AU2009235557B2

AU2009235557B2 - Drive device comprising two drive motors for a ship

Info

Publication number: AU2009235557B2
Application number: AU2009235557A
Authority: AU
Inventors: Jurgen Eckert; Rainer Hartig; Christian Meyer; Ingo Schuring
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2008-04-10
Filing date: 2009-03-25
Publication date: 2013-02-21
Anticipated expiration: 2029-03-25
Also published as: EP2265489A2; EP2265489B1; ES2455093T3; KR20100133412A; WO2009124841A3; AU2009235557A1; WO2009124841A2; DE102008018420A1

Abstract

The invention relates to a drive device (1) for a ship comprising a drive shaft (3) for driving a propulsion unit (4) of the ship and a first and a second electric motor (5 and 6) for driving the propulsion unit (4). Both of the motors (5, 6) are arranged behind each other on the drive shaft (3). The first motor (5) comprises a rotor (21) and a stator (23) that are arranged in a motor housing (25). The current converters (27) for feeding the first motor (5) with electric current are arranged in the motor housing (25), preferably at least partially in an area (26) between the drive shaft (3) and the rotor (21). According to the invention, the ratio of the power rating of the first motor (5) in relation to the power rating of the second motor (6) is between 1:3 and 3:1. The second motor (6) is arranged on the drive shaft (3) in a spatial manner between the propulsion unit (4) and the first motor (5).

Description

PCT/EP2009/053478 2008P06552WOIN Description Drive device having two drive motors for a marine vessel The invention relates to a drive device having two drive motors for a marine vessel according to the precharacterizing clause of patent claim 1; by way of example, a drive -device such as this is known from EP 1 233 904 Bl. EP 1 233 904 B1 discloses a drive device for a marine vessel having two electric motors which are arranged one behind the other on a driveshaft. A first electric motor with a drive power of less than one-twentieth of the maximum drive power is used to drive the driveshaft for a lower rotation-speed range up to about 30% of the rated rotation speed of the driveshaft. The motor in this case complies with all the mechanical, electrical and acoustic constraints which are characteristic of slow movement of the marine vessel, in particular of a submarine. A synchronous motor with a permanent-magnet rotor is preferably used in this case. The second drive motor is a drive motor with a considerably higher power than the first drive motor (drive ratio greater than or equal to 20:1). This drive motor is designed for high-speed movement of the marine vessel, in which the extreme structure-borne sound requirements applicable to slow movement do not exist. The first motor in this case has a rotor and a stator which are arranged in a motor housing, wherein converters are likewise arranged in the motor housing, in order to feed electric current to the motor. EP 0 194 433 BI discloses an electrical machine in which an electronic controller for feeding electric current to the machine is arranged at least partially in an area between the driveshaft, the rotor and the motor housing of the machine. For this purpose, the machine has a rotor in the form of a bell, on which permanent magnets are arranged. The machine and, in particular, its electronic 2 controller are therefore particularly well protected against undesirable energy emissions of an acoustic and electrical nature. Object of the Invention It is the object of the present invention to substantially overcome or ameliorate one or more of the above disadvantages. Summary of the Invention The present invention provides a drive device for a marine vessel, in particular a submarine, having a driveshaft for driving a propulsion unit, for example a propeller, of the marine vessel and having a first and a second electric motor for driving the driveshaft, wherein the two motors are arranged one behind the other on the driveshaft, wherein the first motor has a rotor and a stator which are arranged in a motor housing, wherein converters for feeding the first motor with electric current are arranged in the motor housing, wherein the ratio of the rating of the first motor to the rating of the second motor is between 1:3 and 3:1, and wherein the second motor is physically arranged between the propulsion unit and the first motor on the driveshaft, wherein the two motors drive the driveshaft individually or jointly, depending on a requirement, for example a rotation speed of the propulsion unit, and wherein the drive device further comprises a nominal-value transmitter for presetting a nominal value, for example a nominal value for a rotation speed of the propulsion unit or for the marine-vessel speed, an operating mode transmitter for presetting an operating mode, and a control device which is designed to control the respective power output to the driveshaft from the two motors such that the sum of these power outputs allows a total power which is dependent on the nominal value to be emitted to the driveshaft, and wherein the total power output is split between the power outputs of the individual motors as a function of the nominal value and the operating mode. Preferably, the converters are arranged at least partially in an area between the driveshaft and the rotor. According to the invention, the ratio of the rating of the first motor to the rating of the second motor is between 1:3 and 3:1, wherein the second motor is physically arranged between the propulsion unit, for example a propeller, and the first motor on the driveshaft.

