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AIXRO GmbH in Aachen

At AIXRO GmbH, we are recognized for the highest quality standards, precision and innovations. Rotary engines can be used in a wide field of application, as they continue to impress with minimum weight, small dimensions and a great performance. Josef Rothkrantz' company has buildt rotary engines since 1999 in small and medium-sized batches and is one of a few manufacturers in Europe.

AIXRO succeeds where others fail - namely in the manufacturing of rotary engines. AIXRO has managed to produce economically viable engines at a reasonable price; a true cost-effective alternative. The precise manufacturing of each component part presents a particular challenge in the batch production of rotary engines. At AIXRO, we produce those high-precision components, micron-precise, using the latest CNC technology. Each part undergoes continuous 3D testing.

We produce standardized engines and small batches but we love to customize our engines. We design and build your individual AIXRO engine which will meet your highest requirements. Please contact us for further information on how to make the perfect choice.

AIXRO's engines

The Wankel engine is a rotary piston engine named after its inventor Felix Wankel. Two different versions are available: The DKM 54 and the KKM 57 - the numbers indicating the years of their developments. Contrary to a common reciprocating piston engine (HKM), the combustion energy is instantly turned into a rotation. Only the KKM constructed by Hanns Dieter Paschke - commonly known as Wankel engine - developed  commercial relevance.

The KKM 57P's (constructed in 1957 by Hanns Dieter Paschke) three-ow-shaped-sided rotor is not only responsible for the force output but it also controls the intake/exhaust changing process. A KKM has an eccentric shaft and is therefore imbalanced - a fact that can be compensated fully by counterweights. The DKM 54 has no eccenter shaft. The rotor and the oval-like bow-shaped housing (epitrochoid) rotate around their own CGs without any imbalance. The axis are mounted eccentrically to each other. With the DKM 54 the outer rotor - the housing -  is responsible for the force output while the inner rotor controls the intake and exhaust.

Versatile applications

Wankel engines faded into oblivion for quite some time. Today, they resurface - not least because of the ideas of innovative companies such as AIXRO. They are used in racing and automotive, as well as in manned and unmanned air vehicles for traffic control, farming and in scientific aerial observation. They are also used in watercrafts.
Wherever a motor's power to weight ratio and flexibility are vital, a rotary engine is often more suited than a traditional reciprocating piston engine. AIXRO utilizes these benefits and specializes in the production of rotary engines for niche and utility vehicles.



  • reliability
  • optimal power/weight ratio
  • reduced exhaust emission
  • vibration-free