Planetary Gear Transmission

An assembly of meshed gears consisting of a central or sun gear, a coaxial inner or ring gear, and a number of intermediate pinions supported upon a revolving carrier. Sometimes the word planetary gear train can be used broadly as a synonym for epicyclic gear teach, or narrowly to indicate that the ring gear is the fixed member. In a simple planetary gear train the pinions mesh at the same time with the two coaxial gears (find illustration). With the central equipment set, a pinion rotates about it as a planet rotates about its sun, and the gears are called appropriately: the central gear is the sun, and the pinions are the planets.
This is a concise, ‘single’ stage planetary gearset where in fact the output is derived from another ring gear varying a few teeth from the primary.
With the initial style of 18 sun teeth, 60 band teeth, and 3 planets, this resulted in a ‘single’ stage gear reduced amount of -82.33:1.
A normal planetary gearset of the size could have a reduction ratio of 4.33:1.
That is a whole lot of torque in a small package.
At Nominal Voltage
Voltage (Nominal) 12V
Voltage Range (Recommended) 3V – 12V
Speed (No Load)* 52 rpm
Current (No Load)* 0.21A
Current (Stall)* 4.9A
Torque (Stall)* 291.6 oz-in (21 kgf-cm)
Gear Ratio 231:1
Gear Material Metal
Gearbox Style Planetary
Motor Type DC
Output Shaft Diameter 4mm (0.1575”)
Output Shaft Style D-shaft
Result Shaft Support Dual Ball Bearing
Electrical Connection Male Spade Terminal
Operating Temperature -10 ~ +60°C
Mounting Screw Size M2 x 0.4mm
Product Planetary Gear Transmission Weight 100g (3.53oz)
In an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference operate between a gear with internal teeth and a gear with exterior teeth on a concentric orbit. The circulation of the spur gear occurs in analogy to the orbiting of the planets in the solar system. This is how planetary gears obtained their name.
The parts of a planetary gear train can be split into four main constituents.
The housing with integrated internal teeth is known as a ring gear. In the majority of cases the casing is fixed. The generating sun pinion is usually in the heart of the ring gear, and is coaxially arranged with regards to the output. The sun pinion is usually attached to a clamping system to be able to provide the mechanical link with the motor shaft. During operation, the planetary gears, which are installed on a planetary carrier, roll between the sunlight pinion and the ring equipment. The planetary carrier also represents the result shaft of the gearbox.
The sole purpose of the planetary gears is to transfer the mandatory torque. The number of teeth does not have any effect on the transmitting ratio of the gearbox. The number of planets can also vary. As the amount of planetary gears increases, the distribution of the strain increases and therefore the torque which can be transmitted. Increasing the amount of tooth engagements also reduces the rolling power. Since just part of the total output has to be transmitted as rolling power, a planetary gear is incredibly efficient. The benefit of a planetary equipment compared to an individual spur gear is based on this load distribution. It is therefore feasible to transmit high torques wit
h high efficiency with a concise design using planetary gears.
Provided that the ring gear has a continuous size, different ratios could be realized by various the amount of teeth of the sun gear and the amount of tooth of the planetary gears. The smaller the sun equipment, the higher the ratio. Technically, a meaningful ratio range for a planetary stage is approx. 3:1 to 10:1, because the planetary gears and sunlight gear are extremely small above and below these ratios. Higher ratios can be obtained by connecting many planetary levels in series in the same ring gear. In this instance, we talk about multi-stage gearboxes.
With planetary gearboxes the speeds and torques can be overlaid by having a ring gear that’s not fixed but is driven in virtually any direction of rotation. It is also possible to repair the drive shaft in order to grab the torque via the band equipment. Planetary gearboxes have become extremely important in lots of areas of mechanical engineering.
They have grown to be particularly well established in areas where high output levels and fast speeds must be transmitted with favorable mass inertia ratio adaptation. High transmission ratios can also easily be performed with planetary gearboxes. Because of their positive properties and compact design, the gearboxes have many potential uses in industrial applications.
