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 world gears are externally mesh and ring gear internally meshes.
Planetary gear is situated in many variation and arrangements to meet up a broad selection of speed-ratio in the deign requirements. Planetary gear system is make use of in varies applications such as, clocks, lunar calendar, car mirror, toys, gearhead motor, turbine engine and much more.
For detail understanding on the planetary
Planetary gear program will no assemble unless the number of teeth in each equipment is selected properly.
Planetary spur gear drive ratio 5:1 means sunlight 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 employed in the metric unit every dimension will be in 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 the sun gear is 24.
Calculate the number 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 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 your projects
There are many types of geared motors that can be utilized in search for the perfect movement within an engineering project. Considering the technical specifications, the required performance or space restrictions of our design, you should ask yourself to use one or the additional. In this article we will delve on the planetary gear motors or epicyclical gear, so you will know completely what its advantages are and find out some successful applications.
The planetary gear systems are seen as a 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 larger size and rotates on the central axis.
The planet carrier: Its objective is to hold up to 3 gears of the same size, which mesh with the sun gear.
Crown or ring: an outer band (with teeth upon its inner aspect) meshes with the satellites possesses the complete epicyclical train. In addition, the core can also become a center of rotation for the external ring, and can easily change directions.
For accuracy and reliability, many automated transmissions currently use planetary gear 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 an infinite number of spaces, ensuring a huge reduction in an extremely contained space.
Regularly this kind of drives can be utilized in applications that want higher levels of precision. For example: Industrial automation machines, 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 apparatus. In addition, uniform tranny and low vibrations at different loads provide a perfect repeatability.
Ideal precision: Most rotating angular stability enhances the accuracy and reliability of the movement.
Lower noise level since 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 lessen 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 because of its design and internal layout losses are minimized during their work. Actually, today, this type of drive mechanisms are those that offer greater efficiency.
Improved torque transmission: With an increase of teeth connected, the mechanism will be able to transmit and endure more torque. Furthermore, it does 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 instance:
Planetary reducers give you high torque in a compact package; sharing the load between several world gears allows the reducer to handle the same torque that bigger parallel axis gear units 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 challenging to achieve higher than 5:1 within a parallel axis stage.
Because 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 enable coaxial alignment, meaning no offset result shaft in relation to the motor shaft.
The output shaft on Planetary reducers rotates in the same direction because the electric motor without needing an idler equipment, since in a parallel axis equipment set.
Planetary reducers are ideal for intermittent duty applications but also can be utilized in continuous duty applications.
Finally, Ever-Power planetary’s have a built-in housing, meaning the ring gear is built-into the outer housing for the gearbox, increasing the robusticity.
Compared to the benefits 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).
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 apparatus ratio determines just how many planet gears can be utilized.
You should look at planetary reducers when designing for applications requiring high torques in a little package with an result shaft must be co-axially aligned with the motor.
Product Overview
Product Usage:
All Ever-Power gearboxes require grease for proper operation and extended life. We recommend using our reddish tacky grease, am-2768. We also encourage that the user powers the gearbox constantly for thirty minutes without grease to allow the gear teeth to wear in. While we do style with short run moments in mind, this ‘run in’ period for smooth gearbox operation, is recommended. Once that is completed, thorough grease of the gear teeth periodically to make sure smooth operation.
Solitary speed planetary gearbox, with the same installation and output interface as a 2.5″ CIM motor. Each planet gear 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 upon 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 band 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 face 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 world gears which rotate between these.
This assembly concept explains the term planetary transmission, as the earth gears rotate around the sun gear as in the astronomical sense the planets rotate around our sun.
The benefit of a planetary transmission depends upon load distribution over multiple planet gears. It is thereby feasible to transfer high torques utilizing a compact design.
Gear assembly 1 and gear assembly 2 of the Ever-Power 500/14 have two selectable sun gears. The first equipment step of the stepped planet gears engages with sunlight gear #1. The second equipment step engages with sun gear #2. With sun gear 1 or 2 2 coupled to the axle,or the coupling of sun equipment 1 with the ring gear, three ratio variations are achievable with each equipment assembly.
The decision between helical and spur gears in gearboxes may seem straightforward. Proceed with helical gears if you would like the gearbox to perform as easily and quietly as possible. Choose spur gears when you need to maximize the gearbox’s torque density or working life under higher loads.
These rules of thumb are mostly what you need to know when specifying traditional fixed-axis gearboxes. Simply size the gearbox properly, and the choice between helical and spur gears will often 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 completely different loading features. With their zero helix angle, spur gears lack an axial load element. And they suffer from very little sliding tooth contact.
Helical gears, by contrast, 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 variety of 15 to 30 degrees. As the position increases, both axial forces and sliding get in touch with increase.
The primary reason for using helical gears is the increased number of teeth connected at any given time, which really is a fundamental requirement for smooth torque transmission. With their
increased contact ratio compared to spur gears, helical gears have 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 function in the functioning of the gearbox. The bearings should just support the rotating equipment shafts, but they do not play an active part in torque transfer.
The existence 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 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 contact or tapered roller bearings, both of which are made to withstand axial loads.
Space restrictions within planetary gearboxes imply that the earth gear bearings should be chosen more for their size than their tolerance for high axial loads.
In planetary gearboxes, however, it’s much more difficult to design around these axial forces for just two related reasons. 1st, there is typically very little space in a planetary gearbox to include the type of bulky bearings that can tolerate high axial forces.
Second, the earth gear bearings need to play an active role in torque transfer. Planetary systems split the torque insight from sunlight gear amongst the planet gears, which transfer torque to a world carrier connected to the gearbox result. The bearings that support the planets on the carrier need to bear the entire brunt of this 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. Generally, compact needle roller bearings are the most typical choice in these settings.
Needle roller bearings do a good work with radial loads that are evenly distributed along the space of the needle. However 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 planet sees significant tilting second defined by the axial force times gear pitch diameter. This tilting instant creates an uneven load distribution along the needle rollers, significantly lowering the bearings’ load carrying capability and lifecycle.
Loads on the roller bearings will vary, depending on their placement around the shaft. Instant 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 Equipment Gets The Input AS THE 3 Planet Gears SUPPLY THE Ouput WITH 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 Software IN A VARIETY OF Industries – Specifically In High Torque Requirements RENDERING IT The Most Economical Alternative.
Being A Proud Provider Of Planetary Gearbox, We Provide A FANTASTIC 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 Producers Association (AGMA) Standards.
The Shafts ARE MADE 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 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