EP3395669A1

EP3395669A1 - Outboard propulsion unit for boats and boat provied with said propulsion unit

Info

Publication number: EP3395669A1
Application number: EP18169583.4A
Authority: EP
Inventors: Donatella PANCHETTI
Original assignee: Hythem Srl
Current assignee: Hythem Srl
Priority date: 2017-04-28
Filing date: 2018-04-26
Publication date: 2018-10-31
Also published as: IT201700046145A1

Abstract

An outboard propulsion unit (2) in a boat (1), preferably a sailing boat; the propulsion unit comprising two electric propulsion devices (3), each one provided at least with: - an external accommodation housing (4), which is fixed to the transom (5) of the boat; - a propeller assembly (6), which can be shifted between an active condition in which it is extracted from the corresponding housing, and an inactive condition, in which it is accommodated in the corresponding housing; - an electric motor (7) for driving the propeller assembly; wherein the propeller assemblies of the electric propulsion devices, in the active condition, are extended at an angle with respect to a central plane of symmetry (Y) of the hull (S) of the boat.

Description

The present invention relates to an outboard propulsion unit for boats, preferably for sailing boats, and a boat, preferably a sailing boat, which is provided with such propulsion unit.
As is known boats, for example sailing boats, are usually provided with a propulsion unit which is provided with an engine which is useful, for example, for mooring maneuvers in port, or when there is no wind.
In some conventional forms, such outboard engines can be applied to the transom of the boat and are installed only when necessary, in order to avoid leaving the propeller in the sea, which would have a negative effect on the hydrodynamics of the boat as it would increase its drag.
Such solutions are not devoid of intrinsic drawbacks, among which is the fact that whenever the motor needs to be used it is necessary to fix it to the transom, which requires rather inconvenient maneuvers.
Outboard engines are also known which are stably fixed to the transom and can optionally be swung about a horizontal axis in order to extract the propeller from the water when not in use.
A drawback of this solution is that when the motor is not in use the propeller increases the space occupation of the boat, protruding considerably from the transom and obstructing, for example, the stern mooring.
Furthermore, in boats with a central rudder, the motor has to be installed to port or starboard of the rudder, with the consequence that, when the boat is listing, the propeller might not be immersed.
The aim of the present invention is to provide an outboard propulsion unit for boats, preferably for sailing boats, and a boat, preferably a sailing boat, provided with such propulsion unit, that solves the above technical problem, eliminates the drawbacks, and overcomes the limitations of the known art, by making it possible to have an outboard propulsion unit available which can profitably be used even when the boat is listing.
Within this aim, an object of the present invention is to provide a propulsion unit and a boat that comprises such unit, in which the space occupation can be contained.
Another object of the invention consists in providing a propulsion unit and a boat that comprises such unit, which can be easily used.
Another object of the invention consists in providing a propulsion unit and a boat that comprises such unit, which are sturdy and capable of sustaining collisions with jetties or wharfs, especially during mooring.
Another object of the invention consists in providing a propulsion unit and a boat that comprises such unit, which are easy to clean.
This aim and these and other objects which will become better apparent hereinafter are achieved by an outboard propulsion unit in a boat, preferably a sailing boat, said propulsion unit comprising two electric propulsion devices, each one provided at least with:

an external accommodation housing, which is fixed to the transom of the boat;
a propeller assembly, which can be shifted between an active condition in which it is extracted from the corresponding housing, and an inactive condition, in which it is accommodated in the corresponding housing;
an electric motor for driving the propeller assembly, accommodated in the corresponding housing;

Further characteristics and advantages of the invention will become better apparent from the description of some preferred, but not exclusive, embodiments of a propulsion unit and a boat, which are illustrated by way of non-limiting example with the aid of the accompanying drawings wherein:

