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. The cycloidal propeller according to the invention is characterised by an air injection device which comprises at least one air outlet that is positioned so as to apply an airflow to the blades.

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] From an efficiency perspective, the highest possible efficiency of such a cycloidal propeller is desirable in order to convert the applied propulsion energy into thrust as effectively as possible. At the same time, the cycloidal propeller should be robust and durable.

[0007] The present invention is based on the object of providing a cycloidal propeller for propelling a ship with improved efficiency. In particular, the efficiency improvement should be possible with simple means for different types of cycloidal propellers, such as those mentioned above, without extensive modifications to the design. Furthermore, a method for generating thrust with such a cycloidal propeller should 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 13. 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 rotation axis, on which thrust-generating blades are arranged along its outer circumference, each of which can be pivoted about axes of rotation running parallel to the rotation axis.

[0010] According to the invention, the cycloidal propeller further comprises an air injection device having at least one air outlet arranged to apply an air flow to the blades. By applying an air flow to the blades during operation of the cycloidal propeller, i.e., when the wheel body rotates about the rotational axis with a superimposed pivoting movement of the blades about the rotational axes, the blades are hydrodynamically less effective in an area exposed to the air flow. This allows the conventional influence of an area with unfavorable thrust generation to be reduced, thereby improving the efficiency of the cycloidal propeller.

[0011] Particularly preferably, when propelling a ship with a cycloidal propeller, the at least one air outlet of the air injection device is arranged in front of the cycloidal propeller in the direction of travel or in the front region of the cycloidal propeller in such a way that the air flow is directed from the front onto the wings in the direction of travel. This can be achieved by having the at least one air outlet open at least on one side of the wings that is located in front of the wings, opposite to the direction of a joint thrust force generated by the wings.

[0012] Preferably, the wheel body is also exposed to an air flow. For this purpose, the air outlet is arranged accordingly, with the wheel body preferably exposed to the air flow on its radially outer circumference.

[0013] 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.

[0014] The cycloidal propeller preferably comprises a pot-shaped propeller well that circumferentially surrounds the wheel body and has a well bottom and a well side wall. In a ship, the propeller well is typically positioned in the ship's bottom and opens vertically downwards. The at least one air outlet preferably opens into the well bottom and / or the well side wall. According to a further embodiment, at least one air outlet opens radially outside the propeller well, in particular into a ship's bottom. This arrangement can also be combined with one or more of the aforementioned air outlet positions.

[0015] 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.

[0016] 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.

[0017] Preferably, a control device is provided which is configured to actuate the switching device such that only the air outlets in a circumferential region of the wheel body, for example the air outlets assigned to the front wheel body half, are supplied with air, wherein the circumferential region is positioned on a side of the vanes which, viewed in front of the vanes, is opposite a direction of a common thrust force generated by the vanes. According to a particularly advantageous embodiment of the invention, an air quantity flowing through the at least one air outlet or an air quantity flowing through each individual air outlet is variably adjustable. This enables particularly effective adjustment of the required air cushion at the individual vanes and / or on the wheel body.

[0018] 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.

[0019] 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.

[0020] The method according to the invention for generating thrust with a cycloidal propeller comprises the following steps:

[0021] - Driving the wheel body around the rotation axis; and

[0022] - simultaneous pivoting of the wings around the respective axis of rotation.

[0023] According to the invention, the wings are exposed to an air stream from the air injection device.

[0024] Preferably, the wings are exposed to the air flow on a front side in the thrust direction, as shown.

[0025] According to a further development of the invention, the air flow is fed to the blades in such a way that it forms an air cushion in the area of ​​the wheel body, where it is sealed with a seal in the propeller well. This creates a barrier between the seal and the water, such as seawater, in which the blades are immersed to propel the ship. This can increase the service life of the seal and correspondingly extend maintenance intervals.

[0026] In a further development of the method, one or more air outlets are provided in the rotating wheel body (2), wherein the compressed air is generated in the wheel body itself or is supplied via a rotary feedthrough from the stationary part of the cycloidal propeller.

[0027] The air flow can also be sucked in from the environment due to the suction effect of the cycloidal propeller or generated by an air compressor.

[0028] The invention will be described below using an exemplary embodiment and the figures.

[0029] They show:

[0030] Figure 1 shows a ship with cycloidal propellers according to the invention;

[0031] Figure 2 is a schematic representation of a cycloidal propeller according to the invention.

