Parallel or redundant hybrid marine drive train for a propulsion unit

Abstract

A parallel or redundant hybrid drive of a marine drivetrain of a propulsion unit includes an input shaft, which is configured to be driven by a primary drive source; a clutch unit attached to the input shaft with which rotation of the input shaft can be either connected, reversed, or disconnected; a countershaft transverse to the input shaft and driven by the input shaft via a gear; and a secondary drive source arranged via an interconnected clutch at an end of the countershaft, so that upon driving of the input shaft by the primary drive source, the secondary drive source drives the countershaft either on its own or in cooperation with the primary drive source.

Claims

1. A parallel or redundant marine drive train for a propulsion unit, comprising: an input shaft configured to be driven by a primary drive source; a clutch unit coupled to the input shaft, wherein the clutch unit selectively connects, reverses, or disconnects rotation of the input shaft, wherein the clutch unit is configured, in conjunction with a shift between forward and reverse positions, momentarily to brake the rotation; an output shaft transverse to the input shaft and driven by the input shaft via a gear; and a secondary drive source arranged via a clutch at one end of the output shaft such that, depending on whether the input shaft is driven or not, the secondary drive source runs either on its own or in cooperation with the primary drive source.

2. The drive train of claim 1, wherein the clutch comprises either a hydraulically or electrically applied clutch configured for connecting or disconnecting either the primary drive source or the secondary drive source.

3. The drive train of claim 1, wherein the secondary drive source comprises an electric motor/generator that operates as a motor or a generator depending on voltage polarity and rotational direction.

4. The drive train of claim 1, wherein the clutch unit comprises a plurality of clutch units journalled at each side adjacent to the gear on the output shaft and configured such that when at least one of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the primary drive source, and such that when none of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the secondary drive source.

5. The drive train of claim 1, wherein the clutch unit comprises a planetary gear arranged on the input shaft, the planetary gear having at least one ratio and being configured selectively to transfer force and momentum to the output shaft in a same or opposite rotational direction of the input shaft and selectively to disconnect the output shaft from the primary drive source.

6. The drive train of claim 1, wherein the drive train is configured to connect or disconnect the primary drive source while the secondary drive source is driven.

7. The drive train of claim 1, wherein the clutch unit comprises a dry or wet centrifugal clutch that is arranged either adjacent to the gear on the output shaft or on the input shaft.

8. The drive train of claim 7, wherein the clutch comprises either a hydraulically or electrically applied clutch configured for connecting or disconnecting either the primary drive source or the secondary drive source.

9. The drive train of claim 7, wherein the secondary drive source comprises an electric motor/generator that operates as a motor or a generator depending on voltage polarity and rotational direction.

10. The drive train of claim 7, wherein the clutch unit comprises a plurality of clutch units journalled at each side adjacent to the gear on the output shaft and configured such that when at least one of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the primary drive source, and such that when none of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the secondary drive source.

11. The drive train of claim 7, wherein the clutch unit comprises a planetary gear arranged on the input shaft, the planetary gear having at least one ratio and being configured selectively to transfer force and momentum to the output shaft in a same or opposite rotational direction of the input shaft and selectively to disconnect the output shaft from the primary drive source.

12. The drive train of claim 7, wherein the drive train is configured to connect or disconnect the primary drive source while the secondary drive source is driven.

13. The drive train of claim 1, wherein the clutch unit comprises a planetary gear arranged on the input shaft.

14. The drive train of claim 13, wherein the clutch comprises either a hydraulically or electrically applied clutch configured for connecting or disconnecting either the primary drive source or the secondary drive source.

15. The drive train of claim 13, wherein the secondary drive source comprises an electric motor/generator that operates as a motor or a generator depending on voltage polarity and rotational direction.

16. The drive train of claim 13, wherein the clutch unit comprises a plurality of clutch units journalled at each side adjacent to the gear on the output shaft and configured such that when at least one of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the primary drive source, and such that when none of the plurality of clutch units is applied, the output shaft and thereby the gear is reversibly driven by the secondary drive source.

17. The drive train of claim 13, wherein the planetary gear has at least one ratio and is configured selectively to transfer force and momentum to the output shaft in a same or opposite rotational direction of the input shaft and selectively to disconnect the output shaft from the primary drive source.

18. The drive train of claim 13, wherein the drive train is configured to connect or disconnect the primary drive source while the secondary drive source is driven.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention will in the following be described with reference to the embodiments thereof shown on the enclosed drawings, in which:

(2) FIG. 1 shows a simplified cross section over the inventive concept with its engines and propulsion unit, and

(3) FIG. 2 shows a simplified plan over a drivetrain according to the invention in an alternative configuration as compared to the embodiment shown in FIG. 1.

