planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet gear and ring gear. Sun gear is located at the guts that transmits torque to planet gears orbiting around sunlight gear. Both systems can be found inside the ring gear. In the toothed formation sun and planet gears are externally mesh and ring gear internally meshes.
Planetary gear is found in many variation and arrangements to meet up a broad range of speed-ratio in the deign requirements. Planetary gear system is make use of in varies applications such as for example, clocks, lunar calendar, car mirror, toys, gearhead engine, turbine engine and much more.
For details understanding on the planetary
Planetary gear system will simply no assemble unless the number of teeth in each equipment is selected properly.
Planetary spur gear drive ratio 5:1 means the sun gear must make 5 revolutions for each revolution of the output carrier.
Desired number of teeth in the sun gear is 24.
Design requirements:
Ratio = 5:1
Sun gear = 24
Module = 1
Since, I am working in the metric device every dimension will be in mm. Choosing gears in metric device the apparatus tooth profile of the spur equipment will be in Module.
M = Module
N = Number of teeth
Nr = Number of teeth on the band gear
Pd= Pitch Diameter
R = Ratio
PDs=N/M=24/1=24mm Eq. 01
Pitch diameter of sunlight gear is 24.
Calculate the quantity if teeth needed in the ring gear for the ratio 5:1.
R=1+Nr/Pd Eq. 02
Solve for Nr
Nr=Pd (R-1)=24(5-1)=24(4)=96 teeth
Pitch diameter of the band gear with 96 the teeth and 1 module is.
Pd=Nr/M Eq. 03 Pd=96/1=96mm
Pitch diameter of the earth gears should be found from.
PDp=(Nr-PDs)/2=(96-24)/2=72/2=36mm
Number of the teeth in the planet gears may now end up being found from.
PDp=N/M Eq. 04 36mm=N/1 è 36mm (1)=N è N =36 teeth
Check:
R=1+Nr/P_D =1+96/24=1+4=5
The ratio is 5:1, as design was required.
Benefits of using planetary gear motors in your projects
There are several types of geared motors that can be utilized in search for the perfect movement in an engineering project. Taking into account the technical specs, the required performance or space limitations of our design, you should ask yourself to make use of one or the additional. In this post we will delve on the planetary gear motors or epicyclical equipment, which means you will know completely what its advantages are and discover some successful applications.
The planetary gear products are seen as a having gears whose disposition is very not the same as other models like the uncrowned end, cyclical (step-by-step) or spur and helical gears. How could we classify their elements?
Sun: The central equipment. It has a larger size and rotates on the central axis.
The planet carrier: Its objective is to carry up to 3 gears of the same size, which mesh with sunlight gear.
Crown or ring: an outer ring (with teeth on its inner part) meshes with the satellites and contains the whole epicyclical train. Furthermore, the core may also become a center of rotation for the outer ring, and can easily change directions.
For accuracy and reliability, many automated transmissions currently use planetary gear motors. If we discuss sectors this reducer offers great versatility and can be used in very different applications. Its cylindrical shape is easily adaptable to thousands of spaces, ensuring a large reduction in a very contained space.
Regularly this type of drives can be used in applications that want higher levels of precision. For instance: Industrial automation devices, vending machines or robotics.
What are the main benefits of planetary gear motors?
Increased repeatability: Its higher speed radial and axial load offers reliability and robustness, minimizing the misalignment of the apparatus. In addition, uniform transmitting and low vibrations at different loads give a perfect repeatability.
Ideal precision: Most rotating angular stability boosts the accuracy and reliability of the movement.
Lower noise level since there is more surface contact. Rolling is much softer and jumps are virtually nonexistent.
Greater durability: Because of its torsional rigidity and better rolling. To boost this feature, your bearings lessen the losses that could occur by rubbing the shaft on the package directly. Thus, greater efficiency of the apparatus and a much smoother procedure is achieved.
Very good degrees of efficiency: Planetary reducers offer greater efficiency and because of its design and internal layout losses are minimized throughout their work. Actually, today, this type of drive mechanisms are those that provide greater efficiency.
Improved torque transmission: With an increase of teeth in contact, the mechanism has the capacity to transmit and withstand more torque. In addition, it can it in a more uniform manner.
Maximum versatility: The mechanism is within a cylindrical gearbox, which may be installed in almost any space.
