Volvo using Getrag Powershift 6DCT450 dual clutch transmission with start-stop in diesel models
01 February 2012
|
|
| The 6DCT450. Click to enlarge. |
For its S60, V60, V70 and S80 models with 1.6-liter diesel engines, available from early 2012, Volvo has opted for Getrag’s six-speed 6DCT450 Powershift transmission for further reductions in fuel consumption and CO2 emissions. The S60 diesel with start-stop technology, with 114 g CO2/km (119 g CO2/km in the V60, V70 and S80), now achieves the levels of the manual model equivalents. This equates to NEDC average fuel economy figures of 4.3 and 4.5 liters/100 km (55 and 52 mpg US) respectively.
The transmission’s software has been further improved and additional economy has been achieved by reducing friction between transmission components. The start-stop facility enables a further contribution to fuel economy. To achieve this, the 6DCT450 dual-clutch transmission incorporating wet clutches needs no additional hardware such as a pressure accumulator or electrically driven pump.
Getrag Powershift is Getrag’s product line for modern dual clutch transmissions. All Getrag Powershift transmissions work without torque interruption. When compared to conventional automatic transmissions at a vehicle level, the Powershift transmissions achieve a 5 – 10 % reduction in fuel consumption and CO2 emissions—depending on application, even up to 15%. The high flexibility in the selection of transmission ratios in connection with further optimized transmission efficiency characteristics is an important basic principle.
The six-speed 6DCT450 and 6DCT470 transmissions were developed for front-transverse installation in the mid-size to large-size car segment, as well as in sport utility vehicles (SUV). The transmissions differ mainly in terms of their architecture (shaft arrangement), but use a multitude of the same assemblies. This difference allows the transmissions to be installed in vehicles with different space requirements and torques up to 470 N·m (347 lb-ft).
The GETRAG PowerShift transmissions can be combined with an all-wheel drive as well as an engine start/stop function. Combined with an electric motor, the transmission can also be used in a hybrid drive.
The shortened response times during the gearshift process (compared to conventional multi-step automatic transmissions with a torque converter) allow for greater driving pleasure and provide a more direct driving experience. With a transmission control system that allows individual adaptation of all shifts, it is possible to provide multiple driving profiles (comfortable, sporty, racing, etc.).
Compared to the conventional hydrodynamic converter, dual clutches offer the advantage of targeted actuation resulting in optimized vehicle launch and gearshift processes with respect to the dynamics and driving comfort. In addition, GETRAG PowerShift transmissions combine the high degree of efficiency of a manual transmission with an application-specific shifting strategy, thereby resulting in a considerable reduction of fuel consumption and CO2 emissions compared to conventional automatic transmissions. The transmission control, embedded in a mechatronic module, also works directly with the engine management system.
The 6DCT450 and 6DCT470 front-transverse transmissions have six forward gears and one reverse gear. The even gears (2, 4, 6) and odd-numbered gears (1, 3, 5, R) are divided into two partial transmissions. The engine and the two partial transmissions are connected by means of a double wet clutch. The clutches and the gear selection are controlled hydraulically. Both transmissions share the automation components—dual clutch, integrated or external dampers, pump, mechatronics with hydraulic and electronic control and regulation, sensors, and shift cylinders.
Both transmissions contain integrated and control units, customized to the transmission.
Comments