hw to INCREASE TORQUE

alokpatra

am nt sure if am posting in the right section bcoz this is my 1st post..

plz could i get help in understanding how to increase the torque of a dc motor without changing the rpm..
n how are gearboxes designed exaclty which increase torque..
i basically want a mechanism 2 deliver higher torque maybe some way 2 increase torque externally (outside the motor )to use in ROBO WARs.....

Lancelot59

Welcome to PF. You are in the right section since this is a general question. If it was a specific homework problem it would go up in the homework section.

As for your problem, the simplest solution is a gear box. The long story short with gears:

A smaller gear that turns a larger gear will turn the larger gear slower, but with more torque.
A larger gear turning a smaller gear will turn the smaller gear faster, but with less torque.
The gear ratio is the ratio of the RPM in and out of any group of gears.



I don't know what kind of physics background you have, but torque is just a force that causes rotation. Torque itself is calculated by multiplying the force that is perpendicular to the axis of rotation by the distance from the axis, or the "lever arm".
In this animation the dark blue arrow that appears on the ball is the force that creates the torque. The lever arm is the length of the arm that goes from the axis to the ball.


Same idea with a see saw. If you place the fulcrum (point of rotation) three quarters up the board and place a big mass on the short end you'll be able to counter balance it with a lighter mass on the other side, because of the longer lever arm.

Gears follow the same principle, the larger gear has a much larger radius that it exerts the force over, as opposed to the smaller one. So that's how it works.

"Gear reduction" basically sums up to less speed, but more torque. Which is what you're looking for. For robotics specifically you should be able to find pre-made assemblies in hobby shops, or just pick up some gears and experiment with different ratios yourself.

alokpatra

But could you tell me how to increase the torque without making any change in the torque? or is it not possible?

Lancelot59

Your motor RPM will stay the same, but your output will spin slower if you want to get more torque. Your only other option is to increase the speed of the motor driving your system.

firavia

A DC motor usually has a system curve , torque over RPM and the sytem you want to operate usually can operate at a certain torque the less torque your system need the less torque your motor provide with higher rpm.

Check this page out : http://industrial.panasonic.com/ww/i...geared_e_9.pdf

in a hoist mechanism the torque a motor must provide is equal to : the radius of the gear head x the mass of the body lifted x g"which is the gravitational acceleration".

koolraj09

Hi alok!!
You could try doubling the voltage supplied to the motor. It'll also double the torque and RPM of the motor.
For more details & queries related to robowars you could also check out: www.teammass5.tk