2a The invention therefore departs from the previous approach of adding a second low-power drive to a high-power main drive and, instead of this, uses two motors whose rating differs only in a limited range. Two motors of virtually the same power are therefore used, as a result of which, if one of the two motors fails, a large proportion of the drive power is still available from the other motor, thus making it possible to ensure high availability of the drive PCT/EP2009/053478 - 3 2008P06552WOIN device even for relatively high power demands for the propulsion unit. Joint operation of the two motors also allows a considerably greater maximum power to be emitted to the driveshaft, and therefore makes it possible to increase the power of the propulsion unit, and therefore the speed of the marine vessel and its acceleration capability for the same weight and drag of the marine vessel, or to increase the weight and/or the drag of the marine vessel at the same speed. Since the second motor is physically arranged between the propeller and the first motor on the driveshaft, this allows accessibility to the converters which are arranged in the motor housing of the first motor, as a result of which the drive device is highly servicing- and repair-friendly. Because the converters are arranged in the motor housing, the first motor normally occupies a greater amount of space in the circumferential direction than the second motor. Since, in general, the driveshaft has a diameter which likewise increases in the direction of the propulsion unit because of the increasing torque forces acting on it, the first motor is, according to the invention, arranged in the area of the driveshaft with the smallest diameter, rather than in that part of the driveshaft which faces the propulsion unit and has the larger diameter, which would result in a correspondingly even greater diameter of the first motor. This makes it possible to keep the space required for the first motor in the circumferential direction, and therefore that required by the total drive device, small. In principle, widely differing motor types, with which a person skilled in the art will be familiar and which are suitable for marine vessels, can be used for the two motors, for example asynchronous motors or synchronous motors in the form of alternating-current motors, as well as direct-current motors.

PCT/EP2009/053478 - 4 2008P06552WOIN The first motor is preferably in the form of a synchronous motor with a permanent-magnet rotor, and the second motor is preferably in the form of an asynchronous motor. A synchronous motor with a permanent-magnet rotor makes it possible to comply with the particularly stringent requirements relating to structure-borne sound and electromagnetic emissions, with a high motor power density at the same time, as exist for silent running of the marine vessel, in particular of a submarine. The asynchronous motor can then be designed cost-effectively for less critical requirements, such as those for high-speed movement of a marine vessel, in particular of a submarine. A clutch is preferably arranged between the first and the second motor in the driveshaft. If the first motor fails, this can then be disconnected from the driveshaft. In order to ensure the shock resistance of the drive device and to prevent structure-borne sound from being transmitted from the motors to the marine-vessel hull, both motors can in their own right be connected directly or indirectly to the marine vessel hull by means of elastic mounting elements. However, the two motors are advantageously mounted on a common foundation. This foundation can then be connected directly or indirectly to the marine-vessel hull by means of elastic mounting elements. The motors themselves can then be mounted on the foundation without elastic mounting elements, as a result of which they are rigidly connected to one another. There is therefore no need for an elastic coupling in the driveshaft between the two motors. To this end, an elastic coupling is arranged in the driveshaft between the second motor and the propulsion unit in order to compensate for movements of the foundation and therefore of the two motors with respect to the marine-vessel hull and the propulsion unit.

PCT/EP2009/053478 - 5 2008P06552WOIN As has been found, it is sufficient with an arrangement such as this for the driveshaft to be borne by means of two bearings in the first motor and to be borne only by means of a single bearing in the second motor. This makes it possible to dispense with a second bearing for the second motor. The two motors can drive the driveshaft individually or jointly depending on the requirement, for example a desired speed of the marine vessel. According to one particularly advantageous refinement of the invention, the drive device comprises a nominal-value transmitter for presetting a nominal value, for example a nominal value for a rotation speed of the propulsion unit or for the marine-vessel speed, an operating mode transmitter for presetting an operating mode, and a control device which is designed to control the respective power outputs of the two motors to the driveshaft such that the sum of these power outputs allows a total power which is dependent on the nominal value to be emitted to the driveshaft and, in this case, this total power output is split between the power outputs of the individual motors as a function of the nominal value and the operating mode. In this case, drive controllers can be associated with the individual motors in order to control their respective power output, wherein the control device controls the power output of the motors by presetting rotation-speed nominal values or torque nominal values for these drive controllers. The predeterminable operating mode may be an operating mode in which the noise emissions and/or electromagnetic emissions and/or heat emissions from the drive device, preferably including internal combustion engines for producing the electrical power for the two motors, are a minimum.

PCT/EP2009/053478 - 6 2008P06552WOIN The predeterminable operating mode may also be an operating mode in which the total consumption of electrical power of the two motors is a minimum. Furthermore, the predeterminable operating mode may be an operating mode in which the acceleration of the marine vessel is a maximum. In addition, the predeterminable operating mode may be an operating mode in which the total fuel consumption of internal combustion engines for producing electrical power for the motors is a minimum. The first motor preferably drives the propulsion unit in a lower speed range of the marine vessel, in particular in the speed range for silent running of the marine vessel, and the second motor together with the first motor drives the propulsion unit in a higher speed range, in particular in the high-speed running range of the marine vessel, up to the maximum speed of the marine vessel. Advantageously, in the lower speed range, the first motor controls the rotation speed of the driveshaft and, in the higher speed range, the second motor controls the rotation speed of the driveshaft, wherein, when the two motors are being operated jointly, the second motor controls the rotation speed of the driveshaft, and the rotation speed of the first electric motor is controlled by the driveshaft, and by the second motor, and, governed by the nominal value preset, emits a torque to the driveshaft such that the torques emitted by each of the two motors are added in the driveshaft. Preferably, each of the motors is designed for a maximum power which is less than the total power required as a maximum for propulsion of the marine vessel. Both motors must therefore PCT/EP2009/053478 - 6a 2008P06552WOIN contribute to achieving the maximum required total power. Since the maximum required total power is normally PCT/EP2009/053478 - 7 2008P06552WOIN required only rarely, however, the motors can be designed to be optimized for a lower power, thus improving the efficiency of the two motors and reducing their space requirement and weight. If both motors are designed such that they can emit torque to the driveshaft up to the maximum rotation speed of the propulsion unit, they can be used particularly flexibly in order to set desired optimum operating points of the drive device, without any torque surges, over the entire rotation speed range of the propulsion unit. Particularly rapid and cost-effective production of the drive device is possible in that the drive device consists of a combination of a first motor with a fixed rating and one of a plurality of second motors with a different rating. Since, because of its more complex design and the particularly stringent requirements, the first motor is also correspondingly complex and time-consuming to design, produce and test, in comparison to the second motor, a drive device is preferably produced which always makes use of a first motor of a motor type which has already been developed and tested and has a fixed power, to which one of a plurality of available second motors of different power is then added in order to achieve the required total power. A drive device system based on this concept for marine-vessel drive devices of different rating is distinguished by a standardized first motor with a fixed predetermined rating, and a plurality of standardized second motors which each have a different rating, wherein, in order to achieve different ratings of the marine-vessel drive devices, the first motor and the second motors are designed and can be operated such that the first motor can be combined with any of the second motors in order to drive the driveshaft.

