42. ROTARY ENGINE AND THE REULEAUX TRIANGLE

The Wankel rotary engine makes clever use of a rotating Reuleax triangle in its design. There are three combustion chambers, and the engine design with its single rotating shaft makes this engine lighter, simpler and more compact than its piston equivalents. In the early days there were problems with the seals between the vertices and the outer chamber, but these have been overcome.

The Reuleaux triangle has the property of constant width (see Photo #6) and this property is made use of here. Other properties which are used are the three-fold symmetry and the relative ‘pointiness’ of the three vertices of the triangle.


http://en.wikipedia.org/wiki/Wankel_engine