Cycloidal propeller, ship comprising at least one cycloidal propeller, and method for producing thrust by means of a cycloidal propeller

Abstract

The invention relates to a cycloidal propeller for powering a ship, said cycloidal propeller comprising: a wheel body which rotates about a rotational axis and along the outer periphery of which thrust-generating blades are arranged, each of which can be pivoted about axes of rotation running parallel to the rotational axis; and a housing in which the wheel body is rotatably mounted, wherein the housing has a housing interior into which the wheel body projects and surrounds a propeller well that adjoins the housing interior in the direction of the rotational axis and that encloses the wheel body in the peripheral direction, forming a gap, and the housing interior is sealed from the propeller well by means of a seal. The cycloidal propeller according to the invention is characterised by an air injection device which comprises at least one air outlet that opens into the gap.

Description

[0001] Cycloidal propeller, ship with at least one cycloidal propeller and method for generating thrust with a cycloidal propeller

[0002] The present invention relates to a cycloidal propeller according to the preamble of claim 1, a ship having at least one such cycloidal propeller and a method for generating thrust with such a cycloidal propeller.

[0003] Cycloidal propellers, especially Voith-Schneider propellers, as specifically addressed by the present invention, have been known for almost 100 years. These are used to propel a ship, with several cycloidal propellers also being used in parallel within a ship. The thrust generated by the cycloidal propeller can be adjusted as desired in magnitude and direction without having to change the speed.

[0004] Cycloidal propellers, which also include trochoidal propellers as a special case, have a wheel body rotating around a rotational axis, with thrust-generating blades arranged along its outer circumference, each pivoting about axes of rotation parallel to the axis of rotation. The pivoting movement around the axes of rotation is superimposed on the rotational movement around the axis of rotation. Typically, the axis of rotation and the axes of rotation are vertical. The thrust direction is perpendicular to these axes.

[0005] The blades can be designed as symmetrical, streamlined bodies, but also as airfoil profiles. The blades are either mechanically coupled, at least indirectly, to the drive of the wheel body about the rotational axis for their pivoting, for example, via a coupling gear. A planetary gear can also be used for the coupling. Alternatively, the pivoting movement can also be applied decoupled from the drive of the wheel body, for example, via at least one electric, hydraulic, or compressed air motor. In this case, the superposition of the pivoting movement and the rotational movement is adjusted by a control device. Cycloidal propellers of this type are disclosed, for example, in DE 27 01 914 C1 and DE 43 37 761 C2.

[0006] The wheel body of known cycloidal propellers is rotatably mounted in a housing. The housing encloses an interior chamber into which the wheel body protrudes, for example, with a drive pin. The housing further encloses a propeller well that adjoins the interior chamber in the direction of the wheel body's rotation axis and encloses the wheel body, forming a circumferential gap. The interior chamber is sealed off from the propeller well by a seal. This seal is subject to wear. This limits the service life of the seal, and it must be replaced regularly during cycloidal propeller service.

[0007] The present invention is based on the object of providing a cycloidal propeller for propelling a ship, in which the service interval can be extended by reducing seal wear. Furthermore, a method for generating thrust with such a cycloidal propeller is to be provided.

[0008] The object of the invention is achieved by a cycloidal propeller having the features of claim 1 and a method having the steps of claim 16. The dependent claims describe particularly advantageous and expedient embodiments of the invention, as well as a ship having at least one such cycloidal propeller.

[0009] The cycloidal propeller according to the invention for propelling a ship comprises a wheel body rotating about a rotational axis, on which thrust-generating blades are arranged along its outer circumference, each of which can be pivoted about axes of rotation parallel to the rotational axis. The cycloidal propeller further comprises a housing in which the wheel body is rotatably mounted. The housing encloses an interior space into which the wheel body projects. A propeller well adjoins the interior space in the direction of the wheel body's rotational axis. The propeller well encloses the wheel body in the circumferential direction, forming a gap.

[0010] The propeller well is sealed from the housing interior with a gasket.

[0011] According to the invention, the cycloidal propeller comprises an air injection device which comprises at least one air outlet opening into the gap.

