Patent ID: 8074592

Claim:
A submarine, comprising: a boat hull including a stern; and a propulsion drive arranged in the longitudinal direction of the submarine as an extension of the stern and outside the boat hull, the propulsion drive comprising: a housing forming a channel for a flow of water through the channel in a main direction of flow from an inlet to an outlet of the channel, a first electric motor including a rotor, which is arranged in the channel and supported rotatably around an axis of rotation in the housing, the rotor embodied in the shape of a ring with a ring inner side and a ring outer side, and a plurality of blades arranged on the ring inner side of the rotor of the first electric motor for propelling the submarine, wherein the housing of the propulsion drive is attached movably on the boat hull, wherein the propulsion drive further comprises: a second electric motor including a rotor, which is arranged in the channel and supported rotatably in the housing, with the rotor being embodied in the form of a ring with a ring inner side and a ring outer side, and a plurality of blades being on the ring inner side of the rotor of the second electric motor, wherein the rotor of the first electric motor and the rotor of the second electric motor are arranged in the channel in the main direction of flow of the water behind each other, wherein the rotor of the first electric motor is rotated independently of the rotor of the second electric motor, in order to divert an outflow of the water caused by the rotor of the first electric motor which deviates from the main direction of flow at least partly back into the main direction of flow, and wherein the rotors of the first and second electric motors are supported to enable them to rotate in opposite directions to each other in the housing.