Mechanical Engineering
Gearbox & Belt Drive Calculations
Calculate gear ratio, output speed, output torque and efficiency for gearboxes, belt drives and chain drives.
Units:
Gearbox efficiency is typically 96–99% per stage for helical gears. Worm gears are 50–90% depending on lead angle — use helical gears when efficiency matters. Belt drives have efficiency of 95–98%.
i = n_in / n_out = T_out / T_in | P_out = P_in × η
Input
Input speed iRotational speed at the input shaft in rpm.
rpm
Input torque iTorque at the input shaft in N·m.
N·m
Gear ratio i iGear ratio = input speed / output speed. A ratio of 10:1 means output turns at 1/10 of input speed.
Mechanical efficiency iGearbox efficiency. Helical: 96–99%. Worm: 50–90%. Belt: 95–98%. Chain: 96–98%.
%
Result
Output speed [rpm]
—
Output torque [N·m]
—
Input power [kW]
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Output power [kW]
—
Power loss (heat) [W]
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