DETAILED DESCRIPTION

(4) In FIG. 1 an embodiment in its simplest form is depicted. This embodiment comprise a primary drive source 1, a shaft 4 which devolves into a pinion of a conical gear 12, in the vicinity of which a couple of cluthes 5, 6 are journalled on a countershaft 7. At the coaxial extension end of the driven shaft of said clutch 5, a secondary drive source is located, preferably an electric or hydraulic motor, having a between said countershaft 7 and the drive source 2 arranged electrically or hydraulically manouvred releasable clutch 3. At the other end of said transmission 12, the clutch 6 is located, also this in a coaxial relationship with the shaft 7. In the embodiment shown the shaft 7 leads on to a double conical gear 8, which together with double counter-rotating propellers 21, 22 driven by said gear 8, establish an extraordinarily efficient propulsion unit.

(5) In an alternative a bit more advanced embodiment as shown i FIG. 2, the invention comprise a primary drive source 1 corresponding to that of the first embodiment, while the shaft 4 constitutes the input shaft of a planetary gear 25 and along its length also include a friction disc carrier 9a of a clutch 9 in said planetary gear 25. The shaft 4 continues after said friction disc carrier and devolves in the planetary gear 25 in a sun wheel 10a provided with gearteeth. The housing (not shown) of the planetary gear 25 comprise a brake 11 for the ring wheel 14 of the planetary gear 25. The shaft 13 is thereafter coupled to a conical gear 12 of the same kind as that shown in the first embodiment. Apart from the fact that this embodiment of the invention for obvious reasons lack the clutches 5 and 6 which are arranged co-axially on and around the countershaft 7, the second embodiment is in all other parts identical to the first embodiment.

(6) The embodiment shown in FIG. 2 thus differs from that shown according to FIG. 1 in that it on the one hand lacks the cluthes 5, 6 on the shaft 7 and on the other hand in that it has a planetary gear on the shaft 4 before the transmission 12. The planetary gear 25 comprise in order to achieve a direct drive making use of the primary drive source 1, the coupling 9, which when closed makes the gear teeth of the planetary gear 25 planet portion, ie. ring wheel 14, planetary wheel 15 and sun wheel 10a be loaded statically and thus follow the rotation of the engine, which will positively affect life and durability of the gear. In order to reverse making use of the primary drive source, the brake 11 is brought to engage, preferably with the use of hydraulic means, in order to reduce the speed of the ring wheel to thereby force the planetary gears to rotate, whereby the rotaional direction of the output shaft from the planetary gear is reversed and thus reversation becomes a fact. Other ways of manouvering the brake 11 except for hydraulics, such as by electrical or mechanical means, are of course also possible.

(7) In the following context the function of the marine drive line according to the invention will be further elucidated. Starting with he emebodiment according to FIG. 1 it can be stated that the drive line is constructed in such a fashion, that if the secondary drive 2 and its clutch 3 did not exist, the drive line would work as a conventional INU drive comprising a sligthly differently constituted reversing gear, made up from the clutches 5 and 6. Either the one or the other of said cluthes 5, 6 has to be engaged for making a drive forwardly or rearwardly possible. In a case where neither of the clutches are engaged, the shaft 7 will be completely disengaged. Since this is possible, it is also possible to let an engine 2 operate on the shaft 7, being disconnected from the engine 1, making use of a clutch 3. The engine 2 is reversed making use of electrical polarity reversal.

