Propulsion system for a watercraft

Abstract

A drive system for driving a watercraft (12), comprising an internal combustion engine (22) for introducing a mechanical drive torque; a first electric motor (24) having a generator and motor function for introducing a first electrical drive torque or for generating electrical energy; a coupling device (26) for rotationally coupling or decoupling an output shaft (20) of the internal combustion engine (22) to a rotor input shaft (28) of the first electric motor (24); a first drive device (34) for driving the watercraft (12), connected directly or indirectly to a rotor output shaft of the first electric motor (24) via a first drive shaft (32); a second electric motor (38) for introducing a second electrical drive torque; a second drive device (44) for driving the watercraft (12), connected directly or indirectly to a rotor shaft of the second electric motor (38) via a second drive shaft (42);an energy storage device (46) for storing and providing electrical energy. The small number of drive components required enables a space-saving and cost-effective drive system (10).

Description

The following embodiments relate to a drive system for driving a watercraft, in particular a two-body watercraft, which can be installed in the watercraft at low cost with a low installation space requirement. Furthermore, the following explanations relate to a watercraft having a drive system and method for operating a drive system of the watercraft.DE 10 2005 058 843 A1 discloses a drive system for a sailyacht of the Katamaran type, in which two E-machines are provided for driving the sailyacht, one E-machine operable as a generator for generating electrical energy and one internal combustion engine, which is mechanically decoupled from the two first E-machines for driving the generator and mechanically decoupled from the two first E-machines.There is a constant need to reduce the costs of a drive system and its installation space requirement in a watercraft.Proceeding from this situation, it is an object of the present invention to show measures which make possible a drive system for a watercraft which is saving in installation space and cost-effective.The present object is achieved by the features of the independent main claim. Advantageous embodiments are specified in the dependent claims. Insofar as technically possible, the teachings of the subclaims can be combined as desired with the teachings of the main and dependent claims.The object is accordingly achieved by a drive system for driving a watercraft, in particular a two-body watercraft, having an internal combustion engine for introducing a mechanical drive torque; a first E-machine having a generator and motor function for introducing a first electrical drive torque or for generating electrical energy; a clutch device for coupling or decoupling an output shaft of the internal combustion engine in a rotationally fixed manner to a rotor input shaft of the first E-machine; a first drive device, which is connected indirectly or directly to a rotor output shaft of the first E-machine via a first drive shaft, for driving the watercraft; a second E-machine for introducing a second electrical drive torque; a second drive device, which is connected indirectly or directly to a rotor shaft of the second E-machine via a second drive shaft, for driving the watercraft; an energy store for storing and providing electrical energy; wherein the first drive device can be driven by the mechanical drive torque of the internal combustion engine and / or the first electrical drive torque of the first electric machine, wherein the second drive device can be driven by the second electrical drive torque of the second electric machine.The drive system has, in particular, a first drive train and a second drive train, wherein the first drive train has at least the internal combustion engine, the clutch device, the first electric machine, the first drive shaft and the first drive device. The second drive train has, in particular, at least the second electric machine, the second drive shaft and the second drive device. The internal combustion engine can be, in particular, an internal combustion engine which can be driven with liquid or gaseous fuel. The internal combustion engine has a motor shaft designed as an output shaft. The mechanical drive torque generated by the internal combustion engine can be introduced into the first drive train by the output shaft. The downstream clutch device can be designed in particular as a separating clutch and, in a closed state, can enable the torque transmission between the output shaft of the internal combustion engine and the rotor input shaft of the first electric machine. In the closed state of the clutch device, the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine are coupled to one another in a rotationally fixed manner. In an open state of the clutch device, the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine are decoupled from one another. In an open state, consequently, no torque transmission takes place between the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine. The first electric machine is in particular a first electric motor that can be operated as a generator. The first electric machine can thus generate electrical energy in a generator mode or a first electrical drive torque in a motor mode. In the case of a closed clutch device, the mechanical drive torque and the first electrical drive torque can be transmitted via the rotor output shaft of the first electric machine indirectly or directly via the first drive shaft to the first drive device. The first drive device is designed such that a rotational movement of the first drive device results in a forward movement or a