Wind turbine having a rotating rotor ring and a stationary ring

Abstract

A wind turbine is described which includes a support structure, a rotor which includes one or multiple rotor blades and which is situated on the support structure so that the rotor is freely rotatable about a rotation axis, and a generator which is connected to the rotor and which converts the wind energy into electrical energy when the rotor is rotating. The support structure includes a stationary ring on which the rotor is rotatably guided and on which the stator of the generator is situated.

Claims

1. A wind turbine, comprising: a support structure including a stationary ring; a rotor including a rotor ring and a plurality of rotor blades, wherein the rotor ring is rotatably supported on the stationary ring by a bearing so that the rotor is rotatable about a horizontal rotation axis, wherein each rotor blade is connected at the beginning of an inner end of each rotor blade thereof to the rotor ring, wherein the rotor ring has a diameter, and wherein each rotor blade has a length extending from the inner end to a free end of the rotor blade, wherein: induction coils are situated on the stationary ring; the rotor ring of the rotor is provided with magnets; the induction coils and the magnets form a generator that converts wind energy into electrical energy when the rotor is rotating; and a ratio of the diameter of the rotor ring to the length of each rotor blade as measured from an external surface of the rotor ring is one of 1:2, 1:1.5, and 1:1.

2. The wind turbine as recited in claim 1, wherein the bearing supporting the rotor ring on the stationary ring comprises one of a plurality of roller bearings and a plurality of rolling elements.

3. The wind turbine as recited in claim 2, further comprising at least one guide rail that transmits a rotary motion of the rotor to the roller bearings, wherein the guide rail is fixed to the rotor in a circumferential direction.

4. The wind turbine as recited in claim 1, wherein the rotor ring is supported in a floating manner on the stationary ring by a magnetic force.

5. The wind turbine as recited in claim 1, wherein the plurality of rotor blades is at least three rotor blades.

6. The wind turbine as recited in claim 1, wherein: the support structure includes a T-shaped upright with a tower and a crossmember, and the stationary ring is fastened to ends of the crossmember.

7. The wind turbine as recited in claim 1, wherein the diameter of the rotor ring is one of 25 m, 33 m, and 50 m.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an axonometric overall view of a wind turbine.

(2) FIG. 2 shows an axonometric view of a support structure together with a stationary ring.

(3) FIG. 3 shows an axonometric view of a rotor together with a plurality of rotor blades which rotates on the stationary ring.

(4) FIG. 4 shows the wind turbine in a partial cutaway view for explaining the rotor bearing.

DETAILED DESCRIPTION

(5) FIGS. 1 and 4 show one embodiment of the wind turbine according to the present invention, which is denoted overall by reference numeral 11. Wind turbine 11 includes a rotor 13 which is supported so that it is rotatable about a stationary ring 15.

(6) Stationary ring 15 is supported or held by a T-shaped upright 17.

(7) Rotor 13 includes a rotor ring 19 and a plurality of rotor blades 21 connected to the rotor ring at the beginning of an inner end of each rotor blade. Rotor ring 19 preferably has a diameter that essentially corresponds to the length of the rotor blades as measured from an external surface of the rotor ring 19. For example, the diameter of rotor ring 19 and the length of the rotor blades is 50 meters in each case. Despite the considerable diameter of the rotor ring relative to the length of rotor blades 21, the surface area of rotor ring 19 is only 10% of the circular area defined by the free ends of rotor blades 21. The utilizable wind surface is thus only slightly reduced due to rotor ring 19. The length of rotor blades 21 may therefore be reduced by approximately ⅓, compared to the rotor blade length for wind turbines of the related art, without significantly reducing the utilizable wind surface. The material costs of wind turbine 11 according to the present invention may thus be significantly reduced, since the material costs of the rotor blades are lower.

(8) Rotor ring 19 is rotatably guided on the outer side of stationary ring 15. The bearing may be assumed by a plurality of rolling elements 23, as shown in FIG. 4. Rolling elements 23 may be rotatably accommodated in depressions on the outer side of stationary ring 15, and situated in two or more concentric rails on stationary ring 15. Rolling elements 23 may slide directly on a running surface on the inner side of rotor ring 19, or may slide indirectly on guide rails 25. Rolling elements 23 may be wheels, rollers, drums, pins, and other rotationally symmetrical bodies. Guide rails 25 are fixedly connected to rotor ring 19, and shift the rotary motion of rotor ring 19 onto rolling elements 23. The high mechanical load resulting from the weight of the rotor blades does not have to be accommodated by a central bearing, as is the case with conventional wind turbines, and instead may be distributed over the plurality of rolling elements 23. The repair costs for wind turbine 11 may thus be reduced. It is also conceivable to increase the rotor blade length for wind turbine 11, since for the stated dimensions, the load capacity of rolling elements 23 does not reach its maximum.

(9) It is also conceivable for the bearing of rotor ring 19 on stationary ring 15 to take place due to magnetic forces which keep rotor ring 19 suspended on stationary ring 15.

(10) The generator of wind turbine 11, which converts the wind energy into electrical energy, is preferably situated between rotor ring 19 and stationary ring 15. Since only a motion of a magnetic field relative to an induction coil is important for a generator, it is preferred when the stator of the generator is situated in stationary ring 15, which is stationary anyway. The rotor of the generator is advantageously situated in rotor ring 19. To simplify withdrawal of the generated electrical current, it is preferred when the current withdrawal takes place at stationary ring 15, even though withdrawal using slide elements may also take place at rotor ring 19. For the simplified current withdrawal, the generator magnets 31 are thus situated in rotor ring 19, and the induction coils 30 are situated in stationary ring 15.

(11) It is also conceivable for individual generators to be integrated into rolling elements 23, or for individual generators to be mechanically connected to rolling elements 23. Depending on the wind power, individual generators may be connected, or are disconnected by the transmission of rotation by rolling elements 23.

(12) Wind turbines of the related art usually include three rotor blades. This number may be increased in the wind turbine according to the present invention, since due to their ring structure, the rotor blades are able to withstand higher mechanical loads.

(13) The T-shaped upright includes a tower 27 and a crossmember 29. Stationary ring 15 is situated on the ends of crossmember 29. A sufficiently stable mounting, and at the same time, preferably low wind resistance, may be achieved in this way.

(14) Due to providing a stationary ring 15 and a rotor ring 19, the mechanical forces may be decentralized, and do not act in a central point of the rotation axis, as is the case for wind turbines of the related art. The mechanical forces may be distributed over a plurality of rolling elements.