How does a gear ratio affect speed


The gear ratio tells us how fast one gear is rotating when compared to another.

If our input gear (10 teeth) is rotating at 5 rpms , and it is connected to our output gear (50 teeth), our output gear will rotate at 1 rpms. 

Why?
Our gear ratio is 50:10... or 5:1

If our small gear rotates 1x, our large gear only rotates 1/5. It takes 5 rotations of our small gear to = 1 rotation of our large gear. Thus our large gear is rotating at 1/5 the speed = 1rmp. 

What if our gear ratio where 1:3 ?
In this case our input gear is 3x larger as large as our output gear. 

If our input gear were rotating at 20rmps.... each rotation, would result in 3 rotations of our output gear. Our output would be 60rpms.

10 Responses so far.

  1. Blogs are so informative where we get lots of information on any topic. Nice job keep it up!! VCDB Tool

  2. great website and very informative contents,its better to have a bigger input gear in order to achieve a better gear ratio, nice write up.http://www.johnyscarblog.com/

  3. I wanted to know how to make different gears give different torque so that i can have 2 gears of the same rpm produce different torque. I have seen involute, stacked, and planetary gears give different torque at the same rpm. Im hoping someone can help me solve this. This is to make an object of less weight move an object of greater weight at the same rpm. To put a involute gearbox on a motor and move it at 3 rpm and put a planetary gearbox on the other side of the motor and have it move at 3 rpm with more strength than the involute gearbox requires. I hope someone will help me

  4. I also wanted to know if a planetary gearbox with 2 opinions moving the sun at a 4 to 1 ratio has less torque than a planetary gearbox with 4 pinions moving the sunat a 4 to 1 ratio

  5. I also wanted to know if a planetary gearbox with 2 opinions moving the sun at a 4 to 1 ratio has less torque than a planetary gearbox with 4 pinions moving the sunat a 4 to 1 ratio

  6. I wanted to know how to make different gears give different torque so that i can have 2 gears of the same rpm produce different torque. I have seen involute, stacked, and planetary gears give different torque at the same rpm. Im hoping someone can help me solve this. This is to make an object of less weight move an object of greater weight at the same rpm. To put a involute gearbox on a motor and move it at 3 rpm and put a planetary gearbox on the other side of the motor and have it move at 3 rpm with more strength than the involute gearbox requires. I hope someone will help me

  7. I wanted to know if the gear ratio of the dc motor is 1:9.78 but i want to use this motor in speed reduction process(i.e. gear ratio i calculated 5:1) whether that will work or damage the gear of motor.

  8. Unknown says:

    I have a big problem: I have a generator which need input of 500 RPM & 500N.m. At the generator I link a speed multiplier. What must be the input Torque at speed multiplier if the input RPM of speed multiplier is 2RPM?
    Resume:
    Generator:
    input RPM: 500
    input torque: 500

    speed multiplier:
    input RPM: 2
    Output RPM: 500
    input torque: ?
    Thank you


  9. Unknown says:

    I wanted to gear ratio efected chart

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