With four core components, calculating the gear ratio of planetary gear systems, also known as epicyclic gear systems, may seem daunting. An epicyclic gear train consists of two gears mounted so that the centre of one gear revolves .. The fundamental formula of the planetary gear train with a rotating carrier is obtained by recognizing that this formula remains true if the angular. This tutorial shows the usage of MESYS shaft calculation with shaft systems. A two-stage For a planetary gear stage we need at least two shaft groups. With a.

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To make calculating planetary gear ratios as simple as possible, note the number of teeth on the sun and ring gears.

Epicyclic gearing

The fundamental equation becomes:. How to Calculate Gear Pitch. Disadvantages include high bearing loads, constant lubrication requirements, inaccessibility, and design complexity.

Copyright Leaf Group Ltd. The three basic components of the epicyclic gear are:. Hypocycloidal gearing Antikythera mechanism — ancient mechanical astronomical computer Continuously variable transmission CVT Cycloidal drive Epicycloid Ford Model T — had a calculatoons speed planetary transmission.

Just be sure to note the state of the carrier in the gear system. The axes of all gears are usually parallel, but for special cases like pencil sharpeners and differentials caculations, they can be placed at calcularions angle, introducing elements of bevel gear see below. The number of teeth in the planet gear is irrelevant. Epicyclic gearing or planetary gearing is a gear system consisting of one or more outer gears, or planet gears, revolving about a central, or sun gear.


Compound planetary gears can easily achieve larger transmission ratio with equal or smaller volume. At around BC, the Greeks invented the idea of epicycles, of circles travelling on the circular orbits. This method analyses the motion of one planet gear.

The equations which determine torque are: For example, if the sun gear has 20 teeth and the ring gear has 60, the planetary gear has 80 teeth. An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of a fixed, outer gear ring, or ring gear, sometimes called an annular gear.

The planet and epichclic gears mesh so that their pitch circles roll without slip. How to Calculate Gear Ratio. Typical Epicyclic Gear Arrangement. The Ring Gear is fixed. In this case, all the loading is concentrated on a few contacting surfaces, making the gears wear quickly and sometimes crack. If the carrier is acting as the output in the planetary gear system, being rotated by the sun gear while the ring gear stays still, divide the number of teeth on the planetary gears the driven gear by the number of teeth on the sun gear the driving gear.

They have never seen Seinfeld and are deathly scared of wasps. Therefore, several turns of the “sun” gear made the “planet” gears complete a single revolution, which in turn made the rotating ring gear rotate by a single tooth like a Calculationa drive.

Planetary gear ratio calculations

If the ratio of rotation of the follower member R A has a ratio of R relative to the driving member R B rotation i. The load in a planetary gear train is shared among multiple planets; therefore, torque calculationw is greatly increased. In other projects Wikimedia Commons. A point on the pitch circle of the planet gear traces an epicycloid curve. Epicyclic gearing systems also incorporate the use of an outer ring gear or annuluswhich meshes with the planet gears.


The follower is the annulus ring A The the sun gear Epicjclic is fixed.

Epicyclic Gears

When calculating planetary or epicyclic gear ratios, first note the number of teeth on the sun and ring gears.

This is the way some automatic transmissions work. The whole set of planetary gear system revolves on its own axis and along the external gear ring where the output shaft connected to the planetary carrier epicyxlic the goal of speed reduction. The sun S is fixed.

The gewr gear carrier is used as input. This rotation of the planet gears can in turn drive the ring gear not depicted in diagramin a corresponding ratio.

Arrangement as above The epiicyclic is the Sun S. Next, add the two numbers together: A convenient approach to determine the various speed ratios available in a planetary gear train begins by considering the speed ratio of the gear train when the carrier is held fixed.