Abstract: First pivot bodies are received for rotation in first recesses in the housing member. A piston member is mounted in a eccentric portion of the drive shaft such to orbit in operation. Second pivot bodies are received for rotation in second recesses in the piston member. Dividing vanes are inserted at their ends in slots, formed in the first and second pivot bodies in a free floating manner such to reciprocate in operation of the engine. These vanes define a number of combustion chambers. The ends of the vanes received in the first pivot bodies of the housing member perform pivoting movements and the ends received in the second pivot bodies of the piston members perform orbiting movements. Thus, only small frictions and wear at the vanes in and the pivot bodies occur and the engine can be designed with small dimensions.

Abstract: First pivot bodies are received for rotation in first recesses in the housing member. A piston member is mounted in a eccentric portion of the drive shaft such to orbit in operation. Second pivot bodies are received for rotation in second recesses in the piston member. Dividing vanes are inserted at their ends in slots, formed in the first and second pivot bodies in a free floating manner such to reciprocate in operation of the engine. These vanes define a number of combustion chambers. The ends of the vanes received in the first pivot bodies of the housing member perform pivoting movements and the ends received in the second pivot bodies of the piston members perform orbiting movements. Thus, only small frictions and wear at the vanes in and the pivot bodies occur and the engine can be designed with small dimensions.