[0012] The invention allows the air injection device to generate a volume of air in the propeller well, which shields the seal from contact with water, especially salt water. This shielding prevents any marine growth that typically occurs in the propeller well, and also prevents abrasive sediments or the like from entering the seal area. This can significantly extend the service life of the seal, significantly extending the maintenance intervals for seal replacement.

[0013] The wheel body preferably has a drive pin that projects into the housing interior. A wheel body drive is connected to the drive pin to drive the wheel body about the rotational axis. For example, the wheel body drive is connected to the drive pin via an angular gear, in particular a bevel gear.

[0014] Preferably, the drive pin is sealed against the housing with the seal, which is in particular a contact seal. The seal particularly advantageously comprises at least one shaft seal.

[0015] In order to further extend the maintenance interval or to prevent it from being shortened compared to a seal replacement interval, at least one separate vane drive is preferably provided for pivoting the vanes about the axes of rotation, which is free of any drive connection to the wheel body drive. Thus, the vanes are not indirectly driven by the wheel body drive. This eliminates the need for conventional mechanical drive connections and gears between the wheel body drive and the vanes. Instead, an electronic vane drive control device is preferably provided, which is designed to control the pivoting of the vanes about the axes of rotation as a function of the rotation of the wheel body about the axis of rotation. The electronic vane drive control device thus takes over the task that was conventionally performed by gears, rods or the like.

[0016] The wheel body drive and / or the at least one wing drive can be designed, for example, as an electric motor. This provides a maintenance-free, compact drive.

[0017] According to an advantageous embodiment of the invention, the propeller well comprises a well base and a well side wall, which, together with the impeller body, define the gap. At least one air outlet is positioned in the well base and / or at least one air outlet is positioned in the well wall. This allows the air volume provided in the gap to be built up particularly easily.

[0018] The wheel body is mounted, for example, in the housing by means of at least one rolling bearing so that it rotates around the rotational axis. In this case, the at least one rolling bearing is preferably positioned on the side of the seal facing away from the propeller well. However, the invention even allows the rolling bearing to be positioned on the side facing the propeller well.

[0019] The housing interior typically contains oil-lubricated components, such as gears for transmitting drive power to the wheel body. The seal prevents oil from escaping into the propeller well.

[0020] According to an advantageous embodiment of the invention, the at least one air outlet is positioned such that it supplies the wings with an air flow.

[0021] By exposing the blades to an airflow during operation of the cycloidal propeller—that is, with the wheel body rotating around the rotational axis and the blades pivoting around the rotational axes superimposed—the blades are hydrodynamically less effective in the area exposed to the airflow. This reduces the conventional influence of an area with unfavorable thrust generation, thereby improving the efficiency of the cycloidal propeller.

[0022] When propelling a ship with a cycloidal propeller, the at least one air outlet of the air injection device is particularly preferably arranged in front of the cycloidal propeller in the direction of travel or in the front region of the cycloidal propeller such that the air flow is directed from the front onto the blades in the direction of travel. This can be achieved by the at least one air outlet opening at least on one side of the blades which, viewed opposite to a direction of a joint thrust force generated by the blades, is in front of the blades. Preferably, the wheel body is also subjected to an air flow. For this purpose, the air outlet is arranged accordingly, with the wheel body preferably being subjected to the air flow on its radially outer circumference.

[0023] The at least one air outlet is preferably arranged such that air is directed to the low-pressure areas on the wings. This can create a suction effect on the airflow.

[0024] According to a further embodiment, at least one air outlet is additionally provided radially outside the propeller well, in particular in a ship's bottom. This allows the illustrated application of an air flow to the blades to be achieved even more effectively.

[0025] The wheel body can be arranged in the propeller well such that it is completely enclosed in the direction of the rotation axis, thus not protruding from the propeller well. The blades, however, preferably protrude, particularly completely, from the propeller well, usually downwards.