The construction of the planetary reducer lends itself to numerous advantages, for instance:
Planetary reducers offer you high torque in a compact package; sharing the strain between several planet gears allows the reducer to take care of the same torque that larger parallel axis gear sets handle.
They are highly efficient with a single stage typically 95% efficient.
These reducers provide for ratios as high as 11:1 to be performed within a stage, whereas, it is difficult to achieve much higher than 5:1 within a parallel axis stage.
Because the sun gear contacts multiple planet gears, resistance to elastic deformation, is higher in a planetary gear set than parallel axis gear set, giving the planetary reducer high torsional stiffness.
They enable coaxial alignment, meaning no offset output shaft in relation to the motor shaft.
The output shaft upon Planetary reducers rotates in the same direction as the electric motor without needing an idler gear, as in a parallel axis gear set.
Planetary reducers are ideal for intermittent duty applications but also can be utilized in constant duty applications.
Finally, Ever-Power planetary’s possess a housing, meaning the ring gear is built-into the external housing for the gearbox, adding to the robusticity.
Compared to the advantages of the planetary reducers, the disadvantages are minimal for some applications for example:
High ratio of length to diameter when working with multiple stages (gearhead will get very long).
Potentially high cost if low backlash, high precision gearing is necessary.
Specific numbers of gear teeth are needed equally spaced planets (simple assembly) and noise mitigation.
The gear ratio determines how many planet gears may be used.
You should look at planetary reducers when designing for applications requiring high torques in a little package with an result shaft needs to be co-axially aligned with the engine.
Product Overview
Product Usage:
All Ever-Power gearboxes require grease for proper procedure and long life. We suggest using our red tacky grease, am-2768. We also motivate that an individual powers the gearbox constantly for thirty minutes without grease to allow the gear teeth to put on in. While we do design with short run times in mind, this ‘run in’ period for smooth gearbox operation, is recommended. Once this is completed, comprehensive grease of the apparatus teeth periodically to ensure smooth operation.
Solitary speed planetary gearbox, with the same mounting and output interface as a 2.5″ CIM motor. Each planet equipment has its own bearing to spin freely on the carrier plate pins. A 2.5″ CIM Motor could also be used as the motor input, but needs this pinion equipment ( am-0556) and a CIM Spacer (am-0555).
Motor Input:
9015 motor fits on this gearbox
550 motor fits on this gearbox
2.5″ CIM Motor could be installed, with a bored-out sun equipment and a spacer
Included Hardware:
Two – 8mm id ball bearings, (19mm od, 22mm od) supporting output shaft
One – Steel planet and sun gears, 32 dp, 20 degree p.a.
Five – Planet gears (12 tooth)
One – 15 tooth sun gear, with 0.125 inch bore
One – 40 tooth ring gear
Performance Data:
(with the insight being a 9015 motor)
Input voltage: 12 volts
Stall Torque: 1.12 ft-lb.
Free speed: approximately 4,000 rpm
Assembly Tip:
Install the aluminum plate to the facial skin of the motor BEFORE pressing the pinion gear onto the motor shaft.
Specifications
Material: body is aluminum, shaft is 4140 steel
Mounting Holes: #10-32 tapped holes (2), on a 2″ bolt circle to attach at output shaft
Outdoors dimension: 2.5 in.
Ratio: 3.67:1
Shaft Diameter: 0.313 inch,with 2mm keyway
Weight: 0.63 lbs
PLANETARY GEAR SYSTEM
A planetary transmission system (or Epicyclic system since it can be known), consists normally of a centrally pivoted sun gear, a ring gear 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 benefit of a planetary transmission is determined by load distribution over multiple planet gears. It is thereby feasible to transfer high torques employing a compact design.
Gear assembly 1 and gear assembly 2 of the Ever-Power 500/14 possess two selectable sunlight gears. The first gear stage of the stepped planet gears engages with sunlight gear #1. The second gear step engages with sun gear #2. With sun gear 1 or 2 2 coupled to the axle,or the coupling of sun gear 1 with the band gear, three ratio variations are achievable with each equipment assembly.
The decision between helical and spur gears in gearboxes may appear straightforward. Move with helical gears if you want the gearbox to run as easily and quietly as feasible. Choose spur gears if you want to maximize the gearbox’s torque density or working existence under higher loads.
These guidelines are mainly what you should know when specifying traditional fixed-axis gearboxes. Simply size the gearbox properly, and the decision between helical and spur gears may also be obvious for a given set of software requirements. With planetary gearboxes, however, the choice between helical and spur gears requires some extra thought.
