A very important application, also, of this Mechanism is on a wind turbine, achieving the transmission of the endless rotation of the propeller shaft, onto the rotating nacelle, to the shaft of an electric generator, onto the stationary tower, independently of the endless rotation of the nacelle, and consequently achieving the relocation of the speed increaser and the electric generator from the rotating nacelle to the stationary tower.
The objection to such a proposal is usually summarized in the following three points:
a) the simplest way to transmit power from the rotating nacelle to the ground is to use an electric cable,
b) there is no a mechanical mechanism for this transmission, which is simple, efficient and of low construction cost, and
c) even if the above reasons were not met, the weight of the gearbox and the generator is required to balance the weight of the propeller shaft with the blades and the wind forces.
The first point is refuted by a careful study of what is required for the transmission of electrical power from a rotating frame to a stationary one:
a too complicated and too inefficient "cable unwinding" technique which "sometimes forces the nacelle to oscillate as if it was drunk" or the traditional slip-rings and other components, their lifespan and the ease or not of their replacement.
The third point appears to be the strongest to date, but with the advent of the wind turbine type with direct drive technology (
for example), it is obvious that it does not exist in substance.
The second point was probably reinforced by persistently repeated proposals such as
or even JP3157729
However, a brand new Mechanism, the "ELEUTHERO"
, is now coming to the fore, to overturn this point, while the introduction of this Mechanism is a major breakthrough in the core of the operation of a wind turbine, turning the evolution path of its design to a totally new direction, resulting in the next generation of wind turbines.
In this first phase, the proposal is to relocate the speed increaser and the electric generator on the top of the stationary tower;
but for the power transmission, purely mechanically, from the top to the base of the tower of the wind turbine, except the classic full-section long marine propeller shaft, today there are also solid but more sophisticated, light and yet strong structures, while the vertical direction of transmission (comparing with the horizontal one in the case of a marine transmission) facilitates the situation.
In all cases, it is, also, proposed the replacement of the speed increaser currently in use with the "EXTREME"
Being more specific, there is a scheduled progressive development in three STAGES:
: keeping the current in-line configuration of a wind turbine and inserting just ONE moving part between the propeller shaft and the generator shaft, achieving an overall transmission ratio 1:150
STAGE 2: keeping only the propeller shaft and the brakes on the rotating nacelle and relocating the generator onto the top of the stationary tower, inserting just FOUR moving parts between the propeller shaft and the generator shaft and achieving an overall transmission ratio 1:150
STAGE 3: continuing the STAGE 2 by relocating the generator as far from the top of the tower as to achieve the optimal situation for construction, installation and maintenance costs and overall efficiency
So, one can just imagine a wind turbine where there is a purely mechanical mechanism, which -independently of the rotation of the nacelle- transmits power, with a very high transmission ratio, directly from the propeller shaft to a generator shaft which stands onto the stationary tower, on its top or even on its base; and this is a result of using FOUR only additional moving parts between the propeller shaft and the generator shaft.
The most significant advantages for this application are:
The relocation of the gearbox and the electric generator from the rotating nacelle to the stationary tower, even at its top, lowers the costs of construction, installation and maintenance, allowing the approach for inspection and maintenance to the majority of the components of the whole configuration, even without stopping the operation of the wind turbine.
Besides these, the nacelle, having only the propeller shaft and its brakes, can be aerodynamically shaped in the best way, lowering the horizontal wind force onto the top of the stationary tower to the minimum possible.
However, a significant advantage is the deliverance from the "too complicated and too inefficient 'cable unwinding' technique" or the traditional slip-rings and the other components for the transmission of the electric power from the rotating nacelle to the stationary tower.
THE NACELLE NOW IS FREE TO ROTATE ENDLESSLY WITHOUT SLIP-RINGS AND OTHER RELATED COMPONENTS.
There are already fully operational Prototypes, in scale.
However, in close collaboration with the
National Technical University of Athens, a Project is running for:
- the designing (being in the last stage) and construction of a fully operational Prototype, where power is transmitted from the propeller shaft, onto the rotating nacelle, to the shaft of an electric generator, onto the stationary tower, independently of the endless rotation of the nacelle, with an overall transmission ratio 1:150, using FOUR only additional moving parts and -what is very important, as well- using STANDARD GEARS only,
- the standardization of all critical parameters involved in the configuration of all the proposed wind turbines, while the final goal is to render these configurations as the standard references for the wind turbines of the next generation.