The invention relates to a watercraft having a hull which has a flow duct or which is assigned a flow duct, wherein the flow duct is assigned a motor-driven water acceleration arrangement, in particular a propeller.
A watercraft of said type is known from DE 10 2004 049 615 A1. Watercraft of said type are used in particular as diver propulsion vehicles. They have a handle arrangement which can be gripped by a user while the user lies with a subregion of his or her torso on the top side of the hull of the watercraft. Arranged within the hull is a flow duct in which a propeller is accommodated. The propeller is driven by an electric motor which is supplied with electricity by way of a battery. During operational usage, the battery and the motor generate waste heat which must be dissipated into the surroundings in order to be able to maintain reliable continuous operation. For this purpose, the batteries are inserted into an aluminum housing, wherein the batteries are in heat-conducting contact with the aluminum housing. The hull has a receptacle on the underside, wherein the aluminum housing can be inserted into and locked in said receptacle. In this way, the aluminum housing is in contact, at the underside, with the flowing water, and dissipation of heat can take place here.
For the purposes of cooling, the electric motor is arranged within the flow duct. The water that is conducted through the flow duct is conducted around a housing of the electric motor, whereby effective motor cooling is made possible. The electric motor restricts the free flow cross section in the flow duct. The flow duct must therefore be of adequately large dimensions in order to compensate for the shadow created by the electric motor. This influences the structural size of the watercraft.
With the known watercraft, in order that both underwater travel and above-water travel are possible, precise taring in terms of weight is necessary. Accordingly, the watercraft should generate sufficient buoyancy that it is adequately capable of floating and consequently cannot sink. The buoyancy should however not be too great, in order that a rapid changeover from above-water travel to submerged travel is possible. Owing to the inherent weight of the electrical components, the watercraft must, in the hull, have an adequately large buoyancy body, which influences the structural size and thus the traveling dynamics of the watercraft.
It is an object of the invention to provide a watercraft of the type mentioned in the introduction which, while having adequate operational reliability, offers good traveling dynamics.
Said object is achieved in that the hull has a flooding chamber which is connected to the surroundings via water passage openings, in particular water inlet and water outlet openings.
The flooding chamber consequently provides a variable mass component, by means of which the inherent weight of the watercraft can be influenced. The flooding chamber fills up during operation. When diving with the watercraft, air is forced out of the flooding chamber, and the watercraft can dive rapidly and easily. When the watercraft is lifted out of the water after use, the flooding chamber empties, and does not influence the transport weight of the watercraft.
In a preferred variant of the invention, it may be provided that at least one electrical component is arranged in the flooding chamber. The flooding chamber is consequently additionally used for the cooling of the electrical component. The electrical component can dissipate its heat losses to the water flowing in the flooding chamber. An effective exchange of heat is possible in particular because the flooding chamber is connected to the surroundings both via water inlet openings and via water outlet openings. Consequently, a flow can be generated in the flooding chamber, by means of which cool water is continuously replenished. In a manner dependent on the traveling speed of the watercraft, it is then also possible for the flow speed in the flooding chamber to vary. This has the advantage that, during fast travel, in the case of which high heat losses are also generated, a large cooling volume is available.
As electrical component, it is for example possible for the control electronics, the electric motor which drives the water acceleration arrangement, and/or an energy store to be arranged in the flooding chamber. Said components generate relatively high power losses and are therefore particularly suitable for use in the flooding chamber.
A simple design for the watercraft is attained if it is provided that the hull has an upper part and a lower part, between which the flooding chamber is formed, and if the upper part and/or the lower part at least regionally form the outer shell of the hull.
It may advantageously be provided that the lower part is detachably connected to the upper part. It is then possible for the flooding chamber to be made accessible for the purposes of straightforward maintenance. For example, if dirt has infiltrated into the flooding chamber, said dirt can be easily removed again. If electrical components are arranged in the flooding chamber, these can be easily serviced or exchanged after the lower part has been removed.
An effective flow through the flooding chamber can be attained by virtue of the hull forming at least one inlet opening in the region of the bow and at least one outlet opening in the region of the rear end.
A preferred design variant of the invention is such that the flow duct is arranged at least regionally in the region of the flooding chamber and narrows the free cross section of the flooding chamber, and that an electrical component is arranged in the region of the narrowed cross section. By means of the cross-sectional narrowing, the flow speed in the flooding chamber can be varied. Accordingly, the flow speed regionally increases in the narrowed cross section, such that the cooling power can be influenced in this way.
It is also conceivable that, in the flooding chamber, two subregions are structurally delimited with respect to one another, wherein each subregion is assigned a water inlet and/or water outlet opening. By this measure, too, it is possible in targeted fashion for the volume flow in the individual subregions, and thus the cooling power, to be influenced.
A particularly preferred refinement of the invention is such that the flow duct at least regionally delimits two subregions in the flooding chamber with respect to one another, and that an electrical component is arranged in each of the subregions. By virtue of the fact that the flow duct is used for regional delimitation, the expenditure on parts can be reduced.
One possible design variant of the invention is such that the electrical component is fastened by a suspension means, and that the suspension means holds the electrical component spaced apart from the wall elements which delimit the flooding chamber. In this way, it is possible to realize a flow around the electrical component over a large area, and in association therewith, an effective dissipation of heat.
A preferred refinement of the invention provides that, when the flooding chamber is flooded, the watercraft has a buoyancy of at least 4 kilograms. In this way, the watercraft is kept adequately buoyant even when at sea. It is particularly advantageous if the buoyancy of the watercraft amounts to at least 7 kilograms. Then, even in the event of damage, an adequate buoyancy force can be provided which keeps both the watercraft and the user buoyant.
The invention will be discussed in more detail below on the basis of an exemplary embodiment illustrated in the drawings, in which:
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At its end averted from the intake opening 61 in the flow direction, the hollow body forms a flange region on which an in impeller housing 63 can be flange-mounted. The propeller 52 projects into the impeller housing 63. A flow stator 53 is arranged behind the propeller 52 in the flow direction. During operation, the propeller 52 draws water into the flow duct 16 through the intake opening 61, accelerates said water and discharges it through the impeller housing 63 in the region of a jet outlet 34. In this case, the stator 53 has the task of straightening the rotating water movement, such that, for the purposes of improving efficiency, the flow emerges with the least possible swirl at the jet outlet.
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Number | Date | Country | Kind |
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10 2013 100 544.6 | Jan 2013 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/077896 | 12/23/2013 | WO | 00 |