PCT/EP2009/053478 - 8 2008P06552WOIN In order to produce a marine-vessel drive device, this device can then be formed from the standardized first motor and one of the standardized second motors such that the sum of the ratings of the two motors results in a desired rating of the marine vessel drive device. The invention as well as further advantageous refinements of the invention according to the features of the dependent claims will be explained in more detail in the following text with reference to exemplary embodiments in the figures, in which: Figure 1 shows a drive device according to the invention for a marine vessel, in particular a submarine, Figure 2 shows a partial section through one fundamental embodiment of a particularly advantageous refinement of the first motor shown in Figure 1, Figure 3 shows an outline illustration of a particularly advantageous bearing arrangement in the motors of the drive device shown in Figure 1, and Figure 4 shows a particularly advantageous refinement of a drive device according to the invention. A drive device 1, which is illustrated in the form of an outline illustration in Figure 1, is arranged in the stern of a submarine, of which only the stern-end outer casing 2 of the marine-vessel hull is partially illustrated. In a corresponding manner, a drive device such as this could, of course, also be arranged in the stern of a surface vessel. The drive device 1 has a driveshaft 3 for driving a propeller 4 as a propulsion unit for the submarine, and a first electric motor 5 and a second electric motor 6 for driving the driveshaft 3. The two motors 5, 6 are arranged one behind the other on the driveshaft 3, that is to say arranged one behind the other with respect to the driveshaft, with their rotors, which are not illustrated in any more detail, connected to the driveshaft 3 such that they rotate with it. In this case, the motor 6 is physically PCT/EP2009/053478 - 9 2008P06552WOIN arranged between the propeller 4 and the first motor 5 on the driveshaft 3. The ratio of the rating of the first motor 5 to the rating of the second motor 6 is between 1:3 and 3:1. By way of example, the rating of the two motors is 3 MW, thus resulting in a total rating of the drive device 1 of 6 MW each. The first motor 5 is preferably in the form of a synchronous motor with a permanent-magnet rotor, and the second motor 6 is in the form of an asynchronous motor. In this case, as is illustrated in the detail in Figure 2, the first motor 5 has a rotor 21 which is in the form of a bell and on which permanent magnets 22 are arranged, and which is connected to the driveshaft 3 such that they rotate together, a stator 23 having a stator winding 24 and a motor housing 25, in which the rotor 21 and the stator 23 are arranged. Converter modules 27 are arranged in an area 26 between the driveshaft 3, the rotor 21 and the motor housing 25, with the aid of a holding framework which is not illustrated in any more detail, in order to feed the stator winding 24 of the electric motor 5. The converter modules 27 can be replaced through an opening 28 in the motor housing 25. Accommodation of the converter modules 27 within the rotor 21, which is in the form of a bell, results in the energy emission of an acoustic and electrical nature to the exterior being shielded particularly effectively. The motor 5 is therefore particularly advantageously suitable for driving the driveshaft 3 for silent running of the submarine. In order to disconnect the first motor 5 from the second motor 6 if the first motor 5 fails, a clutch 7 is arranged between the first motor 5 and the second motor 6 in the driveshaft 3. The two motors 5, 6 are mounted on a common foundation 8. The foundation 8 is in turn connected to the casing 2 of the submarine via elastic elements 9. Shock influences from the marine-vessel casing 2 on the motors 5, 6 are reduced by means of the elastic elements 9 and, conversely, they prevent PCT/EP2009/053478 - 9a 2008P06552WOIN structure-borne sound from being transmitted from the motors 5, 6 to the casing 2. In order to compensate for movements of the drive PCT/EP2009/053478 - 10 2008P06552WOIN motors 5, 6 with respect to the part of the driveshaft 3 which is fixed with respect to the casing 2 by means of the bearing 10 and is connected to the propeller 4, an elastic coupling is arranged between the second motor 6 and the propeller 4 in the driveshaft 3. When the two motors 5, 6 are jointly rigidly mounted in this way on the foundation 8, it is sufficient - as shown in Figure 3 - for the driveshaft 3 to be borne in the two motors 5, 6 only by means of a total of three bearings 11, 12, 13. In this case, the driveshaft 3 is borne in the second motor 6 only by means of a single bearing 11, which is arranged on the output drive side of the second motor 6, and is borne in the first motor 5 by a respective bearing 12 or 13, which are respectively arranged on the output drive side and the input drive side of the first motor 5. The output-drive side bearing 12 of the first motor 5 therefore also supports a proportion of the weight of the driveshaft 3 in the area of the second motor 6. However, overall, this makes it possible to dispense with a bearing on the drive side of the second motor 6. Alternatively, instead of being mounted on a common foundation 8, the two motors 5, 6 can also each be separately connected to the casing 2 via elastic elements 9. In this case, the coupling 7 may also be in the form of an elastic coupling. The two motors 5, 6 drive the driveshaft 3 individually or jointly depending on the requirement, for example the propeller rotation speed. The first motor 5 drives the propeller 4 in a lower speed range of the submarine (in particular for silent running), and the second motor 6 together with the first motor 5 drives the propeller in a higher speed range (particularly for high-speed movement) up to the maximum speed of the submarine.

