Ever-Power new planetary reducers employ a floating sun equipment rather than a set position one.
The saying ”There’s nothing new beneath the sun’ certainly applies to planetary reducers. And, while floating sun gears have been around quite a while, some engineers may not become aware of the huge benefits this unusual gear sun planet gear design can offer.
Traditionally, planetary reducers have used a set sun gear, where the centre gear is attached to or machined into the shaft. When this set 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 fixed position sun gear.
Why a floating sun gear? ‘In the planetary concept, the sun is the driver, or pinion, in the gear set,’Ever-Power design engineer Scott Hulstein stated. ‘Because sunlight gear is in constant contact with the planets, it’s important that it is flawlessly centred among the three planets in order to provide equal load posting among itself and all three planets.’
Due to normal manufacturing tolerances nevertheless, a sun gear which is securely fixed upon a shaft will intermittently have significantly more load using one planet gear than on another gear Hulstein explained. ‘By allowing the sun gear 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 action,’ according to Hulstein. True involute action occurs when the rolling motion between the mating gears is as complete as feasible. The advantage of this total meshing of gears is longer reducer existence, since less internal gear slippage means fewer broken gear teeth.
That also means lower noise amounts. When the sun gear is allowed to completely roll in to the world gears, there’s less ‘rattling’ as one’s teeth mesh. In place, the Ever-Power product offers ‘designed out’ the apparatus mesh noise by allowing sunlight gear to float into place.
So why use a fixed sun gear at all? ‘Fixed sun gears are often used in true servo applications,’ Greg Pennings, Ever-Power Customer Advocate, explained. ‘A set sun gear is necessary when precise positioning and low backlash are an intrinsic part of the program.’ 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 sunlight gears were made 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 have the ability to exceed the torque rankings of similar sized and larger sized parallel shaft reducers, 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 remaining shows a three-dimensional look at while the figure at right offers a cross-section. In this geartrain, inputs and output can be taken from the carrier, ring and sunlight gears, and only the planet 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 rate reducers and automated transmissions. Invest the aside 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 sunlight gears, and both planet gears (the yellow gears) rotate as an individual unit. The sun gears (green and brown) can rotate independently of 1 another. The inputs and result can be chosen from either sun gear and/or the carrier. Very high speed reductions can be achieved with this unit, but it can suffer from low efficiency if not 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. Remember that the carrier rotates clockwise in the computer animation at left and counterclockwise in the computer animation at right – even though the sun rotates counterclockwise in both cases.
The Differential
The gearset shown above is different from the preceding gearsets for the reason that it is made up of miter gears rather than spur (or helical) gears. The ‘sun’ gears are those that do not undergo the epicyclic motion experienced by the earth. And the differential can be used to gauge the difference in quickness between two shafts for the purpose of synchronization. In addition, the differential is frequently used in auto drive trains to get over the difference in wheel swiftness when a car encircles a corner.