Rotary combusion engine system having toroidal compression and expansion chambers

A rotary combustion engine system is provided with compression unit and expansions unit offset which communicate through a transfer port. Each unit defines a toroidal chamber extending annularly about a central cavity, and a plurality of curved pistons displaced within the toroidal chamber to variably form a plurality of sub-chambers therein. A rotor member in each unit is eccentrically coupled to a mechanical member and linked by a plurality of swing rod members to the curved pistons. The curved pistons of the expansion unit are advanced by recursive combustion within sub-chambers defined therebetween, to drive angular displacement of the rotor member. The rotor member in the compression unit is angularly displaced with the mechanical member to incrementally advance the unit's curved pistons for recursive compression of air within sub-chambers defined therebetween. The compressed air is recursively passed through the transfer port to the sub-chambers of the expansion unit for combustion.