Figure 1 is a perspective view of an embodiment of a propulsion unit applied to a boat in a first condition, according to the invention;
Figure 2 is a perspective view of the propulsion unit of Figure 1 in a second condition;
Figure 3 is an exploded perspective view of part of the propulsion unit in the previous figures;
Figure 4 is a side view of part of the boat with the propulsion unit of the previous figures, in an active condition;
Figure 5 is a side view of part of the boat with the propulsion unit of the previous figures, in a moored condition;
Figure 6 is a front elevation view of the transom of the boat with the propulsion unit of the previous figures, in an active condition;
Figure 7 is a perspective view of part of the propulsion unit of the previous figures, in an active condition;
Figure 8 is a perspective view of a second embodiment of a propulsion unit applied to a boat, in a first active condition;
Figure 9 is a perspective view of the propulsion unit of Figure 8 in an initial inactive condition;
Figure 10 is a perspective view of the propulsion unit of Figures 8 and 9 in a final inactive condition;
Figure 11 is a partially cross-sectional front elevation view of the propulsion unit of Figures 8-10 in a final inactive condition.

With reference to the figures, an outboard propulsion unit is shown in a boat 1, preferably a sailing boat, and is generally designated by the reference numeral 2.
The propulsion unit 2 according to the invention comprises two electric propulsion devices 3, which are preferably separate and distinct and are applied to the transom 5 of a boat 1.
Each electric propulsion device 3 in turn comprises an external accommodation housing 4 which is fixed to the transom 5 of the boat and a propeller assembly 6, which can be shifted between an active condition in which it is extracted from the housing 4 and an inactive condition in which it is accommodated in the housing 4.
This makes it possible to have the propeller assembly 6 exit only when necessary, and instead keeping it accommodated in the housing 4 (i.e. not immersed) when it is not necessary; this makes it possible not only to reduce the draft in the aft region of the boat, but also to decrease its drag when the propeller assembly 6 is not required for propulsion, as well as to protect the propeller assembly from corrosion and from damage caused by sea water.
The propeller assembly 6 is driven by an electric motor 7.
In an embodiment, the electric motor 7 is accommodated in the housing 4, preferably in a volume that is separate from the internal chamber that accommodates the propeller assembly 6 when the latter is in the inactive condition.
In some preferred solutions, the volume that accommodates the electric motor and its components is separate and watertight. In this manner the electric motor and its circuits and components remain advantageously isolated from the marine environment and not exposed to the action of sea water, thus extending its operating life and reducing the need for maintenance. In these embodiments, between the motor 7 and the propeller assembly 6 there are kinematic chains for transmitting motion, which are conventional and are not described in detail here.
In other embodiments the electric motor 7 is instead incorporated with the propeller assembly and accommodated in a watertight housing adjacent to the propeller assembly 6.
Note that the electric motor, with respect to a normal heat engine, makes it possible to reduce noise to levels that are substantially imperceptible by the occupants and to also reduce pollution; the electric motor can be powered with conventional means, for example accumulator batteries, solar panels, generators and the like.
As clearly shown in Figure 6, according to the invention, the propeller assemblies 6 of the electric propulsion devices 3, in the active condition, are extended at an angle with respect to a central plane of symmetry Y of the hull S of the boat 1.
Preferably, the propeller assemblies 6 extend diverging downward, when the boat is in the condition of operation.
The central plane of symmetry Y is the plane that longitudinally divides the boat and if the boat has a keel, the plane Y passes through it.
In this manner several advantages are obtained: firstly, even if there is a central rudder, arranged at the stern, the unit 2 will not interfere with it; furthermore, when the boat is listing (inclined) to one side, for example owing to an intense wind, then at least one of the two propeller assemblies 6 will always be in a condition of complete immersion, while the other one can, if necessary, be brought to the inactive position and thus protected from the elements.
In the preferred and non-limiting embodiment illustrated, the electric propulsion device 3 comprises a supporting shaft 8 which supports, at one of its ends, the propeller assembly 6.
