planetary gears also refer as epicyclic gearing consisting 3 elements sun gear, planet gear and ring gear. Sunlight gear is located at the guts that transmits torque to planet gears orbiting around the sun gear. Both systems are located inside the ring gear. In the toothed development sun and world gears are externally mesh and band gear internally meshes.
Planetary gear is found in many variation and plans to meet up a broad range of speed-ratio in the deign requirements. Planetary gear system is use in varies applications such as for example, clocks, lunar calendar, car mirror, toys, gearhead engine, turbine engine and more.
For fine detail understanding on the planetary
Planetary gear system will simply no assemble unless the number of teeth in each gear is selected properly.
Planetary spur equipment drive ratio 5:1 means the sun gear must make 5 revolutions for each revolution of the result carrier.
Desired number of teeth in the sun gear is 24.
Design requirements:
Ratio = 5:1
Sun gear = 24
Module = 1
Since, I am employed in the metric device every dimension will be in mm. Selecting gears in metric device the gear tooth profile of the spur equipment will be in Module.
M = Module
N = Number of teeth
Nr = Quantity of teeth on the band gear
Pd= Pitch Diameter
R = Ratio
PDs=N/M=24/1=24mm Eq. 01
Pitch diameter of the sun gear is 24.
Calculate the quantity if teeth required 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 ring gear with 96 teeth and 1 module is.
Pd=Nr/M Eq. 03 Pd=96/1=96mm
Pitch diameter of the planet gears must be found from.
PDp=(Nr-PDs)/2=(96-24)/2=72/2=36mm
Number of tooth in this world gears may now become 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 equipment motors in your projects
There are several types of geared motors that can be used in search for an ideal movement in an engineering project. Considering the technical specs, the mandatory performance or space limitations of our design, you should consider to make use of one or the additional. In this article we will delve on the planetary gear motors or epicyclical gear, so you will know thoroughly what its advantages are and find out some successful applications.
The planetary gear units are characterized by having gears whose disposition is quite different from other models such as the uncrowned end, cyclical (step by step) or spur and helical gears. How could we classify their elements?
Sun: The central gear. 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 the sun gear.
Crown or band: an outer band (with teeth on its inner side) meshes with the satellites and contains the whole epicyclical train. In addition, the core can also become a middle of rotation for the outer ring, allowing it to easily change directions.
For accuracy and reliability, many automated transmissions currently use planetary equipment motors. If we discuss sectors this reducer provides great versatility and can be utilized in very different applications. Its cylindrical form is very easily adaptable to thousands of spaces, ensuring a big reduction in a very contained space.
Regularly this type of drives can be used in applications that require higher levels of precision. For instance: Industrial automation machines, vending devices or robotics.
What are the primary benefits of planetary gear motors?
Increased repeatability: Its better speed radial and axial load offers reliability and robustness, minimizing the misalignment of the gear. In addition, uniform transmission and low vibrations at different loads give a perfect repeatability.
Ideal precision: Most rotating angular stability increases the accuracy and reliability of the movement.
Lower noise level because there is more surface area contact. Rolling is a lot softer and jumps are practically nonexistent.
Greater durability: Because of its torsional rigidity and better rolling. To improve this feature, your bearings help reduce the losses that could happen by rubbing the shaft on the package directly. Thus, greater effectiveness of the gear and a much smoother procedure is achieved.
Very good levels of efficiency: Planetary reducers offer greater efficiency and thanks to its design and internal layout losses are minimized throughout their work. In fact, today, this type of drive mechanisms are those that offer greater efficiency.
Increased torque transmission: With an increase of teeth in contact, the mechanism has the capacity to transmit and withstand more torque. Furthermore, it can it in a far more uniform manner.
Maximum versatility: Its 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 concise package; sharing the load between several planet gears allows the reducer to take care of the same torque that bigger parallel axis gear sets handle.
They are highly efficient with an individual stage typically 95% efficient.
These reducers provide for ratios as high as 11:1 to be achieved in a single stage, whereas, it is tough to achieve higher than 5:1 in one parallel axis stage.
Since the sun gear contacts multiple world gears, level of resistance to elastic deformation, is higher in a planetary gear set than parallel axis gear set, giving the planetary reducer high torsional stiffness.
They allow for coaxial alignment, meaning no offset result shaft in relation to the motor shaft.
The output shaft on Planetary reducers rotates in the same direction as the motor without needing an idler gear, because in a parallel axis gear set.
Planetary reducers are ideal for intermittent duty applications but also can be used in continuous duty applications.
Finally, Ever-Power planetary’s have a built-in housing, meaning the ring gear is integrated into the external housing for the gearbox, increasing the robusticity.
Compared to the advantages of the planetary reducers, the disadvantages are minimal for most applications for instance:
High ratio of length to diameter when working with multiple stages (gearhead will get very long).
Possibly high cost if low backlash, high precision gearing is necessary.
Specific amounts 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 making 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 operation and long life. We recommend using our reddish colored tacky grease, am-2768. We also encourage that an individual powers the gearbox continually for 30 minutes without grease to allow the apparatus teeth to use in. While we perform design with short run situations in mind, this ‘run in’ period for smooth gearbox operation, is recommended. Once that is completed, thorough grease of the apparatus teeth periodically to make sure smooth operation.
Solitary speed planetary gearbox, with the same mounting and output interface as a 2.5″ CIM motor. Each planet equipment has its bearing to spin freely on the carrier plate pins. A 2.5″ CIM Motor could also be used as the motor input, but requires this pinion gear ( am-0556) and a CIM Spacer (am-0555).
