# How to Calculate the Torque of Gear Motor?

2020-06-15

The torque of the gear motor is determined by the power and speed. The rated output (input) torque of the gear motor is determined by its rated transmission power and rated output (input) speed, and its actual output (input) torque is determined by its actual transmission power (load size) and the actual output (input) speed. In order to choose the most suitable type and specification of the gear motor and ensure the safety of product use, avoid overload use. If the rated output torque of the gear motor is not enough, and the working machine fails to run, just replace the gear motor, select the gear motor with larger rated power, or the one with invariant rated power and low output speed.

Torque Calculation Requirements:

For the service life of gear motor, the calculation of torque is very important. It needs to pay attention to whether the maximum torque (TP) of acceleration exceeds the maximum load torque of gear motor. Different stages of gear motors have different output torques. They are often divided into three types according to stages: 1-stage gear motor (usually＜10:1), 2-stage gear motor (usually＞10:1 and ≤200:1), 3-stage gear motor (some brands have no 3-stage option; maximum reduction ratio is 100:1; it is greater 100:1.) Gear motor is possible to reach 5-stage with the maximum reduction ratio of 4592:1.

Gearbox Torque Calculation Formula:

Reduction ratio = motor output revolutions/reducer output revolutions (“reduction ratio” is also called “gear ratio”)

1. The motor power, ratio and service factor are given. Calculate the gearbox torque via the formula as followed:

Gearbox torque = 9550 × motor power ÷ motor power input revolution ÷ reduction ratio ÷ use coefficient

2. The torque, output revolution of the gearbox and use coefficient are given. Calculate the motor power of the gearbox via the formula as followed:

Motor power = torque ÷ 9550 × motor power input speed ÷ speed ratio ÷ use coefficient.