## What is epicyclic gear box explain with figure?

Epicyclic gearing also called as planetary gearing. It is a gear system that consists of one or more outer gear (planet gear) rotating about a central (sun gear). The planet gear are mounted on a moveable arm (carrier) which itself may rotate relative to the sun gear.

### What are the main advantages of an epicyclic gearbox?

The advantages of planetary gearboxes: Coaxial arrangement of input shaft and output shaft. Load distribution to several planetary gears. High efficiency due to low rolling power. Almost unlimited transmission ratio options due to combination of several planet stages.

#### What is meant by an epicyclic gear train?

Definition. An epicyclic gear train is a coaxial speed reducer or increaser stage comprised of a sun gear, planet gear(s), and a ring gear (Townsend 1992; Coy et al. 1985). The ratio attained from the gear train depends on the component that has its rotational motion constrained or controlled.

How does an epicyclic gear become a differential?

Two inputs, one output and no fixed element. This mechanism combines the speed of the two inputs. One input, two outputs, and no fixed element. This creates a differential that splits the input torque to the two different outputs.

Which of the following is a method to find out the velocity ratio of an epicyclic gear train?

➢ The following two methods may be used for finding out the velocity ratio of an epicyclic gear train. TA = Number of teeth on gear A TB = Number of teeth on gear B.

## What is speed ratio and train value?

The speed ratio (velocity ratio) of a gear train is the ratio of the speed of the driver to the speed of the driven or follower. S p e e d R a t i o = N 1 N 2 = T 2 T 1. Train value: The ratio of the speed of the driven or follower to the speed of the driver is known as train value of the gear train.

### What are the applications of the epicyclic gear unit?

A frequent application of epicyclic gear trains is accomplishing a large speed reduction in a small space. A planetary or epicyclic gear train is one type of gear train used to transmit motion.

#### How many inputs are needed in case of epicyclic gear train degree of freedom for epicyclic gear train?

two inputs
Degree of freedom is the number of inputs required to produce a unique output. In Epicyclic gear train, there are two inputs required to produce a unique output i.e. one at arm and other at sun gear or at ring gear.

Which is correct formula for speed ratio?

To calculate speed ratio, otherwise known as gear ratio, you divide the number of teeth of the input gear by the number of teeth of the output gear.

What is degree of freedom of gear?

Degree of freedom is the number of required independent input motion to define all the movements and positions of the rest of the mechanism [2]. Fixing two or three components to the ground makes the gear train immovable. This gives the mechanism a degree of freedom equal to zero.

## Which of the gearbox sun and planet gear set is used?

In which of the gearbox sun and planet gear set is used? Explanation: In epicyclic gearbox, the sun and planet gears are used. Using this arrangement various gear ratios can be obtained. Also, this type of gearbox is compact in design than other types of gearbox.

### What are the various types of the torques in an epicyclic gear train?

Gear train is in equilibrium under influence three torques namely driving / input torque, output /driven torque, holding /fixing/braking torque.

#### How many degrees of freedom does an epicyclic gear have?

Hence, (3) is the correct answer.

What is meant by an idle gear?

1 : a gear placed between a driving and a driven gear to transfer motion without change of direction or gear ratio. 2 : a gear for support or guidance instead of power transmission.

Where are epicyclic gears used?

Some of the common uses for planetary gear transmissions are robotic arms, hybrid vehicle power transmissions and turbine generators. Despite the advantages of epicyclic gear trains such as compact structure, lightweight and high power density, they may have relatively low efficiency compared to simple gear systems.

## How does a sun gear work?

In a wheel drive planetary gearbox, the sun gear drives the surrounding planetary gears which are fixed to a carrier. When the sun gear is driven, the planet gears rotate the outer ring gear. The wheels can be mounted over the housing of the gearbox.

### How do you calculate gearbox speed?

The gear ratio is calculated by dividing the output speed by the input speed (i= Ws/ We) or by dividing the number of teeth of the driving gear by the number of teeth of the driven gear (i= Ze/ Zs).