Hub mating mechanism applicable to single blade installation of offshore wind turbines

Abstract

A hub mating mechanism for single blade installation of offshore wind turbines. The mechanism includes a rigid circular snap ring having circumferential contact with the hub, spring damper, force actuator, buffer plates made from resilient composite material, controller and electric motor. The ring is connected to the buffer plates through the spring damper and the force actuator. The roots of the buffer plates are connected to the outer edge of the hub by hinges. The force actuator is driven by the controller and electric motor placed in the nacelle. Multiple flange holes are formed in the blades and the hub fixed together through bolts after the mating is completed. Assembly and testing of the hub mating mechanism can be performed during component assembly onshore. The hub mating mechanism includes the circular snap ring, buffer plates, force actuator, spring damper, controller and electric motor which are off-the-shelf commercial products.

Claims

1. A hub mating mechanism applicable to the installation of a blade in an offshore wind turbine, the hub mating mechanism comprising: a circular ring, a spring damper, a force actuator, buffer plates, a controller and an electric motor; wherein the circular ring is a rigid structure and surrounds a hub; the circular ring is connected to the buffer plates by the spring damper and the force actuator; the buffer plates are made of a resilient composite material; one end of each buffer plate is connected to an outer edge of the hub by rotating hinges such that the buffer plates are capable of rotating around a hub root; and the force actuator is driven by the controller and the electric motor, the controller and electric motor being located in a nacelle of the offshore wind turbine.

2. The hub mating mechanism of claim 1, wherein the spring damper is made of rubber.

3. The hub mating mechanism of claim 1, wherein the blade and hub are fixed by bolts extending through flange holes in the blade and the hub.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1(a) is the top view of the hub mating mechanism and blades before mating.

(2) FIG. 1(b) is the top view of the hub mating mechanism and blades before mating.

(3) FIG. 1(c) is the top view of the hub mating mechanism and blades before mating.

(4) FIG. 2 is the side view of the hub mating mechanism, where the force actuator and the spring-damper are not included.

(5) FIG. 3 is the blades installation diagram of the traditional offshore monopile-type wind turbine.

(6) FIG. 4 is the single blade installation diagram.

(7) In the Figs: 1 Automatic lifting installation machine; 2 horizontal cable; 3 blade; 4 crane; 5 hub; 6 nacelle; 7 tower; 8 monopile; 9 hub outer edge; 10 blade root; 11 connecting hinges; 12 flange hole; 13 center of gravity of the blade; 14 circular ring; 15 spring damper; 16 force actuator; 17 buffer plate.

DETAILED DESCRIPTION

(8) Combined with the drawings and examples, further description will be given below.

(9) FIG. 1 is a side view of the offshore blade installation (XZ plane). X is the wind speed direction. Taking the 5 MW wind turbine as an example, the length of the blade 3 is 61.5 meters, the blade root 10 is circular, the diameter is 3.5 meters which is slightly smaller than the hub. The horizontal height is of the nacelle 6 is 90 m above the sea level. The blade 3 is connected to the crane cable 4 by two horizontal cables (11 and 12) and a vertical cable. The movement of blade 3 in the xz plane is limited by the horizontal cables. Lift blade 3 from the jack-up ship 1 by the crane 4 to the horizontal height of hub for the preparation of the mating.

(10) FIG. 2 is the traditional installation process of a single blade. Under the action of turbulent wind, it is difficult to limit the motion of the blade root 10 completely by horizontal cables, and it is not easy to for the alignment and mating of blade 10 and hub 5 in a short time. Thus, manual assistance is needed.

(11) FIG. 3 is the installation way which hub mating mechanism in this invention is adopted and the angle changes of the buffer plate 17 during the mating. Circular ring 14, which is designed to be 10 cm thick, is fixed to the hub 5. The length of the buffer plate is 2 m. the opening angle could vary within 180 degree. Force actuator 16 is a piston structure driven by the electric motor. The range of output force and the diameter of spring damper 15 could be designed according to the wind resources of the wind farm site, blade dimension as well as the ultimate load during the collision.

(12) Before mating, the angle of cushion plate 17 is opened by the remote controller of the force actuator. After the blade root 10 enters the range of buffer plate 17, mating begins. The buffer plate 17 will have a tight contact with the blade root 10 to assist the mating with hub 5. After mating, the end of the buffer plate 17 and the circular ring 14 are fixed by controlling the force actuator 16 remotely. Thus, the blade installation is finished.