Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H11/00—Marine propulsion by water jets
  • B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
  • B63H11/04—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps
  • B63H11/08—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps of rotary type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H11/00—Marine propulsion by water jets
  • B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
  • B63H11/04—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps
  • B63H11/08—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps of rotary type
  • B63H2011/087—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps of rotary type with radial flow

Definitions

• the invention relates to a propulsion system for a watercraft, designed as a pump jet, comprising a housing with at least one inlet channel and at least one outlet nozzle communicating with it, and a propeller arranged between the at least one inlet channel and the at least one outlet nozzle, designed as an impeller and rotatable via a drive motor, by means of which water is drawn into the housing via the inlet channel, accelerated and expelled from the housing as a jet of thrust via the outlet nozzle, wherein the housing is rotatable about a control axis by means of a steering drive and the drive motor comprises an annular stator fixed in the housing and a rotor received therein, which forms the impeller.
• Pump-jet propulsion systems for watercraft are widely known and, due to their operating principle, are also referred to as water jet propulsion. They are primarily a propulsion unit with a reaction drive for a wide variety of applications, such as in specialized vessels and rescue units, but also in amphibious military vehicles and submersible underwater vehicles.
• a high-speed, lightweight gasoline or diesel engine or gas turbine drives an impeller—that is, a shrouded propeller—which draws water from under the hull and expels it through movable nozzles.
• Pump-jet propulsion enables efficient vector control by swiveling the nozzle in the direction the watercraft is to turn. Reverse travel is also possible in this way.
• jet-driven watercraft can be built and operated with an extremely low profile and are highly maneuverable even at very slow speeds.
• a pump-jet waterjet propulsion system for a watercraft in which the inlet and outlet channels are arranged in a housing rotatable around the steering axis, which also acts as a diffuser.
• the drive motor is formed by a magnetic motor integrated into the housing, comprising an annular stator and a similarly annular rotor rotating within it, which also forms the impeller.
• the stator since the stator is located within the rotatable housing, its energy supply must be provided via slip rings in the area of the housing's bearings. This is extremely costly and, due to the design of the sliding contacts, prone to wear, especially in the presence of vibrations, which are unavoidable during ship operation.
• a pump-jet waterjet drive in which the impeller is driven by a drive shaft extending from the housing into the ship's hull and a bevel gear by a drive motor located in the ship's hull.
• the housing has a section fixed to the ship's hull in the area where the drive shaft passes through, and a section rotatable about the control axis, sealed against this section, which also houses the discharge nozzle of the jet.
• Such a drive is structurally very complex and requires a large amount of installation space due to the shaft drive and the drive motor located in the ship's hull, which is extremely disadvantageous.
• the object of the invention is to propose a drive of the type mentioned above which overcomes the disadvantages of the prior art.
• the pump jet has an annular stator fixed in the housing and a rotor received therein, which comprises the impeller, wherein the housing is divided into a stationary, fixed inner part and an outer part rotatably mounted on the inner part about the control axis and the stator is fixed to the inner part, thus also being fixedly connected to the stationary inner part.
• the housing is thus designed in two parts and comprises a stationary inner part and an outer part that is rotatable about the control axis to maintain the control function.
• the stator of the magnetic motor provided according to the invention is fixed to the inner part and, like the inner part, is arranged in a stationary position.
• the rotor is arranged to rotate freely within the stator, and the outer part can be rotated about the control axis relative to the stationary inner part by means of the control drive to ensure the control function of the pump jet drive according to the invention. Since, according to the invention, the inner part and the stator are rigidly connected to each other, the need to ensure the energy supply of the stator via complex and failure-prone slip rings is eliminated.
• the outer part of the housing which is rotatable about the control axis, comprises the at least one inlet channel and the at least one outlet nozzle, which are preferably arranged radially to the outer part and are arranged opposite each other with respect to the control axis.
• the inlet channel and/or the outlet channel in the area of the underside of the pump jet in a manner known per se.
• the outlet channel is preferably always integrated into the outer part in order to achieve the desired rotation about the control axis for controlling the thrust jet.
• the impeller is rotatably mounted on a fixed axle attached to the inner part, thus ensuring a particularly simple mechanical design.
• the mounting can be encapsulated and requires only a dynamic seal against seawater.
