Ever-Power new planetary reducers hire a floating sun gear rather than a fixed position one.
The saying ”There’s nothing new under the sun’ certainly pertains to planetary reducers. And, while floating sunlight gears have already been around quite a while, some engineers may not be aware of the huge benefits this unusual gear design can offer.
Traditionally, planetary reducers have used a set sun gear, where in fact the centre gear is attached to or machined into 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 having a floating sun gear rather than a set position sun gear.
Why a floating sun gear? ‘In the planetary concept, the sun may be the driver, or pinion, in the gear set,’Ever-Power design engineer Scott Hulstein said. ‘Because sunlight gear is in continuous connection with the planets, it’s important that it is properly centred among the three planets to be able to provide equal load posting among itself and all three planets.’
Because of normal manufacturing tolerances however, a sun gear which is securely set upon a shaft will intermittently have significantly more load on one planet gear than on another equipment Hulstein explained. ‘By enabling the sun gear to float, it centres itself among the three planets and creates continuous, equal load sharing.’
Equal load sharing is merely one of the benefits of this design. The floating sunlight gear provides ‘accurate involute actions,’ according to Hulstein. Accurate involute action occurs when the rolling motion between the mating gears is really as complete as possible. The benefit of this full meshing of gears can be longer reducer existence, since less internal gear slippage means fewer damaged gear teeth.
That also means lower noise levels. When sunlight 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 provides ‘designed out’ the gear mesh sound by allowing the sun gear to float into place.
So why make use of a set sun gear at all? ‘Fixed sun gears tend to be used in true servo applications,’ Greg Pennings, Ever-Power Client Advocate, explained. ‘A fixed sun gear is necessary when specific positioning and low backlash are an integral part of the program.’ Ever-Power engineers, nevertheless, were less worried about low backlash and more interested with higher torque and/or lower sound 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 are able to exceed the torque ratings 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 demonstrated in the figures above. The figure at remaining shows a three-dimensional view while the figure at correct offers a cross-section. In this geartrain, inputs and output can be taken from the carrier, ring and sunlight gears, and just the earth experiences epicyclic motion. That is the many common type of planetary gearset (apart from the differential) and it discovers application in speed reducers and automated transmissions. Invest the aside 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 sunlight gears, and the two planet gears (the yellow gears) rotate as a single unit. Sunlight gears (green and brownish) can rotate independently of 1 another. The inputs and result can be chosen from either sun equipment and/or the carrier. Very high speed reductions may be accomplished with this unit, nonetheless it can suffer from low efficiency if not designed correctly.
Red sun input – purple sun fixed
Purple sun input – red 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 remaining and counterclockwise in the computer animation at right – even though sunlight rotates counterclockwise in both situations.
The Differential
The gearset demonstrated above differs from the preceding gearsets for the reason that it is composed of miter gears instead of spur (or helical) gears. The ‘sun’ gears are those that do not undergo the epicyclic motion experienced by the planet. And the differential can be utilized to gauge the difference in velocity between two shafts for the intended purpose of synchronization. In addition, the differential is frequently used in auto drive trains to overcome the difference in wheel rate when a car goes around a corner.