The benefits of planetary gearboxes:
Coaxial arrangement of input shaft and output shaft
Load distribution to many planetary gears
High efficiency due to low rolling power
Almost unlimited transmission ratio options because of combination of several planet stages
Appropriate as planetary switching gear because of fixing this or that section of the gearbox
Possibility of use as overriding gearbox
Favorable volume output
Suitability for a wide selection of applications
Within an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference operate between a gear with internal teeth and a gear with exterior teeth on a concentric orbit. The circulation of the spur equipment occurs in analogy to the orbiting of the planets in the solar program. This is how planetary gears obtained their name.
The elements of a planetary gear train can be split into four main constituents.
The housing with integrated internal teeth is actually a ring gear. In nearly all cases the housing is fixed. The generating sun pinion is definitely in the center of the ring gear, and is coaxially organized in relation to the output. The sun pinion is usually mounted on a clamping system in order to provide the mechanical link with the electric motor shaft. During procedure, the planetary gears, which are installed on a planetary carrier, roll between the sun pinion and the band gear. The planetary carrier also represents the result shaft of the gearbox.
The sole purpose of the planetary gears is to transfer the mandatory torque. The amount of teeth has no effect on the transmitting ratio of the gearbox. The amount of planets may also vary. As the number of planetary gears increases, the distribution of the strain increases and therefore the torque that can be transmitted. Raising the number of tooth engagements also decreases the rolling power. Since only part of the total output needs to be transmitted as rolling power, a planetary equipment is extremely efficient. The benefit of a planetary gear compared to an individual spur gear lies in this load distribution. It is therefore feasible to transmit high torques wit
h high efficiency with a concise style using planetary gears.
Provided that the ring gear has a constant size, different ratios can be realized by varying the number of teeth of sunlight gear and the number of tooth of the planetary gears. The smaller the sun equipment, the greater the ratio. Technically, a meaningful ratio range for a planetary stage is usually approx. 3:1 to 10:1, since the planetary gears and the sun gear are extremely little above and below these ratios. Higher ratios can be obtained by connecting many planetary phases in series in the same ring gear. In this case, we talk about multi-stage gearboxes.
With planetary gearboxes the speeds and torques can be overlaid by having a ring gear that is not set but is driven in any direction of rotation. It is also possible to fix the drive shaft to be able to pick up the torque via the band equipment. Planetary gearboxes have become extremely important in lots of areas of mechanical engineering.
They have grown to be particularly well established in areas where high output levels and fast speeds should be transmitted with favorable mass inertia ratio adaptation. High transmission ratios can also easily be achieved with planetary gearboxes. Because of their positive properties and compact design, the gearboxes possess many potential uses in industrial applications.
The benefits of planetary gearboxes:
Coaxial arrangement of input shaft and output shaft
Load distribution to many planetary gears
High efficiency because of low rolling power
Almost unlimited transmission ratio options due to combination of several planet stages
Ideal as planetary switching gear because of fixing this or that part of the gearbox
Possibility of use as overriding gearbox
Favorable volume output
Suitability for an array of applications
Epicyclic gearbox can be an automatic type gearbox where parallel shafts and gears arrangement from manual equipment box are replaced with more compact and more dependable sun and planetary kind of gears arrangement and also the manual clutch from manual power teach is definitely replaced with hydro coupled clutch or torque convertor which produced the transmission automatic.
The idea of epicyclic gear box is taken from the solar system which is considered to an ideal arrangement of objects.
The epicyclic gearbox usually comes with the P N R D S (Parking, Neutral, Reverse, Drive, Sport) modes which is obtained by fixing of sun and planetary gears based on the require of the drive.
In an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference operate between a gear with internal teeth and a gear with external teeth on a concentric orbit. The circulation of the spur gear occurs in analogy to the orbiting of the planets in the solar system. This is how planetary gears obtained their name.
The parts of a planetary gear train can be split into four main constituents.
