The invention relates to a thermodynamic energy converter (1) with at least one first and one second volume element (10a, 10b) for enclosing a working medium (102) inside a variable inner volume, including a wall that divides the inner volume into heat exchanger compartments (110, 120) and a working compartment (200), wherein a partition (230) is formed inside the working compartment (200) which divides the working compartment (200) into a working chamber (210) supplied with the working medium (201) and a force transmission chamber (212) supplied with a displacement fluid (202), the heat exchanger compartments (110, 120) and the working chamber (210) are interconnected such that the working medium (102) inside the volume element (10a, 10b) has the same pressure, and each heat exchanger compartment (110, 120) is connected to the working chamber (210) via an inlet and an outlet that is formed separately from the inlet. According to the invention, a respective inlet or outlet is designed, as a connection between the heat exchanger compartments (110, 120) and the working chamber (210), with at least one rotary valve (220) so as to prevent a flow through at least one of the heat exchanger compartments (110, 120) and to support a flow through at least one other heat exchanger compartment (110, 120).