Supported rotor blade spacer structure for wind turbines with axial cable bracing

Abstract

Rotor blade support structure for a wind turbine, including: - a spacer (10) arranged between a rotor hub (12) and a rotor blade (14), - wherein a unit consisting of a spacer (10) and a rotor blade (14) is rotatably mounted on the rotor hub (12) via a pitch bearing (16), - wherein a bearing unit (20) for radial and axial support of the rotor blade (14) is provided at the free end of the spacer (10), - wherein the bearing unit (20) comprises an inner bearing body (22), at least one bearing arrangement (24) and an outer bearing shell (26), - wherein the inner bearing body (22) is screwed to both the spacer (10) and the rotor blade (14), - wherein the outer bearing shell (26) is connected to a pylon (32) via a pull rope (30), - wherein the pylon (32) is positioned axially in the wind direction in front of the rotor hub (12) along the rotor axis (A).

Description

1. Title of the invention

[0001] Supported rotor blade spacer structure for wind turbines with axial cable bracing 2. Technical field

[0002] The invention relates to wind turbines, in particular support and bearing structures for receiving, storing and stabilizing large rotor blades, which are connected to the rotor hub via a spacer and stabilized by an external cable system to reduce bending moments. 3. State of the art

[0003] In conventional wind turbines, rotor blades (14) are attached directly to the rotor hub (12) via a pitch bearing (16). With increasing blade length and mass, the mechanical loads on the pitch bearing (16), spacer structure, and blade root increase. External, structurally integrated supports that reduce bending moments in the area of ​​a spacer (10) via a cable system and support the bearing of the rotor blade (14) at the free end of this spacer are not yet established. 4. Object of the invention

[0004] The object of the invention is to provide a support structure that reduces the loads on the pitch bearing (16), the spacer (10) and the blade root without impairing the pitch function, and at the same time enables a robust, weight- and cost-optimized design of large rotor blades. 5. Summary of the invention

[0005] This task is solved by a rotor blade support structure in which a spacer (10) is arranged between the rotor hub (12) and the rotor blade (14). At the free end of the spacer (10), a bearing unit (20) is provided for the radial and axial support of the rotor blade (14). The bearing unit (20) comprises an inner bearing body (22), at least one bearing assembly (24), and an outer bearing shell (26). The inner bearing body (22) is bolted to both the spacer (10) and the rotor blade (14). The outer bearing shell (26) is connected via a tension cable (30) to a pylon (32) positioned along the rotor axis (A) in the wind direction in front of the rotor hub (12). The cable force reduces the bending moment resulting from the rotor blade (14) and the spacer (10), thereby relieving the spacer (10) and the pitch bearing (16). 6. Brief description of the drawings

[0006] Fig.Figure 1 schematically shows a rotor blade support structure with spacer (10), bearing unit (20) with inner bearing body (22), bearing arrangement (24) and outer bearing shell (26), a rotor blade (14), a rotor hub (12), a pitch bearing (16) and the connection of the outer bearing shell (26) via a tension cable (30) to a pylon (32) which is positioned along the rotor axis (A) in the wind direction in front of the rotor hub (12). 7. Example of implementation

[0007] In a preferred embodiment, a fiber-reinforced spacer (10) in the form of a hollow profile connects the rotor hub (12) to the rotor blade (14). The pitch bearing (16) of the unit consisting of the spacer (10) and rotor blade (14) is located at the rotor hub (12). The rotor blade (14) is supported at the free end of the spacer (10) via the bearing unit (20). The bearing unit (20) comprises an inner bearing body (22), two oppositely preloaded tapered roller bearings (24a, 24b) as a bearing arrangement (24), and an outer bearing shell (26). The inner bearing body (22) is bolted to both the spacer (10) and the rotor blade (14). The outer bearing shell (26) is connected to a pylon (32) via a tension cable (30). The pylon (32) is arranged axially along the rotor axis (A) in the wind direction in front of the rotor hub (12) and in one embodiment has a height of 10 m to 15 m.Optionally, a damping element is provided in the force transmission between the outer bearing shell (26) and the pylon (32) to reduce rope-induced vibrations. This arrangement significantly reduces the bending moments in the spacer (10) and the loads in the pitch bearing (16). Reference symbol list

[0008] 10 Spacer; 12 Rotor hub; 14 Rotor blade; 16 Pitch bearing; 20 Bearing unit; 22 Inner bearing body; 24, 24a, 24b Bearing assembly / tapered roller bearing; 26 Outer bearing shell; 30 Pull cable; 32 Pylon; A Rotor shaft.

Claims

[1] Rotor blade support structure for a wind turbine, comprising: - a spacer (10) arranged between a rotor hub (12) and a rotor blade (14), - wherein a unit consisting of a spacer (10) and a rotor blade (14) is rotatably mounted on the rotor hub (12) via a pitch bearing (16), - wherein a bearing unit (20) for radial and axial support of the rotor blade (14) is provided at the free end of the spacer (10), - wherein the bearing unit (20) comprises an inner bearing body (22), at least one bearing arrangement (24) and an outer bearing shell (26), - wherein the inner bearing body (22) is screwed to both the spacer (10) and the rotor blade (14), - wherein the outer bearing shell (26) is connected to a pylon (32) via a pull rope (30), - wherein the pylon (32) is positioned axially in the wind direction in front of the rotor hub (12) along the rotor axis (A). [2] Support structure according to claim 1, characterized by , that the bearing arrangement (24) comprises two oppositely preloaded tapered roller bearings (24a, 24b). [3] Support structure according to one of the preceding claims, characterized by , that the spacer (10) is designed as a fiber-reinforced hollow profile. [4] Support structure according to one of the preceding claims, characterized by , that the pylon (32) has a height between 10 m and 15 m. [5] Support structure according to one of the preceding claims, characterized by , that the pull rope (30) is made of pre-stretched steel or a high-strength composite material. [6] Supporting structure according to one of the preceding claims, characterized by , that at least one elastic or active damping element (34) is provided in the force flow between the outer bearing shell (26) and the pylon (32) to reduce rope-induced vibrations.

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