Glossary · Motion control and drives
Nominal torque
Also known as: Rated torque
German: Nennmoment
In electric drives, nominal torque is the torque a motor can deliver continuously at its rated speed and rated conditions (supply, cooling, ambient temperature) without exceeding its permissible temperature.
- Motion control
In one sentence
Nominal torque is the torque a motor delivers continuously at rated speed and conditions without overheating.
Example
The gearmotor's nominal torque of 120 Nm is well above the conveyor's continuous load torque, while short peaks are covered by the overload capacity.
How it applies
- Engineering: Motors are sized so that the RMS torque of the load cycle stays below the nominal (or, for servo motors, the continuous stall) torque, and peaks stay below the peak torque.
- Operation: Operating above nominal torque for long periods overheats the motor and triggers protection.
- Maintenance: A motor that suddenly needs more current than usual may indicate mechanical problems such as worn bearings or jammed mechanics.
- Documentation: Give nominal values with their conditions (speed, ambient temperature, duty type). Don't mix rated, continuous stall and peak torque in datasheets or manuals; each has a distinct meaning.
Nominal torque vs. peak torque
Nominal torque can be delivered continuously. Peak torque is available only briefly, limited by the drive's current and the motor's thermal time constant.