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planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet equipment and ring gear. Sun gear is situated at the center that transmits torque to world gears orbiting around the sun gear. Both systems are located inside the ring equipment. In the toothed development sun and world gears are externally mesh and ring gear internally meshes.
Planetary gear is found in many variation and arrangements to meet a broad range of speed-ratio in the deign requirements. Planetary equipment system is use in varies applications such as, clocks, lunar calendar, car mirror, toys, gearhead engine, turbine engine and many more.
For details understanding on the planetary
Planetary gear system will no assemble unless the number of teeth in each gear is selected properly.
Planetary spur gear drive ratio 5:1 means the sun equipment must make 5 revolutions for every 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 unit every dimension will be in mm. Selecting gears in metric device the gear tooth profile of the spur gear will maintain Module.
M = Module
N = Number of teeth
Nr = Amount of teeth on the ring 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 equipment 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 the 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 teeth in the planet gears may now be 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.
Advantages of using planetary gear motors in work
There are several types of geared motors that can be utilized in search for an ideal movement within an engineering project. Considering the technical specifications, the required performance or space restrictions of our style, you should consider to use one or the various other. In this post we will delve on the planetary equipment motors or epicyclical gear, and that means you will know completely what its advantages are and discover some successful applications.
The planetary gear systems are seen as a having gears whose disposition is very 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 ring: an outer ring (with teeth on its inner part) meshes with the satellites and contains the complete epicyclical train. In addition, the core may also become a middle of rotation for the external ring, allowing it to easily change directions.
For accuracy and reliability, many automated transmissions currently use planetary equipment motors. If we talk about sectors this reducer provides great versatility and can be utilized in completely different applications. Its cylindrical form is easily adaptable to thousands of areas, ensuring a sizable reduction in a very contained space.
Regularly this type of drives can be used in applications that require higher levels of precision. For example: Industrial automation devices, vending devices or robotics.
What are the main advantages of planetary gear motors?
Increased repeatability: Its better speed radial and axial load offers reliability and robustness, minimizing the misalignment of the apparatus. In addition, uniform transmission and low vibrations at different loads give a perfect repeatability.
Ideal precision: Most rotating angular stability improves the accuracy and reliability of the movement.
Lower noise level because there is more surface contact. Rolling is a lot softer and jumps are virtually nonexistent.
Greater durability: Due to its torsional rigidity and better rolling. To improve this feature, your bearings help reduce the losses that would take place by rubbing the shaft on the box directly. Thus, greater effectiveness of the apparatus and a much smoother operation is achieved.
Very good levels of efficiency: Planetary reducers provide greater efficiency and because of its design and internal layout losses are minimized throughout their work. Actually, today, this kind of drive mechanisms are those that provide greater efficiency.
Improved torque transmission: With more teeth connected, the mechanism is able to transmit and withstand more torque. In addition, it can it in a far more uniform manner.
Maximum versatility: The mechanism is within a cylindrical gearbox, which can be installed in almost any space.
The construction of the planetary reducer lends itself to many advantages, for instance:
Planetary reducers offer you high torque in a concise package; sharing the load between several world 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 give ratios as high as 11:1 to be performed in a single stage, whereas, it really is hard to achieve much higher than 5:1 within a parallel axis stage.
Since the sun gear contacts multiple world 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 with regards to the motor shaft.
The output shaft upon Planetary reducers rotates in the same direction since the motor without needing an idler equipment, because in a parallel axis equipment 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 housing, meaning the ring gear is built-into the outer housing for the gearbox, adding to the robusticity.
Compared to the advantages of the planetary reducers, the drawbacks are minimal for some applications for example:
High ratio of length to diameter when using multiple stages (gearhead will get very long).
Potentially high cost if low backlash, high precision gearing is required.
Specific numbers of gear teeth are required equally spaced planets (simple assembly) and noise mitigation.
The gear ratio determines how many planet gears may be used.
You should consider 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 electric motor.
Product Overview
Product Usage:
All Ever-Power gearboxes require grease for proper procedure and extended life. We suggest using our red tacky grease, am-2768. We also motivate that the user powers the gearbox continually for thirty minutes without grease to allow the apparatus teeth to use in. While we do style with short run times 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.
Single 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 may also be used as the motor input, but requires this pinion equipment ( am-0556) and a CIM Spacer (am-0555).
Motor Input:
9015 motor fits upon this gearbox
550 motor fits on this gearbox
2.5″ CIM Motor could be mounted, 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 input being 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 facial skin of the motor BEFORE pressing the pinion gear onto the engine shaft.
