With all the exhaustive attention that we’ve given the 2016 Chevrolet Volt already, you might think there’s not a solitary aspect of its evolutionary new Voltec powertrain we haven’t already shone light on.
Alas, Motor Trend recently wrote their own dissection of the 2016 Volt’s new combination of engine and electric motors, revealing still more of what makes the plug-in hybrid-electric vehicle go.
What we didn’t previously know about the 2016 Volt’s two electric motors: how their designs differed to offer complimentary respective “sweet spots.” Of course, we had been aware that the new Volt’s plural motors were far from twins, and had been designed with different sizes and different duties in-mind to synergize, and create a cohesive electric torque system. But previously, the nitty gritty had been unknown.
First off, Motor Trend reports that the smaller motor in the General Motors Voltec 2.0 powertrain eliminates rare earth materials altogether by using simple ferrite magnets. These magnets are optimized by their arrangement into a dozen regularly-spaced clusters encircling the central rotor, with each cluster containing four concentric elements. This allows for a maximization of both magnetic, and reluctance (or “magnetic resistance”) torque.
The larger motor, meanwhile, does contain a rare earth metal in the form of the element Dysprosium, but its presence is reduced thanks to some clever engineering. Says Motor Trend, a trick of metallurgy concentrates the Dysprosium into the corners of the larger motor’s magnetic elements, where it’s most effective. Together, not only do the complimentary motors of the new Voltec powertrain manage to use 80 percent less rare earth metals, but they also prove to be ideal counterparts in the revised system. The small motor hits peak efficiency at 5-9k RPM, at relatively lower torque, while the larger motor peaks in efficiency at higher torque, at around 2-4k RPM.
Understanding the newly re-engineered Voltec powertrain of the 2016 Chevrolet Volt is by no means necessary to benefiting from its careful engineering. But at the very least, even if one doesn’t understand it, one can certainly appreciate the complexity.