DRIVE FOR A VEHICLE, WATERCRAFT HAVING A DRIVE OF THIS TYPE, METHOD FOR OPERATING A WATERCRAFT, AND CONTROL DEVICE FOR A WATERCRAFT OF THIS TYPE

Abstract

A drive for a vehicle includes: an internal combustion engine; a freewheel device, a drive shaft, the internal combustion engine configured for being drive-operatively connected to the drive shaft of the drive via the freewheel device, the freewheel device being configured to decouple the internal combustion engine from the drive shaft if a rotational speed of the drive shaft exceeds a rotational speed of the internal combustion engine; and a bridging device which is designed to couple the internal combustion engine to the drive shaft in at least one operating situation of the drive if the internal combustion engine is separated from the drive shaft by the freewheel device.

Claims

1. A drive for a vehicle, the drive comprising: an internal combustion engine; a freewheel device, a drive shaft, the internal combustion engine configured for being drive-operatively connected to the drive shaft of the drive via the freewheel device, the freewheel device being configured to decouple the internal combustion engine from the drive shaft if a rotational speed of the drive shaft exceeds a rotational speed of the internal combustion engine; and a bridging device which is designed to couple the internal combustion engine to the drive shaft in at least one operating situation of the drive if the internal combustion engine is separated from the drive shaft by the freewheel device.

2. The drive according to claim 1, wherein the drive in addition includes an electric machine, wherein the internal combustion engine and the electric machine are configured for being drive-operatively connected with the drive shaft via the freewheel device in such a way that (a) only the internal combustion engine is, (b) only the electric machine is, or (c) the internal combustion engine and the electric machine together are configured for driving the drive shaft, the drive being for a vehicle formed as a watercraft.

3. The drive according to claim 1, wherein the freewheel device is formed as a mechanical freewheel, as a transmission mechanism, and as a part of a transmission mechanism.

4. The drive according to claim 1, wherein the bridging device is arranged on the freewheel device, is integrated into the freewheel device, or is arranged parallel to the freewheel device.

5. The drive according to claim 1, wherein the bridging device is formed as a coupling, in particular as a magnetic coupling.

6. The drive according to claim 1, wherein the bridging device is formed as a magnetic coupling.

7. A watercraft, comprising: a drive, including: an internal combustion engine; a freewheel device, a drive shaft, the internal combustion engine configured for being drive-operatively connected to the drive shaft of the drive via the freewheel device, the freewheel device being configured to decouple the internal combustion engine from the drive shaft if a rotational speed of the drive shaft exceeds a rotational speed of the internal combustion engine; and a bridging device which is designed to couple the internal combustion engine to the drive shaft in at least one operating situation of the drive if the internal combustion engine is separated from the drive shaft by the freewheel device, the drive shaft being a propeller shaft of the watercraft, being configured for being drive-operatively connected with a propeller shaft of the watercraft, or being drive-operatively connected with a propeller shaft of the watercraft.

8. The watercraft according to claim 7, further comprising a shift transmission which is arranged between the freewheel device and the propeller of the watercraft, the shift transmission being configured to reverse a direction of rotation of the propeller relative to a direction of rotation of the internal combustion engine when the shift transmission is shifted.

9. The watercraft according to claim 7, further comprising a control device which is operatively connected with the bridging device, wherein the control device is configured for carrying out a method for operating the watercraft, the method comprising the steps of: providing that the watercraft includes the drive; closing the bridging device during a braking maneuver to reduce a rotational speed of the propeller shaft, the internal combustion engine being coupled with the propeller shaft and being dragged by the propeller shaft.

10. A method for operating a watercraft, the method comprising the steps of: providing that the watercraft includes: a drive, including: an internal combustion engine; a freewheel device, a drive shaft, the internal combustion engine configured for being drive-operatively connected to the drive shaft of the drive via the freewheel device, the freewheel device being configured to decouple the internal combustion engine from the drive shaft if a rotational speed of the drive shaft exceeds a rotational speed of the internal combustion engine; and a bridging device which is designed to couple the internal combustion engine to the drive shaft in at least one operating situation of the drive if the internal combustion engine is separated from the drive shaft by the freewheel device, the drive shaft being a propeller shaft of the watercraft, being configured for being drive-operatively connected with a propeller shaft of the watercraft, or being drive-operatively connected with a propeller shaft of the watercraft; and closing the bridging device during a braking maneuver to reduce a rotational speed of the propeller shaft, the internal combustion engine being coupled with the propeller shaft and being dragged by the propeller shaft.

11. The method according to claim 10, wherein prior to the braking maneuver the watercraft is driven by only the internal combustion engine or by an electric machine of the drive together with the internal combustion engine, wherein the following steps are performed for the braking maneuver: stopping a fuel supply to the internal combustion engine; closing the bridging device; controlling the electric machine to decelerate the propeller shaft.

12. The method according to claim 10, wherein prior to the braking maneuver the watercraft is driven only by an electric machine, wherein the internal combustion engine is stopped, wherein the following steps are performed for the braking maneuver: redirecting the electric machine to decelerate the propeller shaft; and closing the bridging device.

