Mazda Patents Rotary Engine for Range-extended EV

According to a report in Autoblog, Mazda has filed two new patents in the United States that could herald the return of the rotary engine. The first patent is for a small rotary engine which will act as range extender for a plug-in hybrid EV. This could work in a fashion that is similar to the arrangement that was seen in a Mazda2 prototype which the company debuted in 2013, with the rotary engine being mounted in the rear and helping to keep the Lithium-ion batteries charged while an electric motor powers the front wheels.

The second patent has been filed to help protect a start-stop system that is meant exclusively for use in rotary engines. In the case of the rotary engine, the position of the rotor is highly important as it affects the opening and closing of the intake and exhaust ports. The rotor needs to stop in a specific position so that the intake remains closed and no fuel or exhaust escapes from the intake. This would help enhance fuel economy. Another separate system would fire a spark plug after the fuel flow has been cut and this too would minimize emissions. In the patent application, this engine has also been listed as a range extender. A rotary engine offers motorists several specific advantages including its light weight, small size and high power-to-displacement ratio. The patents point towards Mazda’s possible plans to revive this engine which would go a long way towards increasing fuel economy. The small size of the engine would also free up more space for cargo, batteries and people thus contributing to better overall design of new models.