In this embodiment the supporting shaft 8 extends inclined along an axis M which constitutes the axis of translation of the propeller assembly 6 from the inactive position to the active position and which is inclined with respect to the central plane of symmetry Y of the hull S of the boat 1.
The propeller assembly 6, in the preferred and illustrated form, comprises an actual propeller 6A and a substantially cylindrical section of duct 6B, in the form of a tube, which improves the propulsive work overall and at the same time protects the propeller 6A from any impacts, for example in mooring maneuvers or with very shallow sea floors.
The supporting shaft 8 is preferably contoured with a profile that is adapted to reduce drag.
Preferably, the supporting shaft 8 can translate along the direction of motion M in order to allow the transition of the propeller assembly 6 between the active condition and the inactive condition, and vice versa.
The direction of motion M is substantially parallel to a plane that contains the transom 5 of the boat and is inclined with respect to the aforesaid central plane of symmetry Y.
Descending into more detail about the non-limiting embodiment shown in the accompanying figures, the housing 4 comprises an engagement portion 9 which can be fixed to the transom 5 (for example by way of interposition of a fixing plate 20 or directly, by way of screw connections or the like) and a closing cover 10.
The engagement portion 9 and the cover 10 define an internal accommodation chamber for containing at least the propeller assembly 6 when in the inactive condition.
Preferably, there are impact-resistant protections 11 at least on a part of the closing cover 10.
The protections 11 can be made for example of impact-resistant plastic material, such as ABS or the like, and optionally they can have a metallic stiffening core 11A which is at least partially covered by the plastic material 11B.
In general, the impact-resistant protections 11 extend at least on a wall of the closing cover 10 that lies opposite from the engagement portion 9, i.e. on that part of the propulsion device 3 that is most exposed to impacts.
Preferably, the protections 11 extend on the cover 10 so as to define a "cage" structure that encompasses at least part of the cover 10 and extends until it is fixed on the engagement portion 9, so that any stresses can be partially absorbed and partially relieved by way of the engagement portion 9 on the hull.
This makes it possible to protect the entire electric propulsion device 3 from any impacts for example against a wharf B which may occur during mooring, as shown in Figure 5.
Furthermore, it is possible to moor the boat as close as possible to the wharf B, without the propulsion unit causing significant encumbrances.
Preferably, in order to reduce the maintenance needs, the housing 4 comprises a lower wall (delimiting the internal chamber) which can be opened, for example provided at least with closing fins 12 for opening and closing an opening 13 for access to the accommodation chamber and allowing at least the passage of the propeller assembly 6 (and of the shaft 8 in the embodiment shown) in the transition between the active condition and the inactive condition and vice versa.
Preferably the fins 12, once closed, define a watertight closure, so that when the propeller assembly 6 is in the retracted, inactive, position the chamber in which it is accommodated is watertight.
In general, irrespective of whether the closure of the fins 12 is watertight or otherwise, their presence makes it possible to isolate or at least protect the propeller assembly from external agents, to the advantage of reducing maintenance and cleaning.
Also in order to keep the chamber defined in the housing as isolated or protected as possible from sea water, in the preferred embodiment the supporting shaft 8 comprises a transverse wall 14 the dimensions and shape of which substantially coincide with those of the access opening 13.
The transverse wall 14 is provided on the shaft 8 in a fixing position, in which, when the propeller assembly 6 is in the active condition, it closes the access opening 13.
In this manner, even when the propeller assembly 6 is active, the inside of the chamber is protected from external agents.
Optionally, the housing 4 comprises a coupling flange 15 for a duct of a cleaning liquid and a diffuser for the cleaning liquid which is directed toward the accommodation chamber.
The cleaning liquid could be for example fresh water (optionally with the addition of a washing agent) which is sprayed on the propeller assembly 6 when it is in the inactive condition, accommodated in the housing, in order to clean it of sea water and of any dirt or vegetation that may form thereupon, thus extending its useful life and reducing the need for maintenance.
