Ever-Power new planetary reducers hire a floating sun equipment rather than a fixed position one.
The saying ”There’s nothing new under the sun’ certainly pertains to planetary reducers. And, while floating sun gears have been around a long time, some engineers might not be aware of the benefits this unusual gear style can offer.
Traditionally, planetary reducers have used a fixed sun gear, where in fact the centre gear is mounted on or machined in to the shaft. When this fixed sun equipment revolves, it turns the earth gears to create movement and/or power. Ever-Power new planetary reducers, however, are employing a floating sun equipment rather than a set position sun gear.
Why a floating sunlight equipment? ‘In the planetary idea, the sun may be the driver, or pinion, in the gear set,’Ever-Power style engineer Scott Hulstein said. ‘Because the sun gear is in constant connection with the planets, it’s important that it is perfectly centred among the three planets to be able to provide equal load sharing among itself and all three planets.’
Due to normal manufacturing tolerances however, a sun gear which is securely set on a shaft will intermittently have more load on one planet equipment than on another equipment Hulstein explained. ‘By 
permitting the sun equipment to float, it centres itself among the three planets and creates continuous, equal load sharing.’
Equal load sharing is just one of the advantages of this design. The floating sunlight gear provides ‘true involute action,’ according to Hulstein. Accurate involute action occurs when the rolling motion between your mating gears is really as complete as feasible. The advantage of this complete meshing of gears is definitely longer reducer existence, since less internal equipment slippage means fewer damaged gear teeth.
That does mean lower noise levels. When sunlight gear is allowed to completely roll into the world gears, there’s much less ‘rattling’ as the teeth mesh. In effect, the Ever-Power product has ‘designed out’ the gear mesh noise by allowing the sun gear to float into place.
So why make use of a fixed sun gear at most? ‘Fixed sun gears tend to be used in accurate servo applications,’ Greg Pennings, Ever-Power sun planet gear Customer Advocate, explained. ‘A fixed sun gear is necessary when exact positioning and low backlash are an intrinsic part of the app.’ Ever-Power engineers, nevertheless, were less concerned with low backlash and more interested with higher torque and/or lower noise applications.
Our planetary reducers with floating sun gears were made to compete with parallel shaft reducers, where backlash was less critical,’ Pennings said.
By using the floating sun gear concept, the Ever-Power planetary reducers have the ability to exceed the torque ratings of similar sized and larger sized parallel shaft reducers, and yet maintain a lesser noise levels.
Sun, Ring and Planet
The most basic type of planetary gearset is proven in the figures above. The figure at still left shows a three-dimensional view as the figure at right offers a cross-section. In this geartrain, inputs and output can be extracted from the carrier, ring and sun gears, and only the earth experiences epicyclic motion. This is the many common type of planetary gearset (apart from the differential) and it discovers application in acceleration reducers and automated transmissions. If you take apart a cordless drill, you will most probably find this kind of planetary gearset directly behind the drill chuck.
Two Suns – Two Planets gearset
Cross-sectional view
Two Suns, Two Planets
The gearset shown above has two sun gears, and both planet gears (the yellow gears) rotate as an individual unit. The sun gears (green and dark brown) can rotate independently of 1 another. The inputs and result can be chosen from either sun gear and/or the carrier. High speed reductions may be accomplished with this unit, nonetheless it can have problems with low efficiency if not designed correctly.
Red sun input – purple sun fixed
Purple sun input – reddish sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sunlight as input and the other sun fixed. Note that the carrier rotates clockwise in the animation at remaining and counterclockwise in the computer animation at right – despite the fact that sunlight rotates counterclockwise in both cases.
The Differential
The gearset shown above differs from the preceding gearsets in that it is composed of miter gears instead of spur (or helical) gears. The ‘sun’ gears are those that do not go through the epicyclic movement experienced by the earth. And the differential can be used to gauge the difference in speed between two shafts for the purpose of synchronization. Furthermore, the differential is frequently used in automotive drive trains to conquer the difference in wheel quickness when a car encircles a corner.