Epicyclic gears get their name from their earliest program, that was the modelling of the motions of the planets in the heavens. Believing the planets, as everything in the heavens, to be perfect, they could only travel in perfect circles, but their motions as viewed from Earth cannot 
end up being reconciled with circular movement. At around 500 BC, the Greeks invented the idea of epicycles, of Planetary Reducer Gearbox circles travelling on the circular orbits. With this theory Claudius Ptolemy in the Almagest in 148 AD was able to predict planetary orbital paths. The Antikythera Mechanism, circa 80 BC, acquired gearing which was in a position to approximate the moon’s elliptical route through the heavens, and actually to improve for the nine-season precession of that route.[3] (The Greeks would have seen it not as elliptical, but instead as epicyclic motion.)
EP, a versatile and multi-use remedy, is not simply another simple planetary gearbox. EP high-tech planetary reducer can be a true integrated concept, including many functions combined alongside one another to provide a complete sub-assembly to the most demanding machines.
EP is the best high-tech servo-reducer, specially dedicated to designs requiring:
Superior output torsional stiffness
Ultra-substantial output radial stiffness and Tilting moment
Patented output bearing design
A high-tech planetary gear train, based on REDEX’s differential know-how
ISO 9409-1 productivity drive flange for installation pinions, pulleys, couplings, etc.
High input speeds
Superior acceleration and excellent torque density
Minimum backlash (1 – 3 arc-minutes)
In-Line or correct angle arrangements
This versatile design helps it be easy for design engineers to find specific solutions to the most demanding applications.
Parallel shaft Gearmotors
Helical Single-Stage
The S Series style may make this gearmotor particularly effective for fan, pump and blower applications. To meet the needs of customers in these sectors, the S Series can be available in the foot or flange variations and will be completed with an array of electric motors entirely made by EP. Asynchronous motors both IEC and small (B-BE-BX/M-ME-MX), servomotors (BMD) and reluctance motors (BSR) could be in conjunction with the S Series: with the breadth of its portfolio, EP provides buyers with an outstanding balance of cost effectiveness, dynamics and efficiency.
The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train.[1][2] In cases like this, the ring gear is generally fixed and the sun gear is driven.