All heat engines need two different temperatures T1 < T2 for their work. The effiiciency is bounded by the Carnot limit. In the unterlying paper a new type of head engine is introducted. In opposition to classical heat engines here  the working medium possessses an aditional degree of freedem, the rotation around an axis. The added oder removed heat can lead to the change of classical thermodynamic parameters temperature, pressure  and volume but also to the change of the rotary state. In all calculations of the efficiency the angular velocity has to be taken into account. In many cases this leads to surprissing results, different from proposed by classical thermodynamics, that the efficienncy of head engine cycles cann exceed the Carnot limit. The efficiences do no only depend on temperatures and angular velocities but on material data as well.

The suggested new type of heat engines makes it possible to exploit very small temperature differencies, and in combination with ideal heat pumps, to draw heat from the enviroment and to convert it into mechanical energy.

Calculation result are presented for a simple geometry.