PCT/EP2009/053478 - 11 2008P06552WOIN In the lower speed range, the first motor 5 controls the rotation speed of the driveshaft 3 and, in the higher speed range, the second motor 6 controls the rotation speed of the driveshaft 3, wherein, when the two motors 5, 6 are being operated jointly, the second motor 6 controls the rotation speed of the driveshaft 3, and the rotation speed of the first motor 5 is controlled by the driveshaft 3 and by the second motor 6 and, governed by the nominal value preset, emits a torque to the driveshaft 3 such that the torques emitted by each of the two motors 5, 6 are added in the driveshaft 3. Each of the motors 5, 6 is in this case designed for a maximum power which is less than the total power required as a maximum for the propulsion of the submarine. However, both motors 5, 6 are designed such that they can emit torque to the driveshaft 3 up to the maximum rotation speed of the propeller 4. As is illustrated in a simplified form in. Figure 4, the respective power outputs PEl and PE2 Of the motors 5, 6 to the propeller 4 are controlled by a superordinate control device 30 as a function of a predeterminable nominal value S, for example a nominal value for the rotation speed of the propeller 4 or for the marine-vessel speed, and a predeterminable operating mode B, such that the sum of these power outputs results in a total power Ps to the propeller 4 which is dependent on the nominal value S, with this total power output being split in this case between the power outputs PEi and PE2 Of the respective motors 5, 6, that is to say the magnitudes of the respective power elements PEl and PE2 to be emitted by each of the two motors 5, 6 to achieve the total power PS = PE1 + PE2, as a function of the nominal value S and the predeterminable operating mode B.

PCT/EP2009/053478 - lla 2008P06552WOIN The superordinate control device 30 receives the nominal value S from a nominal value transmitter 31, for example a speed control lever on the control console or from an autopilot system, and the PCT/EP2009/053478 - 12 2008P06552WOIN operating mode B from an operating-mode transmitter 32, for example an operating-mode selection switch, which is arranged on the control console in the submarine. Tn order to control the power outputs PEl, PE2 Of the motors 5, 6 as a function of a predetermined nominal value S and a predetermined operating mode B, the superordinate control device 30 transmits nominal values SEI, SE2 (for example, nominal values for the rotation speed or the torque) to drive controllers 35, 36, which control the respective power output PEl and PE2 Of the motors 5 and 6. The superordinate control device 30 controls the total power output and the split of the total power to be emitted between the motors 5, 6 via the nominal values SE1, SE2, and automatically selects optimum operating points for the predetermined operating mode B. The predeterminable operating mode B may be an operating mode in which the noise emissions (that is to say structure-borne sound and airborne sound emissions) and/or the electromagnetic emissions and/or the thermal emissions from the drive device 1, preferably including internal combustion engines for producing the electrical power for the two motors 5, 6, are a minimum. The predeterminable operating mode B may also be an operating mode in which the total consumption of electrical power of the two motors 5, 6 is a minimum. Furthermore, the predeterminable operating mode B may be an operating mode in which the acceleration of the submarine is a maximum. The predeterminable operating mode B may also be an operating mode in which the total fuel consumption of the internal combustion engines for producing the electrical power for the motors 5, 6 is a minimum. Characteristics and/or characteristic data for controlling the total power output Ps and the split in the total power output PCT/EP2009/053478 - 12a 2008P06552WOIN Ps between the individual motors 5, 6 may be stored in the superordinate control device 30, describing the PCT/EP2009/053478 - 13 2008P06552WOIN relationship between the nominal value S, for example the propeller rotation speed or the marine-vessel speed, the respective power output and operating parameters which characterize the respective operating mode, such as the electrical power consumption, the fuel consumption, the noise emissions, the thermal emissions, heat losses. Furthermore, the characteristics describe the maximum possible power output. The relationships described above for individually and jointly driving the two electric motors, for controlling the power outputs of the two motors as a function of a predeterminable nominal value and a predeterminable operating mode, the various possible operating modes and the drive split and rotation speed control in the various speed ranges are in this case fundamentally applicable to any combination of two motors for driving a propulsion unit, that is to say also for a combination in which no converters for the first motor are arranged in the motor housing.

Claims

1. A drive device for a marine vessel, in particular a submarine, having a driveshaft for driving a propulsion unit, for example a propeller, of the marine vessel and having a first and a second electric motor for driving the driveshaft, wherein the two motors are arranged one behind the other on the driveshaft, wherein the first motor has a rotor and a stator which are arranged in a motor housing, wherein converters for feeding the first motor with electric current are arranged in the motor housing, wherein the ratio of the rating of the first motor to the rating of the second motor is between 1:3 and 3:1, and wherein the second motor is physically arranged between the propulsion unit and the first motor on the driveshaft, wherein the two motors drive the driveshaft individually or jointly, depending on a requirement, for example a rotation speed of the propulsion unit, and wherein the drive device further comprises a nominal-value transmitter for presetting a nominal value, for example a nominal value for a rotation speed of the propulsion unit or for the marine-vessel speed, an operating mode transmitter for presetting an operating mode, and a control device which is designed to control the respective power output to the driveshaft from the two motors such that the sum of these power outputs allows a total power which is dependent on the nominal value to be emitted to the driveshaft, and wherein the total power output is split between the power outputs of the individual motors as a function of the nominal value and the operating mode.