In this sense it is possible to note that, if the walls 12 are adapted to define a watertight closure, then it is possible to achieve, at the same time, a considerable saving of the cleaning liquid used (particularly important when this is fresh water originating from a tank on the boat), since it is possible to perform the cleaning while keeping the propeller assembly immersed in the chamber proper for the necessary period of time, thus avoiding waste; when the cleaning action is considered concluded it is possible to discharge the cleaning liquid into the sea simply by opening the fins 12.
The invention generally also relates to an outboard propulsion unit 2 for a boat 1, which comprises a single propulsion unit 3 of the type just described and on which therefore we will say nothing further.
The invention generally also relates to a boat 1, preferably a sailing boat, characterized in that it comprises an outboard propulsion unit 2 of the type described above.
Operation of the invention is clear and evident from the foregoing description.
Figures 8-11 show a second embodiment of the propulsion unit 2 according to the invention.
In such embodiment the propulsion unit 2 comprises the housing 4 similarly to the previous embodiment and the propeller assembly, now designated with the reference numeral 26 and constituted by the propeller 26A and by the supporting shaft 28 inside which a shaft 30, supported by bearings 31-33, is accommodated for actuating the propeller 26A.
The shaft 30 is driven by a motor 40.
Again in the second embodiment, the propeller assembly 26 can be shifted between an active condition in which it is extracted from the housing 4, and an inactive condition, in which it is accommodated in the housing 4.
Differently from the previous embodiment, the propeller assembly 26 is configured so that the propeller can be positioned along the shaft 8, as illustrated in Figure 9, and therefore it can be retracted into the housing 4, thus making it possible to have an opening or passage 13 of reduced dimensions and therefore not excessively invasive for the boat.
Conveniently, furthermore, the propeller assembly 26 can be rotated so as to bring the propeller 26A into many active conditions, at different angles from the longitudinal axis of the boat.
To this end the propeller assembly 26 comprises, fitted on the shaft 8, a disk-like element 35, constituted preferably by a pair of disks, which is provided on the side surface with a rack that permits the engagement of a pinion 36 of a motor 37.
The motor 37 makes it possible to rotate, by way of the rack, the propeller assembly 26 so as to change the position of the propeller 26A.
It is therefore possible for example to rotate the propeller 26A so that it is arranged with the vanes at right angles to the direction of the bow-stem axis of the boat, so as to enable lateral movements of the boat, or according to any other angle with respect to the longitudinal axis of the boat.
In an additional variation, not shown, aimed at reducing the space taken up by the housing 4, the propeller 26A can be raised into the housing so that it comes into abutment with a locator defined inside the housing 4, so as to angle it and enable its storage inside the housing in an angular position.
In this manner the propeller 26A occupies less space than the propeller in the vertical position, and therefore the housing 4 can be made with reduced dimensions.
Each one of the propulsion units 2 of the first embodiment can be provided according to what is described for the second embodiment.
In practice it has been found that the outboard propulsion unit 2 and/or the boat 1, according to the present invention, achieve the intended aim and objects, since they can profitably be used even when the boat is listing.
Another advantage consists in having an outboard propulsion unit 2 and/or a boat 1, according to the invention, the encumbrances of which are contained.
Another advantage consists in having an outboard propulsion unit 2 and/or a boat 1, according to the invention, that requires little maintenance.
Another advantage consists in having an outboard propulsion unit 2 and/or a boat 1, according to the invention, that are sturdy and capable of sustaining impacts with jetties or wharfs, especially during mooring.
Another advantage consists in having an outboard propulsion unit 2 and/or a boat 1, according to the invention, that are easy to clean.
The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
Moreover, all the details may be substituted by other, technically equivalent elements.
In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. 102017000046145 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