Motor Input:
9015 motor fits on this gearbox
550 motor fits upon this gearbox
2.5″ CIM Motor can be mounted, with a bored-out sun gear 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 level p.a.
Five – Planet gears (12 tooth)
One – 15 tooth sunlight gear, with 0.125 inch bore
One – 40 tooth ring gear
Performance Data:
(with the input being truly a 9015 motor)
Input voltage: 12 volts
Stall Torque: 1.12 ft-lb.
Free speed: approximately 4,000 rpm
Assembly Tip:
Install the aluminium plate to the face of the motor BEFORE pressing the pinion equipment onto the motor shaft.
Specifications
Material: body is usually aluminum, shaft is 4140 steel
Mounting Holes: #10-32 tapped holes (2), upon 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 as it is also known), consists normally of a centrally pivoted sun gear, a ring equipment and several world gears which rotate between these.
This assembly concept explains the word planetary transmission, as the planet gears rotate around sunlight 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 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 sunlight gears. The first gear stage of the stepped planet gears engages with sun gear #1. The next gear step engages with sun gear #2. With sun gear one or two 2 coupled to the axle,or the coupling of sun equipment 1 with the band gear, three ratio variations are achievable with each gear assembly.
The decision between helical and spur gears in gearboxes may seem straightforward. Proceed with helical gears if you want the gearbox to perform as easily and quietly as possible. Choose spur gears if you want to maximize the gearbox’s torque density or working existence under higher loads.
These rules of thumb are mostly what you need to know when specifying traditional fixed-axis gearboxes. Just size the gearbox correctly, and the choice between helical and spur gears may also be obvious for confirmed set of software requirements. With planetary gearboxes, however, the choice between helical and spur gears requires some additional thought.
Helical Gears Create Axial Forces
As you may expect from their different mesh geometries, spur and helical gears have very different loading features. With their zero helix position, spur gears absence an axial load component. And they suffer from hardly any sliding tooth contact.
Helical gears, in comparison, generate significant axial forces in the apparatus mesh. They also exhibit more sliding at the point of tooth contact, adding friction forces into the mix.
Helix angles in gearboxes usually fall in a range of 15 to 30 degrees. As the position increases, both the axial forces and sliding contact increase.
The primary reason for using helical gears is the increased number of teeth in contact at any given time, which 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 gear mesh stiffness.
Helical Gears Place Better Demand on Bearings
Since they won’t need to withstand any axial forces, spur gear bearings play just a supporting role in the functioning of the gearbox. The bearings simply need to support the rotating gear shafts, but they do not play an active part in torque transfer.
The presence of axial forces makes things very 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 excess axial forces total little more than a hassle. Gearbox designers will most likely upsize the bearings to accommodate the additional forces.
Or, in acute cases, they may select angular get in touch with or tapered roller bearings, both of which are made to withstand axial loads.
Space limitations within planetary gearboxes mean that the planet gear bearings must be chosen more for his or her size than their tolerance for high axial loads.
In planetary gearboxes, however, it’s a lot more difficult to design around these axial forces for just two related reasons. Initial, there is typically hardly any area in a planetary gearbox to incorporate the kind 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 input from sunlight gear amongst the earth gears, which transfer torque to a world carrier connected to the gearbox output. The bearings that support the planets on the carrier need to bear the entire brunt of that torque transfer.
And Here Is the Difficulty
The limited space within planetary gearboxes means that the bearings used for the earth gears must be chosen more for their size than their tolerance for high axial loads. In general, small needle roller bearings are the most common choice in these settings.
Needle roller bearings do a good job 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. Therefore the world sees significant tilting second defined by the axial power times equipment pitch diameter. This tilting instant produces an uneven load distribution along the needle rollers, significantly decreasing the bearings’ load holding capability and lifecycle.
Loads on the roller bearings will vary, depending on their position around the shaft. Second is approximately the Z-axis, and models are in ins and pounds.
The Planetary Motion Is The Theory For The Planetary Gearbox.
The Accurately Positioned And Meshed Planet Gears (3) With The Sun Gear AT THE HEART And THE INNER Teeth Of The Outer Band Gear Compose Each Stage Of A Planetary Gearbox.
The Sun Gear Gets The Input AS THE 3 Planet Gears SUPPLY THE Ouput Via A Planet Carrier .
The Torque Handling Capability Is Very High Because Of Its Flexibility , And A Very High Weight /Volume Ratio , Thus It Lends Its Application In Various Industries – Specifically In High Torque Requirements Making It The Most Economical Option.
Being A Proud Supplier Of Planetary Gearbox, We Provide An Excellent Distinguished Service To Our Clientile.
Planetary Gearbox Product Specifications :
Provides High Torque In Slow Speeds.
Our Range Of Gearboxes And Geared Motors Are Manufactured ACCORDING TO The American Gear Producers Association (AGMA) Standards.
The Shafts Are Made Up Of Hardened And Tempered Special Alloy Steel.
Sun And Planet Gears ARE MADE FROM Case Carburised And Surface Alloy Steel.
Ring Gears ARE MADE Of Forged Alloy Metal.
Best Load Sharing DUE TO Accurate Positioning Of Planets.
Low Noise Levels.
No Oil Leakage.
TOP QUALITY Taper Roller Bearings For Input And Output Shafts.
Very High Efficiency