320) use a similar arrangement where the clutches are located on the same axis of the flywheel. The difference is that the clutches are at different positions on this axis (i.e. one in front of the other) and the same size as each other. This design is used by the ''Tremec TR-9070'' DCT used by the 2020 Ford Mustang Shelby GT500. * Another design (as used by the ''Volkswagen DQ200'' transmission) arranges two identical-size clutches located side-by-side. This design requires two side-by-side input shafts, which are driven from the crankshaft via gears.


History

The concept of a dual-clutch transmission was invented by French engineer
Adolphe Kégresse Adolphe Kégresse (1879, Héricourt, Haute-Saône - 1943) was a French military engineer who invented the half-track and dual clutch transmission. Born at Héricourt, and educated in Montbéliard, he moved in 1905 to Saint Petersburg, Russi ...
in 1939. The transmission was intended for use in the
Citroën Traction Avant The Citroën Traction Avant () is the world's first mass-produced, semi-monocoque bodied, front-wheel drive car. A range of mostly four-door saloon (automobile), saloons and executive cars, as well as longer wheelbased ''"Commerciale"'', and thre ...
, however Kégresse ran out of money before a working model could be developed. One of the first production DCTs was the ''Easidrive'' unit developed in the late 1950s by
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
's
Smiths Industries Smiths or Smith's may refer to: Companies *Smith Electric Vehicles, or Smith's, a manufacturer of electric trucks *Smith's Food and Drug, or Smith's, an American supermarket chain ** Smith's Ballpark, a baseball stadium in Salt Lake City, Utah, U. ...
and Rootes. This DCT – introduced on the 1961 Hillman Minx (Series IIIC) – used two electro-magnetic clutches, along with analogue
electronics Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield ...
and a series of
solenoid upright=1.20, An illustration of a solenoid upright=1.20, Magnetic field created by a seven-loop solenoid (cross-sectional view) described using field lines A solenoid () is a type of electromagnet formed by a helix, helical coil of wire whos ...
s to implement the gear shifts. The ''Easidrive'' was offered as an option on Hillman and Singer models, however it was not a reliable device and many were replaced by conventional manual transmissions.
Porsche Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see below), is a German automobile manufacturer specializing in luxury, high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany. Th ...
began development of DCTs for racing cars in the late 1970s, due to the possibility of a DCT preventing a drop in boost during gear shifts on a turbocharged engine. As the electronics required to control the transmission became compact enough to be practical, the ''Porsche Doppelkupplungsgetriebe'' ('dual-clutch gearbox') (PDK) transmission was installed as a prototype in a
Porsche 956 The Porsche 956 was a Group C sports-prototype racing car designed by Norbert Singer and built by Porsche in 1982 for the Fédération Internationale de l'Automobile, FIA World Sportscar Championship. It was later upgraded to the 956B in 1984. I ...
Le Mans racing car in 1983. The first use of a PDK in competition was the 1985 Porsche 962 C Le Mans racing car, which won the
World Sportscar Championship The World Sportscar Championship was the world Endurance racing (motorsport), endurance racing series run for sports car racing, sanctioned by the Fédération Internationale de l'Automobile (FIA), from 1953 World Sportscar Championship, 1953 t ...
in 1986. The PDK transmission was also used in the 1985 Audi Sport Quattro S1 Group B rally car. The first mass-production passenger car to use a DCT was the 2003 Volkswagen Golf R32.


