planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet gear and ring gear. Sun gear is situated at the center that transmits torque to world gears orbiting around the sun gear. Both systems can be found inside the ring equipment. In the toothed development sun and world gears are externally mesh and band 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 gear system is make use of in varies applications such as for example, clocks, lunar calendar, car mirror, toys, gearhead electric motor, turbine engine and many more.
For detail understanding on the planetary
Planetary gear system will simply no assemble unless the amount of teeth in each gear is selected properly.
Planetary spur gear drive ratio 5:1 means the sun gear must make 5 revolutions for every revolution of the result carrier.
Desired number of teeth in sunlight 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 unit the apparatus tooth profile of the spur equipment will maintain 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 sunlight 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 band gear with 96 tooth 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 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.
Advantages of using planetary gear motors in work
There are numerous types of geared motors that can be used in search for the perfect movement in an engineering project. Considering the technical specs, the required performance or space restrictions of our style, you should ask yourself to make use of one or the other. In this post we will delve on the planetary equipment motors or epicyclical gear, so you will know thoroughly what its advantages are and find out some successful applications.
The planetary gear models are characterized by having gears whose disposition is quite different from 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 bigger size and rotates on the central axis.
The earth carrier: Its objective is to hold up to 3 gears of the same size, which mesh with sunlight gear.
Crown or band: an outer band (with teeth upon its inner aspect) 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, and can easily change directions.
For accuracy and reliability, many automatic transmissions currently use planetary gear motors. If we talk about sectors this reducer offers great versatility and can be used in very 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 degrees of precision. For example: Industrial automation devices, vending devices or robotics.
What are the main advantages of planetary gear motors?
Increased repeatability: Its higher 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 improves the accuracy and reliability of the movement.
Lower noise level because there is more surface area contact. Rolling is much 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 would occur by rubbing the shaft on the box directly. Thus, greater effectiveness of the gear 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. In fact, today, this kind of drive mechanisms are those that provide greater efficiency.
Improved torque transmission: With an increase of teeth in contact, the mechanism will be able to transmit and endure more torque. Furthermore, it can it in a 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 give 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 models handle.
They are highly efficient with a single stage typically 95% efficient.
These reducers provide for ratios as high as 11:1 to be achieved in a single stage, whereas, it is hard to achieve higher than 5:1 in one parallel axis stage.
Because 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 allow for coaxial alignment, meaning no offset output shaft with regards to the motor shaft.
The output shaft upon Planetary reducers rotates in the same direction because the electric motor without needing an idler equipment, because in a parallel axis equipment set.
Planetary reducers are well suited for intermittent duty applications but also can be used in constant duty applications.
Finally, Ever-Power planetary’s have an integrated housing, meaning the ring gear is built-into the external housing for the gearbox, adding to the robusticity.
Compared to the benefits of the planetary reducers, the disadvantages 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 necessary.
Specific amounts of gear teeth are necessary equally spaced planets (simple assembly) and noise mitigation.
The gear ratio determines just how many planet gears can be utilized.
You should consider planetary reducers when making for applications requiring high torques in a small package with an result shaft must be co-axially aligned with the electric motor.
Product Overview
Product Usage:
All Ever-Power gearboxes require grease for proper procedure and long life. We recommend using our reddish colored tacky grease, am-2768. We also encourage that the user powers the gearbox consistently for thirty minutes without grease to allow the gear teeth to wear in. While we perform style with short run moments at heart, this ‘run in’ period for smooth gearbox procedure, is recommended. Once that is completed, comprehensive grease of the apparatus teeth periodically to ensure smooth operation.
Solitary speed planetary gearbox, with the same installation 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 needs this pinion gear ( 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 can 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 level p.a.
Five – Planet gears (12 tooth)
One – 15 tooth sunlight equipment, with 0.125 inch bore
One – 40 tooth ring gear
Performance Data:
(with the insight 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 facial skin of the motor BEFORE pressing the pinion gear onto the engine shaft.