[0026] According to a particularly preferred embodiment of the invention, a plurality of air outlets are provided, which are arranged at a distance from one another over the entire circumference of the wheel body, but generally outside the wheel body, wherein the air injection device comprises a switching device with which the air outlets in at least one individual circumferential region of the wheel body can be selectively supplied with air. This means that only a portion of the air outlets always emit the air flow. Thus, not all blades of the cycloidal propeller are always supplied with the air flow, but only selected blades that are positioned in a specific circumferential region of the wheel body, for example, in the front half of the wheel body. This can prevent an adverse influence of the air flow on thrust generation.Preferably, a control device is provided which is configured to actuate the switching device in such a way that only the air outlets in a circumferential region of the wheel body, for example the air outlets assigned to the front half of the wheel body, are supplied with air, wherein the circumferential region is positioned on a side of the wings which, viewed opposite to a direction of a common thrust force generated by the wings, lies in front of the wings.

[0027] According to a particularly advantageous embodiment of the invention, the air volume flowing through the at least one air outlet, or the air volume flowing through each individual air outlet, can be variably adjusted. This allows for a particularly effective adjustment of the required air cushion at the individual vanes and / or the wheel body.

[0028] According to one embodiment of the invention, the required air can be provided with an air compressor, for example, in a ship's compressed air system or separately from the ship's compressed air system, or air inlets can be provided that open into atmospheric ambient air. If at least one air outlet then opens into the area of ​​negative pressure in the cycloidal propeller, the air flow can be supplied to the blades without an additional air compressor. Of course, this type of air supply can also be combined with a compressed air compressor.

[0029] A ship according to the invention has at least one cycloidal propeller of the type according to the invention, wherein the at least one cycloidal propeller is arranged with the rotation axis vertically on a ship's bottom.

[0030] The method according to the invention for generating thrust with a cycloidal propeller comprises the following steps:

[0031] - Driving the wheel body around the rotation axis; and

[0032] - Simultaneous pivoting of the vanes around their respective rotational axes. According to the invention, the air injection device generates a volume of air in the gap that covers the seal.

[0033] Particularly preferably, the wings are also exposed to an air flow from the air injection device.

[0034] The invention will be described below using an exemplary embodiment and the figures.

[0035] They show:

[0036] Figure 1 shows a ship with cycloidal propellers according to the invention;

[0037] Figure 2 is a schematic representation of a cycloidal propeller according to the invention.

[0038] Figure 1 shows a ship 13 with two cycloidal propellers 12 according to the invention in a side view and a bottom view. The cycloidal propellers 12 have air outlets 6 distributed around the circumference, which are arranged below a waterline 14 and are in flow connection with at least one air inlet 10 arranged above the waterline 14. Alternatively or additionally, a compressed air reservoir could also be provided in the ship 13 instead of the air inlet 10.

[0039] The cycloidal propellers 12 each have a wheel body 2, which is positioned in a respective propeller well 7 and with this each delimits a gap 18. Each wheel body 2 carries a plurality of blades 3 that protrude vertically downward from the propeller well 7. In the view from below, the blades 3 are not shown in detail. Figure 2 schematically shows a cycloidal propeller 12 according to the invention. This comprises the wheel body 2, which can be driven to rotate about a rotation axis 1. The blades 3 are mounted at the bottom of the rotation body 2 so as to be pivotable about the rotation axes 4.

[0040] An air injection device 5 is provided, which in the illustrated embodiment comprises various air outlets 6, which are distributed over the circumference of the wheel body 2, a switching device 8 and a control device 9, as well as an air compressor 11. The control device 9 controls the switching device 8 in such a way that only individual air outlets 6 are specifically supplied with compressed air from the air compressor 11, thus generating an air flow that specifically supplies the vanes 3.

[0041] Here too, in addition to or as an alternative to the air compressor 11, an air inlet 10 in atmospheric ambient air could be provided, as shown in Figure 1.

[0042] The switching device 8 is controlled in such a way that preferably only those air outlets 6 are supplied with compressed air which are positioned in the region of a front half of the wheel body 2, viewed in a direction of travel of the ship propelled by the cycloidal propeller 12.