rearward movement of the watercraft. The second electric machine is in particular a second electric motor with a corresponding rotor shaft. The second electric machine can generate a second electric drive torque during motor operation and transmit this torque via the rotor shaft indirectly or directly via the second drive shaft to the second drive device. The second electric machine can be driven exclusively in motor operation by means of electrical energy from the energy store or the first electric machine. As a result, the second electric machine can be smaller and more cost-effective than the first electric machine. The energy store can be, in particular, a rechargeable battery or a rechargeable accumulator. The second drive device is in particular configured such that a rotational movement of the second drive device results in a forward movement or a rearward movement of the watercraft. By using a second E-machine, a second internal combustion engine for driving the second drive device can be dispensed with. Electric machines are generally smaller and more cost-effective than internal combustion engines, as a result of which the required installation space and the production costs of the drive system can be reduced. Thus, a maximum of two electric machines are installed in the drive system, whereby the required installation space and the manufacturing costs of the drive system are reduced. The first electric machine that can be mechanically coupled to the internal combustion engine and the second electric machine that can only be operated in the motor mode make it possible to dispense with a second internal combustion engine, in particular one mounted upstream of the second drive device, thereby enabling a drive system that is saving space and cost-effective.Advantageous aspects are explained below and preferred modified embodiments are described further below. Explanations, in particular regarding advantages and definitions of features, are basically descriptive and preferred, but non-limiting examples. Where an explanation is limiting, this is expressly mentioned.The above-described drive system enables a plurality of operating modes for driving the watercraft. By means of the internal combustion engine that can be coupled to one another via the clutch device and the first electric machine, the watercraft can be driven, for example, by the mechanical drive torque of the internal combustion engine and / or the first electric drive torque of the first electric machine via the first drive device. In the case of a simultaneous motor operation of the internal combustion engine and of the first electric machine, the mechanical drive torque introduced into the first drive train for driving the watercraft can be additionally increased by the first electric drive torque. In particular, the second electric machine can introduce a second drive torque into the second drive train and thereby contribute to increasing the travel speed of the watercraft. Alternatively, the first electric machine can be driven by the internal combustion engine in a generator mode and electrical energy can be generated in the first electric machine by means of electromagnetic induction. While the first electric machine is being driven in generator operation, the propulsion of the watercraft by the second electric machine can continue to be maintained. The second electric machine can in particular introduce a second electric drive torque into the second drive train by means of the electric energy provided by the energy store. In this way, a second internal combustion engine for driving the second drive device can be dispensed with.In the drive system described above, the first drive shaft and the second drive shaft can be arranged parallel to one another within the watercraft. In particular, it is provided that the longitudinal extension of the first drive train extends parallel to the longitudinal extension of the second drive train. The rotor input shaft of the first E-machine can be formed integrally with the rotor output shaft of the first E-machine.The term "watercraft" stands as a generic term for a vehicle which is exclusively or predominantly on or in bodies of water. A watercraft is in particular a means of transportation that is used mainly on waterways such as seas, rivers, seas and oceans. The term "watercraft" can be understood in particular to mean boats, ships, yachts or the like.In a preferred embodiment of the above, it is provided that a first transmission unit for torque transmission of the mechanical drive torque and / or of the first electric drive torque is arranged between the first electric machine and the first drive device. The first transmission unit allows the rotor output shaft of the first electric machine to be connected to the first drive shaft. The torque transmitted in this case can be adjusted or changed as required by the first transmission unit. The first transmission unit can control, in particular, the torque and speed ratios between the internal combustion engine / the first electric machine and the first drive device. In particular, the rotation direction of the first drive device can be changed by the first transmission unit. As a result, the watercraft can be driven backwards.In a preferred embodiment of the above, it is provided that a second transmission unit for torque transmission of the second electric drive torque is arranged between the second electric machine and the second drive device. The rotor shaft of the second electric machine can be connected to the second drive shaft by the second gear unit. The torque transmitted in this case can be adjusted or changed as required by the second transmission unit. The second transmission unit can control the torque and speed ratios between