Good news for rotary engine fans with word Mazda has lodged some new patents for the much-loved powerplant.
According to Autoblog the Japanese giant’s new patents cover a rotary engine used as a range-extender for electric cars and an auto-start-stop system to improve emissions and fuel consumption.
The EV application follows the Mazda2 RE (range-extender electric car - pictured, top of page) which Mazda showed two years ago and is similar to say the BMW i3 and Chevrolet Volt. In the Mazda patent application an electric motor drives the front wheels and a rotary engine at the rear (a tiny 0.3-litre rotary in the Mazda2RE) provides power for an electric generator (a mid-mounted lithium ion battery stores the power).
However the start-stop system for a rotary engine is the most interesting and also includes the range-extender patent (so the vehicle could be driven on pure electric power with the rotary engine shut-down).
When shut-down, the engine’s rotor is stopped in a position which closes the intake port (so no fuel or exhaust emissions leak out) – remember rotary engines have no valves with intake and exhaust provided via ports operated by the rotor.
Mazda’s system also fires a spark plug after shut-down to rid any leftover emissions.
In production form, this would take advantage of the compact dimensions and light weight of a rotary engine. So diverse applications could be possible – everything from a sports car to a delivery van, in fact.