The housing with integrated internal teeth is actually a ring gear. In the majority of cases the casing is fixed. The traveling sun pinion is in the heart of the ring gear, and is coaxially arranged with regards to the output. The sun pinion is usually mounted on a clamping system in order to provide the mechanical link with the engine shaft. During procedure, the planetary gears, which are mounted on a planetary carrier, roll between your sunlight pinion and the ring equipment. The planetary carrier also represents the output shaft of the gearbox.
The sole reason for the planetary gears is to transfer the mandatory torque. The number of teeth has no effect on the transmitting ratio of the gearbox. The number of planets may also vary. As the number of planetary gears boosts, the distribution of the load increases and then the torque that can be transmitted. Raising the number of tooth engagements also reduces the rolling power. Since only part of the total result needs to be transmitted as rolling power, a planetary equipment is incredibly efficient. The benefit of a planetary gear compared to an individual spur gear is based on this load distribution. It is therefore possible to transmit high torques wit
h high efficiency with a compact style using planetary gears.
So long as the ring gear includes a continuous size, different ratios can be realized by different the number of teeth of the sun gear and the amount of the teeth of the planetary gears. The smaller the sun equipment, the higher the ratio. Technically, a meaningful ratio range for a planetary stage is approx. 3:1 to 10:1, since the planetary gears and sunlight gear are extremely little above and below these ratios. Higher ratios can be obtained by connecting a number of planetary levels in series in the same ring gear. In this instance, we talk about multi-stage gearboxes.
With planetary gearboxes the speeds and torques can be overlaid by having a band gear that is not set but is driven in any direction of rotation. Additionally it is possible to repair the drive shaft to be able to pick up the torque via the band gear. Planetary gearboxes have grown to be extremely important in many areas of mechanical engineering.
They have become particularly well established in areas where high output levels and fast speeds should be transmitted with favorable mass inertia ratio adaptation. High transmission ratios can also easily be achieved with planetary gearboxes. Because of their positive properties and small design, the gearboxes possess many potential uses in industrial applications.
The advantages of planetary gearboxes:
Coaxial arrangement of input shaft and output shaft
Load distribution to many planetary gears
High efficiency due to low rolling power
Almost unlimited transmission ratio options because of combination of several planet stages
Suitable as planetary switching gear because of fixing this or that portion of the gearbox
Chance for use as overriding gearbox
Favorable volume output
In a planetary gearbox, many teeth are involved at once, that allows high speed decrease to be performed with relatively small gears and lower inertia reflected back again to the electric motor. Having multiple teeth share the load also enables planetary gears to transmit high degrees of torque. The mixture of compact size, large speed decrease and high torque tranny makes planetary gearboxes a popular choice for space-constrained applications.
But planetary gearboxes do involve some disadvantages. Their complexity in design and manufacturing tends to make them a far more expensive solution than other gearbox types. And precision production is really important for these gearboxes. If one planetary equipment is put closer to the sun gear than the others, imbalances in the planetary gears may appear, leading to premature wear and failing. Also, the compact footprint of planetary gears makes temperature dissipation more difficult, therefore applications that run at high speed or encounter continuous procedure may require cooling.
When using a “standard” (i.e. inline) planetary gearbox, the motor and the powered equipment must be inline with each other, although manufacturers provide right-angle designs that include other gear sets (frequently bevel gears with helical teeth) to provide an offset between the input and output.
Input power (max)27 kW (36 hp)
Input speed (max)2800 rpm2
Output torque (intermittent)12,880 Nm(9,500 lb-ft)
Output torque (continuous)8,135 Nm (6,000 lb-ft)
1 Actual ratio would depend on the drive configuration.
2 Max input speed linked to ratio and max output speed
3 Max radial load positioned at optimum load position
4 Weight varies with configuration and ratio selected
5 Requires tapered roller planet bearings (not available with all ratios)
Approximate dry weight100 -181 kg (220 – 400 lb)4
Radial load (max)14,287kg (31,500 lb)3
Drive typeSpeed reducer
Hydraulic engine input SAE C or D hydraulic
A planetary transmission system (or Epicyclic system as it can be known), consists normally of a centrally pivoted sunlight gear, a ring equipment and several planet gears which rotate between these.