the second electric machine and the second drive device. In particular, the rotation direction of the second drive device can be changed by the second transmission unit. As a result, the watercraft can be driven backwards.In a preferred embodiment of the above, it is provided that the internal combustion engine, the first E-machine and the first drive device are arranged in the watercraft mechanically separately from the second E-machine and the second drive device. In particular, it is provided that the internal combustion engine and the first E-machine are arranged in a first hull and the second E-machine is arranged in a second hull of the watercraft. As a result, the drive components of the first drive train, in particular the internal combustion engine and the first electric machine, and the respective drive components of the second drive train, in particular the second electric machine, can be arranged in a water craft in a spatially separated and space-saving manner. By spatially separating the powertrains, the performance and efficiency of the propulsion system may be improved with respect to the speed at which the watercraft may be propelled. In particular, the negative influences due to the vortices in the water generated by the first drive device on the operation of the second drive device and vice versa can thus be reduced.In a preferred embodiment of the above, it is provided that the energy store is connected to the first electric machine and the second electric machine by means of electrical lines. By electrically connecting the energy store to the first electric machine and the second electric machine, the electric machines can generate a first and a second electric drive torque by means of the electric energy provided by the energy store in an engine mode. By electrically connecting the energy store to the first electric machine, it is possible in particular to store the electrical energy generated by the first electric machine in the generator mode in the energy store. In particular, it is provided that the first electric machine and the second electric machine are directly connected to one another by means of separate electrical lines. The electrical lines can be used in particular to transmit the electrical energy generated by the first electric machine in generator operation directly to the second electric machine in order to generate a second electrical drive torque. The term "electrical line" is a linear electrical conductor for transporting electrical energy. These lines can be part of an electrical circuit or power network and connect the power source and the load to one another.In a preferred embodiment of the above, it is provided that the first drive device and / or the second drive device is / are designed as a ship's propeller. A "marine propeller", often also referred to simply as a propeller or marine propeller, is a rotating device that is typically mounted on the rear of a watercraft and serves to propel the watercraft forwardly or rearwardly. The functioning of a ship's propeller is based on the principle of traction and reaction. As the screw rotates, it moves water rearward. The rearward movement of the water generates a forward force which drives the watercraft. The propeller may have various sizes and shapes. The ship's propeller can be manufactured in particular from bronze or stainless steel. As a result, a long-lived and efficient drive can be realized. By a corresponding modification of the propeller, the fuel consumption can be reduced and the performance of the water truck can be improved.The object is furthermore achieved by a watercraft having a drive system described above. The watercraft can be designed as a two-hull watercraft. The watercraft can be, in particular, an at least motor-driven catamaran. These usually have two carcasses. As a result, a drive train can be arranged in each case in one of the fuselages. The respective drive devices can be arranged in particular at the rear of the watercraft, wherein in each case one drive device is arranged on in each case one fuselage.The object is furthermore achieved by a method for operating a drive system of the previously described watercraft, wherein the first drive device is driven by the first electric drive torque of the first electric machine and / or the second drive device is driven by the second electric drive torque of the second electric machine. In this operating mode, the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine are decoupled from one another by the clutch device. Consequently, no torque transmission takes place between the electric machine and the internal combustion engine. As a result, the watercraft can also be driven purely electrically via the first electric machine in addition to the second electric machine. By this operating mode, the watercraft can be driven purely electrically by the first electric machine via the first drive device or by the second electric machine via the second drive device. In particular, the watercraft can be driven by the simultaneous operation of the first E-machine and the second E-machine via the first and second simultaneous drive devices. By switching on or off the respective electric machines, the desired travel speed of the watercraft can be set in a targeted manner. In particular, the energy consumption can be reduced by operating only one electric machine and the travel duration in electric operation can be increased. By connecting both electric machines with electric drive torques rotating in opposite rotational directions, the watercraft can be turned quickly and easily. The required turning radius can be reduced in such an operation of the two E-machines. In particular, the wear of the individual components of the unused drive