Dual Clutch in 2010
Dual-Clutch Transmissions Explained
Posted Oct 3, 2007, 07:24 AM by Bob Lee
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Bob Lee is vice president of powertrain at Chrysler
It’s absolutely essential that every aspect of a vehicle be pushed for fuel efficiency. And how many new technologies can make a tank of gas go further but also improve torque and responsiveness? The new six-speed dual-clutch transmission – developed in partnership with Getrag – can do just that. Getrag is a well-known company in Europe and is famous for creating innovative solutions for rapidly changing times.
In essence, the new dual-clutch transmissions—or DCTs as they're called—mix the best attributes of manual and automatic transmissions. The DCT is expected to deliver up to a six percent improvement in fuel economy when it joins the Chrysler lineup in the 2010 model year.
A DCT operates at a high level of mechanical efficiency, which results in better fuel economy. The new transmissions also are extremely responsive. With two shafts and two clutches, there’s a preconditioning event that allows the shift to happen very quickly. Today, a standard automatic transmission may shift in 300 milliseconds, but the DCT can cut that time in half. The ability to shift twice as fast delivers greater performance and adds to the “fun-to-drive” factor.
As part of Chrysler’s Recovery and Transformation Plan, a new plant in Tipton County, Indiana, will build 700,000 DCTs annually.
Chrysler is working on a number of new technologies to improve fuel economy and performance, such as diesel engines, biofuels, our multi-displacement system in a V-6, a new common axle program and parasitic loss initiatives just to name a few. Chrysler is taking a holistic view on improving fuel economy in every aspect of the vehicle and the processes that create it.
How Dual-clutch Transmissions Work
by Bill Harris
Inside This Article
1. Introduction to How Dual-clutch Transmissions Work 2. Dual-clutch Transmission Shafts 3. Pros and Cons of Dual-clutch Transmissions 4. Dual-clutch Transmissions: Past, Present and Future 5. Lots More Information 6. See all Under the Hood articles
Photo courtesy Audi Press Database
Audi Direct-shift Gearbox. See more pictures of dual-clutch transmissions.
Most people know that cars come with two basic transmission types: manuals, which require that the driver change gears by depressing a clutch pedal and using a stick shift, and automatics, which do all of the shifting work for drivers using clutches, a torque converter and sets of planetary gears. But there's also something in between that offers the best of both worlds -- the dual-clutch transmission, also called the semi-automatic transmission, the "clutchless" manual transmission and the automated manual transmission.
In the world of racecars, semi-automatic transmissions, such as the sequential manual gearbox (or SMG), have been a staple for years. But in the world of production vehicles, it's a relatively new technology -- one that is being defined by a very specific design known as the dual-clutch, or direct-shift, gearbox.
Thank You
Thanks to Jeff Beckman for his assistance with this article.
This article will explore how a dual-clutch transmission works, how it compares to other types of transmissions and why some predict that it is the transmission of the future.
Hands-On or Hands-Off
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