Ever-Power new planetary sun planet gear reducers hire a floating sun equipment rather than a fixed position one.
The word ”There’s nothing new under the sun’ certainly pertains to planetary reducers. And, while floating sunlight gears have been around a long time, some engineers might not be aware of the huge 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 in to the shaft. When this fixed sun gear revolves, it turns the planet 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 sunlight equipment? ‘In the planetary concept, 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 continuous connection 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.’
Due to normal manufacturing tolerances however, a sun equipment which is securely set on a shaft will intermittently have significantly more load using one planet gear than on another equipment Hulstein explained. ‘By permitting the sun equipment to float, it centres itself among the three planets and generates constant, equal load sharing.’
Equal load posting is just one of the benefits of this design. The floating sunlight gear provides ‘true involute actions,’ according to Hulstein. True involute action happens when the rolling motion between your mating gears is really as complete as feasible. The benefit of this finish meshing of gears is usually longer reducer lifestyle, since less internal gear slippage means fewer broken gear teeth.
That also means lower noise levels. When sunlight gear is permitted to completely roll into the planet gears, there’s less ‘rattling’ as one’s teeth mesh. In place, the Ever-Power product has ‘designed out’ the gear mesh sound by allowing the sun gear 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 Consumer Advocate, explained. ‘A set sun gear is essential when specific positioning and low backlash are an intrinsic 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 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 can exceed the torque ratings of similar sized and larger sized parallel shaft reducers, 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 left shows a three-dimensional view as the figure at correct offers a cross-section. In this geartrain, inputs and result can be taken from the carrier, ring and sunlight gears, and only the earth experiences epicyclic motion. This is the the majority of common kind of planetary gearset (with the exception of the differential) and it discovers application in quickness reducers and automated transmissions. If you take apart a cordless drill, you will most probably find this type of planetary gearset right 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 both planet gears (the yellow gears) rotate as a single unit. The sun gears (green and brownish) can rotate independently of one another. The inputs and result can be selected from either sun equipment and/or the carrier. Very high speed reductions may be accomplished with this unit, but it can suffer from low efficiency if not really designed correctly.
Crimson 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 animation at left and counterclockwise in the animation at right – even though the sun rotates counterclockwise in both instances.
The Differential
The gearset shown above differs from the preceding gearsets in that it is composed 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 earth. And the differential can be used to measure the difference in speed between two shafts for the purpose of synchronization. In addition, the differential is often used in automotive drive trains to conquer the difference in wheel velocity when a car goes around a corner.