Prof. Dr.-Ing. Peter Gutzmer, deputy CEO of Schaeffler AG, held opening speech at the International Vienna Motor Symposium
In the future, engine and transmission developers will have to work more closely together in order to achieve significant improvements in fuel economy. In his opening speech at the 36th International Vienna Motor Symposium, Prof. Dr.-Ing. Peter Gutzmer, Deputy CEO of Schaeffler AG, called on them to do just that. “We must consider internal combustion engines, electrical components, and transmissions as a whole”, he told the audience of more than 1,000 participants.
Experts from Schaeffler carried out simulations to demonstrate how the ongoing electrification and transmission design processes influence one another. The first calculation compares a C-segment vehicle with and without a 48-volt hybrid system, respectively. The 1.4-liter gasoline engine is identical in both cases but, while the non-electrified vehicle features a seven-speed transmission, the 48-volt hybrid has only four gears. The use of this electrified transmission provides a fuel economy improvement of 18 percent in the WLTC (Worldwide harmonized Light Vehicles Test Cycle), which will apply in the future.
In its second simulation, Schaeffler tested a sports utility vehicle (SUV) equipped with a 3-liter V6 engine. While the conventional vehicle features an eight-speed planetary transmission, the electrified version is equipped with a 24 kW electric motor installed in a five-speed automatic transmission. The fuel economy improvement achieved in the WLTC is 14 percent in this case, but significant savings can also be achieved even without electrification. “The optimization of the internal combustion engine therefore remains immensely important for Schaeffler”, explained Gutzmer. As an example, he demonstrated how the use of a fully-variable valve train allows fuel consumption to be influenced by changing the opening and closing times of the valves. The engine can thus be operated without throttling at low loads, which reduces fuel consumption by more than eight percent at specific operating points. At high loads, lengthening the intake valve opening time allows the tendency towards knocking and the need for enrichment to be reduced. Further savings could be achieved in all relevant operating ranges through the use of variable compression. “When it comes to energy efficiency, variability pays off”, explained Gutzmer. “However, it must always be assessed together with the number of gears, the degree of electrification, and the system costs.”
Electrification allows a greater number of drive architectures to be achieved. “Because of the wide variety of possible combinations, the automotive industry is under increasing pressure to provide an answer to the question of which drive architecture is the right one”, said Gutzmer. As an automotive supplier, Schaeffler therefore develops technical solutions that allow the overall level of efficiency of the drivetrain to be increased. These include components and systems for modern high-efficiency engines with a high power density as well as clutches and bearings for transmissions. Schaeffler also makes efficient electrification possible at every voltage level, from 48-volt hybrids through to plug-in hybrids with high-voltage technology.
