Electric Axle Drives: Scalable propulsion system for electrified powertrains

摘要

In electrification of the powertrain, electric axles play a decisive role. They are appropriate for use both in hybrid and in pure electric drive concepts which, as a function of the application, have very different performance and design envelope requirements. In functional terms, various options such as parking lock, differential lock or torque vectoring must be taken into consideration. For optimization of the design envelope, weight and costs, there is a clear trend towards the integration of the transmission, electric motor and electronic power system in one assembly. To this end, these principal components must be modularized in such a way that scalability is easily achieved while optimizing the specific design envelope. On the basis of the Schaeffler lightweight differential, transmission solutions of high performance density can be presented in a coaxial or axially parallel design. A scalable modular concept was also developed for the electric drive. In addition to magnet circuits employing various technology, power electronics modules were defined that fulfill the high requirements for cycle strength, performance density and robustness in relation to the ambient conditions in the assembly. The paper shows the design of mechanical and electric modules as well as their functional and physical integration in a specific electric axle.