Assembly for rotating a suspended load
The present invention relates to an assembly for rotating a suspended load around a substantially vertical axis, the assembly comprising an inner rim configured to have a fixed relationship with the suspended load to be rotated, an outer rim engaging the inner rim in a manner so that the inner and outer rims are configured to perform rotational movements relative to each other during rotation of the suspended load, and a drive unit for performing the relative rotational movement between the inner and outer rims. The assembly of the present invention may be secured to a lifting yoke for lifting wind turbine related components, such as entire wind turbine towers, wind turbine tower sections, nacelles, rotor blades or containers.
1. An assembly for rotating a suspended load around a substantially vertical axis, the assembly comprising:
an inner rim configured to have a fixed relationship with the suspended load to be rotated,
an outer rim engaging the inner rim in a manner so that the inner and outer rims are configured to perform rotational movements relative to each other during rotation of the suspended load without the outer rim carrying the weight of the suspended load, and
a drive unit for performing the relative rotational movement between the inner and outer rims.
2. The assembly according to claim 1 , wherein the inner rim takes the form of a ring-shaped element, and wherein the outer rim takes the form of a portion of a ring-shaped element.
3. The assembly according to claim 1 , wherein the assembly is configured to not carry the weight of the load during use.
4. The assembly according to claim 3 , further comprising a fixation arrangement for limiting rotation of the outer rim in relation to one or more fixed points outside the assembly, the fixation arrangement being configured to provide a substantially constant tension to the one or more adjustable fixation points.
5. The assembly according to claim 4 , wherein the one or more adjustable fixation points are configured for attachment of a tag line system of a lifting yoke configured for lifting the load.
6. The assembly according to claim 1 , wherein a belt member is secured to and provided around the inner rim, and wherein the drive unit is configured to engage with said belt member in order to perform the relative rotational movement between the inner and outer rims.
7. The assembly according to claim 1 , wherein the inner rim comprises a toothed surface, and wherein the drive unit is configured to engage with said toothed surface in order to perform the relative rotational movement between the inner and outer rims.
8. The assembly according to claim 1 , wherein the drive unit is rigidly secured to the outer rim, and wherein the drive unit comprises an electrical motor, a pneumatic system or a hydraulic system for performing the relative rotational movement between the inner and outer rims.
9. The assembly according to claim 1 , wherein a plurality of alignment wheels are provided for correct positioning of the outer rim relative to the inner rim.
10. The assembly according to claim 9 , wherein one or more alignment wheels are arranged to follow an outer surface of the inner rim, and wherein one or more other alignment wheels are arranged to follow an inner surface of the inner rim.
11. The assembly according to claim 9 , wherein the plurality of alignment wheels are configured to rotate around respective wheel axles secured to the outer rim.
12. The assembly according to claim 1 , further comprising a counterweight for outbalancing the weight of the drive unit.
13. The assembly according to claim 1 , further comprising a platform for installation personnel.
14. The assembly according to claim 1 , further comprising one or more brackets adapted to secure the assembly to a lifting yoke for lifting wind turbine related loads.
15. A wind turbine tower or wind turbine tower section comprising an assembly according to claim 1 .
16. The assembly according to claim 2 , wherein the outer rim takes the form of a about half of an entire ring-shaped element.
17. A lifting arrangement for handling a suspended load, comprising:
a lifting yoke configured for attachment to the suspended load, the lifting yoke further configured for attachment to a hoisting device for lifting the suspended load;
an assembly for rotating the suspended load around a substantially vertical axis, the assembly configured to be attached to the lifting yoke such that the assembly does not carry the weight of the suspended load, the assembly comprising:
an inner rim configured to have a fixed relationship with the suspended load to be rotated;
an outer rim engaging the inner rim in a manner so that the inner and outer rims are configured to perform rotational movements relative to each other during rotation of the suspended load, and
a drive unit for performing the relative rotational movement between the inner and outer rims.