[0043] The wheel body 2 is arranged in the propeller well 7 and is completely enclosed by it in the circumferential direction. The blades 3 protrude downwards from the propeller well 7. The propeller well 7 has a well base 7.1 and a well side wall 7.2. For example, air outlets 6 are provided in both the well base 7.1 and the well side wall 7.2. However, corresponding air outlets 6 could also be provided only in the well base 7.1 and / or only in the well side wall 7.2. According to the invention, the arrangement of air outlets 6 in the propeller well 7 has the effect of forming an air cushion or air volume in the propeller well 7, which prevents water from penetrating the propeller well 7 to the extent that it reaches the seal 15 with which the wheel body 2 is sealed in the propeller well 7.In detail, adjoining the propeller well 7 in the housing 16 of the cycloidal propeller 12 in the direction of the rotation axis 1 is a housing interior 17 into which the wheel body 2 projects with a drive pin 19. A wheel body drive 20 is provided on the drive pin 19, which is also connected in particular in the housing interior 17 or externally to the housing 16 in order to drive the wheel body 2 about the rotation axis 1. For example, the wheel body drive 20 is connected to the drive pin 19 via a bevel gear, with a corresponding gearing 22 being provided between the wheel body drive 20 and the drive pin 19. However, other connections and / or other gearings are also conceivable.

[0044] The wheel body 2 is cantilevered on the drive pin 19, which in turn is mounted in the housing 16 by at least one roller bearing 21. The roller bearing 21 is positioned on the side of the seal 15 facing away from the propeller well 7. The seal 15 is designed as a shaft seal and preferably includes a corresponding shaft seal ring. The seal 15 seals the drive pin 19 against the housing 6 and thus the housing interior 17 against the propeller well 7.

[0045] The air volume in the propeller well 7 extends the service life of the seal 15, as it is not exposed to salt water and / or sediment, for example. This can extend the service interval for replacing the seal 15.

[0046] A further measure, which is preferred but not mandatory, to extend the service interval is the exemplary separate drive for the wings 3. Thus, a separate wing drive 23 is provided, preferably in the wheel body 2, with which the wings 3 can be pivoted about their axes of rotation 4. A common wing drive 23 can be provided for all or several wings 3, or separate wing drives 23 can be provided for each wing 3.

[0047] The wing drive 23 is controlled by an electronic wing drive control device 24, which ensures that the pivoting movement of the wings 3 about the rotation axes 4 is superimposed, as desired, on the rotation of the wheel body 2 about the rotation axis l.

[0048] Alternatively, an indirect drive of the wings 3 with the wheel body drive 20 can of course also be considered.

[0049] Reference symbol

[0050] 1 rotation axis

[0051] 2 wheel bodies

[0052] 3 wings

[0053] 4 axis of rotation

[0054] 5 Air injection device

[0055] 6 Air outlet

[0056] 7 Propeller fountains

[0057] 7.1 Well bottom

[0058] 7.2 Well side wall

[0059] 8 Switching device

[0060] 9 Control device

[0061] 10 Air intake

[0062] 11 air compressors

[0063] 12 cycloidal propellers

[0064] 13 Ship

[0065] 14 Waterline

[0066] 15 Seal

[0067] 16 housings

[0068] 17 Housing interior

[0069] 18 gap

[0070] 19 drive pins

[0071] 20 Wheel center drive

[0072] 21 rolling bearings

[0073] 22 Gearing

[0074] 23 Wing drive

[0075] 24 electronic wing drive device

Claims

Patent claims 1. A cycloidal propeller (12) for propelling a ship (13), comprising a wheel body (2) rotating about an axis of rotation (1), on which thrust-generating blades (3) are arranged along its outer circumference, each blade being pivotable about axes of rotation (4) running parallel to the axis of rotation (1); comprising a housing (16) in which the wheel body (2) is rotatably mounted, the housing (16) enclosing a housing interior (17) into which the wheel body (2) projects, and a propeller well (7) adjoining the housing interior (17) in the direction of the axis of rotation (1), which propeller well encloses the wheel body (2) in the circumferential direction, forming a gap (18), and the housing interior (17) being sealed off from the propeller well (7) by a seal (15); characterized by an air injection device (5) which comprises at least one air outlet (6) opening into the gap (18).

