Mazda’s new rotary engine’s variable valve timing is stranger than Wankel itself

What’s really interesting about the range extender’s control system is the addition of an electric motor to assist the rotary engine. Driven from a high-voltage traction battery via a proprietary inverter, the assist motor applies positive or negative torque to the rotary engine’s output shaft during the intake stroke, momentarily accelerating or decelerating the rotation of the rotor. , to optimize the inspiratory charge. Enter the combustion chamber.

This effectively lengthens or shortens the intake stroke without using traditional VVT mechanisms. According to Mazda, a VVT mechanism cannot be properly packaged for this kind of rotary engine.

Obviously, these impulses cause strange vibrations in the engine’s rotors, but since the rotary engine is only used to generate electricity and is not connected to the drive wheels, these speed fluctuations should not be noticeable while driving. , and the average engine speed remains nearly constant.