Ever-Power new planetary reducers employ a floating sun gear rather than a fixed position one.
The saying ”There’s nothing new beneath the sun’ certainly pertains to planetary reducers. And, while floating sun gears have been around a long time, some engineers may not end up being aware 
of the benefits this unusual gear style can offer.
Traditionally, planetary reducers possess used a fixed sun gear, where the centre gear is mounted on or machined in to the shaft. When this fixed sun equipment revolves, it turns the planet 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 sun gear? ‘In the planetary idea, the sun is the driver, or pinion, in the gear set,’Ever-Power style engineer Scott Hulstein said. ‘Because the sun gear is in constant sun planet gear contact with the planets, it’s important that it’s properly centred among the three planets in order to provide equal load posting among itself and all three planets.’
Because of normal manufacturing tolerances however, a sun equipment which is securely fixed upon a shaft will intermittently have more load on one planet gear than on another gear Hulstein explained. ‘By enabling the sun gear to float, it centres itself among the three planets and produces continuous, equal load sharing.’
Equal load sharing is merely one of the advantages of this design. The floating sunlight gear provides ‘accurate involute action,’ according to Hulstein. True involute action happens when the rolling movement between your mating gears is as complete as feasible. The benefit of this finish meshing of gears is usually longer reducer existence, since less internal equipment slippage means fewer broken gear teeth.
That does mean lower noise levels. When the sun gear is allowed to completely roll into the planet gears, there’s less ‘rattling’ as one’s teeth mesh. In effect, the Ever-Power product provides ‘designed out’ the gear mesh sound by allowing the sun gear to float into place.
So why use a fixed sun gear at most? ‘Fixed sun gears are often used in accurate servo applications,’ Greg Pennings, Ever-Power Client Advocate, explained. ‘A fixed sun gear is necessary when precise positioning and low backlash are an integral part of the software.’ Ever-Power engineers, nevertheless, were less worried about low backlash and more interested with higher torque and/or lower noise applications.
Our planetary reducers with floating sun gears were designed to contend with parallel shaft reducers, where backlash was less critical,’ Pennings said.
By using the floating sun equipment concept, the Ever-Power planetary reducers are able to exceed the torque ratings of similar sized and bigger sized parallel shaft reducers, and yet maintain a lower noise levels.
Sun, Ring and Planet
The most basic type of planetary gearset is demonstrated in the figures above. The figure at remaining shows a three-dimensional look at while the figure at correct offers a cross-section. In this geartrain, inputs and result can be taken from the carrier, band and sunlight gears, and just the planet experiences epicyclic motion. This is the the majority of common kind of planetary gearset (apart from the differential) and it finds application in velocity reducers and automatic transmissions. Invest the apart a cordless drill, you’ll probably find this kind of planetary gearset right behind the drill chuck.
Two Suns – Two Planets gearset
Cross-sectional view
Two Suns, Two Planets
The gearset shown above has two sunlight gears, and the two planet gears (the yellow gears) rotate as an individual unit. Sunlight gears (green and brownish) can rotate independently of 1 another. The inputs and output can be selected from either sun gear and/or the carrier. Very high speed reductions can be achieved with this unit, but it can have problems with low efficiency if not really designed correctly.
Reddish colored sun input – purple sun fixed
Purple sun input – reddish colored sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sun as input and the other sun fixed. Note that the carrier rotates clockwise in the computer animation at remaining and counterclockwise in the computer animation at right – even though the sun rotates counterclockwise in both instances.
The Differential
The gearset proven above is different from the preceding gearsets in that it is made up of miter gears rather than 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 utilized to measure the difference in acceleration between two shafts for the intended purpose of synchronization. In addition, the differential is frequently used in automotive drive trains to get over the difference in wheel acceleration when a car encircles a corner.
