The peculiarity of this engine is that its cylinder is not fixed statically, but swings in accordance to the wheel rotation.
As you can see on the model in a transparent mode, the cylinder is connected to the source by the right aperture and by the left to the exhaust pipe. In the other extreme position, the apertures are interchanged.
You can find a lot of practical implementations of steam engines with oscillating cylinder in the Internet. Thatâs because of the simplicity of its construction.