An important part of the gear motor is the gearbox and its gear pairs or stages. The gears transmit the force of the motor from the input to the output shaft. The gear box therefore functions as a converter of torque and speed. In general, the gear unit slows down the rotational speed of the motor while simultaneously transmitting significantly higher torques than the electric motor alone could provide. Based on this principle, the design of the gear unit determines whether a gear motor is suitable for light, medium or heavy loads and for short or long operating times.
Gear ratio and torque
A gear ratio or reduction ratio steps down the incoming speed from the motor (input speed). The speed ratio ‘I’ between the input speed and output speed of the gear unit serves as a measure of this. Another important variable for a gear motor is the maximum torque on the output side. This torque is specified in newton meters (Nm) and is the measurement for the force of the gear motor and the load that it can move with that force. At the same incoming speed this results in a low torque at low ratio and a high torque at a high ratio of the gearbox.