Specifications
Material: body is definitely aluminum, shaft is 4140 steel
Mounting Holes: #10-32 tapped holes (2), on a 2″ bolt circle to add at output shaft
Outside 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 program (or Epicyclic system as it is also known), consists normally of a centrally pivoted sunlight gear, a ring equipment and several world 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 utilizing a compact design.
Gear assembly 1 and gear assembly 2 of the Ever-Power 500/14 have two selectable sunlight gears. The first gear step of the stepped planet gears engages with sun gear #1. The second gear step engages with sunlight gear #2. With sunlight gear 1 or 2 2 coupled to the axle,or the coupling of sun gear 1 with the ring gear, three ratio variations are achievable with each gear assembly.
The decision between helical and spur gears in gearboxes may seem straightforward. Go with helical gears if you would like the gearbox to perform as efficiently and quietly as feasible. Choose spur gears if you want to maximize the gearbox’s torque density or functioning existence under higher loads.
These guidelines are mostly what you should know when specifying traditional fixed-axis gearboxes. Just size the gearbox properly, and the choice between helical and spur gears will often be obvious for a given set of app requirements. With planetary gearboxes, however, the choice between helical and spur gears requires some extra thought.
Helical Gears Create Axial Forces
As you may expect from their different mesh geometries, spur and helical gears have completely different loading features. With their zero helix angle, spur gears lack an axial load element. Plus they suffer from hardly any sliding tooth contact.
Helical gears, by contrast, generate significant axial forces in the apparatus mesh. In addition they exhibit more sliding at the idea of tooth contact, 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 is the increased number of teeth in contact at any moment, which is a fundamental requirement for smooth torque transmission. With their
increased contact ratio compared to spur gears, helical gears have got a lower fluctuation
of the gear mesh stiffness.
Helical Gears Place Greater Demand on Bearings
Since they don’t need to withstand any axial forces, spur gear bearings perform just a supporting part in the functioning of the gearbox. The bearings simply need to support the rotating equipment shafts, but they do not really play an active part in torque transfer.
The existence 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 amount to little more than a hassle. Gearbox designers will most likely upsize the bearings to support the additional forces.
Or, in acute cases, they may select angular get in touch with or tapered roller bearings, both which are created to withstand axial loads.
Space limitations within planetary gearboxes mean that the planet gear bearings must be chosen more for their size than their tolerance for high axial loads.
In planetary gearboxes, however, it’s much more difficult to create around these axial forces for just two related reasons. 1st, there is typically very little area in a planetary gearbox to include the kind of bulky bearings that may tolerate high axial forces.
Second, the earth gear bearings need to play an active role in torque transfer. Planetary systems split the torque input from the sun gear amongst the earth gears, which in turn transfer torque to a planet carrier connected to the gearbox output. The bearings that support the planets on the carrier have to bear the entire brunt of that torque transfer.
And This is actually the Difficulty
The limited space within planetary gearboxes implies that the bearings used for the planet gears must be chosen more because of their size than their tolerance for high axial loads. Generally, small needle roller bearings are the most typical choice in these configurations.
Needle roller bearings execute a good work with radial loads that are evenly distributed along the space of the needle. However they don’t handle 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 second described by the axial power times gear pitch diameter. This tilting instant creates 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 placement around the shaft. Second is approximately the Z-axis, and units are in ins and pounds.
The Planetary Motion MAY BE THE Theory For The Planetary Gearbox.
The Accurately Positioned And Meshed Planet Gears (3) With SUNLIGHT Gear In The Centre And The Internal Teeth Of The Outer Band Gear Compose Each Stage Of A Planetary Gearbox.
The Sun Gear Gets The Input AS 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 Program In Various Industries – Specifically In High Torque Requirements RENDERING IT The Most Economical Remedy.
Being A Proud Provider Of Planetary Gearbox, We Provide An Excellent Distinguished Service To Our Clientile.
Planetary Gearbox Product Specifications :
Provides High Torque In Slow Speeds.
Our SELECTION OF Gearboxes And Geared Motors Are Manufactured As Per The American Gear Manufacturers Association (AGMA) Standards.
The Shafts Are Made Up Of Hardened And Tempered Particular Alloy Steel.
Sun And World Gears Are Made Of Case Carburised And Ground Alloy Steel.
Ring Gears ARE MADE Of Forged Alloy Steel.
Best Load Sharing Because Of Accurate Positioning Of Planets.
Low Noise Levels.
No Oil Leakage.
Good Quality Taper Roller Bearings For Input And Output Shafts.
Very High Efficiency