Manufacturers

; BorgWarner
BorgWarner BorgWarner Inc. is an American automotive and Electric vehicle, e-mobility supplier headquartered in Auburn Hills, Michigan. As of 2023, the company maintains production facilities and sites at 92 locations in 24 countries, and generates revenu ...
produced the first mass-production DCT, as used in the ''R32'' model introduced to the Volkswagen Golf range in 2003. The company have produced many of the DCTs used by the
Volkswagen Group Volkswagen AG (), known internationally as the Volkswagen Group, is a German public multinational conglomerate manufacturer of passenger and commercial vehicles, motorcycles, engines and turbomachinery. Headquartered in Wolfsburg, Lower Saxon ...
(marketed as '' DSG'' for Volkswagen-branded cars) and produced various components for the 2007
Nissan GT-R The Nissan GT-R (''Gran Turismo–Racing''; model code: R35; Japanese: 日産・GT-R; ''Nissan GT-R'') is a series of cars built by Japanese marque Nissan from 2007 to 2025. It has a 2+2 (car body style), 2+2 seating layout and is considered b ...
sports car, an early application for DCTs involving high torque loads. The company supplies several car manufacturers with complete transmission units, wet-clutches and/or
mechatronic Mechatronics engineering, also called mechatronics, is the synergistic integration of mechanical, electrical, and computer systems employing mechanical engineering, electrical engineering, electronic engineering and computer engineering, and also ...
control modules. ; Getrag
Getrag Getrag (), stylized as GETRAG, was a major supplier of transmission systems for passenger cars and commercial vehicles. The company was founded on 1 May 1935, in Ludwigsburg, Germany, by Hermann Hagenmeyer; as the ''Getriebe und Zahnradfabrik ...
began production of DCTs in 2008 and has supplied manufacturers including
BMW Bayerische Motoren Werke AG, trading as BMW Group (commonly abbreviated to BMW (), sometimes anglicised as Bavarian Motor Works), is a German multinational manufacturer of vehicles and motorcycles headquartered in Munich, Bavaria, Germany. Th ...
,
Dacia Dacia (, ; ) was the land inhabited by the Dacians, its core in Transylvania, stretching to the Danube in the south, the Black Sea in the east, and the Tisza in the west. The Carpathian Mountains were located in the middle of Dacia. It thus ro ...
,
Dodge Dodge is an American brand of automobiles and a division of Stellantis, based in Auburn Hills, Michigan. Dodge vehicles have historically included performance cars, and for much of its existence, Dodge was Chrysler's mid-priced brand above P ...
,
Ferrari Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello. Founded in 1939 by Enzo Ferrari (1898–1988), the company built Auto Avio Costruzioni 815, its first car in 1940, adopted its current name in 1945, and be ...
,
Mercedes-Benz Mercedes-Benz (), commonly referred to simply as Mercedes and occasionally as Benz, is a German automotive brand that was founded in 1926. Mercedes-Benz AG (a subsidiary of the Mercedes-Benz Group, established in 2019) is based in Stuttgart, ...
, Ford,
Mitsubishi The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group traces its origins to the Mitsubishi zaibatsu, a unified company that existed from 1870 to 194 ...
,
Renault Renault S.A., commonly referred to as Groupe Renault ( , , , also known as the Renault Group in English), is a French Multinational corporation, multinational Automotive industry, automobile manufacturer established in 1899. The company curr ...
,
Smart ''SMart'' was a British CBBC television programme based on art, which began in 1994 and ended in 2009. The programme was recorded at BBC Television Centre in London. Previously it had been recorded in Studio A at Pebble Mill Studios in Birmingha ...
