Electric cars: "There will still be gearboxes"
Anybody who thought that most of the classic engine and drive train components would be superfluous in a pure electric car would be mistaken. An "electric", of course, doesn't need a turbocharger or carburetor. But is that true for the other apparently superfluous components, such as the gearbox or the cooling system? And what is the significance of this general development for LMT, whose gear cutting tools are responsible in so many places for the efficient production of engine building components?
The VDA’s reference to "variants" should be noted carefully. There are important differences between the "mild hybrid", "plug-in hybrid" and the pure electric car:
• In the mild hybrid, for instance, the electric motor only supports the combustion motor when required, but does not provide forward drive on its own. (In the full hybrid this is precisely what is possible in city traffic.)
• In the plug-in hybrid, the electric motor is also charged at an electric socket. Here again, many models still include a combustion engine.
• Only the pure electric car no longer has a combustion engine.
2020: Every fifth vehicle with an electric motor
The exhibition makes one thing clear: in the future, engine building will involve far more diversification than in the past. The spectacular figures from a current Roland-Berger study must also be seen in this context. As early as 2020, according to this study, every fifth newly licensed vehicle in Europe will have an electric motor. "All the same, this estimate does not mean that 20% of vehicles will be pure electric cars. In most cases these will be hybrid models, which will also have a combustion engine" explained Friedrich Momper, marketing manager for the gear cutting segment at LMT. What do these figures mean for engine building? Bearing the hybrid models in mind, the answer is quite simple. The combustion engine, which is still included, works according to the familiar principles. Gears, starter, clutch and radiator are all there. The range of parts needed, for instance, for a classic gearbox, will therefore be substantially unchanged.Which gearboxes for electric cars?
The situation for the pure electric car is rather different. All the same, the list of engine components that are no longer required is a lot smaller than many would at first assume. Under certain conditions, even gearboxes and clutches, or the cooling system, may indeed be present. Consider cooling the motor for example: the more powerful the motors become, the more waste heat they generate. Drive components such as the voltage converter, the electric motor itself, and the power electronics therefore have to be cooled if they are to stay functioning for a long time.The situation in the gear field is similar – at least if we do not assume exclusive use of the so-called hub motors, in which the gearbox, and the tooth wheels required, are a great deal smaller, single-stage or even absent. However, there are a number of reasons why it is improbable that the electric cars of the future will only be driven with hub motors: it is indeed true that these motors are particularly efficient, since friction losses can be avoided. To a certain extent the motor and drive form a single unit here. "On the other hand, the direct connection between the engine and the wheels increases the total proportion of non-sprung mass. That is something that we try to avoid in car design as far as possible. It makes the running gear, for instance, more awkward. In addition, the drive is subject to high impact stresses.The use gears is therefore not improbable for conventional electric motor - in order, for example, to be able to exploit the range of the motor’s rotation speeds, which is now carried by the suspension, optimally. On the whole they are likely to be smaller constructions (as, therefore, are the components and gearwheels required). And one more thing: the number of components often depends on the general concept of the solution. In the hybrid drive there is also an "electric drive" module in addition to the "combustion engine" drive module and so forth. This implies an increase in the number of cutting operations and the cutting times. Experts estimate that, in comparison to a conventional drive train, the manufacture of a hybrid vehicle will involve 26 per cent more turning and 13 percent more milling.
LMT is ready for technical development
Gear hobs have proven themselves for more than a hundred years now in the manufacture of gear wheels and other tooth-cutting tasks. And LMT Fette, as a tooth cutting specialist, has pushed forward the development and production of these and other tooth-cutting tools for nearly as long. "Gear cutting technology also remains a field with a future in car building", adds Momper.
The powerful solutions developed for machining lightweight materials such as aluminum, plastics and composite materials also illustrate how technical advances in car-making will involve the innovative capabilities of the tool development engineers at LMT. Large manufacturers are right now beginning to make structural automobile components from composite materials. This, in turn, is of great importance for electric vehicles, since every kilo taken off the total weight increases the range of the vehicle. LMT Belin and LMT Onsrud have specialized in machining these materials.