Ever-Power new sun planet gear planetary reducers employ a floating sun gear rather than a fixed position one.
The saying ”There’s nothing new under the sun’ certainly applies to planetary reducers. And, while floating sunlight gears have been around a long time, some engineers might not become aware of the benefits this unusual gear design 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 equipment revolves, it turns the earth gears to create motion and/or power. Ever-Power new planetary reducers, however, are having a floating sun equipment rather than a fixed position sun gear.
Why a floating sun gear? ‘In the planetary concept, the sun may be the driver, or pinion, in the apparatus set,’Ever-Power design engineer Scott Hulstein stated. ‘Because the sun gear is in continuous contact with the planets, it’s important that it is properly centred among the three planets in order to provide equal load sharing among itself and all three planets.’
Due to normal manufacturing tolerances nevertheless, a sun equipment which is securely fixed upon a shaft will intermittently have significantly more load on one planet equipment than on another gear Hulstein explained. ‘By permitting the sun equipment to float, it centres itself among the three planets and creates continuous, equal load sharing.’
Equal load sharing is merely one of the benefits of this design. The floating sunlight gear provides ‘true involute actions,’ according to Hulstein. Accurate involute action occurs when the rolling motion between the mating gears is really as complete as feasible. The advantage of this finish meshing of gears can be longer reducer existence, since less internal gear slippage means fewer damaged gear teeth.
That also means lower noise amounts. When the sun gear is permitted to completely roll in to the world gears, there’s much less ‘rattling’ as the teeth mesh. In place, the Ever-Power product has ‘designed out’ the apparatus mesh sound by allowing sunlight gear to float into place.
So why make use of a set sun gear at every? ‘Fixed sun gears are often 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, nevertheless, were less concerned with low backlash and more interested with higher torque and/or lower sound applications.
Our planetary reducers with floating sun gears were made to compete with parallel shaft reducers, where backlash was less critical,’ Pennings said.
Utilizing the floating sun equipment concept, the Ever-Power planetary reducers have the ability to exceed the torque rankings of similar sized and bigger sized parallel shaft reducers, and yet maintain a lesser 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 look at as the figure at correct provides a cross-section. In this geartrain, inputs and output can be taken from the carrier, band and sunlight gears, and only the planet experiences epicyclic motion. That is the most common kind of planetary gearset (with the exception of the differential) and it finds application in quickness reducers and automatic transmissions. If you take apart a cordless drill, you’ll probably find this kind of planetary gearset directly 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 both 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 selected 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 designed correctly.
Crimson sun input – purple sun fixed
Purple sun input – crimson sun fixed
The animations above show the ‘two suns – two planets’ gearset with one sun as input and the other sun 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 shown above differs from the preceding gearsets in that it is made up of miter gears instead of 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 swiftness between two shafts for the intended purpose of synchronization. Furthermore, the differential is often used in automotive drive trains to conquer the difference in wheel quickness when a car goes around a corner.