Look For The Power LLC
U.S. Patent Pending
The common 4-stroke engine (intake, compression, power, and exhaust) gets the job done, albeit with great inefficiencies regarding reciprocating mass. Walking by taking one powerful step forward, followed by 3 smaller steps backward, also works, albeit with similar great inefficiency. Of the 4 strokes, only one produces power (the power stroke), while the other 3 are drags on the power produced. And, the strokes reciprocate. That is, they move in opposite directions. So a piston moves violently in one direction (the power stroke), then reverses direction 180° for the exhaust stroke, then reverses 180° again for the intake stroke, then once again reverses direction 180° for the compression stroke. This is extremely inefficient.
The Wankel rotary engine was an attempt to produce intermittent combustion WITH rotary motion, and WITHOUT the inherent inefficiencies of 4 reciprocating strokes. This held great promise during the 1980's, with Mazda leading the way. However, there were problems, largely centered on the 3-lobed rotor, the eccentric combustion chamber, and the seals between them. Today, there is no commercial production of a rotary, internal combustion engine.
Below, you will see a sketch of an internal combustion engine, utilizing intermittent combustion (as opposed to continuous combustion like a jet engine), producing rotary motion. Apart from the compressor, it has a single moving part, the rotor.