(8) The secondary drive source is as previously mentioned constituted from a primary magnetised motor PMM, which if it is connected at the same time as the primary engine, may run either as an engine/motor or as a generator. The PPM may work as a generator up to its maximum rpm. Above this limit the field voltage of the PMM will exceed the blueprint voltage for its running as a motor, which is unsuitable, so the rpm must be limited, either by making use of the clutch 3 or by the use of a suitable reduction. The current voltage while it is being run as a generator is mainly linear to the rpm with which it is driven. If the field voltage therefore substantially increases the blueprint voltage, the drive electronics may be at risc of being knocked out and arcings may occur in the field winding, which likely will lead to a total failure. The same happens if the boat or the ship is being towed at high speed, whereby the propeller/-s as a consequence of it/they being run as a turbine may get the PMM to overspeed, which in a corresponding fashion probably will lead to a failure of a corresponding kind. During such circumstances the rpm of the PMM must either be lowered to zero or reduced, which may be realised on many ways which we refrain from discussing here and now. When driving making use of the secondary drive source and a sudden need for reversing or reversation emerges, however, account must be taken to the mass inertia, which the parts like in the counterrotating direction in rotation put propellers and their transmission parts represent. Depent upon whether in this circumstance the primary engine is running or not, according to the case with the solution as shown in FIG. 1 either one of the cluthes 5 or 6, or in the planetary gear case according to FIG. 2, the clutch 9 or the brake 11 be used to reduce the rotation of the propellers to a value that either the electrical motor can cope with having regard to the voltage, or the hydraulic engine can handle with regard to pressurisation, without causing operational problems both in short terms and in the long run. With an embodiment according to FIG. 2, a possibility to at low speed control the outgoing speed of the shaft 4 in both directions, ie. both forward and reverse, is obtained. This is accomplished by making it possible to control the application pressure of the brake 11 or the clutch 9 to an rpm that is lower than the idling rpm of the primary engine. Beyond this, a skilled person should realise that the drivetrain in both its embodiments can be used to grant a gear change from hog speed forward or rearward to its opposite, in that it becomes possible to by braking reduce said mass inertia, which is a consequence of the rotation of the masses contained in the transmission- and propulsionelements. This also leads to a considerable improvement of the riding comfort when driving a boat or a ship that is equipped with one or more INU-units of the described type, and this completely independently of whether the drive train is of hybrid type or is of the conventional kind. Apart from this it should be realised that variants of the shown embodiments may be understood and be exerted by such people that this publication is directed to while exerting the invention starting from a study of the drawings, the description and the enclosed patent claims. In the claims the word includes does not exclude the possible presence of other steps or elements and the indefinite article a/an does not exclude the existence of a feature in plural. The fact that certain features have been mentioned in different dependant claims is not an indication of that a combination can not be used to the advantage of the applicant.

(9) Change of Rotational Direction in Drive Source 2

(10) The secondary drive source 2 rotational direction as a primary magnetised motor (PMM) is simply changed for change between drivning forwards or backwards by a polarity reversal of its field winding. In order to achieve this in the most convenient fashion not causing current surge, the voltage is disconnected at the same time as in the case that the primary engine is stopped and the clutches 5 or 6 are used to reduce the rotation of the propellers 21, 22, so that after the the shaft 7 has reached a predetermined rpm, a polarity reversal to the new rotational direction can be made without any danger. This goes for both the described embodiments. For the embodiment making use of a planetary gear according to FIG. 2, either the cluth 9 or the brake 11 is used for said reduction of the rotation.

(11) In the case where the main engine 1 is driven with a low rpm, on a short term basis, that clutch or brake is chosen that gives the new rotational direction wanted. In this manner said load on the secondary drive source 2 is deminished or even eliminated.

(12) When driving using the secondary drive source and a sudden need for reversal emanate, the inertia that the in the opposite direction rotating propeller/-s represent has to be taken into account. Dependent upon whether in this situation the primary drive source 1 is running or not, in the case according to FIG. 1 either one of the clutches 5 or 6 or in the planetary gear case either the clutch or the brake 11, may be used to brake the rotation of the propellers to an rpm value that the motor can handle with regard to the voltage in order to avoid operational problems either on the long run or in a shorter term. In an embodiment with this kind of configuration also a possibility to at low rpm:s control the rpm of the output shaft 13 in both rotational directions, ie. both forwardly and backwardly. This is done by making it possible to control the application pressure in the brake 11 or the clutch 9 to an rpm that is lower than the idling speed of the primary drive source 1.

(13) Apart from this it should be noted that variants of the shown embodiments may be understood and be exerted by such people that this publication is directed to while exerting the invention starting from a study of the drawings, the description and the enclosed patent claims. In the claims the word comprise does not exclude the possible presence of other steps or elements and the indefinite article a/an does not exclude the existence of a feature in plural. The fact that certain features have been mentioned in different dependant claims is not an indication of that a certain combination can not be used to the advantage of the applicant.

SPECIFICATION OF DETAILS

(14) 1. Primary drive source 2. Secondary drive source 3. Clutch 4. Shaft 4 Output shaft from planetary gear 5. Clutch 6. Clutch 7. Countershaft 8. Twin conical gear 9. Clutch (planetary gear, direct drive) 9a friction disc carrier 10. Shaft 11. Brake for reversal when reversing 12. Conical gear 13. Planetary gear carrier 14. Ring wheel 15. Planetary gear 21, 22 Counterrotating propellers 25 Planetary gear