• the impeller can also have an axle or axle stub projecting towards the inner part, which is rotatably mounted in the fixed inner part.
• the drive according to the invention can be permanently installed on or in a ship's hull or designed as a retractable drive which, when installed in the hull of a watercraft, can be moved between a retracted rest position and an extended working position, wherein the drive can be extended in the extended working position to such an extent that the at least one inlet channel and at least one outlet nozzle protrude above the hull of the watercraft.
• connection of the drive according to the invention to the hull of a watercraft can be achieved, for example, by connecting the inner part to a flange for fixing it in the watercraft, wherein the flange can be firmly connected to the hull of the watercraft due to the fixed arrangement of the inner part, for example by bolting it. It is also possible to fix the flange to the watercraft via elastically compliant shock bearings in order to minimize operating noise and/or to make the drive resistant to external shock loads.
• the inner part comprises a deflecting arch for reversing the flow direction of the water drawn in by the impeller via the inlet channel and accelerated towards the at least one outlet nozzle.
• the inner part comprises a pot-shaped receiving chamber that is separated from the water-carrying areas of the inner part and from the areas that come into contact with the water conveyed by the drive.
• the stator is fixedly inserted into this receiving chamber, with the rotor arranged to rotate within the stator; that is, the receiving chamber serves to hold both the stator and the rotor.
• the rotor is connected to the impeller running in the outer part via a corresponding shaft that extends from the receiving chamber in a sealed bearing.
• the stator is fixedly connected to the inner part via retaining struts and that the electrical connecting lines of the stator, as well as optionally control lines, sensor lines, etc., run along or within the retaining struts from the inner part to the stator, which is why the retaining struts are preferably designed as a hollow profile.
• the retaining struts can, according to a further proposal of the invention, also be shaped in such a way or with such a flow profile.
• the supports must be designed to counteract the swirl induced in the accelerated water by the impeller.
• the rotating impeller which propels the water jet, imparts a corresponding swirl to the accelerated water due to its rotational motion, leading to efficiency losses.
• this swirl can be counteracted; that is, the accelerated water jet is de-swirled by the support struts, thereby significantly increasing efficiency.
• the support struts can be arranged at equal or different intervals from each other, depending on the requirements, and can have the same or different cross-sections.
• some support struts can be larger to accommodate the connecting lines to the stator, as well as any control and measuring lines, while other support struts have a special contour on their flow-enclosed surfaces to reduce the swirl of the accelerated water jet.
• FIG. 1 shows a perspective view of a section through a pump jet drive 1 of a watercraft, which generates a thrust jet exiting from a nozzle 15, generating propulsion and a steering torque for the watercraft equipped with it.
• the drive 1 comprises a housing 10 with several inlet channels 14 for water drawn in from outside the hull, which then enters a vestibule 140 located inside the housing 10.
• a vertically oriented propeller in the form of an impeller 13 is arranged, which is set in rotation by a drive motor which will be explained in more detail below and by means of its propeller blades not only causes the water to be drawn into the antechamber 140 via the inlet channels 14, but also accelerates the water from the antechamber 140 vertically upwards in the direction of a deflecting arch 16, along which the accelerated water jet is reversed in the flow direction indicated by arrows and flows downwards in the direction of the outlet nozzle 15 which is arranged diametrically opposite to the inlet channels 14, through which the water jet is then expelled from the drive 1.
• the housing 10 of the drive 1 is divided into an inner part 100 and an outer part 101, wherein the inner part 100 is fixed in a fixed position in the hull of the watercraft (not shown here) via a flange 18 in a manner not shown in detail, for example by screwing it in place and is thus fixed in position.
• the outer part 101 is sealed to the inner part 100 by means of double-acting seals 105, 103, but is freely rotatable about the vertically extending control axis S by means of a drive motor 17 in order to rotate the outlet nozzle 15 endlessly into any desired orientation about the control axis S in a manner known per se and to generate control impulses for the watercraft thus equipped by means of the drive 17.
• a circumferential annular gap 104 is provided between the inner part 100 and the outer part 101, which ensures the free rotation of the outer part 101 relative to the stationary inner part 100, the annular space 106 formed between the inner part 100 and the outer part 101 behind the annular gap 104 being sealed by the gap seal 103.
• Radially outward-leading relief bores can also be arranged in this area to provide pressure relief.
• the upper end of the drive 1 is formed by an annular cover 180 resting on the flange 18.
