# What is called many gear in epicyclic gearbox?

## What is called many gear in epicyclic gearbox?

An epicyclic gear train (also known as a planetary gearset) consists of two gears mounted so that the center of one gear revolves around the center of the other. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train.

### How do you calculate planetary gear?

To make calculating planetary gear ratios as simple as possible, note the number of teeth on the sun and ring gears. Next, add the two numbers together: The sum of the two gears’ teeth equals the number of teeth on the planetary gears connected to the carrier.

**How do you know how many teeth ring gear?**

This ensures that the teeth mesh. That is to say, the number of teeth in the ring gear is equal to the number of teeth in the middle sun gear plus twice the number of teeth in the planet gears….Working out planetary gear turns ratios.

Tr | Turns of the ring gear |
---|---|

R | Ring gear teeth |

S | Sun gear teeth |

P | Planet gear teeth |

**What does epicyclic gear do?**

A planetary or epicyclic gear train is one type of gear train used to transmit motion. Epicyclic gear trains consist of two or more gears mounted so that the center of one gear revolves around the center of the other.

## How many gear ratios are in a planetary gear set?

Single-stage planetary gearhead ratios range from 3:1 to 10:1. Gear ratios cannot exceed 10:1 because pinion gears can be made only so small. Gear ratios greater than 10:1 are possible with an additional planetary stage, although this normally increases length and cost.

### What is holding torque in an epicyclic gear train *?

1. Input torque = (60*voltage*current)/ (2*22/7*input speed) 2. Output torque = (60*voltage*current)/ (2*22/7*output speed) 3. Holding torque = Output torque – Input torque.

**What is the difference between simple compound and epicyclic gear train?**

1. In simple gear only one gear in every shaft and there is a relative motion among shaft axis. In compound gear there is extra than one gear on shaft which is firmly fix and mash through the gear on another shaft forming gear train. In a compound gear train, every gear has its own shaft for rotation.

**What is an epicylic gear?**

An epicylic gear is a planetary gear arrangement consisting of one or more planet (epicyclic) gears (P) meshed and rotating round a central sun gear (S). The planet gears are also meshed and rotate within an internal ring gear (A). The planet gears are fixed to a planet carrier-crank arm (L) designed to rotate on the same centre as the sun gear.

## How many planet-carriers are used in an epicyclic gear train?

Only one planet-carrier /crank arm is used in a single epicyclic gear train. This complicated arrangement (see below) has a number of modes of operation depending on which members are locked.

### What is the overall gear ratio of the gear train?

With the rotation of each element of the gear train in hand, the overall gear ratio becomes easy. If the arm is the input and the planet is the output, the overall gear ratio is 3/1 = 3. For a more involved epicyclic gear train example, please refer to the Epicyclic Gear Train Example section.

**What is the formula for planet gear rotation?**

Rotation planet gear = Rotation arm + Rotation planet gear relative to arm. In the following illustration and analysis, the sun gear has twice the diameter of the planet gear.