The reciprocating internal combustion engine has been a ubiquitous source of rotational power for many decades now. However, it came with its own set of complications that made it quite unsatisfactory for one particular gentleman who found it wasteful to use reciprocating motion to generate rotational motion. His frustration resulted in the development of the Wankel engine.
A Wankel engine is a type of internal combustion engine that produces crank power by rotary motion, rather than reciprocating motion. The engine is named to honor its inventor, Felix Wankel, who came up with this idea when he was only 17 years of age.
The design was intended to be a simple and more compact unit with fewer moving parts and more efficiency, while also rotating in a single direction. This was very different to conventional reciprocating engines, which had many moving parts and involved the nearly instantaneous reversal of motion of these parts.
Construction of a Wankel Engine
Any rotational motion that occurs around a point other than the center of the rotating object is known as eccentric motion. A Wankel engine is considered an eccentric motion engine, as rotational forces generated at the crankshaft are due to eccentric motion of the moving parts. It is simple in its construction, in that it uses fewer moving parts when compared to an internal combustion engine.
The rotor is the most critical part of a Wankel engine. It is a three-dimensional structure loosely shaped around the Releaux triangle, which is an equilateral triangle with slightly rounded sides. The rotor consists of chambers built into the sides to accommodate for combustion. It also has sealing surfaces at the vertices and the face to prevent losses from the leakage of energy generated due to combustion.
The housing in which the rotor moves is designed in a roughly elongated oval shape, also known as an epitrochoid. The benefit of such a shape is that all vertices of the rotor remain in contact with the housing at all times. It’s also important to note that there is always a small gap between the face of the rotor and the inner surface of the housing.
The housing also has holes for the inlet and exhaust ports for the induction and discharge of gases.