Variables
Description
What is this formula?
This formula calculates the shaft torque produced by an induction motor from its mechanical power output and rotational speed.
When to use it
Use this formula when sizing motors, analyzing mechanical loads, selecting gearboxes, evaluating drive systems, and estimating motor performance.
Example
An induction motor delivers:
Mechanical power = 15 kW
Rotor speed = 1750 rpm
Formula:
T = 9550P / Nr
Substitution:
T = (9550 × 15) / 1750
Result:
T = 81.86 N·m
Applications
Motor sizing
Drive system design
Gearbox selection
Mechanical power transmission
Industrial machinery analysis
Note
The constant 9550 is derived from the relationship between power, torque, and rotational speed when power is expressed in kilowatts and speed in revolutions per minute. Alternative forms of this equation exist when using watts, horsepower, or angular velocity in rad/s.