Ever-Power new planetary reducers hire a floating sun gear rather than a fixed position one.
The word ”There’s nothing new under the sun’ certainly applies to planetary reducers. And, while floating sunlight gears have already been around a long time, some engineers might not be aware of the benefits this unusual gear style can offer.
Traditionally, planetary reducers possess 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 earth gears to create motion 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 equipment? ‘In the planetary idea, the sun may be the driver, or pinion, in the apparatus set,’Ever-Power style engineer Scott Hulstein said. ‘Because the sun gear is in continuous connection with the planets, it’s important that it’s perfectly centred among the three planets in order to provide equal load sharing among itself and all three planets.’
Because of normal manufacturing tolerances however, a sun equipment which is securely set on a shaft will intermittently have more load on one planet equipment 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 merely one of the advantages of this design. The floating sun gear provides ‘true involute actions,’ according to Hulstein. Accurate involute action happens when the rolling motion between your mating gears is really as complete as possible. The benefit of this finish meshing of gears is definitely longer reducer lifestyle, since less internal equipment slippage means fewer damaged gear teeth.
That does mean lower noise amounts. When sunlight gear is permitted to completely roll into the planet gears, there’s much less ‘rattling’ as the teeth mesh. In effect, the Ever-Power product provides ‘designed out’ the gear mesh sound by allowing the sun equipment to float into place.
So why make use of a set sun gear at most? ‘Fixed sun gears tend to be used in accurate servo applications,’ Greg Pennings, Ever-Power Consumer Advocate, explained. ‘A fixed sun gear is essential when exact positioning and low backlash are an integral part of the application.’ Ever-Power engineers, however, were less worried about low backlash and more interested with higher torque and/or lower sound applications.
Our planetary reducers with floating sun gears were designed to compete with parallel shaft reducers, where backlash was less critical,’ Pennings said.
Utilizing the floating sun gear 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 kind of planetary gearset is demonstrated in the figures above. The figure at still left shows a three-dimensional watch as the figure at correct offers a cross-section. In this geartrain, inputs and result can be extracted from the carrier, band and sun gears, and just the earth experiences epicyclic motion. That is the many common kind of planetary gearset (apart from the differential) and it finds application in swiftness reducers and automatic transmissions. If you take apart a cordless drill, you will most sun planet gear 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 proven above has two sun gears, and the two planet gears (the yellow gears) rotate as an individual unit. Sunlight gears (green and dark brown) can rotate independently of one another. The inputs and result can be selected from either sun equipment and/or the carrier. High speed reductions may be accomplished with this unit, nonetheless it can have problems with low efficiency if not really designed correctly.
Red sun input – purple sun fixed
Purple sun input – crimson sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sunlight as input and the other sunlight fixed. Note that the carrier rotates clockwise in the animation at remaining and counterclockwise in the computer animation at right – despite the fact that sunlight rotates counterclockwise in both instances.
The Differential
The gearset proven above differs from the preceding gearsets in that it is composed of miter gears rather than spur (or helical) gears. The ‘sun’ gears are the ones that do not go through the epicyclic movement experienced by the planet. And the differential can be utilized to gauge the difference in rate between two shafts for the purpose of synchronization. Furthermore, the differential is often used in automotive drive trains to overcome the difference in wheel velocity when a car goes around a corner.