New Transmissions from Getrag and Kia Help Refocus Interest in DCTs
With industry interest in dual clutch transmissions running at a high level following the announcement of Volkswagen’s upcoming ten-speed DSG and Honda’s torque converter-equipped eight-speed, leading independent transmission producer Getrag has announced the first production application for its latest DCT and the Korean Hyundai-Kia group has unveiled its seven-speed, developed in-house using experience from its earlier six-speed unit.
Undoubtedly the big hitter in the dual clutch transmission business, Germany-based Getrag’s new 7DCT300 is part of a modular family spanning a wide range of torque capacities, as well as different electrification and hybridization options. In the lead-up to the Geneva motor show, Getrag executive vice president for sales Bernd Eckl announced that the first series application for the new 7DCT300 would be in the prestigious new Renault Espace luxury crossover, set to go on sale later this year.
Getrag’s latest dual clutch transmission, the seven-speed wet clutch 7DCT300, will launch on the new Renault Espace.
According to Eckl, further models and brands will follow. “The launch of the 7DCT300 for the Renault Espace is only the beginning. With already over 100 planned applications, the 7DCT300 has the greatest potential in our company’s history. We are very happy that this initial launch is running so smoothly and completely to plan,” he said.
The transmission has just started production at Getrag’s Neuenstein plant in Germany and will begin manufacture in China in 2017. In the medium term, says the company, the new unit with its wet clutches and 300 Nm torque handling capacity will sit alongside the smaller 6DCT150, the dry clutch unit that is used in the Renault Mégane and Clio, as well as Ford and Volvo models. In the longer term, members of the new wet clutch modular family with lower torque capacities, and perhaps fewer ratios, are likely to replace the dry clutch models.
The Getrag modular system enables cost reduction through intelligent sharing of components and systems. One such example is Smart Actuation, an intelligent power-on-demand actuation system which, says Getrag, adds to the high efficiency of the 7DCT300: “Its use enables power consumption of under 40 W to be achieved – less energy than a light bulb and 3.5 percent more efficient than second generation DCTs.”
This further consolidates Getrag’s “best in class” position, says the company.
The modular nature of the transmission family also means that package space is very nearly the same for all versions, whether conventional, 48 V mild hybrid or full-specification high-voltage plug-in hybrid. This translates into useful savings on the assembly line, when all versions can be produced interchangeably on the same track.
Kia’s seven-speed dual clutch transmission is paired with the new one-liter three-cylinder turbo gasoline engine in a state-of-the-art downsized power train.
Unusually, in its first production application the Kia transmission (above) will be paired with the group’s new Kappa one-liter, three-cylinder turbo gasoline engine, as well as with the more familiar 1.6 liter CRDi diesel, where it replaces the earlier six-speed planetary automatic in the mid-range cee’d GT model line. The former combination is precisely the type of downsized powertrain that most automakers are expected to employ to meet upcoming CO2 regulations for 2020 and beyond.
The Kia transmission uses twin dry clutches, placing it somewhat against the most recent trend for wet clutches, even on low-torque systems. Even so, Kia quotes a maximum torque handling capacity of 300 Nm for the new unit, well above the 1.6 diesel’s 285 Nm and the gasoline Kappa’s 172 Nm. During the transmission’s development, Kia engineers targeted a 3 to 5 percent improvement in acceleration and five to seven percent gain in fuel efficiency.
Last month, we reported on the new high-torque seven-speed DSG dual clutch transmission from the Volkswagen group. With its use of wet clutches and closely stacked lower gear ratios, it offers markedly better driveability than the familiar dry-clutch seven speed employed on smaller VW Group products, especially those with gasoline engines.
SOURCE: DRIVELINE NEWS
