Epicyclic gear train

What is epicyclic gear? An epicyclic gear train (also known as planetary gear ) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates to carry one gear , called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. It is used as a transmission system to get various speed ratios in forward as well as in reverse directions.

Introduction of Transmission Systems: As you know that they are two types of Transmission systems.

The epicyclic gear trains are useful for transmitting high velocity ratios with gears of moderate size in a comparatively lesser space. View chapter Purchase book. With the rotation of each element of the gear train in han the overall gear ratio becomes easy. Epicyclic gear train is a special type of gear train which is used to transmit motion and power from one shaft to another shaft. In simple, compound and reverted gear train , gear shaft axis is fixed or not movable but in epicyclic gear trains , the shaft axes are not fixed means the shaft axis is movable.

Simple Train - three or more wheels connected in series. Compound Train - an intermediate shaft carries two wheels connected in series.

The Structure of an Epicyclic gear - The Sun wheel, the planet wheels, the Annulus and the Spider. Analysing epicyclic gear trains Three methods: Tabular Method. It is a gear system that consists of one or more outer gear (planet gear ) rotating about a central (sun gear ). Reverted gear trains are a type of compound gear trains in which input and output shafts are on the same axis.

In above example, gear -and gear -are on the same axis. In an epicyclic gear train , the axes of the shafts, over which the gears are mounte move relative to a fixed axis. They are used to achieve high gear ratio within limited space. A simple epicyclic gear train is shown in Fig. This apparatus consists of two standard epicyclic gear trains.

Each gear train consists of a sun gear in the centre, three planet gears , a planet linkage and an internal or ring gear. The sun gear , ring gear and planet carrier all rotate about the same axis. A planetary or epicyclic gear train is one type of gear train used to transmit motion. The planet gears are mounted on shafts that turn in planet carrier and meshes with both.

A 3D view of the epicyclic gear train arrangement Unlike the previous section, however, we begin by giving the ARM one positive turn (instead of the entire assembly one positive turn). The technique is to choose an arbitrary rotation in which gear movements are intuitively obvious. As such, this article aims to provide assistance and guidelines for people designing epicyclic gear trains for the first time—and perhaps, if you will, ease their degree of suffering.

Himanshu Vasishta,. Epicyclic gearing requires a step-by-step process to make it work, and some of the steps are not necessarily intuitive. A spur gear differential is constructed from two identical coaxial epicyclic gear trains assembled with a single carrier such that their planet gears are engaged. This forms a planetary gear train with a fixed carrier train ratio R = -1.

In contrary, human-designed gearing systems are versatile, ranging from simple, compoun reverte to epicyclic gear trains (33). In this regar manmade machinery provides us a rich yet more. Related Resources: gears.

Where: D = Rotation of driver per revolution of follower or the driven gear or Pulley. Gear Design and Engineering. Product number: HTM13.

Epicyclic gear sets are used because they are smaller than offset gear sets since the load is shared among the planed gears. This makes them lighter and more compact, versus countershaft gearboxes. Also, when configured properly, epicyclic gear sets are more efficient. In an epicyclic or planetary gear train , several spur gears distributed evenly around the circumference run between a gear with internal teeth and a gear with external teeth on a concentric orbit.

The circulation of the spur gear takes place in analogy to the orbiting of the planets in the solar system. Most of the automatic transmissions use this kind of gear train. Epicyclic Gearbox, which can supply a lot of speed reduction and torque in a small compact package, have operating characteristics beyond those of fixed-axis gear trains. Epicyclic Gearing Epicyclic or planetary gearing is a gear system that consists of one or more outer gears , or planet gears , rotating about a central, or sun gear. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear.

One of the planetary gearsets from our transmission has a ring gear with teeth and a sun gear with teeth. Epicyclic gearbox is an automatic type gearbox in which parallel shafts and gears arrangement from manual gear box are replaced with more compact and more reliable sun and planetary type of gears arrangement and also the manual clutch from manual power train is replaced with hydro coupled clutch or torque convertor which in turn made the transmission automatic. We can get lots of different gear ratios out of this gearset. The gear B meshes with gear A and has its axis on the arm O about which the gear B can. In the first three types of gear trains , the axes of the shafts over which the gears are mounted are fixed relative to each other.

But in case of epicyclic gear trains , the axes of the shafts on which the gears are mounted may move relative to a fixed axis. Epicyclic Train Example: We use the method introduced in Epicyclic Ratio Calculation for determining the final gear ratio of an epicyclic gear train. This method is extremely methodical, which is appropriate since use of intuition is quite futile with an epicyclic gear train such as the following example.

The fundamental formula of the planetary gear train with a rotating carrier is obtained by recognizing that this formula remains true if the angular.