In the past few years, the emergence of wind turbines has become a critical part of energy production. A wind turbine harnesses wind power to generate electricity. The most common application for a modern wind turbine is a horizontal axis wind turbine (HAWT).
A wind turbines power plant consists of these three major components:
- A rotor, to which are attached blades to convert the kinetic energy of wind to rotational energy used to turn the shaft.
- A gearbox, which takes the relatively slow speed of a wind turbines rotor, and increases its speed to rotate the generator.
- A generator, which is coupled to the output shaft of the gearbox. The generator’s stator rotates, changing the wind energy to electricity.
Proper shaft alignment of a wind turbine is critical for these reasons:
- Wind turbines are attached to the tops of tall masts, often several hundred feet in the air. They must be engineered to withstand the effects of weather, and not create any excessive detrimental forces due to improper assembly.
- The high speed of the generator requires precise shaft centerline alignment to minimize unwanted radial and axial forces exerted upon the bearings and gears of the machine assembly.
- Given their often remote locations, high speeds, lack of frequent operator and maintenance interaction, and the general danger of mounting heavy, high speed machinery on a mast several hundred feet in the air, proper shaft alignment is one of the crucial components of wind turbine operation.
Wind Turbine Alignment is normally done by treating the gearbox as the stationary machine, and the generator as the moveable machine. The misalignment is measured almost exclusively with a laser shaft alignment tool. The generator is shimmed vertically to achieve the proper elevation, and to correct for both vertical parallel and angular misalignment. The generator is moved horizontally to achieve proper horizontal positioning, and to correct for both horizontal parallel and angular misalignment. Both vertical and horizontal movement of the generator is done by the use of engineered jacking bolts. These can accurately position the generator, when used in conjunction with a laser shaft alignment tool.
Proper wind turbine alignment can minimize wasted energy, increase component life of the machines, and help reduce the possibility of catastrophic failure.
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