sun planet gear

Ever-Power new planetary reducers employ a floating sun gear 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 already been around a long time, some engineers might not become aware of the 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 earth gears to create movement and/or power. Ever-Power new planetary reducers, however, are having a floating sun gear rather than a fixed position sun gear.
Why a floating sun gear? ‘In the planetary idea, the sun may be the driver, or pinion, in the apparatus set,’Ever-Power design engineer Scott sun planet gear Hulstein said. ‘Because the sun gear is in constant contact with the planets, it’s important that it’s properly centred among the three planets to be able to provide equal load sharing among itself and all three planets.’
Because of normal manufacturing tolerances nevertheless, a sun equipment which is securely fixed on a shaft will intermittently have significantly more load on one planet equipment than on another equipment Hulstein explained. ‘By allowing the sun gear to float, it centres itself among the three planets and creates constant, equal load sharing.’
Equal load sharing is merely one of the benefits of this design. The floating sun gear provides ‘true involute action,’ according to Hulstein. Accurate involute action happens when the rolling motion between your mating gears is really as complete as possible. The advantage of this complete meshing of gears can be longer reducer lifestyle, since less internal gear slippage means fewer broken gear teeth.
That also means lower noise amounts. When the sun gear is allowed to completely roll in to the planet gears, there’s much less ‘rattling’ as one’s teeth mesh. In place, the Ever-Power product provides ‘designed out’ the apparatus mesh noise by allowing sunlight equipment to float into place.
So why make use of a fixed sun gear at every? ‘Fixed sun gears are often used in accurate servo applications,’ Greg Pennings, Ever-Power Customer Advocate, explained. ‘A set sun gear is essential when specific positioning and low backlash are an intrinsic part of the application.’ 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 sun 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 easily exceed the torque rankings of similar sized and larger sized parallel shaft reducers, and 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 watch as the figure at right provides a cross-section. In this geartrain, inputs and result can be taken from the carrier, ring and sunlight gears, and just the planet experiences epicyclic motion. This is the most common kind of planetary gearset (with the exception of the differential) and it discovers application in quickness reducers and automatic transmissions. If you take apart a cordless drill, you’ll probably find this type 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 sun gears, and the two planet gears (the yellow gears) rotate as an individual unit. Sunlight gears (green and brown) can rotate independently of one another. The inputs and result can be chosen from either sun equipment 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 – reddish sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sun as input and the other sunlight fixed. Remember that the carrier rotates clockwise in the animation at still left 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 for the reason that it is made up of miter gears rather than 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 used to gauge the difference in swiftness between two shafts for the purpose of synchronization. Furthermore, the differential is often used in automotive drive trains to overcome the difference in wheel quickness when a car encircles a corner.

Tags:

Find us

Ep Screw Jack Co., Ltd.

Mail: [email protected]

As one of leading manufacturers, suppliers and exporters of mechanical products in China, We offer reducers, sprockets, industrial and conveyor chain, belts, pulleys, gears, racks, gearboxes, motors, PTO Shafts, taper lock Bushing, vacuum Pumps, screw air compressors and many other products. Please contact us for details.

Recent Posts