## Which gearbox is sun and planet?

In a planetary gearbox we see a sun (solar) gear, satellite (ring) gear and two or more planet gears. Normally, the sun-gear is driven and thus move the planet gears locked in the planet carrier and form the output shaft. The satellite gears have a fixed position in relation to the outside world.

How do sun and planet gears work?

As mentioned above, the central “sun” gear is usually the input gear. Around it, two or more planet gears rotate within an outside ring gear and are connected to the output shaft via a carrier. As the sun gear turns, it causes the planet gears to rotate in place along the inside of the ring.

What is sun and planet gear train?

The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines. It was invented by the Scottish engineer William Murdoch, an employee of Boulton and Watt, but was patented by James Watt in October 1781.

### How do you calculate torque of a planetary gearbox?

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 a common sun gear?

n. (in an epicyclic train) the central gear around which the planet gears revolve.

How do planetary gears increase torque?

A planetary gearhead takes a high-speed, low-torque input, say from an electric motor, then increases torque and reduces speed at the output by the gearhead ratio. This lets motors run at higher, more-efficient rpms in equipment that operates at low speeds.

#### Why do we use planetary gear?

Generally, planetary gears are used as speed reducers. They are used to slow down motors and increase the torque. Torque is the working power of the machine. But we’ve seen our planetary gears turned around to be used as speed increasers, too.

What is a sun gear used for?

The load from the sun gear is distributed to several planetary gears which can either be used to drive an outer ring or a shaft or spindle. The central sun gear takes a high-speed, low-torque input. It drives several rotating external gears which increases the torque.

How do you calculate gearbox speed?

A gear is made up of toothed wheels (“teeth”) connected to shafts. 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.

## How do gears increase torque?

The arrangement of the driver and driven gears determine if the gear train will increase torque or speed. To increase output torque using a gear train, a power source should be directly connected to a smaller gear and used to drive a larger gear.

Is the sun gear always driven?

The planet and sun gears mesh so that their pitch circles roll without slip. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train. In this case, the ring gear is usually fixed and the sun gear is driven.

What is sun gear used for?

### How is the sun gear connected to the planet gear?

The sun gear is engaged to the three planet gears which are at 120° apart from each other. The planet gear meshes with the sun gear and ring gear which produces two tangential forces, therefore twice the tangential force is require to hold the planet gear. Fig -2: F.B.D of epicyclic gear train

What is the function of the planetary gear?

In the planetary transmission mechanism, the planetary gear is comprised of four parts: the sun gear, carrier, and ring and planet gear. The function of the planet gear is to connect the sun gear, planet carrier, and the ring gear together; it can’t be used as an external component for power output.

How does the epicyclic gear train ( PGT ) work?

The epicyclic gear train (EGT) is known as planetary gear train (PGT). Epicyclic gear train is a gearing system consisting of one or more ring gears, or planet gears, revolving about a central, or sun gear. The planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear.

#### How does a planetary gear mechanism change the reduction ratio?

Planetary gear mechanisms have a characteristic of being able to change the reduction ratio by choosing which of the components is to be fixed. For example, suppose internal gear C is fixed, the input axis is connected to sun gear A, and the output axis carrier D. When sun gear A rotates one time, planet gear B will rotate times.