2. The drive device as claimed in claim 1, wherein the converters are arranged at least partially in an area between the driveshaft and the rotor.

3. The drive device as claimed in claim 1 or 2, wherein the first motor is in the form of a synchronous motor with a permanent-magnet rotor, and the second motor is in the form of an asynchronous motor.

4. The drive device as claimed in any one of the preceding claims, wherein a clutch is arranged in the driveshaft between the first and the second motor.

5. The drive device as claimed in any one of the preceding claims, wherein the two motors are mounted on a common foundation, wherein an elastic coupling is arranged in the driveshaft between the second motor and the propulsion unit. 15

6. The drive device as claimed in claim 5, wherein the driveshaft is borne by means of two bearings in the first motor, and by means of only a single bearing in the second motor.

7. The drive device as claimed in any one of the preceding claims, comprising drive controllers, which are associated with the individual motors, for controlling their respective power output, wherein the control device controls the power output of the motors by presetting rotation-speed nominal values or torque nominal values for the drive controllers.

8. The drive device as claimed in any one of the preceding claims, wherein the predetermined operating mode is an operating mode in which noise emissions and/or electromagnetic emissions and/or heat emissions from the drive device, preferably including internal combustion engines for producing the electrical power for the two motors, are a minimum.

9. The drive device as claimed in any one of claims 1 to 7, wherein the predetermined operating mode is an operating mode in which the total consumption of electrical power of the two motors is a minimum.

10. The drive device as claimed in any one of claims 1 to 7, wherein the predetermined operating mode is an operating mode in which the acceleration of the marine vessel is a maximum.

11. The drive device as claimed in any one of claims 1 to 7, wherein the predetermined operating mode is an operating mode in which the total fuel consumption of internal combustion engines for producing electrical power for the motors is a minimum.

12. The drive device as claimed in any one of the preceding claims, wherein the first motor drives the propulsion unit in a lower speed range of the marine vessel, in particular in the speed range for silent running of the marine vessel, and the second motor together with the first motor drives the propulsion unit in a higher speed range, in particular in the high-speed running range of the marine vessel, up to the maximum speed of the marine vessel.

13. The drive device as claimed in claim 12, wherein, in the lower speed range, the first motor controls the rotation speed of the driveshaft and, in the higher speed range, the second motor controls the rotation speed of the driveshaft, wherein, when the two motors are being operated jointly, the second motor controls the rotation speed of the driveshaft, and the rotation speed of 16 the first electric motor is controlled by the driveshaft, and by the second motor, and, governed by the nominal value preset, emits a torque to the driveshaft such that the torques emitted by each of the two motors are added in the driveshaft.

14. The drive device as claimed in any one of the preceding claims, wherein each of the motors is designed for a maximum power which is less than the total power required as a maximum for propulsion of the marine vessel.

15. The drive device as claimed in any one of the preceding claims, wherein both motors are designed such that they can emit torque to the driveshaft up to the maximum rotation speed of the propulsion unit.

16. The drive device as claimed in any one of the preceding claims, wherein the drive device comprises a combination of a first motor with a fixed rating and one of a plurality of second motors with a different rating.

17. A drive device system for marine-vessel drive devices of different rating as claimed in any one of the preceding claims, comprising a standardized first motor with a fixed predetermined rating, and a plurality of standardized second motors which each have a different rating, wherein, in order to achieve different ratings of the marine-vessel drive devices, the first motor and the second motors are designed and can be operated such that the first motor can be combined with any of the second motors in order to drive the driveshaft.

18. A method for producing a marine-vessel drive device as claimed in any one of claims 1 to 16 with the aid of a drive device system as claimed in claim 17, wherein the marine-vessel drive device is formed from the standardized first motor and one of the standardized second motors such that the sum of the ratings of the two motors produces a desired rating of the marine-vessel drive device.

19. A drive device for a marine vessel substantially as hereinbefore described with reference to any one of the embodiments as that embodiment is shown in the accompanying drawings. 17

20. A method for producing a marine-vessel drive device substantially as hereinbefore described with reference to the accompanying drawings. Dated 31 January 2013 Siemens Aktiengesellschaft Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON