WO1992021877A1

WO1992021877A1 - Underwater turbine

Info

Publication number: WO1992021877A1
Application number: PCT/BE1992/000025
Authority: WO
Inventors: Louis Worms
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-06-05
Filing date: 1992-06-03
Publication date: 1992-12-10
Anticipated expiration: 1993-12-05
Also published as: BE1004939A3; AU1775692A

Abstract

Underwater turbine containing a supporting structure (1) and a rotor (2, 3) mounted therein having a rotor shaft (2) and blades (3) which each define a main blade surface which stretches out through the axis of rotation of the rotor (2, 3), whose blades (3) each contain a bearer (5) fixed onto the rotor shaft (2), at least one plate (6) which can pivot with regard to the bearer (5) around a hinge pin which is parallel to the rotor shaft (2) and a stop (8) for the plate (6) which is fixed onto the bearer (5) and practically lies in the main blade surface, whose blades (3) can rotate over at least nearly 90 degrees from a working position in which they are situated against the stop (8), almost in the main blade surface, whereby the underwater turbine further contains a deflector (12 or 13) on both sides of the rotor (2, 3) to divert the current to the active part of the rotor (2, 3), whereby said deflector (12 or 13) is attached to the supporting structure (1) in a hingeable manner around a shaft situated parallel to the rotor shaft (2), characterized in that one deflector (12) is mounted opposite one half of the rotor (2, 3), being the non-active rotor part when the current flows in one particular direction, in a rotatable manner, whereas the other deflector (13) is mounted opposite the other half of the rotor (2, 3), being the non-active rotor part when the current flows in the opposite direction, in a rotatable manner.

Description

Underwater turbine.

The invention concerns an underwater turbine containing a supporting structure and a rotor mounted therein having a rotor shaft and blades which each define a main blade surface which stretches out through the axis of rotation of the rotor, whose blades each contain a bearer fixed onto the rotor shaft, at least one plate which can pivot with regard to the bearer around a hinge pin which is parallel to the rotor shaft and a stop for the plate which is fixed onto the bearer and practically lies in the main blade surface, whose blades can rotate over at least nearly 90 degrees from a working position in which they are situated against the stop, almost in the main blade surface, whereby the underwater turbine further contains a deflector on both sides of the rotor to divert the current to the active part of the rotor, whereby said deflector is attached to the supporting structure in a hingeable manner around a shaft situated parallel to the rotor shaft.

An underwater turbine of this type is known from patent BE-A- 903 237 of 16 September 1985 in the name of the applicant. Such a turbine is placed with its rotor shaft across the current.

From the nature of its construction only one half of the rotor works at a time, namely the half which, as the rotor rotates, moves with the current direction and thus in which the blades are situated in the main blade surface, whereas in the other half the blades usually stretch out with the current direction. Due to a deflector placed upstream, the current, which would otherwise flow through the non-active half of the rotor, is diverted to the active half, as a result of which che output increases. Such a deflector is only reguired upstream the rotor and according to patent BE-A-903 237, with a horizontal rotor shaft, such a deflector is erected on both sides of the rotor in case the turbine is put up in a tidal current and the current alternately flows in two opposite directions.

In this known underwater turbine the two deflectors can rotate with regard to the same, lower half. They can both rotate around.a shaft situated at the height of the horizontal rotor shaft and during the working of the rotor they both rest on the bottom with their free ends.

When the direction of the current changes, the sense of rotation of the rotor must also be reversed. However, this is very difficult to do. Each blade must be provided with two stops which can be switched on and off, one for each sense of rotation, which entails a very complicated construction. In a rotor as described in patent BE-A-897.766, BE-A-900.281 and BE-A-903.327 in the name of the applicant, which is particularly suited for an underwater turbine, such a construction and thus the reversal of the sense o* rotation of the rotor is even impossible in practice.

The invention aims to correct said disadvantage and to provide an underwater turbine which can work in a tidal current and thus can work in opposite directions in case of alternating current directions, but whereby the rotor should only work in one sense of rotation.

To this aim one deflector is mounted opposite one half of the rotor, being the non-active rotor part when the current flows in one particular direction, in a rotatable manner, whereas the other deflector is mounted opposite the other half of the rotor, being the non-active rotor part when the current flows in the opposite direction, in a rotatable manner.

The hingeably mounted deflectors increase the yield of the turbine. Depending on the direction of the current, one of the deflectors lies opposite the non-active rotor part and deflects the current to the active rotor part, while the other, lying opposite the active rotor part, is hinged in a position wherein it lets through the current.

According to a practical embodiment of the invention the axis of rotations of the two deflectors are situated practically in a theoretical plane extending through the axis of rotation of the rotor and parallel to the direction of the current.

According to a special embodiment of the invention the rotor shaft is practically horizontal and one deflector is situated opposite the lower half of the rotor and the other opposite the top half of the rotor in a totatable manner.

Practically, at least the deflector situated opposite the top rotor half works in conjunction with a stop which confines t?-e rotation away from the rotor into a position in which it is pointed slightly upward away from the rotor.

In this embodiment, as soon as the current direction corresponds to a current direction whereby the lower half of the rotor is active, the current itself will cause the partition mounted in a rotatable manner opposite the top half to rotate into the position in which the current is diverted to the lower half.

The other, lower deflector can drop, partly due to the gravity, as soon as the current in the lower rotor half no longer pushes this partition in a rotated position, but this deflector can also work in conjunction with a stop which confines the upward rotation to a rotated position in which it is pointed slightly downward away from the rotor. The rotor may contain for example as described in patent BE-A- 900 281 several pairs of blades situated axially next to one another and the turbine may contain screening plates between the blade pairs.

Since both the one half and the other half of the rotor can be active, the screening plates extend over both halves of the rotor.

Other characteristics and advantages of the invention will become clear from the following description of an underwater turbine according to the invention. This description is given by way of example only and without being limitative in any way. The figures refer to the accompanying drawings where:

Figure 1 shows a schematic top view of an underwater turbine according to the invention;

figure 2 shows an also schematic cross section according to line II-II in figure 1;

figure 3 shows a cross section analogous to that in figure 2, but for an opposite current direction;

figure 4 shows a longitudinal section according to line IV-IV in figure 1, drawn to a larger scale and abstracting the current.

The underwater turbine shown in the figures mainly contains a supporting structure 1 and a rotor with a shaft 2 and pairs of blades 3 mounted thereupon.

The whole formed by the supporting structure 1 and the rotor 2,3 is put up in a river with a tidal current or at sea, such that the rotor 2,3 is entirely immersed and the rotor shaft 2 is pointed horizontally across the current direction of the water .

At the bottom the supporting structure 1 is provided with supports 4 with which it can be placed on the bottom. However, it is also possible to let the supporting structure

1 with the rotor 2,3 float in the water. In the latter case the supports 4 can form floats themselves or the supporting structure can contain floats or can be connected to floats or pontoons.

The rotor 2,3 is in itself of a known type, namely of the type whereby each blade 3 contains a bearer 5 which is fixed to the rotor shaft 2, a number of blades 6 which are attached to the bearer 5 in a hingeable manner around hinge pins 7 stretching out parallel to the rotor shaft 2 and a stop 8 for each blade which is fixed onto the bearer 5 and is situated almost in the main blade surface, being a surface through the rotor shaft

2 and the hinge pins 7 and thus a radially directed surface. F-om the position in which the blade 6 is situated against its stop 8, it can be rotated over at least nearly 90 degrees and preferably over at least 120 degrees.

The blades 3 form pairs which are situated axially next to one another, whereby the radially directed blades of neighbouring pairs have shifted with regard to one another. Both the number of blade pairs 3 as the number of blades 3 per pair as well as the number of plates 6 per blade may differ from one case to the other and are merely given as an example in the figures.

Moreover, each of the plates 6 may in turn consist of two or more lamellas which pivot with regard to one another around little shafts which extend parallel to the rotor shaft and which cooperate with means which, when the lamellas are situated in line, and the plate 6 links up with the corresponding stop 8, make the further mutual hinge movement of the lamellas impossible in the sense which brings the little shaft, around which they both pivot, beyond the surface which is traced by the stop 8 and the hinge pin 7 of the plate 6 with regard to the bearer 5.

A rotor of this type which is particularly suited for the application of the invention is described in detail in patent BE-A-900.281.

The active part of the rotor 2,3 is the part where the plates 6 of the blades 3 assume the position in which they link up with their stop 8 and thus are situated in the main blade surface.

It is clear that for the relative position of the plates 6 and the stops 8 as represented in the figures, the rotor can only be rotated in one direction by the current, namely the direction which is indicated by the arrow 9 in the figures 2,3 and 4. Moreover, with the current direction as represented in these figures by the arrow 10, for example when the tide is rising, the top half of the rotor 2,3 will be active, whereas when the current flows in the opposite direction, represented by arrow 11, for example when the tide is falling, the lower half of the rotor 2,3 will be active.

In order to obtain a current through the active part of the rotor 2,3 that is as strong as possible in both current directions, the underground water turbine contains two synthetic deflectors 12 and 13, one on each side of the rotor 2,3 in the current direction.

Both deflectors 12 and 13 are fixed to the supporting structure 1 in a rotatable manner around a horizontal shaft. The deflector 12 which in case of the current direction according to arrow 10 is situated upstream the rotor 2,3, can be rotated with regard to the lower rotor half, which is the half which is not active in this current direction. Moreover, in this current direction said deflector stretches out downward from its axis of rotation against the current direction to the supports 4 which constitute a stop, as shown in figure 2. The current which would otherwise flow through the lower rotor half is thus derived to the active top rotor half. .The deflector 13 can be rotated on the other side of the rotor 2,3, opposite the top half. In said current direction according to arrow 10 this deflector 13 cannot obstruct the current through the top half of the rotor 2,3 and it is rotated down against a stop 14 such that it is still pointed slightly upward away from the rotor, as shown in figure 2.

In the opposite current direction according to arrow 11, as shown in figure 3, the deflector 12 is rotated upward against a stop 15 in a position in which it is still pointed slightly downward away from the rotor 2,3. The deflector 13, however, due to the current in said direction, is rotated upward against a stop 16 such that it is pointed slightly upward away from the rotor 2,3 and thus derives the current to the lower rotor half.

The above-mentioned stops 14, 15 and 16 have been mounted on the supporting structure 1.

Between two neighbouring pairs of blades 3 a screening plate 17 pointed crosswise to the rotor shaft 2 is fixed to the supporting structure 1. This screening plate 17 is provided with an opening 18 for the rotor shaft 2 and extends both over the top and the lower half of the rotor 2,3.

Although the rotor 2,3 of the above-described underwater turbine can only be driven in one rotation direction by the current, it can also be used in a tidal current because of the position and nature of the deflectors 12 and 13. The output of the turbine is excellent.

The rotor shaft 2 can be coupled to a mechanism to be driven, for example an energy-transforming mechanism such as a current generator, in the known ways.

The invention is in no way limited to the embodiment described above; on the contrary, many modifications can be made to this embodiment, among others as far as form, composition, arrangement and the number of parts used for the realization of the invention are concerned, while still remaining within the scope of the invention.

In particular, the deflectors do not necessarily have to be made of a synthetic.

Neither do they have to be necessarily made in one piece. They may also consist of one or two segments which are fixed to one another around shafts parallel to the rotor shaft or which are ixed to one another in a rotatable manner or which are separately fixed to the supporting structure in a rotatable manner. When being rotated to the position in which the deflectors shut off the opposite rotor half, the rotation of the segments should be restricted, for example by means of stops or by the hinge construction itself, such that the segments cannot go beyond the surface which stretches out in the above-mentioned position through the farthest edges of the deflector as a whole pointed parallel to the rotor shaft.

Claims

Claims .

1. Underwater turbine containing a supporting structure (1) and a rotor mounted therein (2,3) having a rotor shaft (2) and blades (3) which each define a main blade surface which stretches out through the axis of rotation of the rotor (2,3), whose blades (3) each contain a bearer (5) fixed onto the rotor shaft (2) , at least one plate (6) which can pivot with regard to the bearer (5) around a hinge pin which is parallel to the rotor shaft (2) and a stop (8) for the plate (6) which is fixed onto the bearer (5) and practically lies in the main blade surface, whose blades (3) can rotate over at least nearly 90 degrees from a working position in which they are situated against the stop (8) , almost in the main blade surface, whereby the underwater turbine further contains a deflector (12 or 13) on both sides of the rotor (2,3) to divert the current to the active part of the rotor (2,3), whereby said deflector (12 or 13) is attached to the supporting structure (1) in a hingeable manner around a shaft situated parallel to the rotor shaft (2), characterized in that one deflector (12) is mounted opposite one half of the rotor (2,3), being the non-active rotor part when the current flows in one particular direction, in a rotatable manner, whereas the other deflector (13) is mounted opposite the other half of the rotor (2,3), being the non-active rotor part when the current flows in the opposite direction, in a rotatable manner.

2. Underwater turbine according to the above claim, characterized in that the axis of rotations of the two deflectors (12 and 13) are situated practically in a theoretical plane extending through the axis of rotation of the rotor (2,3) and parallel to the direction of the current.

3. Underwater turbine according to any of the above claims, characterized in that the rotor shaft (2) is practically 1 horizontal and in that one deflector (12) is situated opposite the lower half of the rotor (2,3) and in that the other (13) is situated opposite the top half of the rotor in a rotatable manner.

4. Underwater turbine according to the above claim, characterized in that at least the deflector (13) situated opposite the top rotor half works in conjunction with a stop (14) which confines the rotation away from the rotor (2,3) into a position in which it is pointed slightly upward away from the rotor (2,3).

5. Underwater turbine according to any of claims 3 and 4, characterized in that the deflector (12) situated opposite the lower rotor half works in conjunction with a stop (15) which confines the rotation away from the rotor (2,3) to a position in which it is pointed slightly downward away from the rotor (2,3).

6. Underwater turbine according to any of claims 3 to 5, characterized in that at least the deflector (13) situated opposite the top rotor half works in conjunction with a stop (16) mounted on the supporting structure (1) which confines the rotation of the deflector (13) towards the rotor (2,3) and thus to the position in which it derives the current to the lower rotor half.

7. Underwater turbine according to any of the above claims, characterized in that the deflectors (12 and 13) are made of a synthetic.

8. Underwater turbine according to any of the above claims, characterized in that the deflectors (12 and 13) consist of at least two segments.

9. Underwater turbine according to any of the above claims, li characterized in that the rotor (2,3) contains several pairs of blades (3) situated axially next to one another and in that the turbine contains screening plates (17) between the pairs of blades (3) .

10. Underwater turbine according to the above claim, characterized in that the screening plates (17) extend over both halves of the rotor (2,3).