The invention relates to a hydraulic device having, in a housing, a rotor, which can rotate about a first axis, with pistons and chambers on both sides of the rotor, which can rotate about a second axis and are formed by a cylindrical wall and a piston. The cylindrical walls are rotatable about a second axis (m.sub.1 and m.sub.2) and the first axis, such that, during rotation of the rotor, the volumes of the rotor chambers on one side of the rotor and the rotor chambers on the other side of the rotor alternatively have a minimum value.