When there is the need to change the blade pitch of the propeller of a helicopter, there is the problem of the strong natural coupling of the rotation of the regulating shaft with the rotation of the propeller hub, which in fact is a carrier.

The solution for this problem is the transmission of the regulating motion, from the frame of the helicopter to the propeller hub, via rods and thrust bearings which move across the axis of propeller rotation, using the traditional decoupling via motions which are perpendicular to each other; since the regulating motion is finite, this mechanism is suitable for the situation, operating very well.

However, what about the transmission of significant amounts of power through an endless rotation from a shaft onto a frame, to a shaft onto an endlessly rotating carrier, independently of the carrier rotation?

Examples of such a situation are the power transmission from a shaft onto the chassis of a large excavator to a shaft onto its turret, from the propeller shaft onto the nacelle of a wind turbine to a shaft onto its tower, from a shaft onto the hull of a vessel to the propeller shaft onto the bracket of its azimuth thruster.

A mechanism, named "ELEUTHERO-STROPHE", being continuously developed since 1985, solves this problem in a general and effective way.

Eleuthero-Strophe is a purely mechanical mechanism with a simple planetary mechanism onto the already existing carrier of the mechanical system, on which it applies in order to achieve the aforementioned power transmission.

More for this mechanism at: https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2021260400
and: https://engine.green/eleuthero.htm
and more for its applications, in general, at: https://engine.green

It is obvious that this mechanism has plenty of applications, such as:

• power transmission from a shaft onto the chassis of a turret-carrying vehicle, such as an excavator, a crane or a battle tank, to a shaft onto its turret, independently of the endless rotation of this turret with respect to the chassis; more at:
  https://engine.green/turret.htm
• power transmission from a shaft onto the chassis of a vehicle, such as a FWD supercar, a fire-fighting vehicle, an agricultural tractor, an ATV or a military vehicle with very high clearance from the ground, to the wheel shaft onto its steering bracket, independently of the -even endless- rotation of this steering bracket with respect to the chassis, introducing a totally new and effective way of "PROPEL and STEER"; more at:
  https://engine.green/steering.htm
• power transmission from the propeller shaft onto the nacelle of a wind turbine to a shaft onto its stationary tower -at its top or its base, depending on the tower height- independently of the endless rotation of this nacelle with respect to the tower; more at:
  https://engine.green/wind.htm

However, the most significant application, with a maturity degree of 100%, is the power transmission from a shaft onto the hull of a vessel, to the propeller shaft onto the bracket of its AZIMUTH THRUSTER, independently of the endless rotation of this bracket with respect to the hull; more at: https://engine.green/azimuth.htm
and: https://www.azimuthruster.com