Ever-Power new planetary reducers hire a floating sun gear rather than a fixed position one.
The word ”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 be aware of the benefits this unusual 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 fixed sun gear 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 design engineer Scott Hulstein stated. ‘Because the sun gear is in constant contact with the planets, it’s important that it is flawlessly centred among the three planets to be able to provide equal load posting among itself and all three planets.’
Because of normal manufacturing tolerances nevertheless, a sun equipment which is securely set on a shaft will intermittently have significantly more load on one planet gear than on another gear Hulstein explained. ‘By sun planet gear permitting the sun gear to float, it centres itself among the three planets and creates continuous, equal load sharing.’
Equal load posting is merely one of the advantages of this design. The floating sun gear provides ‘true involute action,’ according to Hulstein. Accurate involute action takes place when the rolling motion between the mating gears is as complete as feasible. The advantage of this finish meshing of gears can be longer reducer life, since less internal gear slippage means fewer broken gear teeth.
That does mean lower noise amounts. When sunlight gear is permitted to completely roll in to the planet gears, there’s less ‘rattling’ as the teeth mesh. In place, the Ever-Power product offers ‘designed out’ the gear mesh noise by allowing sunlight equipment to float into place.
So why use a set sun gear at almost all? ‘Fixed sun gears are often used in accurate servo applications,’ Greg Pennings, Ever-Power Consumer Advocate, explained. ‘A fixed sun gear is essential when specific positioning and low backlash are an intrinsic part of the app.’ 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 sun gears were designed to contend with parallel shaft reducers, where backlash was less critical,’ Pennings said.
By using the floating sun gear concept, the Ever-Power planetary reducers have the ability 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 remaining shows a three-dimensional look at as the figure at correct provides a cross-section. In this geartrain, inputs and result can be taken from the carrier, ring and sun gears, and only the planet experiences epicyclic motion. That is the most common type of planetary gearset (with the exception of the differential) and it discovers application in rate reducers and automated transmissions. If you take aside a cordless drill, you’ll 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 shown above has two sunlight gears, and both planet gears (the yellow gears) rotate as an individual unit. Sunlight gears (green and dark brown) can rotate independently of 1 another. The inputs and result can be chosen from either sun gear and/or the carrier. High speed reductions can be achieved with this unit, nonetheless it can have problems with low efficiency if not really designed correctly.
Crimson sun input – purple sun fixed
Purple sun input – red sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sunlight as input and the other sun fixed. Note that the carrier rotates clockwise in the computer animation at still left and counterclockwise in the animation at right – even though sunlight rotates counterclockwise in both cases.
The Differential
The gearset shown above differs 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 the ones that do not undergo the epicyclic motion experienced by the earth. And the differential can be utilized to gauge the difference in acceleration 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 speed when a car goes around a corner.