right-angle wind turbine gearbox

[Windward]

Advice on this topic is requested below. First a description of the arrangement.

The right-angle drive would be installed at the top of the tower. Power would be transferred to the base through a vertical drive shaft. This would reduce tower top weight and put the generator and electricals at ground level. The cost of erecting and maintaining the turbine would be substantially reduced. There would be no heavy power cables running from tower top to base.

The vertical drive shaft would also act as a torsional spring. It would absorb the shock from wind gusts that cause much of the gearbox damage in conventional turbines.

A right-angle gearbox would allow the rotor shaft to be straddle mounted on dedicated bearings, eliminating gearbox stresses caused by supporting some or all of the rotor weight and bending moments. The rotor shaft would be hollow to allow access to the hub for controls.

Direct drive has none of these advantages. The tower top weight of direct drive is just one of its insoluble problems. One estimate for the tower top weight of an 8 MW direct drive wind turbine is 800 tons. There are several other good reasons to abandon direct drive for large wind turbines.

The only question I cannot answer at this time about this arrangement is whether there would be unacceptable torsional vibrations in the vertical drive shaft that could not be counteracted. Any advice on this question would be appreciated.

 

[Windward]

Here is an article about a new two-bladed wind turbine. Some comments relate to the subject of this post:

"For instance, having just one fewer blade than a convention three-blade turbine reduces production costs, and that lightens the up-tower mass which means the tower can weigh less making it easier to transport and erect. Furthermore, the two-blade design allows lifting the blade and nacelle at once, further cutting construction costs...

"Transformers and converters are mounted in enclosures at the base of the tower, not in the nacelle. That makes them easier to maintain when offshore."

Link to the turbine company website is in the article.

It looks like a direct drive turbine, but I can find no explanation of the drive train.

http://www.windpowerengineering.com...mw-turbine-boast-lower-costs-lighter-weights/