13. The method according to claim 10, wherein the watercraft includes a control device configured for carrying out the steps of the method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0049] FIG. 1 is a schematic representation of a design example of a drive and a design example of a watercraft;

[0050] FIG. 2 is a schematic representation of a first embodiment of a method for operating a watercraft; and

[0051] FIG. 3 is a schematic representation of a second embodiment of the method for operating a watercraft.

[0052] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0053] FIG. 1 shows a schematic representation of a design example of a vehicle 2, herein in particular of a watercraft 1, which shows a design example of a drive 3. Drive 3 includes an internal combustion engine 5, optionally a diesel engine, wherein internal combustion engine 5 is drive-operatively connectable via a freewheel device 7 with a propeller shaft 9. Freewheel device 7 is arranged to decouple internal combustion engine 5 from propeller shaft 9, if a rotational speed assigned to propeller shaft 9 exceeds a rotational speed of internal combustion engine 5. Drive 3 moreover includes a bridging device 11 which is designed to couple internal combustion engine 5 with propeller shaft 9 in at least one operating situation of watercraft 1, if combustion engine 5 is separated from propeller shaft 9 by way of freewheel device 7. This makes it possible in an advantageous manner, in particular, that combustion engine 5 when braking propeller shaft 9 can be dragged by propeller shaft 9, wherein the friction torque of internal combustion engine 5 additionally contributes to braking of propeller shaft 9. Therefore, braking maneuvers, especially optionally emergency stop maneuvers of watercraft 1 can be expedited, that is, a time and distance over which watercraft 1 is stopped can be shortened.

[0054] A propeller 13 is optionally connected with propeller shaft 9 in a rotationally fixed manner.

[0055] Drive 3 also includes an electric machine 15. Internal combustion engine 5 and electric machine 15 are both drive-operatively connectable with propeller shaft 9 via freewheel device 7, namely in such a way that, in a first operating state only internal combustion engine 5, and in a second operating state only electric machine 15, and in a third operating state, internal combustion engine 5 and electric machine 15 can drive propeller shaft 9 together, insofar, drive 3 is designed as a hybrid drive.

[0056] An electric storage 17, in particular an accumulator or a battery, is operatively connected with electric machine 15. Electric machine 15 can—depending on the respective operating state of drive 3—be operated as a motor or as a generator. Specifically, when it is operated as a motor it draws electric energy from electric storage 17, and when operated as a generator it feeds electric energy into electric storage 17.

[0057] Freewheel device 7 is optionally designed as mechanical freewheel, as a transmission mechanism or as part of a transmission mechanism. Freewheel device 7 can in particular also be designed as planetary gearing to which in addition another electric machine is connected.

[0058] A shift transmission 19 is optionally arranged between freewheel device 7 and propeller 13, which is designed to reverse a direction of rotation of propeller 13 relative to a direction of rotation of internal combustion engine 5, when shift transmission 19 is shifted. In particular, two functions can be implemented with shift transmission 19. In other words, one can switch between two operating states of drive 3, namely between forward and reverse drive of watercraft 1. It is possible that shift transmission 19 also has a plurality of different gears, that is different transmission ratios between the rotational speed of internal combustion engine 5 on the one hand and the rotational speed of propeller 13 on the other hand.

[0059] Between freewheel device 7 and shift transmission 19 a clutch 21 is optionally arranged, which is designed to optionally connect freewheel device 7 and thus at the same time in particular internal combustion engine 5 with shift transmission 19 or separate from shift transmission 19. Clutch 21 can in particular be designed as a hydraulic or an electric clutch, permitting especially comfortable and in particular also automated control of clutch 21.

[0060] The rotational speed assigned to propeller shaft 9 which ultimately determines in comparison to the rotational speed of internal combustion engine 5, whether internal combustion engine 5 is coupled with propeller shaft 9 via freewheel device 7 or not, is in particular the rotational speed of a drive shaft 22 which, in the herein illustrated design example is an input shaft of clutch 21. Depending on the design of shift transmission 19, this rotational speed of drive shaft 22 can correspond with the rotational speed of propeller shaft 9, that is with the propeller shaft rotational speed. It may however deviate from this, particularly if shift transmission 19 is designed as a step-up or step-down transmission. In another embodiment of watercraft 1, it is possible for propeller shaft 9 to be coupled to internal combustion engine 5, in particular without an intermediate shift transmission in such a way that propeller shaft 9 and internal combustion engine 5 have an identical rotational speed in the coupled state. Drive shaft 22 is in this case in particular, propeller shaft 9, and the rotational speed assigned to propeller shaft 9 is directly the propeller shaft rotational speed.

[0061] In an optional embodiment, freewheel device 7 is designed as an intermediate gear unit.

[0062] Bridging device 11 is optionally arranged on freewheel device 7 or integrated into freewheel device 7. According to the herein illustrated design example of watercraft 1 and drive 3, bridging device 11 is arranged parallel to freewheel device 7.

[0063] Bridging device 11 is optionally designed as a coupling, in particular as a magnetic coupling.

