Wankel type rotary engine is endoskeletal engine epitrochoidal piston housing in which lubrication is a major challenge and central shaft is continuously under high temperature. Among many disadvantages there is loss of fuel during rotary flame propagation. through sectoral chambers. Compression ratio is also low. Piston based motion generating engines there is loss of mechanical energy during conversion of translational motion to rotary motion of crankshaft. Also rotation force is not uniform as is evident from turning moment diagram. Exhaust phase is a parasitic phase.

Basic idea: This engine is advancement of aeolipile. Scotch-Yoke actuator helps to transfer compressed air-fuel mixture into continuously rotating combustion chamber. Scotch-Yoke actuator is used as double action actuator with the help of unconventional yoke.

In this engine combustion chamber is cylinderical encloser uncapped at the rear side. It has flywheel mounted on the front side. It has two nozzles at antipodal points. This engine has rear compression chamber on the rear portion and Scotch-Yoke operation chamber (SOC). Rear compression chamber have poppet valve for the supply of air-fuel mixture.

Scotch-Yoke actuator have yoke which is a single rod with longitudinal hole with piston having inwardly opening valves at its rear side and a piston with outwardly opening valve on its front side. This yoke with the help of piston helps to suck and compress the air-fuel mixture and transfer compressed air-fuel mixture from rear compression chamber to combustion chamber via longitudinal hole and valve action.

(SOC) have spur gears mounted on its four sides of external surface which in turn is connected to scotch-yoke actuator pins. These gears are appropriately coupled so that there is no conflict between their actions to rotate scotch-yoke Pins. There are four different configurations in the gears can coupled.

Combustion chamber have a crown gear coaxially mounted on its rear side which is coupled to gears on four sides of (SOC).

Yoke slots are front dwell slots so that pistons stops for a moment at top dead center. (SOC) has cylindrical extension on the front side into the combustion chamber which house the front piston attached to yoke slot. This extension has a spark plug attached at its wall which connected to the battery via wire coming through (SOC).

Rotation motion of combustion chamber is generated by thrust vectoring action nozzle on the flame. Combustion causes reciprocating action on Scotch yoke actuator via crown gear. Part of the compression air-fuel mixture happens in cold temperature in the rear compression chamber. Since Scotch-Yoke actuator is quadlaterally operated with two yoke slots arranged in series it will have higher durability and require less frequent maintenance. Actuator will suffer minimum torsional load, sideward load and friction. Since air-fuel mixture undergoes double compression it will have higher compression ratio.