2. Cycloidal propeller (12) according to claim 1, characterized in that the wheel body (2) projects into the housing interior (17) with a drive pin (19), wherein a wheel body drive (20) is connected to the drive pin (19) in order to drive the wheel body (2) about the rotation axis (1).

3. Cycloidal propeller (12) according to claim 2, characterized in that the drive pin (19) is sealed against the housing (16) by the seal (15).

4. Cycloidal propeller (12) according to claim 3, characterized in that the seal (15) comprises at least one shaft sealing ring.

5. Cycloidal propeller (12) according to one of claims 2 to 4, characterized in that at least one separate blade drive (23) is provided for pivoting the blades (3) about the axes of rotation (4), which is free of a drive connection with the wheel body drive (20), and an electronic blade drive control device (24) is provided, which is designed to control the pivoting of the blades (3) about the axes of rotation (4) as a function of the rotation of the wheel body (2) about the axis of rotation (1).

6. Cycloidal propeller (12) according to one of claims 1 to 5, characterized in that the propeller well (7) comprises a well bottom (7.1) and a well side wall (7.2) which delimit the gap (18) together with the wheel body (2), and at least one air outlet (6) is positioned in the well bottom (7.1) and / or at least one air outlet (6) is positioned in the well side wall (7.2).

7. Cycloidal propeller (12) according to one of claims 1 to 6, characterized in that the wheel body (2) is mounted in the housing (16) by means of at least one rolling bearing (21) so as to rotate around the axis of rotation (1) and the at least one rolling bearing (21) is positioned on the side of the seal (15) facing away from the propeller well (7).

8. Cycloidal propeller (12) according to one of claims 1 to 7, characterized in that oil-lubricated components are arranged in the housing interior (17), in particular at least one toothing (22) for transmitting drive power to the wheel body (2).

9. Cycloidal propeller (12) according to one of claims 1 to 8, characterized in that the at least one air outlet (6) is positioned such that it supplies the blades (3) with an air flow.

10. Cycloidal propeller (12) according to claim 9, characterized in that the at least one air outlet (6) opens at least on one side of the blades (3) which lies in front of the blades (3) opposite to a direction of a common thrust force generated by the blades (3).

11. Cycloidal propeller (12) according to one of claims 1 to 10, characterized in that the air injection device (5) is designed such that it generates an air volume in the propeller well (7) which completely covers the seal (15) on its surface facing the propeller well (7).

12. Cycloidal propeller (12) according to one of claims 1 to 11, characterized in that the air injection device (5) comprises at least one air inlet (10) which opens into atmospheric ambient air.

13. Cycloidal propeller (12) according to one of claims 1 to 12, characterized in that the air injection device (5) comprises at least one air compressor (11) which generates a compressed air flow supplied to the at least one air outlet (6).

14. Cycloidal propeller (12) according to one of claims 1 to 12, characterized in that the air injection device (5) is free of an air compressor (11).

15. Ship (13) with at least one cycloidal propeller (12) according to one of claims 1 to 14, wherein the at least one cycloidal propeller (12) is arranged with the rotation axis (1) vertically in or on a ship's bottom.

16. A method for generating thrust with a cycloidal propeller (12) according to any one of claims 1 to 14, comprising the following steps: - Driving the wheel body (2) around the rotation axis (1 ), and - simultaneous pivoting of the wings (3) about the respective axis of rotation (4); characterized in that an air volume covering the seal (15) is generated in the gap (18) by the air injection device (5).

17. Method according to claim 16, characterized in that the wings (3) are subjected to the air flow on a front side in the thrust direction.

18. Method according to claim 16 or 17, characterized in that the air flow is directed out of the wheel body (2) in such a way that this air flow also keeps the vane seals free of water.

19. Method according to claim 17, characterized in that the air flow is sucked in from the environment due to a suction effect of the cycloidal propeller (12).

20. Method according to one of claims 16 or 17, characterized in that the air flow is generated with an air compressor (11).

Images