[0064] It is possible that watercraft 1 has two identically designed drives 3, which are placed optionally parallel to and separately from one another, optionally one drive on port side and one drive on starboard side. Accordingly, watercraft 1 also has two propellers 13, wherein each propeller 13 has its own drive 3 assigned to it.

[0065] Watercraft 1 also has optionally one control unit 23 which is operatively connected with bridging device 11 and which is designed to carry out a procedure which is explained in further detail below. Control unit 23 is moreover operatively connected with clutch 21 and optionally with shift transmission 19. In addition, the control unit is also operatively connected—in a non-illustrated manner—with internal combustion engine 5 and with electric machine 15.

[0066] A method for operating watercraft 1 provides that during a braking maneuver to reduce the propeller shaft rotational speed, bridging device 11 is closed, so that internal combustion engine 5 is coupled with propeller shaft 9 and is dragged by propeller shaft 9. In this way, the propeller shaft rotation speed is reduced especially quickly and effectively. Such a braking maneuver is optionally an emergency stop maneuver.

[0067] FIG. 2 shows a first embodiment of such a method for operating a watercraft 1.

[0068] In a first step S1, watercraft 1 (abbreviated WFZ) is driven prior to the braking maneuver either by only internal combustion engine 5 (abbreviated BKM) or together with internal combustion engine 5 and electric machine 15 (abbreviated EM). In order to initiate the braking maneuver, a fuel supply for internal combustion engine 5, especially injection for the diesel engine, is terminated in a second step 2. In a third step S3, bridging device 11 is closed, so that internal combustion engine 5 is dragged by propeller shaft 9.

[0069] In a fourth step S4, electric machine 15 is controlled in order to decelerate propeller shaft 9. Depending on whether electric machine 15 was used previously to drive watercraft 1 or whether it was at rest it is now reversed with respect to its direction of rotation or newly controlled. Optionally, electric machine 15 is controlled at full power in order to decelerate propeller shaft 9 as quickly as possible, that is, to reduce its rotational speed. Combustion engine 5 and electric machine 15 now act together to reduce the propeller shaft rotational speed, wherein a torque is actively introduced into propeller shaft 9 by electric machine 15 and wherein internal combustion engine 5 is passively dragged by propeller shaft 9.

[0070] If an idle speed of internal combustion engine 5 is reached, clutch 21 is opened in a fifth step S5. Subsequently, internal combustion engine 5 is operated in idle mode in a sixth step S6.

[0071] In a seventh step S7, shift transmission 19 is shifted into a direction of rotation, opposite to the previous direction of rotation, for example from forward motion to reverse, or vice versa.

[0072] If shift transmission 19 is shifted, clutch 21 is closed in an eighth step S8. In a ninth step S9, propeller shaft 9 is accelerated—now in opposite direction of rotation—by internal combustion engine 5 together with electric machine 15, optionally respectively at maximum power. In this way, the braking process for watercraft 1 can be performed very efficiently, quickly and over a short distance.

[0073] FIG. 3 shows a schematic representation of a second embodiment of the method. In this case, watercraft 1 is driven in a first step S1 prior to the braking maneuver by only electric machine 15. Internal combustion engine 5—in particular the fuel supply to the combustion chamber, in particular to all combustion chambers of internal combustion engine 5—is stopped.

[0074] It the braking maneuver is now to be initiated, electric machine 15 is redirected in a second step S2, that is, it is reversed in respect to its direction of rotation in order to decelerate propeller shaft 9. Electric machine 15 is thereby operated optionally at its maximum power, in order to decelerate propeller shaft 9 as quickly as possible. In a third step S3, bridging device 11 is closed, so that internal combustion engine 5 is additionally dragged by propeller shaft 9. As a result, propeller shaft rotational speed is additionally and more quickly reduced, than would be the case if it would be decelerated only by electric machine 15.

[0075] When the idle speed of internal combustion engine 5 is reached, clutch 21 is opened in a fourth step S4. Internal combustion engine 5 is started in a fifth step S5 and is operated in idle mode in a sixth step S6.

[0076] In a seventh step S7, clutch 21 is shifted into the opposite direction of rotation. Once this has occurred, clutch 21 is closed in an eighth step S8 and, in a ninth step S9, the propeller shaft—now in opposite direction—is accelerated by internal combustion engine 5 and electric machine 15 together, optionally with respectively maximum power. An especially rapid deceleration of watercraft 1 over the shortest possible distance can be achieved also with this embodiment of the method.

[0077] In a first embodiment of the method according to FIG. 2, steps S3 and S4 can be performed simultaneously. Also, second step S2 can be performed simultaneously with third step S3 and fourth step S4. In the second embodiment of the method according to FIG. 3, second step S2 and third step S3 can be performed simultaneously.

[0078] If, in sixth step S6, according to both embodiments of the method according to FIGS. 2 and 3, internal combustion engine 5 is operated in idle mode, electric machine 15 also rotates in particular without power output with the idle speed of internal combustion engine 5, since it is connected with same via freewheel device 7, in particular via the intermediate gear unit.

[0079] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.