train can be reduced by the operation of one of the electric machines. The first electric machine and / or the second electric machine can be driven with electrical energy from the energy store in this operating mode.The object is furthermore achieved by a method for operating a drive system of the previously described watercraft, wherein the first drive device is driven by the mechanical drive torque of the internal combustion engine. In this operating mode, the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine are coupled to one another in a rotationally fixed manner by the clutch device. The first electric machine can be operated at idle in this case by the mechanical drive torque of the internal combustion engine being transmitted via the rotor output shaft of the first electric machine indirectly or directly via the first drive shaft as far as the first drive device. As a result, the watercraft can be driven exclusively via the internal combustion engine. In particular, in addition to the mechanical drive torque of the internal combustion engine, the first drive device can be driven by the first electrical drive torque of the first electric machine and / or the second drive device can be driven by the second electrical drive torque of the second electric machine. By connecting the first E-machine and / or the second E-machine, the speed of the watercraft can be increased additionally. In the case of an activation of the first E-machine, the first E-machine is switched from idle operation to engine operation and adds an additional first electric drive torque to the mechanical drive torque introduced into the first E-machine via the clutch device. As a result, the first drive device can be operated with a higher drive torque, in comparison to the mechanical or first electrical drive torque. In the case of only activation of the second E-machine, the first E-machine can continue to be operated at idle. As a result, the first drive device can be operated by the mechanical drive torque and the second drive device by the second electrical drive torque.The object is furthermore achieved by a method for operating a drive system of the previously described watercraft, wherein the first electric machine is driven in generator operation by the mechanical drive torque of the internal combustion engine and the electrical energy generated by the first electric machine is stored in the energy store or is provided to the second electric machine for generating a second electrical drive torque. In this operating mode, the output shaft of the internal combustion engine and the rotor input shaft of the first E-machine are coupled to one another in a rotationally fixed manner by the clutch device. The mechanical drive torque transmitted via the clutch device drives the rotor input shaft in the first electric machine, as a result of which electrical energy is generated by means of electromagnetic induction. The electrical energy can subsequently be output to the energy store and stored therein. As a result, the energy store can be charged by operating the internal combustion engine. The energy provided thereby can be used for driving the watercraft and / or for operating other electrical devices on the watercraft. With the electrical energy stored in the energy store, in particular the second drive device can be driven by the second electrical drive torque generated in the second electric machine. In particular, the second electric machine can be driven directly by the electrical energy generated in the first electric machine. For this purpose, the first electric machine and the second electric machine can be connected to one another by means of electrical lines.It is preferred that the order of method steps can be varied, unless technically required in an explicit order. However, the sequence of the method steps mentioned above is particularly preferred.A preferred technical solution is explained in more detail below with reference to the attached drawings on the basis of preferred exemplary embodiments. The phrase "figure" is abbreviated "Figure" in the drawings.The drawings show FIG. 1 shows a schematic view of a two-body watercraft.The described exemplary embodiment is merely an example which can be modified and / or supplemented in a variety of ways within the scope of the claims.FIG. 1 shows a propulsion system 10 for propelling a watercraft 12, wherein the watercraft 12 is designed as a two-body catamaran, having a first hull 14 and a second hull 16. The first fuselage 14 has a first drive train 18 with an internal combustion engine 22 having an output shaft 20 for introducing a mechanical drive torque, a first electric machine 24 having a generator and motor function for introducing a first electric drive torque or for generating electrical energy, a clutch device 26 for coupling or decoupling the output shaft 20 in a rotationally fixed manner to a rotor input shaft 28 of the first electric machine 24, a first transmission unit 30 for torque transmission of the mechanical drive torque and / or the first electric drive torque, and a first drive device 34 coupled in a rotationally fixed manner to the first transmission unit 30 via a first drive shaft 32 for driving the watercraft 12, a second transmission unit 40 for torque transmission of the second electric drive torque and a second drive device 44 for driving the watercraft 12 coupled in a rotationally fixed manner to the second transmission unit 40 via a second drive shaft 42. By means of the drive system 10 described above, the watercraft 12 can be driven with different operating modes. For example, the watercraft 12 can be driven purely electrically by the first electric machine 24 and / or the second electric machine 38. In a further operating