Wankel engine

A Wankel engine is a special way to make power using spinning parts. Most engines use pistons that move up and down to create motion. Instead, the Wankel engine uses a spinning rotor that looks like a triangle with curved sides.

This rotor spins inside a housing that has a shape like a figure-eight. As the rotor turns, it creates three separate spaces called working chambers. These chambers move through four steps: taking in fuel, squeezing it, burning it, and letting out exhaust.

This design is very small and light. It also has fewer parts than many other types of engines. Because it is so smooth, it works well for things like motorcycles, snowmobiles, and even some small planes.

The way it works depends on how the rotor moves around a central part. The rotor spins around an eccentric shaft, which is a part that sits off-center.

The rotor moves in a way that looks like it is circling a hula hoop. For every three times the shaft spins, the rotor makes one full turn. As the fuel burns inside the chambers, the pressure pushes against the face of the rotor. This push transfers force to the eccentric shaft to create motion.

This specific design is called a Kreiskolbenmotor, or KKM. In this version, the outer part of the engine stays still while the inner rotor spins. This makes it much easier to use in modern machines.

Engineers have been working on this idea for a long time. A German engineer named Felix Wankel first designed a rotary compressor in the 1920s. He got his first patent for a rotary engine in 1934. Later, in 1951, he worked at a company called NSU Motorenwerke. He wanted to make a supercharger for motorcycle engines.

With help from math experts, he turned his ideas into a real engine design. The first working prototype of his design, called the DKM 54, ran on February 1, 1957. It was a big step toward the engines we see today.

Building a perfect engine was a hard job for many people. The early DKM engines were hard to cool and had many moving parts. An engineer named Hanns-Dieter Paschke helped create the KKM design to fix these problems.

The first KKM engine, the KKM 125, was very light and ran for the first time on July 1, 1958. In 1963, NSU made the KKM 502 for the NSU Spider sports car. About 2,000 of those cars were built. Engineers also had to solve problems like "chatter marks" or scratches on the engine walls. They fixed this by using better materials for the seals at the tips of the rotor.

You might see these engines in places you wouldn't expect. Because they are compact, they are great for tools like chainsaws. They are also used in racing cars and personal watercraft.

Some modern cars even use them as range extenders to help electric vehicles. Even though they can use more fuel than some other engines, their smoothness is a big plus. They show how a different shape can change how we move through the world.