Thanks to numerous innovations at component and system level, ZF Friedrichshafen from Germany has achieved a higher power density and energy efficiency with the new generation of electric drives. The focus is on a compact drive design and resource-saving use of materials. The guiding principle behind the so-called “discrete package technology” is a high degree of component uniformity as well as adaptability.
85% continuous output achievable
With the help of a new type of cooling concept combined with innovative winding technology, the power density of ZF’s electric motors can stand out from existing drive solutions. The cooling concept provides for external cooling of the copper rods by an oil flowing around the conductor, which reaches the individual slots through the lamination stack. According to ZF, a continuous output of 85% of the peak output can be achieved. At the same time, the new cooling concept reduces the proportion of rare-earth materials for the permanent magnets in the rotor, as these can be designed for lower thermal loads.
Smaller installation space and winding head height
Instead of conventional hairpin winding technology, the continuous braided winding developed by ZF is used, which, in addition to a smaller installation space, also provides for a significant reduction in the winding head height. In addition, the process of contacting the copper ends, which is one of the most critical steps within stator production, is realized with only 24 welding points by using the new technology.
