dual clutch transmission

A dual-clutch transmission offers the function of two manual gearboxes in one. To understand what this means, it's helpful to review how a conventional manual gearbox works. When a driver wants to change from one gear to another in a standard stick-shift car, he first presses down the clutch pedal. This operates a single clutch, which disconnects the engine from the gearbox and interrupts power flow to the transmission. Then the driver uses the stick shift to select a new gear, a process that involves moving a toothed collar from one gear wheel to another gear wheel of a different size. Devices called synchronizersmatch the gears before they are engaged to prevent grinding. Once the new gear is engaged, the driver releases the clutch pedal, which re-connects the engine to the gearbox and transmits power to the wheels.
So, in a conventional manual transmission, there is not a continuous flow of power from the engine to the wheels. Instead, power delivery changes from on to off to on during gearshift, causing a phenomenon known as "shift shock" or "torque interrupt." For an unskilled driver, this can result in passengers being thrown forward and back again as gears are changed.

A two-part transmission shaft is at the heart of a DCT[dual clutch transmission]. Unlike a conventional manual gearbox, which houses all of its gears on a single input shaft, the DCT splits up odd and even gears on two input shafts. The outer shaft is hollowed out, making room for an inner shaft, which is nested inside. The outer hollow shaft feeds second and fourth gears, while the inner shaft feeds first, third and fifth.
The diagram above shows this arrangement for a typical five-speed DCT. Notice that one clutch controls second and fourth gears, while another, independent clutch controls first, third and fifth gears. That's the trick that allows lightning-fast gear changes and keeps power delivery constant. A standard manual transmission can't do this because it must use one clutch for all odd and even gears.

Commercialization of the dual-clutch transmission, however, has not been feasible until recently. Volkswagen has been a pioneer in dual-clutch transmissions, licensing BorgWarner's DualTronic technology. European automobiles equipped with DCTs include the Volkswagen Beetle, Golf, Touran, and Jetta as well as the Audi TT and A3; the Skoda Octavia; and the Seat Altea, Toledo and Leon.

first look of chassis for the dream cart

Since my childhood, i was fascinated by the racing cars.I always like to see myself designing one of those.So, i started working on them. But the greatest obstacle was "designing" itself. yes, i don't know how to design them.So i started learning basic designs with coral draw. The above picture is the design of chassis for my dream go-kart. The dream will turn into reality as soon as i find the members to form a dedicated team. The project cost approx. 30-40k but believe me it's worth it.The single seater kart will be made of square pipes having an old 50-70cc 2 wheeler petrol engine.It will produce a power of around 6-8kw will will took up it's top speed upto 30kmph. It might not be a big project or worth noticing in the professional world but project is close to me as i myself have designed it.
thnx....palash

Begets of automobile engineering

WORLD’S FIRST CAR
Like all of us have our father's ,automobiles are no different. The history of the automobile engineering begins as early as 1769, with the creation of steam-powered automobiles capable of human transport.In 1806, the first cars powered by internal combustion engines running on fuel gas appeared, which led to the introduction in 1885 of the ubiquitous modern gasoline- or petrol-fueled internal combustion engine.German engineer Karl Benz, is generally regarded as the inventor of the modern automobile.In 1886, Karl Benz applied for a patent for his "vehicle with gas engine operation." Patent DRP 37435 for the Benz Patent Motor Car granted in November of the same year is regarded as the birth certificate of the automobile. The four-stroke petrol (gasoline) internal combustion engine that constitutes the most prevalent form of modern automotive propulsion is a creation of German inventor Nikolaus Otto. The similar four-stroke diesel engine was also invented by a German, Rudolf Diesel. The hydrogen fuel cell, one of the technologies hailed as a replacement for gasoline as an energy source for cars, was discovered in principle by yet another German, Christian Friedrich Schönbein, in 1838. The battery electric car owes its beginnings to Hungarian Ányos Jedlik, one of the inventors of the electric motor, and Gaston Planté, who invented the lead-acid battery in 1859.