Ever-Power new planetary reducers employ a floating sun equipment rather than a set position one.
The saying ”There’s nothing new under the sun’ certainly applies to planetary reducers. And, while floating sunlight gears have already been around quite a while, some engineers might not end up being aware of the benefits this unusual gear design can offer.
Traditionally, planetary reducers have used a fixed sun gear, where in fact the centre gear is attached to or machined in to the shaft. When this set sun equipment revolves, it turns the earth gears to create motion and/or power. Ever-Power new planetary reducers, however, are having a floating sun gear 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 apparatus set,’Ever-Power style engineer Scott Hulstein said. ‘Because sunlight gear is in continuous contact with the planets, it’s important that it is properly centred among the three planets in order to provide equal load sharing among itself and all three planets.’
Because of normal manufacturing tolerances however, a sun equipment which is securely fixed on a shaft will intermittently have significantly more load using one planet equipment than on another equipment Hulstein explained. ‘By enabling the sun equipment to float, it centres itself among the three planets and produces continuous, equal load sharing.’
Equal load sharing is just one of the benefits of this design. The floating sun gear provides ‘accurate involute actions,’ according to Hulstein. True involute action occurs when the rolling motion between your mating gears is really as complete as possible. The benefit of this finish meshing of gears is longer reducer existence, since less internal gear slippage means fewer broken gear teeth.
That does mean lower noise amounts. When sunlight gear is permitted to completely roll into the world gears, there’s much less ‘rattling’ as one’s teeth mesh. In effect, the Ever-Power product offers ‘designed out’ the apparatus mesh sound by allowing sunlight gear to float into place.
So why make use of a fixed sun gear at most? ‘Fixed sun gears are often used in true servo applications,’ Greg Pennings, Ever-Power Consumer Advocate, explained. ‘A set sun gear is necessary when specific positioning and low backlash are an intrinsic part of the application.’ Ever-Power engineers, however, were less worried about low backlash and more interested with higher torque and/or lower noise applications.
Our planetary reducers with floating sunlight 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 can easily exceed the torque rankings of similar sized and bigger sized parallel shaft reducers, yet maintain a lesser noise levels.
Sun, Ring and Planet
The most basic type of planetary gearset is sun planet gear proven in the figures above. The figure at left shows a three-dimensional watch while 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 just the earth experiences epicyclic motion. This is the the majority of common type of planetary gearset (with the exception of the differential) and it discovers application in swiftness reducers and automatic transmissions. If you take apart a cordless drill, you’ll 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 demonstrated above has two sun gears, and the two planet gears (the yellow gears) rotate as a single unit. The sun gears (green and brownish) can rotate independently of 1 another. The inputs and result can be selected from either sun equipment and/or the carrier. High speed reductions may be accomplished with 
this unit, but it can suffer from low efficiency if not designed correctly.
Red sun input – purple sun fixed
Purple sun input – reddish colored sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sunlight as input and the other sunlight fixed. Note that the carrier rotates clockwise in the animation at left and counterclockwise in the computer animation at right – despite the fact that the sun rotates counterclockwise in both instances.
The Differential
The gearset demonstrated above is different from the preceding gearsets in that it is made up 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 planet. And the differential can be utilized to measure the difference in swiftness between two shafts for the purpose of synchronization. Furthermore, the differential is often used in automotive drive trains to overcome the difference in wheel acceleration when a car goes around a corner.
