# Is power, torque and RPM a linear relationship?

• 03-05-2018, 05:25 AM
sp782
Is power, torque and RPM a linear relationship?
[COLOR=#050505][FONT=&quot]
[/FONT][/COLOR][COLOR=#050505][FONT=&quot]Hi I have a problem dealing with rpm power and torque.[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]I have a motor powering a gearbox which has a 20:1 ratio.[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]The power and rpm are not an issue so i have not looked at those figures but the motor produces 240Nm of torque. Since it is a 20:1 gearbox, i have assumed the torque is 20 times greater with the rpm being 20 times slower? Is this correct?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]From there the power is transferred through a number of gears. Can I follow the same method above and assume the torque multiplies each time buy the gear ratio?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]I.e. the gearbox shaft is connected to a 110mm shaft connected to a 600mm gear, therefore is the torque at the outer surface of the gear is equal to (240nm*20)*(600/110) = 26181.8Nm of torque?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]Thank you.[/FONT][/COLOR][COLOR=#050505][FONT=&quot]Hi I have a problem dealing with rpm power and torque.[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]I have a motor powering a gearbox which has a 20:1 ratio.[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]The power and rpm are not an issue so i have not looked at those figures but the motor produces 240Nm of torque. Since it is a 20:1 gearbox, i have assumed the torque is 20 times greater with the rpm being 20 times slower? Is this correct?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]From there the power is transferred through a number of gears. Can I follow the same method above and assume the torque multiplies each time buy the gear ratio?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]I.e. the gearbox shaft is connected to a 110mm shaft connected to a 600mm gear, therefore is the torque at the outer surface of the gear is equal to (240nm*20)*(600/110) = 26181.8Nm of torque?[/FONT][/COLOR]

[COLOR=#050505][FONT=&quot]Thank you.[/FONT][/COLOR]