This assembly concept explains the term planetary transmission, as the planet gears rotate around the sun gear as in the astronomical sense the planets rotate around our sun.
The advantage of a planetary transmission is determined by load distribution over multiple planet gears. It really is thereby possible to transfer high torques employing a compact design.
Gear assembly 1 and gear assembly 2 of the Ever-Power 500/14 possess two selectable sun gears. The first gear step of the stepped planet gears engages with sunlight gear #1. The second equipment step engages with sun gear #2. With sun gear 1 or 2 2 coupled to the axle,or the coupling of sunlight gear 1 with the ring gear, three ratio variations are achievable with each equipment assembly.
Direct Gear 1:1
Example Gear Assy (1) and (2)
With direct gear selected in gear assy (1) or (2), the sun gear 1 is in conjunction with the ring gear in gear assy (1) or gear assy (2) respectively. Sunlight gear 1 and band gear then rotate with each other at the same quickness. The stepped planet gears usually do not unroll. Thus the apparatus ratio is 1:1.
Gear assy (3) aquires direct gear based on the same principle. Sun gear 3 and ring gear 3 are directly coupled.
Many “gears” are used for automobiles, however they are also used for many various other machines. The most frequent one may be the “transmission” that conveys the power of engine to tires. There are broadly two roles the transmission of a car plays : one is certainly to decelerate the high rotation speed emitted by the engine to transmit to tires; the other is to change the reduction ratio relative to the acceleration / deceleration or generating speed of an automobile.
The rotation speed of an automobile’s engine in the overall state of driving amounts to at least one 1,000 – 4,000 rotations each and every minute (17 – 67 per second). Since it is not possible to rotate tires with the same rotation acceleration to perform, it is required to lower the rotation speed utilizing the ratio of the number of gear teeth. This kind of a role is called deceleration; the ratio of the rotation speed of engine and that of tires is named the reduction ratio.
Then, exactly why is it necessary to modify the reduction ratio relative to the acceleration / deceleration or driving speed ? This is because substances need a large force to begin moving however they do not require such a sizable force to keep moving once they have started to move. Automobile could be cited as an example. An engine, however, by its character can’t so finely modify its output. Therefore, one adjusts its result by changing the reduction ratio utilizing a transmission.
The transmission of motive power through gears quite definitely resembles the principle of leverage (a lever). The ratio of the number of tooth of gears meshing with each other can be deemed as the ratio of the distance of levers’ arms. That is, if the decrease ratio is large and the rotation swiftness as output is lower in comparison to that as insight, the power output by transmitting (torque) will be huge; if the rotation speed as output is not so lower in comparison to that as insight, on the other hand, the energy output by tranny (torque) will be little. Thus, to change the decrease ratio utilizing transmission is much akin to the principle of moving things.
Then, how does a transmitting alter the reduction ratio ? The answer is based on the system called a planetary equipment mechanism.
A planetary gear mechanism is a gear system comprising 4 components, namely, sun gear A, several planet gears B, internal gear C and carrier D that connects world gears as observed in the graph below. It includes a very complex framework rendering its design or production most challenging; it can understand the high reduction ratio through gears, nevertheless, it really is a mechanism suited to a reduction system that requires both little size and high performance such as transmission for automobiles.
The planetary speed reducer & gearbox is some sort of transmission mechanism. It utilizes the quickness transducer of the gearbox to reduce the turnover quantity of the electric motor to the required one and obtain a huge torque. How does a planetary gearbox work? We are able to learn more about it from the framework.
The main transmission structure of the planetary gearbox is planet gears, sun gear and band gear. The ring equipment is positioned in close contact with the inner gearbox case. The sun equipment driven by the external power lies in the center of the ring gear. Between the sun gear and band gear, there is a planetary gear set consisting of three gears equally built-up at the earth carrier, which can be floating among them relying on the support of the output shaft, ring equipment and sun gear. When the sun equipment is usually actuated by the input power, the earth gears will be powered to rotate and revolve around the guts together with the orbit of the band equipment. The rotation of the planet gears drives the result shaft linked with the carrier to output the power.