[0032] Figure 1 shows a ship 13 with two cycloidal propellers 12 according to the invention in a side view and a view from below. 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. Figure 2 schematically shows a cycloidal propeller 12 according to the invention. This comprises a wheel body 2 that can be driven to rotate about an axis of rotation 1. Blades 3 are mounted at the bottom of the rotation body 2 and can pivot about the axes of rotation 4.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The wheel body 2 is arranged in a 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 or only in the well side wall 7.2 or even only outside the propeller well 7. The arrangement of air outlets 6 in the propeller well 7 has the advantage that an air cushion is formed in the propeller well 7, which prevents water from penetrating the propeller well 7 far enough to reach the seal 15 with which the wheel body 2 is sealed in the propeller well 7.On the side of the seal 15 facing away from the propeller well 7, a drive (not shown in detail) for the wheel body 2 is provided, which drive comprises, for example, a gear, wherein the drive and / or the gear can be lubricated with oil, which is prevented by the seal 15 from penetrating into the propeller well 7.

[0037] The air cushion in the propeller well 7 extends the service life of the seal 15, since it is not exposed to salt water, for example.

[0038] Reference symbol

[0039] 1 rotation axis

[0040] 2 wheel bodies

[0041] 3 wings

[0042] 4 axis of rotation

[0043] 5 Air injection device

[0044] 6 Air outlet

[0045] 7 Propeller fountains

[0046] 7.1 Well bottom

[0047] 7.2 Well side wall

[0048] 8 Switching device

[0049] 9 Control device

[0050] 10 Air intake

[0051] 11 air compressors

[0052] 12 cycloidal propellers

[0053] 13 Ship

[0054] 14 Waterline

[0055] 15 Seal

Claims

Patent claims 1. Cycloidal propeller (12) for propelling a ship (13) with a wheel body (2) rotating about a rotational axis (1), on which thrust-generating blades (3) are arranged along its outer circumference, each of which is pivotable about axes of rotation (4) running parallel to the rotational axis (1); characterized by an air injection device (5) having at least one air outlet (6) arranged to apply an air stream to the blades (3).

2. Cycloidal propeller (12) according to claim 1, 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) as seen against a direction of a common thrust force generated by the blades (3).

3. Cycloidal propeller (12) according to one of claims 1 or 2, characterized in that the at least one air outlet (6) is arranged such that the wheel body (2), in particular on its radially outer circumference, is also subjected to an air flow.

4. Cycloidal propeller (12) according to one of claims 1 to 3, characterized in that the cycloidal propeller (12) comprises a pot-shaped propeller well (7) which encloses the wheel body (2) in the circumferential direction and has a well bottom (7.1) and a well side wall (7.2), and the at least one air outlet (6) opens into the well bottom (7.1) and / or into the well side wall (7.2).

5. Cycloidal propeller (12) according to claim 4, characterized in that the blades (3), in particular completely, protrude from the propeller well (7).

6. Cycloidal propeller (12) according to one of claims 1 to 5, characterized in that a plurality of air outlets (6) are provided, which are arranged at a distance from one another over the entire circumference of the wheel body (2), wherein the air injection device (5) comprises a switching device (8) with which the air outlets (6) in at least one individual circumferential region of the wheel body (2) can be selectively supplied with air.

7. Cycloidal propeller (12) according to claim 6, characterized in that a control device (9) is provided which is designed to actuate the switching device (8) in such a way that only the air outlets (6) in a circumferential region of the wheel body (2) are supplied with air, which is positioned on a side of the blade (3) which lies in front of the blades (3) as seen against a direction of a common thrust force generated by the blades (3).

8. Cycloidal propeller (12) according to one of claims 1 to 7, characterized in that an amount of air flowing through the at least one air outlet (6) or through each individual air outlet (6) is adjustable.

9. Cycloidal propeller (12) according to one of claims 1 to 8, characterized in that the air injection device (5) comprises at least one air inlet (10) which opens into atmospheric ambient air, wherein the at least one air outlet (6) opens in the region of a negative pressure in the cycloidal propeller (12).

10. Cycloidal propeller (12) according to one of claims 1 to 9, 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).

11. Cycloidal propeller (12) according to one of claims 1 to 9, characterized in that the air injection device (5) is free of an air compressor (11).

12. Ship (13) with at least one cycloidal propeller (12) according to one of claims 1 to 11, wherein the at least one cycloidal propeller (12) is arranged with the rotation axis (1) vertically in or on a ship's bottom 13. A method for generating thrust with a cycloidal propeller (12) according to one of claims 1 to 11, 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 the wings (3) are subjected to an air stream from the air injection device (5).

14. Method according to claim 13, characterized in that the wings (3) are subjected to the air flow on a front side in the thrust direction.

15. Method according to one of claims 13 or 14, characterized in that the air flow is sucked in from the environment due to a suction effect of the cycloidal propeller (12).

16. Method according to one of claims 13 to 15, characterized in that one or more air outlets are located in the rotating wheel body (2), the compressed air being generated in the wheel body itself or being supplied via a rotary feedthrough from the stationary part of the cycloidal propeller. Method according to one of claims 13 or 14, characterized in that the air flow is generated with an air compressor (11).

Images