sun planet gear

Ever-Power new planetary reducers hire a floating sun equipment rather than a fixed 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 benefits this unusual gear design can offer.
Traditionally, planetary reducers possess used a set sun gear, where the centre gear is mounted on or machined in to the shaft. When this set 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 gear rather than a fixed position sun gear.
Why a floating sunlight gear? ‘In the planetary idea, the sun may be the driver, or pinion, in the apparatus set,’Ever-Power style engineer Scott Hulstein stated. ‘Because the sun gear is in constant contact 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 nevertheless, a sun gear which is securely set upon a shaft will intermittently have more load on 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 continuous, equal load sharing.’
Equal load sharing is just one of the benefits of this design. The floating sunlight gear provides ‘true involute action,’ according to Hulstein. Accurate involute action happens when the rolling movement between the mating gears is really as complete as feasible. The benefit of this comprehensive meshing of gears can be longer reducer existence, since less internal equipment slippage means fewer damaged gear teeth.
That does mean lower noise amounts. When the sun gear is permitted to completely roll in to the planet gears, there’s less ‘rattling’ as one’s teeth mesh. In effect, the Ever-Power product offers ‘designed out’ the apparatus mesh noise by allowing sunlight gear to float into place.
So why use 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 set sun gear is necessary when specific positioning and low backlash are an integral part of the software.’ Ever-Power engineers, however, 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 designed to compete 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 demonstrated in the figures above. The figure at 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 sunlight gears, and only the earth experiences epicyclic motion. That is the many common kind of planetary gearset (apart from the differential) and it discovers application in velocity reducers and automated transmissions. If you take apart a cordless drill, you will most probably find this kind 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 sunlight gears, and the two planet gears (the yellow gears) rotate as a single unit. Sunlight gears (green and dark brown) can rotate independently of 1 another. The inputs and output can be chosen from either sun gear and/or the carrier. Very high speed reductions may be accomplished with this unit, nonetheless it can have problems with low efficiency if not really designed correctly.
Reddish colored 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 sunlight fixed. Remember that the carrier rotates clockwise in the animation at left and counterclockwise in the sun planet gear 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 composed of miter gears rather than spur (or helical) gears. The ‘sun’ gears are those that do not undergo the epicyclic movement experienced by the earth. And the differential can be used to measure the difference in speed between two shafts for the purpose of synchronization. Furthermore, the differential is frequently used in automotive drive trains to overcome the difference in wheel velocity when a car goes around a corner.