Manufacturing vehicles with a battery-powered electric motor poses particular challenges to a carmaker. Electric vehicle development is currently focusing on the faster rotational speeds inside the motor, combined with minimizing power loss and maximizing running performance. What does that mean specifically? Unlike a conventional combustion engine, an electric motor is powered by electricity, meaning no gasoline or diesel needs to be burned. Most electric vehicles are supplied with energy from a rechargeable lithium-ion battery consisting of four storage cells and forming the “traction battery” – individual accumulator cells connected up to make an energy storage system. This system delivers electricity to an induction motor, which is made up of two parts: the alternator and the rotary cylinder. Direct current is thus converted into alternating current. A rotating magnetic field is generated that produces the mechanical energy required to get the wheels moving via a gear system. A one-speed gearbox is usually used, whose sole purpose is to reduce and multiply rotational speeds.
Another component inside the gear system is a differential, which provides power transmission and can drive two wheels in such a way that they can rotate at different speeds in corners but with the same propulsion. The speed can be adjusted by changing the frequency of the power supply, which is determined in the inverter – the electric car’s “brain,” so to speak. The electrical drive axle itself has to be sealed using a high-performance gasket. This is where manufacturers set the pace: for instance, those involved are challenged to exceed the values for rotational speed and overall running performance that are standard on the market by 50%. Although this task may seem highly ambitious at first, ElringKlinger Kunststofftechnik GmbH found a solution: a new generation of PTFE-based radial shaft sealing rings developed by product, material, and process specialists working closely together. Besides the key performance characteristic described above, this new product family is capable of overcoming even more challenges set by the customer. Radial shaft sealing rings are used in the gear system, which contains a number of shafts. The rings “sit” on a shaft, e.g., in front of a gearbox housing, where lubrication takes place. This new, more powerful product family is available for the e-axle under the name “ElroSeal™.”