As in most e-systems, the heart of the ConnActive eDrive is a radial flux motor. However, this conventional drive unit has also been intelligently refined.
The motor with a diameter of 250 mm and 20 mm active stator length is responsible for the continuous performance of the e-drive – and thanks to its design and its innovative material it more than fulfills its role!
MAXIMUM PERFORMANCE …
The compactly designed high-speed radial flux motor has an output of 35 kW with 21 Nm and thus ensures continuous powerful propulsion. The power output is throttled at 18.000 rpm, as the corresponding number of available bearings are adjusted for precisely this performance level.
This high speed and an electrical switching frequency of 40 kHz are made possible, first and foremost, by the innovative SMC material which allows the RX motor to perform with low losses.
The result: downsizing and savings on magnetic material with uncompromised performance.
… MINIMAL LOSSES
Because the stator is produced from extra fine Soft Magnetic Composites (SMC) which keep eddy current losses particularly low, reducing them by up to 50% in direct comparison with conventionally manufactured systems.
Similarly, a completely new manufacturing technique has been developed for the rotor to ensure that it can stand up to the particularly high stresses. A special SMC material makes the rotor significantly more stable, whilst the torque ripple can be measurably reduced.
The large outer diameter of 250 millimeters was particularly challenging for the developers when they were producing the stator, as compressing the powder requires extreme force, which currently only very few special presses can deliver. But here, too, the engineers quickly came up with a smart solution: the stator was simply segmented. This is hardly noticeable in the drive’s design, but makes production significantly simpler.
And the ConnActive team have made things as simple as possible with the coils as well: the wire coils of just 6.5 x 2.5 mm diameter are pre-wound and then simply slid onto the corresponding teeth. Not only does this save valuable time, but ultimately it saves material and thus hard cash as well. And best of all: both the thermal and the energetic behaviour are measurably better than with conventional coils.
The use of innovative materials and the sophisticated design deliver enhanced performance and superior robustness: there are considerable weight savings and the required installation space is comparatively small. This effect is further reinforced by additional, integrative approaches and solutions such as the busbar wiring, for example, which is located inside the unit and thus requires no additional space.
Alvier Mechatronics GmbH
„By combining tried-and-tested technology with completely new, innovative components and materials we’re opening up pioneering opportunities in motor development that we can already rely upon today.“