Heat cycle machine for converting heat into electrical power by means of a working rotor onto which a working gas can flow, comprising - a chamber arrangement, which has two cylindrical chambers with substantially identical capacities, wherein each of the chambers is enclosed by a double-walled chamber housing, comprising an inner and an outer housing wall, which consists of two partial housings (24.1, 24.2) thermally insulated from one another and each comprising its own cavity formed between the inner and outer partial housing wall, wherein each of the partial housings (24.1, 24.2) has a thermal fluid inlet in its outer housing wall for introducing a thermal fluid into the cavity formed between the inner and the outer partial housing wall, as well as a thermal fluid outlet for discharging the thermal fluid from the cavity; - at least one working gas supply line from each chamber to a rotor housing enclosing the working rotor, and a working gas discharge line from the rotor housing to the chambers; characterised in that - a displacement piston that is permeable to a working gas is movably arranged inside each of the chambers, the diameter of which is smaller than the inner diameter of the chamber; - both cylindrical chambers are connected to one another by a hydraulic line that is arranged on one of their end faces and can be closed by means of a shut-off valve; - each displacement piston is rigidly connected to a thrust piston movably arranged in the hydraulic line, wherein the thrust piston seals tightly with the inner wall of the hydraulic line; - the working gas discharge line is a hollow cylinder extending between the two chambers along the axis of rotation of the working rotor, on which the working rotor is rotatably mounted; and - a hermetically sealed working gas space is formed by the chambers, the thrust pistons, the working gas supply lines, the working gas discharge line and the rotor housing. - a chamber arrangement, which has two cylindrical chambers with substantially identical capacities, wherein each of the chambers is enclosed by a double-walled chamber housing, comprising an inner and an outer housing wall, which consists of two partial housings (24.1, 24.2) thermally insulated from one another and each comprising its own cavity formed between the inner and outer partial housing wall, wherein each of the partial housings (24.1, 24.2) has a thermal fluid inlet in its outer housing wall for introducing a thermal fluid into the cavity formed between the inner and the outer partial housing wall, as well as a thermal fluid outlet for discharging the thermal fluid from the cavity; - at least one working gas supply line from each chamber to a rotor housing enclosing the working rotor, and a working gas discharge line from the rotor housing to the chambers; characterised in that - a displacement piston that is permeable to a working gas is movably arranged inside each of the chambers, the diameter of which is smaller than the inner diameter of the chamber; - both cylindrical chambers are connected to one another by a hydraulic line that is arranged on one of their end faces and can be closed by means of a shut-off valve; - each displacement piston is rigidly connected to a thrust piston movably arranged in the hydraulic line, wherein the thrust piston seals tightly with the inner wall of the hydraulic line; - the working gas discharge line is a hollow cylinder extending between the two chambers along the axis of rotation of the working rotor, on which the working rotor is rotatably mounted; and - a hermetically sealed working gas space is formed by the chambers, the thrust pistons, the working gas supply lines, the working gas discharge line and the rotor housing.