planetary gears also refer as epicyclic gearing consisting 3 components sun gear, planet gear and ring gear. Sun gear is situated at the center 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 band gear internally meshes.
Planetary gear is situated 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, clocks, lunar calendar, car mirror, toys, gearhead motor, turbine engine and more.
For detail understanding on the planetary
Planetary gear system will no assemble unless the amount of teeth in each equipment is selected properly.
Planetary spur gear drive ratio 5:1 means the sun equipment 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 device every dimension will maintain mm. Choosing 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 band gear
Pd= Pitch Diameter
R = Ratio
PDs=N/M=24/1=24mm Eq. 01
Pitch diameter of sunlight gear is 24.
Calculate the number if teeth required 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 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 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 gear motors in your projects
There are numerous 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 limitations of our style, you should consider to make use of one or the other. In this post we will delve on the planetary equipment motors or epicyclical equipment, which means you will know completely what its advantages are and find out some successful applications.
The planetary gear models are characterized by having gears whose disposition is quite not the same as 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 bigger 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 upon its inner side) meshes with the satellites possesses the whole epicyclical train. Furthermore, the core can also become a center 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 talk about sectors this reducer offers great versatility and can be used in completely different applications. Its cylindrical form is easily adaptable to an infinite number of areas, ensuring a sizable reduction in a very contained space.
Regularly this type of drives can be used in applications that want higher degrees of precision. For instance: Industrial automation devices, 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 transmitting and low vibrations at different loads give a perfect repeatability.
Ideal precision: Most rotating angular stability increases the accuracy and reliability of the motion.
Lower noise level since 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 boost this feature, your bearings lessen the losses that would take place by rubbing the shaft on the container directly. Thus, greater performance of the gear and a much smoother procedure is achieved.
Very good degrees of efficiency: Planetary reducers provide greater efficiency and because of its design and internal layout losses are minimized during their work. In fact, today, this kind of drive mechanisms are those that offer greater efficiency.
Increased torque transmission: With more teeth connected, 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 contained in a cylindrical gearbox, which can be installed in almost any space.
The construction of the planetary reducer lends itself to many advantages, for example:
Planetary reducers give you high torque in a concise package; sharing the strain between several world gears allows the reducer to handle the same torque that larger parallel axis gear models handle.
They are highly efficient with a single stage typically 95% efficient.
These reducers give ratios as high as 11:1 to be achieved in one stage, whereas, it is hard to achieve 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 allow for coaxial alignment, meaning no offset output shaft in relation to the motor shaft.
The output shaft upon Planetary reducers rotates in the same direction since the electric motor without needing an idler gear, since 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 possess a housing, meaning the ring gear is integrated into the external housing for the gearbox, adding to the robusticity.
Compared to the advantages of the planetary reducers, the disadvantages are minimal for most applications for example:
High ratio of length to diameter when using multiple stages (gearhead can get very long).
Possibly high cost if low backlash, high precision gearing is required.
Specific numbers 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 engine.
Product Overview
Product Usage:
All Ever-Power gearboxes require grease for proper operation and long life. We suggest using our reddish tacky grease, am-2768. We also encourage that an individual powers the gearbox continuously for thirty minutes without grease to permit the apparatus teeth to use in. While we perform design with short run moments at heart, this ‘run in’ period for smooth gearbox procedure, is recommended. Once this is completed, comprehensive grease of the apparatus teeth periodically to make sure smooth operation.
Single 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 requires this pinion gear ( 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 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 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 aluminum plate to the facial skin of the motor BEFORE pressing the pinion equipment onto the engine shaft.
Specifications
Material: body is usually 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 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 word planetary transmission, as the earth 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 utilizing 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 world gears engages with sunlight gear #1. The second gear step engages with sunlight gear #2. With sunlight gear one or two 2 coupled to the axle,or the coupling of sunlight gear 1 with the band gear, three ratio variants are achievable with each equipment 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 when you need to maximize the gearbox’s torque density or functioning existence under higher loads.
These guidelines are mainly what you ought to know when specifying traditional fixed-axis gearboxes. Simply size the gearbox properly, and the choice 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 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 component. Plus they suffer from hardly any 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 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 position increases, both the axial forces and sliding contact increase.
The primary reason for using helical gears may be the increased number of teeth in contact at any moment, which is a fundamental requirement of 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 Higher Demand on Bearings
Since they won’t need to withstand any axial forces, spur gear bearings perform just a supporting role in the functioning of the gearbox. The bearings should just support the rotating gear shafts, however they do not play an active role in torque transfer.
The presence of axial forces makes things very different for the bearings that support helical gears. But it is critical to make a distinction between fixed-axis and planetary gearboxes. In fixed-axis gearboxes, the excess axial forces amount to little more than an inconvenience. Gearbox designers will often upsize the bearings to support the additional forces.
Or, in acute cases, they may select angular contact or tapered roller bearings, both which are created to withstand axial loads.
Space limitations within planetary gearboxes mean that the planet gear bearings should be chosen more because of 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 just two related reasons. 1st, there is typically hardly any area in a planetary gearbox to incorporate the type of bulky bearings that may tolerate high axial forces.
Second, the earth gear bearings have to play an active function in torque transfer. Planetary systems split the torque insight from the sun gear amongst the earth gears, which in turn transfer torque to a planet carrier linked to the gearbox result. The bearings that support the planets on the carrier have to bear the entire brunt of this torque transfer.
And This is actually the Difficulty
The limited space within planetary gearboxes means that the bearings used for the earth gears should be chosen more for his or her size than their tolerance for high axial loads. Generally, compact needle roller bearings are the most common choice in these configurations.
Needle roller bearings do a good job with radial loads that are evenly distributed along the length of the needle. However 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 force times gear pitch diameter. This tilting moment creates an uneven load distribution along the needle rollers, drastically decreasing the bearings’ load holding capability and lifecycle.
Loads on the roller bearings will change, depending on their placement around the shaft. Instant is about the Z-axis, and devices are in inches and pounds.
The Planetary Motion MAY BE THE Principle For The Planetary Gearbox.
The Accurately Positioned And Meshed World 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 While The 3 Planet Gears Provide The Ouput Via A Planet Carrier .
The Torque Handling Capacity Is Very High Because Of Its Flexibility , And AN EXTREMELY High Weight /Volume Ratio , Thus It Lends Its App IN A VARIETY OF Industries – Specifically In High Torque Requirements Making It The Most Economical Alternative.
Being A Proud Provider Of Planetary Gearbox, We Provide An Excellent Distinguished Service To Our Clientile.
Planetary Gearbox Product Specs :
Provides High Torque At Slow Speeds.
Our Range 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 Planet Gears Are Made Of Case Carburised And Ground Alloy Steel.
Ring Gears Are Made Up Of Forged Alloy Metal.
Best Load Sharing Because Of Accurate Positioning Of Planets.
Low Noise Levels.
No Oil Leakage.
Good Quality Taper Roller Bearings For Insight And Output Shafts.
Very High Efficiency