In a boat (1), preferably a sailing boat, an outboard propulsion unit (2),
characterized in that
the propulsion unit (2) comprises two electric propulsion devices (3), each one provided at least with:
- an external accommodation housing (4), which is fixed to the transom (5) of the boat;

- a propeller assembly (6), which can be shifted between an active condition in which it is extracted from the corresponding housing (4), and an inactive condition, in which it is accommodated in the corresponding housing (4);

- an electric motor (7) for driving the propeller assembly (6);
wherein the propeller assemblies (6) of the electric propulsion devices (3), in the active condition, are extended at an angle with respect to a central plane of symmetry (Y) of the hull (S) of the boat (1).
The propulsion unit (2) according to claim 1, characterized in that each electric propulsion device (3) comprises a respective supporting shaft (8), which supports the propeller assembly (6) at one of its ends, said supporting shaft (8) being able to translate along a direction of motion (M) in order to allow the transition of the respective propeller assembly (6) between the active condition and the inactive condition, and vice versa, said direction of motion (M) being substantially parallel to a plane that contains the transom (5) of the boat and being inclined with respect to said central plane of symmetry (Y) of the hull (S) of the boat (1).
The propulsion unit (2) according to claim 1 or 2, characterized in that said housing (4) comprises an engagement portion (9) which can be fixed to said transom (5) and a closing cover (10), which are adapted to form an internal accommodation chamber in order to contain at least said propeller assembly (6), impact-resistant protections (11) being provided at least on part of said closing cover (10).
The propulsion unit (2) according to one or more of the preceding claims, characterized in that said impact-resistant protections (11) extend at least on a wall of the closing cover (10) that lies opposite from the engagement portion (9).
The propulsion unit (2) according to one or more of the preceding claims, characterized in that said housing (4) comprises a lower wall which is provided at least with closing fins (12) for opening and closing an opening (13) for access to the accommodation chamber and allowing at least the passage of the propeller assembly (6) in the transition between the active condition and the inactive condition.
The propulsion unit (2) according to one or more of the preceding claims, characterized in that the supporting shaft (8) comprises a transverse wall (14) the dimensions and shape of which correspond substantially to those of said access opening (13), said transverse wall (14) being provided on said supporting shaft (8) in a position for fixing, in which, when the propeller assembly (6) is in the active condition, it closes said access opening (13).
The propulsion unit (2) according to one or more of the preceding claims, characterized in that said housing (4) comprises a coupling flange (15) for a duct of a cleaning liquid and a diffuser for the cleaning liquid which is directed toward the accommodation chamber.
An outboard propulsion unit (2) for a boat (1), characterized in that it comprises:
- an external accommodation housing (4) which can be fixed to a transom (5) of the boat (1);

- a propeller assembly (6), which can be shifted between an active condition in which it is extracted from the housing (4), and an inactive condition, in which it is accommodated in the housing (4);

- an electric motor (7) for driving the propeller assembly, accommodated in the housing (4);
wherein the housing (4) comprises an engagement portion (9) with the transom of the boat and impact-resistant protections (11) which are arranged at least on a wall of the housing (4) which is opposite from said engagement portion (9).
The outboard propulsion unit (2) according to claim 8, comprising a supporting shaft (28) which supports the propeller assembly (26) at one of its ends, said propeller assembly (26) comprising a propeller (26A) which is coupled to the supporting shaft (28), at a free end thereof, said propeller (26A) being positionable in axial alignment with said supporting shaft (28) for the retraction of said propeller (26A) inside said housing (4).
The outboard propulsion unit (2) according to claim 8, characterized in that the propeller assembly (26) comprises, fitted on the shaft (28), a disk-like element (35), which is provided on the side surface with a rack that permits the engagement of a pinion (36) of a motor (37), said motor (37) making it possible to rotate, by way of the rack, the propeller assembly (26) so as to change the position of the propeller (26A).
A boat (1), preferably a sailing boat, characterized in that it comprises an outboard propulsion unit (2) according to one or more of the preceding claims.