Planetary speed reducer applications
Planetary speed reducers & gearboxes have a whole lot of advantages, like little size, light-weight, high load capability, long service life, high reliability, low noise, huge output torque, wide variety of speed ratio, high efficiency and so on. Besides, the planetary speed reducers gearboxes in Ever-Power are made for square flange, which are easy and convenient for installation and ideal for AC/DC servo motors, stepper motors, hydraulic motors etc.
Because of these advantages, planetary gearboxes are applicable to the lifting transportation, engineering machinery, metallurgy, mining, petrochemicals, structure machinery, light and textile sector, medical equipment, device and gauge, automobile, ships, weapons, aerospace and other industrial sectors.
The primary reason to employ a gearhead is that it makes it possible to regulate a large load inertia with a comparatively small motor inertia. Without the gearhead, acceleration or velocity control of the strain would require that the electric motor torque, and thus current, would need to be as much times better as the reduction ratio which is used. Moog offers an array of windings in each frame size that, combined with an array of reduction ratios, offers an range of solution to output requirements. Each combination of engine and gearhead offers exclusive advantages.
Precision Planetary Gearheads
gearheads
32 mm LOW PRICED Planetary Gearhead
32 mm Precision Planetary Gearhead
52 mm Precision Planetary Gearhead
62 mm Precision Planetary Gearhead
81 mm Precision Planetary Gearhead
120 mm Precision Planetary Gearhead
Planetary gearheads are suitable for transmitting high torques as high as 120 Nm. As a rule, the larger gearheads include ball bearings at the gearhead output.
Properties of the Ever-Power planetary gearhead:
– For tranny of high torques up to 180 Nm
– Reduction ratios from 4:1 to 6285:1
– High functionality in the tiniest of spaces
– High reduction ratio within an extremely small package
– Concentric gearhead input and output
Versions:
– Plastic version
– Ceramic version
– High-power gearheads
– Heavy-duty gearheads
– Gearheads with reduced backlash
80mm size inline planetary reducer for NEMA34 (flange 86mm) or NEMA42 stepper motor. Precision less than 18 Arcmin. High torque, compact size and competitive price. The 16mm shaft diameter ensures stability in applications with belt transmitting. Fast mounting for your equipment.
80mm size inline planetary reducer for NEMA34 (flange 86mm) or NEMA42 stepper motor. Precision significantly less than 18 Arcmin. High torque, compact size and competitive cost. The 16mm shaft diameter ensures stability in applications with belt transmission. Fast mounting for your equipment.
1. Planetary ring gear material: metal steel
2. Bearing at result type: Ball bearing
3. Max radial load (12mm distance from flange): 550N
4. Max shaft axial load: 500N
5. Backlash: 18 arcmin
6. Gear ratio from 3 to 216
7. Planetary gearbox duration from 79 to 107mm
NEMA34 Precision type Planetary Gearbox for nema 34 Gear Stepper Engine 50N.m (6944oz-in) Rated Torque
This gear ratio is 5:1, if need other gear ratio, please contact us.
Input motor shaft request :
suitable with regular nema34 stepper engine shaft 14mm diameter*32 length(Including pad height). (plane and Circular shaft and important shaft both available)
The difference between the economical and precision Nema34 planetary reducer:
First of all: the financial and precise installation methods are different. The insight of the cost-effective retarder assembly is the keyway (ie the result shaft of the motor can be an assembleable keyway motor); the insight of the precision reducer assembly is usually clamped and the input motor shaft is a flat or circular shaft or keyway. The shaft can be mounted (take note: the keyway shaft can be removed following the key is removed).
Second, the economical and precision planetary gearboxes possess the same drawings and measurements. The main difference is: the material is different. Accurate gear products are more advanced than economical gear units in terms of transmission efficiency and accuracy, as well as heat and sound and torque output balance.

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