The name of the transaxle is the GR6 and like all other DCTs, it is fundamentally structured like a manual-shift transmission that has been automated. For a racecar, the GTR is certainly on top of the heap when it comes to speed and, although limited in production, is gaining in popularity. The Nissan GTR is some-what unique due to the fact that it is actually an AWD application, which is just a bit uncommon for a high-performance vehicle. The driveshaft merely bolts to a connecting flange at the front of the transmission. The vehicle architecture is that of a Corvette, with both the transmission and differential mounted at the back with a driveshaft connecting the assembly to the engine. In 2007, Nissan chose to use a wet 6-speed DCT for the transaxle assembly. Nissan produces a high-performance racecar called the GTR, which cost in excess of $100,000 and is equipped with a 3.8L, 545 HP engine. The DCT shown is from Nissan but, is not for a run-of-the-mill model. There are, however, a couple of RWD applications, one of which is in Figure 1. Today, there are a multitude of vehicle applications that come equipped with a wet or dry DCT, the bulk of which are FWD models. The two main functions that require control are apply and release of the input (start) clutch, and the upshift and downshift of the transmission speeds.Ĭonfigurations do vary between FWD and RWD applications. Controls for one type of DCT could be strictly electro/mechanical while another type could be hydraulic with computer commands. Regardless of design, this input (start) clutch in effect has two of everything with one set of components driving one input shaft and the other set of components driving the other input.Ĭontrols also vary between wet and dry models as well as early and late model designs. The dual-clutch assembly (wet or dry) is the starting point of the transmission assembly. That arrangement requires a different engine/transmission connection than a traditional manual-shift clutch or automatic torque converter. Enter the DCT.Ī DCT has two input shafts, two output shafts (FWD) with normal gearing in between, all within a single housing. Another approach was needed to improve performance. Whether shifting and clutch operations were controlled by electrical components or not, overall function remained manual shift. Automated or not, transmissions involved were basic manual-shift units with a traditional single-disc clutch assembly. This new format was basically limited to high-performance applications. In an effort to eliminate the third pedal (clutch pedal) in certain vehicles, manufacturers, beginning in the ʼ80s, started to automate regular manual transmissions (AMT). That is the basis of the DCT operation regardless of the frictional elements that the transmission is designed with. The question became, what if a shift could be prestaged making the gear transition less abrupt, in effect, having two transmissions side by side working alternately. The focus behind the DCT was to capture the best attributes of both automatic and manual transmission designs with the emphasis on manufacturing cost, drivability, durability and adaptability.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |