On the future of gears in electrified drive trains

Abstract

The development of transmission types for passenger cars clearly shows a significant increase in vehicles with an electrified powertrain. Due to the electrification of the powertrain the total number of necessary gears is drastically reduced in battery electrical vehicles (BEV). Transmissions become lighter, more compact and their complexity is decreased. These changes leave the question open whether transmissions are still needed in the future. However, the requirements in terms of power density, efficiency and NVH are becoming more demanding. To meet these requirements, a large number of research projects are in progress which face the challenges in electrified transmissions. The following paper gives a broad overview over those research projects and shows the essential necessity of transmissions in electrified powertrains in the future.