Specifications
Material: body is 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 can be 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 word 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 is thereby feasible to transfer high torques employing a compact design.
Gear assembly 1 and equipment assembly 2 of the Ever-Power 500/14 have two selectable sun gears. The first gear stage of the stepped world gears engages with sun gear #1. The second gear step engages with sun gear #2. With sunlight gear one or two 2 coupled to the axle,or the coupling of sunlight gear 1 with the ring gear, three ratio variations are achievable with each gear assembly.
The choice between helical and spur gears in gearboxes may appear straightforward. Move with helical gears if you would like 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 lifestyle under higher loads.
These rules of thumb are mainly what you should know when specifying traditional fixed-axis gearboxes. Just size the gearbox properly, and the decision 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 additional thought.
Helical Gears Create Axial Forces
As you might expect from their different mesh geometries, spur and helical gears have very different loading features. With their zero helix position, spur gears lack an axial load element. Plus 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 idea 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 connected at any moment, which really is a fundamental requirement of smooth torque transmission. With their
increased contact ratio in comparison to spur gears, helical gears have a lower fluctuation
of the apparatus mesh stiffness.
Helical Gears Place Higher Demand on Bearings
Since they won’t need to withstand any axial forces, spur gear bearings enjoy just a supporting function in the functioning of the gearbox. The bearings simply need to support the rotating equipment shafts, but they do not really play an active function in torque transfer.
The existence of axial forces makes things completely different for the bearings that support helical gears. But it’s important to make a distinction between fixed-axis and planetary gearboxes. In fixed-axis gearboxes, the additional axial forces amount to little more than an inconvenience. Gearbox designers will often 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 which are created to withstand axial loads.
Space limitations within planetary gearboxes mean that the planet gear bearings must be chosen more because of 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. First, there is typically very little space in a planetary gearbox to incorporate the kind of bulky bearings that may tolerate high axial forces.
Second, the earth gear bearings need to play an active part in torque transfer. Planetary systems split the torque input from sunlight gear amongst the planet gears, which transfer torque to a world carrier connected to the gearbox output. The bearings that support the planets on the carrier have to bear the full brunt of that torque transfer.
And This is actually the Difficulty
The limited space within planetary gearboxes means that the bearings used for the planet gears must be chosen more for his or her size than their tolerance for high axial loads. Generally, small needle roller bearings are the most common choice in these configurations.
Needle roller bearings execute a good work with radial loads that are evenly distributed along the distance of the needle. But they don’t manage 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-band gear mesh. Therefore the world sees significant tilting instant defined by the axial power times equipment pitch diameter. This tilting instant produces an uneven load distribution along the needle rollers, significantly lowering the bearings’ load having capability and lifecycle.
Loads on the roller bearings will vary, depending on their placement around the shaft. Second is approximately the Z-axis, and products are in inches and pounds.
The Planetary Motion Is The Theory For The Planetary Gearbox.
The Accurately Positioned And Meshed Planet Gears (3) With The Sun Gear In The Centre And THE INNER Teeth Of The Outer Band Gear Compose Each Stage Of A Planetary Gearbox.
The Sun Equipment Gets The Input AS THE 3 Planet Gears Provide The Ouput Via A Planet Carrier .
The Torque Handling Capacity Is Very High DUE TO THE Flexibility , And AN EXTREMELY High Weight /Volume Ratio , Thus It Lends Its Program IN A VARIETY OF Industries – Specifically In High Torque Requirements RENDERING IT The Most Economical Option.
Being A Proud Provider Of Planetary Gearbox, WE OFFER An Excellent Distinguished Service TO YOUR Clientile.
Planetary Gearbox Product Specifications :
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 Of Hardened And Tempered Special Alloy Steel.
Sun And World Gears Are Made Of Case Carburised And Floor 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.
TOP QUALITY Taper Roller Bearings For Insight And Output Shafts.
Very High Efficiency