and
Volvo The Volvo Group (; legally Aktiebolaget Volvo, shortened to AB Volvo, stylized as VOLVO) is a Swedish multinational manufacturing corporation headquartered in Gothenburg. While its core activity is the production, distribution and sale of truck ...
. The ''Getrag 7DCL750'' is a 7-speed DCT which is designed for high-performance engines and has a torque rating of . It is used in mid-engined sports cars such as the 2009
Ferrari 458 The Ferrari 458 Italia (Type F142) is an Italian mid-engine sports car produced by Ferrari. The 458 is the successor of the F430, and was first officially unveiled at the 2009 Frankfurt Motor Show. It was succeeded by the 488 GTB (Gran Turi ...
, the 2014
Mercedes-AMG GT The Mercedes-AMG GT is a series of 2-door sports cars produced by German automobile manufacturer Mercedes-AMG. The car was introduced on 9 September 2014 and was officially unveiled to the public in October 2014 at the Paris Motor Show. While n ...
and the 2017
Ford GT The Ford GT is a Mid-engine design, mid-engine two-seater sports car manufactured and marketed by American automobile manufacturer Ford Motor Company, Ford for the 2005 model year in conjunction with the company's 2003 centenary. The second gene ...
. ; Honda
Honda commonly known as just Honda, is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate automotive manufacturer headquartered in Minato, Tokyo, Japan. Founded in October 1946 by Soichiro Honda, Honda has bee ...
manufactures DCTs for some Honda motorcycles as of 2024, and was the first to add a DCT to motorcycles. Honda also previously manufactured DCTs for some
Acura Acura is the luxury and performance division of Japanese automaker Honda, based primarily in North America. The brand was launched on March 27, 1986, marketing luxury and performance automobiles. Acura sells cars in the United States, Canada, M ...
cars. ; HYUNDAI TRANSYS HYUNDAI TRANSYS manufactures dry 7-speed and wet 8-speed DCTs as of 2024. The DCTs are used in some Hyundai and Kia (e.g. Ceed) vehicles. ; LuK LuK DCTs have been used by Volkswagen Group since 2008, in several smaller cars with relatively low torque outputs. ; Ricardo Ricardo designed and built 7-speed DCT used by the 2005-2015
Bugatti Veyron The Bugatti Veyron EB 16.4 is a mid-engine sports car designed and developed in Germany by the Volkswagen Group and Bugatti, and manufactured in Molsheim, France by French automobile manufacturer Bugatti. It was named after the racing driver Pi ...
, which has a turbocharged 16-cylinder engine producing of torque. ; Stellantis
Stellantis Stellantis N.V. is a multinational automaker formed in 2021 through the Mergers and acquisitions, merger of the Italian–American conglomerate Fiat Chrysler Automobiles (FCA) and the French PSA Group, PSA (Peugeot S.A.) Group. The company's hea ...
manufactures the electrified dual-clutch transmission (eDCT) at the Mirafiori Automotive Park in Italy as of 2024. ; Tremec
Tremec TREMEC (Transmisiones y Equipos Mecánicos SA de CV, formerly Transmission Technology Corporation, TTC) is a manufacturer of automobile transmission (mechanics), transmissions and drivetrain components based in Querétaro, Mexico. Company Torque ...
provides the 8-speed DCT used in the 2020 Chevrolet Corvette C8 and the 7-speed DCT used in the 2020 Ford Mustang Shelby GT500. ; ZF Friedrichshafen
ZF Friedrichshafen ZF Friedrichshafen AG, also known as ZF Group, originally ''Zahnradfabrik Friedrichshafen'' (), and commonly abbreviated to ZF, is a Germany, German technology manufacturing company that supplies systems for passenger cars, commercial vehicles ...
produce the 7-speed DCT used by Porsche (marketed as ''PDK'').


