# Blog

## How is a 1 1 ratio achieved using a planetary gear set? The planet gears (blue) turn in a ratio determined by the number of teeth in each gear. Here, the ratio is −24/16, or −3/2; each planet gear turns at 3/2 the rate of the sun gear, in the opposite direction.

The planet gears (blue) turn in a ratio determined by the number of teeth in each gear. Here, the ratio is −24/16, or −3/2; each planet gear turns at 3/2 the rate of the sun gear, in the opposite direction.

## What is the formula for gear ratio?

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).May 9, 2019

## What does a planetary gear set do?

Inside, you have a sun gear that has a fixed point in the center and a planet gear (or gears) that rotate about the sun gear. As they rotate inside of the ring gear, the planetary gears create pitch circles that can be formed into a gear train that, in turn, is hooked up to input and output shafts.Jan 6, 2017

## What is the advantage of planetary gears?

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.

## How is planetary gear torque calculated?

ANALYTICAL CALCULATIONS

Output torque = (60*voltage*current)/ (2*22/7*output speed) 3. Holding torque = Output torque – Input torque.
Aug 25, 2016

## How do planetary gears increase torque?

The planet gears are mounted on a joint carrier that is connected to the output shaft. The rotational speed of the output is lower than that of the drive, and the torque of the output is higher in reverse proportion. The more gear wheels mesh with each other, the higher the torque.

## Why are planetary gears used in automatic transmissions?

They are used to improve fuel economy, as CVTs are typically designed to keep the engine in its most efficient and ideal power delivery range. There are, however, versions of CVTs that use planetary gears. Called epicyclic CVTs, or planetary CVTs, these transmissions use planet gears to transfer torque.May 10, 2021

## How many forward ratios can a simple planetary gear set create?

Technician A says a simple planetary gearset can provide two reverse gear ratios. Technician B says a simple planetary gearset can provide two forward reduction ratios. Who is correct? Technician A says if the sun and the ring gear are both driven [locked] and the carrier is the output, the condition is direct drive.

## What is 6speed automatic?

A 6-speed automatic transmission uses six different drive gears to give you the best combination of fuel economy and power, as determined by the manufacturer. Since the transmission is automatic, the car determines when it needs to change gears and does it for you--all you have to do is drive the car.

## What is a good gearing ratio percentage?

A gearing ratio lower than 25% is typically considered low-risk by both investors and lenders. A gearing ratio between 25% and 50% is typically considered optimal or normal for well-established companies.  ### Do gear ratios add or multiply?

For example, for the gear at left the blue gears are 7 and 21 teeth, while the green gears are 9 and 30 teeth. Thus, the first gear ratio is 7:21 and the second is 9:30. Multiplying the two together gives (7x9):(21x30) = 63 : 630, which is 1:10.

### How do you find the rpm of a gear ratio?

The general rule is - large to small gear means 'multiply' the velocity ratio by the rpm of the first gear. Divide 60 teeth by 30 teeth to find the velocity ratio. Multiply this number (2) by the rpm (120). This gives an answer of 240rpm.

### How do you calculate gear ratio?

• Gear ratio can be calculated by dividing the diameter of both gears or their number of teeth. If gear ratio > 1 then it’s speed reduction, if smaller then it’s for system to speed up, if equal one it’s just for transmitting power with same speed to transmit it just to another location depending on geometry of design.

### How to calculate gear ratio?

• 1) Start with a two-gear train. To be able to determine a gear ratio, you must have at least two gears engaged with each other — this is called a ... 2) Count the number of teeth on the drive gear. One simple way to find the gear ratio between two interlocking gears is to compare the number of teeth (the ... 3) Count the number of teeth on the driven gear. Next, determine how many teeth are on the driven gear exactly as you did before for the drive gear. 4) Divide one teeth count by the other. Now that you know how many teeth are on each gear, you can find the gear ratio relatively simply.

### What are planetary gears?

• 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. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. ... Planetary gears (or epicyclic gears) are typically classified as simple or compound planetary gears.

### What does a planetary gearbox do?

• A planetary gearbox is a gearbox with the input shaft and the output shaft aligned. A planetary gearbox is used to transfer the largest torque in the most compact form (known as torque density).

### How to calculate the gear ratio of planetary gear set?How to calculate the gear ratio of planetary gear set?

The first, all gears in the planetary gear set have same module. Sun gear has A teeth, planetary gears have B teeth, ring gear has C teeth. Because they will assemble together so we have C=A+2B + We will fix carrier. If sun gear is input power -> Output is ring gear. We can calculate ratio transmission by formula: i = -A/C -> reduce speed system

### How do planetary gears work out?How do planetary gears work out?

The first constraint for a planetary gear to work out is that all teeth have the same pitch, or tooth spacing. This ensures that the teeth mesh. The second constraint is: 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.

### How many teeth does a planetary gear have?How many teeth does a planetary gear have?

In this case, the planet gears have 12 teeth, the sun gear has 18 and the ring gear has 42 teeth. These pictures are part of a fasincatingly complicated planetary gear drive by Ronald Walters.

### How is the demultiplication of multi stage planetary gear units calculated?How is the demultiplication of multi stage planetary gear units calculated?

The overall demultiplication of multi stage planetary gear units is calculated by multiplying the ratios of the single stages. The number of teeth of the planets has no effect on the ratio. Their number of teeth depends on the demultiplication of the gearbox.