Ever-Power new planetary reducers employ a floating sun gear rather than a set position one.
The word ”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 may not become 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 mounted on or machined into the shaft. When this fixed sun gear revolves, it turns the earth gears to create motion and/or power. Ever-Power new planetary reducers, however, are having a floating sun equipment rather than a set position sun gear.
Why a floating sun gear? ‘In the planetary idea, the sun may be the driver, or pinion, in the apparatus set,’Ever-Power design engineer Scott Hulstein said. ‘Because the sun gear is in constant contact with the planets, it’s important that it’s perfectly centred among the three planets in order to provide equal load posting among itself and all three planets.’
Due to normal manufacturing tolerances however, a sun gear which is securely fixed on a shaft will intermittently have more load using one planet gear than on another equipment Hulstein explained. ‘By permitting the sun gear to float, it centres itself among the three planets and produces constant, equal load sharing.’
Equal load sharing is just one of the benefits of this design. The floating sunlight gear provides ‘true involute action,’ according to Hulstein. Accurate involute action takes place when the rolling motion between your mating gears is really as complete as possible. The advantage of this full meshing of gears is certainly longer reducer life, since less internal gear slippage means fewer broken gear teeth.
That also means lower noise levels. When the sun gear is allowed to completely roll in to the planet gears, there’s much less ‘rattling’ as one’s teeth mesh. In place, the Ever-Power product provides ‘designed out’ the gear mesh noise by allowing sunlight equipment to float into place.
So why make use of a fixed sun gear at every? ‘Fixed sun gears tend to be used in accurate servo applications,’ Greg Pennings, Ever-Power Client Advocate, explained. ‘A set sun gear is essential when exact positioning and low backlash are an intrinsic part of the program.’ Ever-Power engineers, however, were less concerned with low backlash and more interested with higher torque and/or lower noise applications.
Our planetary reducers with floating sunlight gears were designed to sun planet gear compete with parallel shaft reducers, where backlash was less critical,’ Pennings said.
By using the floating sun equipment concept, the Ever-Power planetary reducers can exceed the torque ratings of similar sized and larger sized parallel shaft reducers, and yet maintain a lower noise levels.
Sun, Ring and Planet
The most basic type of planetary gearset is proven in the figures above. The figure at remaining shows a three-dimensional watch as the figure at correct provides a cross-section. In this geartrain, inputs and result can be extracted from the carrier, ring and sunlight gears, and just the earth experiences epicyclic motion. That is the most common type of planetary gearset (apart from the differential) and it discovers application in velocity reducers and automatic transmissions. If you take apart a cordless drill, you’ll probably find this type 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 an individual unit. Sunlight gears (green and brown) can rotate independently of 1 another. The inputs and result can be selected from either sun gear and/or the carrier. Very high speed reductions can be achieved with this unit, nonetheless it can suffer from 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 sun as input and the other sunlight fixed. Note that the carrier rotates clockwise in the computer animation at still left and counterclockwise in the animation at right – despite the fact that sunlight rotates counterclockwise in both instances.
The Differential
The gearset proven above 
differs from the preceding gearsets for the reason 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 motion experienced by the planet. And the differential can be used to gauge 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 quickness when a car encircles a corner.