Check valve assembly in the intake side of a hydrostatic engine that can be operated as a pump and motor with the same direction of rotation

The device (30) has an actuator mechanism for actuating a non-return valve (32) between a blocking position (32a) in which a compound of a suction side (S) is closed with a container (9) in a flow direction of the suction side and an open position in which the suction side is opened with the container. An internal combustion engine (2) is drivingly connected with a hydrostatic power unit (7) that is connected with the suction side during a motor operation. The actuator mechanism is provided with a piston (36). Pressure medium is supplied from a pressure accumulator on the suction side.