mode, it is provided that the watercraft 12 is driven by the internal combustion engine 22. The watercraft 22 can likewise be driven from a combination of internal combustion engine 22 and at least one electric machine 24, 38. The electrical energy required for the motor operation of the at least one electric machine 24, 38 can be provided by the energy store 46. The electrical energy generated in the first electric machine 24 in the generator mode can be used to charge the energy store 46 or to drive the second electric machine 28. The energy transmission is realized by electrical lines 48. The first drive device 34 and the second drive device 44 are designed as ship's screws and are arranged in each case at the rear of the first fuselage 14 and of the second fuselage 16. For this purpose, the first drive shaft 32 and the second drive shaft 42 are arranged at least partially inside the watercraft 12 and at least partially outside the watercraft 12.List of reference characters10 Drive system 12 Watercraft 14 First fuselage 16 Second fuselage 18 First drive train 20 Output shaft 22 Internal combustion engine 24 First electric machine 26 Clutch device 28 Rotor input shaft 30 First transmission unit 32 First drive shaft 34 First drive device 36 Second drive train 38 Second electric machine 40 Second transmission unit 42 Second drive shaft 44 Second drive device 46 Energy store 48 Electrical linesReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2005 058 843 A1

[0002]

Claims

Drive system for driving a watercraft (12), in particular a two-body watercraft (12), having an internal combustion engine (22) for introducing a mechanical drive torque; a first electric machine (24), having a generator and motor function, for introducing a first electric drive torque or for generating electrical energy; a clutch device (26) for coupling or decoupling an output shaft (20) of the internal combustion engine (22) in a rotationally fixed manner to a rotor input shaft (28) of the first electric machine (24); a first drive device (34), connected indirectly or directly to a rotor output shaft of the first electric machine (24) via a first drive shaft (32), for driving the watercraft (12); a second electric machine (38) for introducing a second electric drive torque; a second drive device (44), which is indirectly or directly connected to a rotor shaft of the second electric machine (38), for driving the watercraft (12) via a second drive shaft (42); an energy store (46) for storing and providing electrical energy; wherein the first drive device (34) can be driven by the mechanical drive torque of the internal combustion engine (22) and / or the first electrical drive torque of the first electric machine (24), and wherein the second drive device (44) can be driven by the second electrical drive torque of the second electric machine (38).Drive system according to Claim 1, wherein a first transmission unit (30) for torque transmission of the mechanical drive torque and / or of the first electrical drive torque is arranged between the first electric machine (24) and the first drive device (34).Drive system according to Claim 1 or 2, wherein a second transmission unit (40) for torque transmission of the second electric drive torque is arranged between the second electric machine (38) and the second drive device (44).Propulsion system according to one of Claims 1 to 3, wherein the internal combustion engine (22), the first E-machine (24) and the first propulsion device (34) are arranged in the watercraft (12) mechanically separately from the second E-machine (38) and the second propulsion device (44), wherein in particular the internal combustion engine (22) and the first E-machine (24) are arranged in a first hull (14) and the second E-machine (38) is arranged in a second hull (16) of the watercraft (12).Drive system according to one of Claims 1 to 4, wherein the energy store (46) is connected to the first E-machine (24) and the second E-machine (38) by means of electrical lines (48), wherein in particular the first E-machine (24) and the second E-machine (38) are directly connected to one another by means of separate electrical lines (48).Drive system according to one of Claims 1 to 5, wherein the first drive device (34) and / or the second drive device (44) are / is designed as a ship's propeller.Watercraft with a propulsion system (10) according to one of the preceding claims, wherein the watercraft (12) is designed as a two-hull watercraft (12).Method for operating a propulsion system (10) of the watercraft (12) according to Claim 7, wherein the first propulsion device (34) is driven by the first electrical drive torque of the first electric machine (24), and / or the second propulsion device (44) is driven by the second electrical drive torque of the second electric machine (38).Method for operating a drive system (10) of the watercraft (12) according to Claim 7, wherein the first drive device (34) is driven by the mechanical drive torque of the internal combustion engine (22), wherein in particular additionally the first drive device (34) is driven by the first electrical drive torque of the first electric machine (24) and / or the second drive device (44) is driven by the second electrical drive torque of the second electric machine (38).Method for operating a drive system (10) of the watercraft (12) according to Claim 7, wherein the first electric machine (24) is driven in the generator mode by the mechanical drive torque of the internal combustion engine (22) and the electrical energy generated by the first electric machine (24) is stored in the energy store (46) or is provided to the second electric machine (38) for generating a second electrical drive torque.

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