8/7/2015 Direct­shift gearbox ­ Wikipedia, the free encyclopedia Direct­shift gearbox From Wikipedia, the free encyclopedia A direct­shift gearbox (German: Direkt­Schalt­Getriebe[1]), commonly abbreviated to DSG,[2][3] is an electronically controlled dual­clutch[2] multiple­shaft manual gearbox, in a transaxle design – without a conventional clutch pedal,[4] and with full automatic,[2] or semi­manual control. The first actual dual­clutch transmissions derived from Porsche in­house development for 962 racing cars in the 1980s. Part­cutaway view of the Volkswagen In simple terms, a DSG is two separate manual gearboxes (and Group 6­speed Direct­Shift Gearbox. [2] clutches), contained within one housing, and working as one unit. The concentric multi­plate clutches [3][5] It was designed by BorgWarner,[4] and is licensed to the have been sectioned, along with the Volkswagen Group, with support by IAV GmbH. By using two mechatronics module. This also independent clutches,[2][5] a DSG can achieve faster shift times,[2][5] shows the additional power take­off and eliminates the torque converter of a conventional epicyclic for distributing torque to the rear axle automatic transmission.[2] for four­wheel drive applications. ­ View this image with annotations Contents 1 Overview 1.1 Transverse DSG 1.2 Audi longitudinal DSG 2 List of DSG variants 3 Operational introduction 3.1 DSG controls Schematic diagram of a dual clutch 3.1.1 "P" transmission 3.1.2 "N" 3.1.3 "D" mode 3.1.4 "S" mode 3.1.5 "R" 3.1.6 Manual mode 3.1.6.1 Paddle shifters 4 Advantages and disadvantages 5 Applications 5.1 Audi 5.2 Bugatti 5.3 SEAT 5.4 Škoda 5.5 Volkswagen Passenger Cars 5.6 Volkswagen Commercial Vehicles 6 Problems and recalls of DSG­equipped vehicles 6.1 United States of America 6.2 Australia https://en.wikipedia.or6g/.w3ik iC/Dhireinct­ashift_gearbox 1/13 8/7/2015 Direct­shift gearbox ­ Wikipedia, the free encyclopedia 6.3 China 6.4 Sweden 6.5 Japan 6.6 Malaysia 6.7 World wide recall 7 See also 8 References 9 External links 9.1 Official links 9.2 Independent links Dual­clutch gearbox: M: Motor A: Primary drive Overview B: Double Clutch C: shaft Transverse DSG D: main shaft, even gears E: main shaft, odd gears At the time of launch in 2003[2][6] ­ it became the world's first dual F: Output clutch transmission in a series production car,[2][6] in the German­ market Volkswagen Golf Mk4 R32[2][6] and shortly afterwards, worldwide in the original Audi TT 3.2;[7] and for the first few years of production, this original DSG transmission was only available in transversely oriented[2] front­engine, front­wheel­drive — or Haldex Traction­based four­wheel­drive vehicle layouts. The first DSG transaxle that went into production for the Volkswagen Group mainstream marques had six forward speeds (and one reverse),[6][7] and used wet/submerged multi­plate clutch packs[2][4] (Volkswagen Group internal code: DQ250, parts code prefix: 02E).[7][8] It has been paired to engines with up to 350 N·m (260 lb·ft) of torque,[6][7] and the two­wheel­drive version weighs 93 kg (205 lb). It is manufactured at Volkswagen Group's Kassel plant,[2] with a daily production output of 1,500 units.[6] At the start of 2008, another world first,[6] an additional 70 kg (150 lb) seven­speed DSG transaxle[6] (Volkswagen Group internal code: DQ200, parts code prefix: 0AM)[8][9][10] became available. It differs from the six­speed DSG, in that it uses two single­plate dry clutches (of similar diameter).[10] This clutch pack was designed by LuK Clutch Systems, LLC.[11] This seven­speed DSG is used in smaller front­wheel­ drive cars with smaller displacement engines with lower torque outputs,[6][7][10] such as the latest Volkswagen Golf,[6][10] Volkswagen Polo Mk5,[10] and the new SEAT Ibiza.[7] It has been paired to engines with up to 250 N·m (180 lb·ft).[12] It has considerably less oil capacity than the six­speed DQ250; this new DQ200 uses just 1.7 litres (0.37 imp gal; 0.45 US gal) of transmission fluid.[6] In September 2010, VW launched a new seven­speed DSG built to support up to 650 N·m (480 lb·ft), the DQ500. Its first use was in the Audi TT­RS.[13] Audi longitudinal DSG https://en.wikipedia.org/wiki/Direct­shift_gearbox 2/13 8/7/2015 Direct­shift gearbox ­ Wikipedia, the free encyclopedia In late 2008, an all­new seven­speed longitudinal[7][14] S tronic[14] version of the DSG transaxle went into series production (Volkswagen Group internal code: DL501, parts code prefix: 0B5).[8] Initially, from early 2009, it is only used in certain Audi cars, and only with longitudinally mounted engines. Like the original six­speed DSG, it features a concentric dual wet multi­plate clutch.[14] However, this particular variant uses notably more plates — the larger outer clutch (for the odd­numbered gears) uses 10 plates, whereas the smaller inner clutch (driving even­numbered gears and reverse) uses 12 plates.[14] Another notable change over the original transverse DSGs is the lubrication system[15][16] — Audi now utilise two totally separate oil circuits.[14] One oil circuit, consisting of 7.5 litres (1.65 imp gal; 1.98 US gal), lubricates the hydraulic clutches and mechatronics with fully synthetic specialist automatic transmission fluid (ATF),[14] whilst the other oil circuit lubricates the gear trains and front and centre differentials with 4.3 litres (0.95 imp gal; 1.14 US gal) of conventional hypoid gear oil.[14] This dual circuit lubrication is aimed at increasing overall reliability, due to eliminating cross­contamination of debris and wear particles.[14] It has a torque handling limit of up to 600 N·m (440 lb·ft),[7] and engine power outputs of up to 330 kW (450 PS; 440 bhp).[7] It has a total mass, including all lubricants and the dual­mass flywheel of 141.5 kg (312 lb).[7] This was initially available in their quattro all­wheel­drive variants,[8] and is very similar to the new ZF Friedrichshafen­supplied[17] Porsche Doppel­Kupplung (PDK).[18][19] List of DSG variants name speeds max. torque (N·m) type DQ200 7 250 dry DQ250 6 350 wet DQ380[20] 7 380 wet DQ500 7 550 wet DQ511 10 550 wet DL501 7 550 wet Operational introduction The internal combustion engine drives two clutch packs.[2][4][5] The outer clutch pack drives gears 1, 3, 5[2] [4] (and 7 when fitted), and reverse[2] — the outer clutch pack has a larger diameter compared to the inner clutch, and can therefore handle greater torque loadings. The inner clutch pack drives gears 2, 4, and 6.[2][4] Instead of a standard large dry single­plate clutch, each clutch pack for the six­speed DSG is a collection of four small wet interleaved clutch plates (similar to a motorcycle wet multi­plate clutch). Due to space constraints, the two clutch assemblies are concentric, and the shafts within the gearbox are hollow and also concentric.[5] Because the alternate clutch pack's gear­sets can be pre­selected[2][4][5] (predictive shifts enabled via the 'unused' section of the gearbox), un­powered time while shifting is avoided[2][5] because the transmission of torque is simply switched from one clutch­pack to the other.[2] This means that the DSG https://en.wikipedia.org/wiki/Direct­shift_gearbox 3/13 8/7/2015 Direct­shift gearbox ­ Wikipedia, the free encyclopedia takes only about 8 milliseconds to upshift.[3][4] In comparison, the sequential manual transmission (SMT) in the Ferrari F430 Scuderia takes 60 milliseconds to shift,[21] or 150 milliseconds in the Ferrari Enzo.[3] The quoted time for upshifts is the time the wheels are completely non­powered. DSG controls The direct­shift gearbox uses a floor­mounted transmission shift lever, very similar to that of a conventional automatic transmission.[10] The lever is operated in a straight 'fore and aft' plane (without any 'dog­leg' offset movements), and uses an additional button to help prevent an inadvertent selection of an inappropriate shift lever position. "P" P position of the floor­mounted gear shift lever means that the transmission is set in "Park". Both clutch packs are fully disengaged, all gear­sets are disengaged, and a solid mechanical transmission 'lock' is applied to the crown wheel of the DSG's internal differential. This position must only be used when the motor vehicle is stationary. Furthermore, this is the position which must be set on the shift lever before the vehicle ignition key can be removed. "N" N position of the floor­mounted shift lever means that the transmission is in "neutral". Similar to P above, both clutch packs and all gear­sets are fully disengaged; however, the parking lock is also disengaged. "D" mode Whilst the motor vehicle is stationary and in neutral (N), the driver can select D for "drive" (after first pressing the foot brake pedal). The transmission's reverse gear is selected on the first shaft K1,[3] and the outer clutch K2 engages at the start of the 'bite point'. At the same time, on the alternate gear shaft, the reverse gear clutch K1 is also selected[2][3] (pre­selected), as the gearbox doesn't know whether the driver wants to go forward or reverse.