Usage in motor vehicles

Following its 2003 introduction in the Volkswagen Golf R32, a 6-speed DCT (model code ''DQ250''), with two wet-clutches arranged concentrically, has been used in several Volkswagen and Audi models. In 2008, Volkswagen group began production of the ''DQ200'', a 7-speed DCT using two dry-clutches arranged side-by-side (instead of concentrically). Volkswagen claims fuel economy improvements of 6% compared with a 6-speed manual and 20% compared with a traditional (hydraulic) automatic transmission. DCT transmissions have been used on vehicles sold by Alfa Romeo, Volkswagen, Audi, Tata Motors, SEAT, Skoda, and Bugatti, mostly marketed using the term ''Direct-Shift Gearbox'' (except for Alfa Romeo, which has used the term TCT, also Tata Motors uses the term DCA (Dual Clutch Automatic) and Audi, which has also used the term ''S-Tronic''). Usage in high performance cars began in 2005 with the 7-speed DCT used in the
Bugatti Veyron The Bugatti Veyron EB 16.4 is a mid-engine sports car designed and developed in Germany by the Volkswagen Group and Bugatti, and manufactured in Molsheim, France by French automobile manufacturer Bugatti. It was named after the racing driver Pi ...
. Other early high performance applications include the 2007
Nissan GT-R The Nissan GT-R (''Gran Turismo–Racing''; model code: R35; Japanese: 日産・GT-R; ''Nissan GT-R'') is a series of cars built by Japanese marque Nissan from 2007 to 2025. It has a 2+2 (car body style), 2+2 seating layout and is considered b ...
, the 2008 Ferrari California, the 2008
Mitsubishi Lancer Evolution X The Mitsubishi Lancer Evolution X is the tenth and final generation of the Mitsubishi Lancer Evolution, Lancer Evolution, a sports sedan produced by Japanese manufacturer Mitsubishi Motors, designed by Omer Halilhodžić. By September 2005, Mits ...
and the 2009
Porsche 911 (997) The Porsche 997 is the sixth generation of the Porsche 911 sports car manufactured and sold by the German automobile manufacturer Porsche. It was sold between 2004 (for the 2005 model year) and 2013. Production of the Carrera and Carrera S coup ...
. The 2009
Honda VFR1200F The Honda VFR1200F is the 7th generation Honda sport touring motorcycle from the VF and VFR line motorcycles powered by a transverse mounted V4 engine. The VFR1200F has several new technologies including the first dual clutch transmission offer ...
is the first motorcycle to use a DCT. Honda has since expanded the application of the DCT to the Gold Wing model (model year 2018), the Africa Twin, the NT1100, Rebel 1100, and the NC700XD (model year 2012). In 2010, the Mitsubishi Fuso 6-speed ''Duonic'' transmission became the first DCT to be used in a truck. The 2015
Acura TLX The Acura TLX is a four-door entry-level luxury sedan sold by Acura, a luxury division of Honda, since 2014. It is the successor to both the TL and TSX models. As of 2021, the discontinuation of the RLX leaves the TLX as the flagship sedan i ...
uses a
torque converter A torque converter is a device, usually implemented as a type of fluid coupling, that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the ...
(a device typically used in hydraulic automatic transmissions) paired with its 8-speed DCT. The purpose of the torque converter is to improve the smoothness of low-speed driving, through the elimination of jolting and shuddering sometimes found in DCTs at low speed.


Usage in tractors

Several 1970s tractors from eastern European countries (such as the Kirovets K-700 derivatives) used manually operated DCTs. For example, the Fortschritt ZT 300 has an ''Unterlastschaltstufe'' ('shifting under load') function, which needs to be pre-selected by the driver and then activated by pressing the clutch halfway down. This engages the second clutch, which applies a reduction gear to the driven wheels without any interruption in the torque transmission to the wheels.


Usage in railcars

A different type of dual-clutch transmission has been used in some
railcar A railcar (not to be confused with the generic term railroad car or railway car) is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coa ...
s. The two clutches are placed one on the gearbox input shaft and the other on the gearbox output shaft. To make a gear change, both clutches disengage simultaneously and a brake inside the gearbox engages. The gearchange occurs with all gears stationary, so no synchronizing mechanism is needed. After the gear change, both clutches re-engage. There is a significant break in power transmission, so this system is unsuitable for shunting locomotives.


See also

*
Fuel economy in automobiles The fuel economy of an automobile relates to the distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of the volume of fuel to travel a distance, or the distance traveled per unit volume of fue ...
*
Power band The power band of an internal combustion engine or electric motor is the range of operating speeds under which the engine or motor is able to output the most power, that is, the maximum energy per unit of time. This usually means that maximum ...
*
Shift time Shift time refers to the time interval between gear changes in a transmission. This interval is the time in which power delivery is transferred to the next selected gear, and engine speed is reduced or increased to synchronize the speed of the ...
*


References

{{DEFAULTSORT:Dual Clutch Transmission Automotive transmission technologies