Mazda Patent Converts Rotary Engine into High-Tech AWD Hybrid Powertrain

The rear axle is driven by the rotary engine, while the front wheels are turned by the in-wheel motors.

Mazda A Japanese patent has been published This could indicate a return to the brand’s rotary motor. According to the paperwork, the powertrain would include a front-mounted combustion engine and an electric motor that turns the rear wheels. Each wheel would be powered by an electric motor with a capacitor system. Mazda claims that this electric all-wheel drive vehicle could be lighter than other methods.

Mazda’s tech uses a small, 3.5-kilowatt hour lithium-ion battery that operates at 48 volts. The capacitor system underneath the combustion engine allows it to get away with a small capacity. Regenerative braking charges the system. When the voltage between the terminals of the capacitor is at a certain level, the charge goes to battery. The battery can also supply the charge if the driver requires acceleration and the capacitor isn’t able to provide enough energy for the in-wheel motors.

Mazda Patent Converts Rotary Engine into High-Tech AWD Hybrid PowertrainAccording to Mazda’s patent, the capacitor is lighter than a battery that powers the in-wheel motors. Additionally, the high-voltage wiring needs to only run from the motors on the front wheels to the capacitor under the hood. These components are closer together, which means that there is less wiring and thus lower weight.

The rear wheels are driven by the electric motor and the combustion engine when the vehicle is stationary. According to the patent, the in-wheel motors only produce a large output in high vehicle speeds.

Mazda Patent Converts Rotary Engine into High-Tech AWD Hybrid Powertrain

The patent document provides details on how to achieve this layout using rotary, inline or V-configuration engines. The paperwork states that the compact dimensions of the rotary make it particularly useful in this system.

The patent states that the rotary might not return in the same way as the patent says, but the motoring industry may still see Wankel’s return. The engine is being used by the automaker as a small extender to its MX-30 electric crossover.