Helical Gears Create Axial Forces
As you might expect from their different mesh geometries, spur and helical gears have very different loading characteristics. With their zero helix position, spur gears lack an axial load component. And they suffer from very little sliding tooth contact.
Helical gears, in comparison, generate significant axial forces 
in the gear mesh. In addition they exhibit more sliding at the point of tooth get in touch with, adding friction forces in to the mix.
Helix angles in gearboxes usually fall in a variety of 15 to 30 degrees. As the angle increases, both axial forces and sliding get in touch with increase.
The main reason for using helical gears may be the increased number of teeth connected at any moment, which really is a fundamental requirement for smooth torque transmission. With their
increased contact ratio compared to spur gears, helical gears possess a lower fluctuation
of the apparatus mesh stiffness.
Helical Gears Place Greater Demand on Bearings
Since they don’t need to withstand any axial forces, spur gear bearings play just a supporting part in the functioning of the gearbox. The bearings simply need to support the rotating gear shafts, however they do not really play an active part in torque transfer.
The presence of axial forces makes things completely different for the bearings that support helical gears. But it is important to make a distinction between fixed-axis and planetary gearboxes. In fixed-axis gearboxes, the additional axial forces total little more than an inconvenience. Gearbox designers will often upsize the bearings to accommodate the additional forces.
Or, in extreme cases, they may select angular get in touch with or tapered roller bearings, both of which are designed to withstand axial loads.
Space limitations within planetary gearboxes mean that the planet gear bearings should be chosen more for their size than their tolerance for high axial loads.
In planetary gearboxes, however, it’s a lot more difficult to create around these axial forces for two related reasons. First, there is typically hardly any space in a planetary gearbox to include the type of bulky bearings that may tolerate high axial forces.
Second, the earth gear bearings have to play an active part in torque transfer. Planetary systems split the torque insight from the sun gear amongst the planet gears, which in turn transfer torque to a world carrier linked to the gearbox result. The bearings that support the planets on the carrier need to bear the full brunt of that torque transfer.
And Here Is the Difficulty
The limited space within planetary gearboxes implies that the bearings used for the earth gears should be chosen more for their size than their tolerance for high axial loads. Generally, small needle roller bearings are the most typical choice in these settings.
Needle roller bearings execute a good work with radial loads that are evenly distributed along the space of the needle. But they don’t deal with axial loads well.
In planetary systems, the direction of the axial force in the sun-planet mesh opposes that of the force in the planet-ring gear mesh. So the world sees significant tilting instant described by the axial push times equipment pitch diameter. This tilting moment produces an uneven load distribution along the needle rollers, significantly reducing the bearings’ load carrying capability and lifecycle.
Loads on the roller bearings will change, depending on their position around the shaft. Minute is about the Z-axis, and units are in inches and pounds.
The Planetary Motion Is The Theory For The Planetary Gearbox.
The Accurately Positioned And Meshed World Gears (3) With The Sun Gear In The Centre And The Internal Teeth Of The Outer Band Gear Compose Each Stage Of A Planetary Gearbox.
The Sun Equipment Gets The Input While The 3 Planet Gears Provide The Ouput WITH A Planet Carrier .
The Torque Handling Capacity Is Very High DUE TO ITS Flexibility , And AN EXTREMELY High Weight /Volume Ratio , Thus It Lends Its Software IN A VARIETY OF Industries – Specifically In High Torque Requirements Making It The Most Economical Solution.
Being A Proud Supplier Of Planetary Gearbox, We Provide A FANTASTIC Distinguished Service TO YOUR Clientile.
Planetary Gearbox Product Specs :
Provides High Torque At Slow Speeds.
Our SELECTION OF Gearboxes And Geared Motors Are Manufactured ACCORDING TO The American Gear Manufacturers Association (AGMA) Standards.
The Shafts Are Made Up Of Hardened And Tempered Special Alloy Steel.
Sun And World Gears ARE MADE FROM Case Carburised And Surface Alloy Steel.
Ring Gears ARE MADE Of Forged Alloy Steel.
Best Load Sharing DUE TO Accurate Positioning Of Planets.
Low Noise Levels.
No Oil Leakage.
Good Quality Taper Roller Bearings For Input And Output Shafts.
Very High Efficiency