• a key feature of the illustrated drive 1 is that the drive motor of the impeller 13 is powered by a magnet arranged completely within the housing 10. or induction motor, which has a stationary annular stator 11 and an equally annular rotor 12 rotating within the stationary stator 11, which also includes the impeller 13.
• the stationary and thus fixed annular stator 11 is attached to the deflection arch 16 of the also stationary inner part 100 of the housing 10 via a plurality of retaining struts 102, wherein the electrical connecting lines for the winding system of the stator 11 and the sensor system of the stator 11 are led through the retaining struts 102, which are designed as hollow profiles, to the inner part 11 and from there out of the flow space, so that the drive 1 does without slip rings or similar components, since the lines are guided exclusively through stationary components of the drive.
• the rotor 12 which carries the propeller blades of the impeller 13, is rotatably mounted on a centrally formed hub on a rigid axle 108 projecting downwards from the inner part 100.
• the bearing of the hub on the axle 108 can be encapsulated and requires only a dynamic seal above against seawater.
• the support struts 102 can have such a profile or cross-sectional design and orientation that they not only allow the passage of the connecting and control lines for the stator 11, but also give the water jet a flow direction opposite to the swirl, thus resulting in an overall reduction of the swirl in the water jet propagated and accelerated by the impeller 13. This allows the pressure of the thrust jet generated in the drive 1 to be maximized, while simultaneously minimizing the required control torque of the control drive 17 for rotating the outer part 101 about the control axis S during the operation of the impeller 13.
• the housing 10 can be designed as a diffuser to increase the pressure.
• the diffuser can be configured as in Figure 1 It may be depicted or designed as a ring diffuser.
• the drive described above offers a further advantage in that it requires very little oil, so that the required size of a pressure transmitter, for example, can be reduced to less than 10 liters of oil volume.
• the space gained above the housing 1 can be used, compared to conventional pump jets, to arrange a movement mechanism there, which consists, for example, of synchronous cylinders that are controlled by a pump located in the interior, which may be filled with oil at neutral pressure, in order to move the drive as required from a retracted rest position to an extended working position, whereby the drive can be extended in the extended working position to such an extent that the at least one inlet channel 14 and the at least one outlet nozzle 15 project beyond the hull of the watercraft, while in the retracted rest position, piston rods exposed to seawater are retracted and protected from fouling and no change in volume occurs.
• a movement mechanism there which consists, for example, of synchronous cylinders that are controlled by a pump located in the interior, which may be filled with oil at neutral pressure
• the drive 1 is designed with a housing 10 divided into an inner part 100 and an outer part 101, wherein the outer part 101 has both the inlet channels 14 and the outlet nozzle 15 diametrically opposite each other and can be rotated around the control axis S relative to the stationary inner part 100 by means of a control drive 17.
• the impeller 13 rotates about a vertical axis of rotation within the outer part 101 and conveys water from the antechamber 140 along the deflection arch 16 defined by the inner part 100 to the outlet nozzle 15.
• the impeller is mounted on a vertically extending axis 108, which extends vertically upwards and is rotatably mounted in a sealed bearing 109 of the inner part 100.
• the axis 108 extends into a pot-shaped receiving chamber 107, centrally located on the inner part 100 and closed at the top by a cover 110.
• the stator 11 is inserted into the receiving chamber 107, which is thus sealed off from the water-bearing areas or areas that do not come into contact with the pumped water in the drive 1, and is therefore firmly connected to the stationary inner part 100.
• Neither the inner part 100 nor the stator 11 rotates around the control axis S.
• the rotor 12, mounted on the axis 108 is arranged to rotate radially inside the stator 11, thus forming a magnetic motor consisting of the stator 11 and rotor 12 to drive the impeller 13.
• the electrical power supply to the stator can pass directly through the wall of the receiving chamber 107, so that sliding contacts are also not necessary.
• stator 11 and rotor 12 are not in contact with the pumped water of the drive 1.
• the drive described above is suitable for integration into a wide variety of watercraft and, due to its small size, can also be retrofitted to suitable watercraft.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

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• 2024
  • 2024-07-04 DE DE102024119034.5A patent/DE102024119034B3/de active Active
• 2025
  • 2025-07-02 EP EP25186920.2A patent/EP4674748A1/fr active Pending

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