Abstract: The present invention relates to a working cycle for a heat engine, especially of the reciprocating piston type, having a gas as working medium, including the steps of isentropic compression of the gas, isochoric addition of heat to the gas, isentropic expansion of the gas, and isochoric return of the gas to its initial condition. The invention is characterized in that the gas, before or during the compression, is divided into two portions, that the gas portions are compressed to different degrees, that heat is added only or mainly to the gas portion compressed to the lowest degree, and that the two gas portions are brought into connection with each other and are expanded together.

Abstract: A sliding vane machine with a cylindrical rotor (11) eccentrically placed in a housing, the rotor being rotatably mounted in the housing with its periphery in contact with the interior of the housing at one point and being provided with a number of vanes (13). The vanes are guided in grooves (12) in the rotor (11) for essentially radial movement and delimit, together with the rotor (11) and the housing (1), chambers (14) for transporting a medium from an inlet opening (15) to a delivery opening (16). The movement of each of the vanes (13) is guided by at least one guide (17, 18), which runs along a guide race (19) in the housing. The guide race (19) and/or the interior of the housing (1) has such a shape, that the radially distal end of each vane (13) follows the contour of the interior of the housing (1).