How To Calculate Inertia Of Load Reflected To Motor & Inertia Ratio

Understanding Load vs. Motor Inertia

"Inertia mismatch" means the difference of physical inertia between the motor and the load.

If electromechanical systems were rigidly coupled, with no compliance or “wind-up” in the system, performance would be determined by the motor torque, and inertia would be irrelevant. But since mechanical components aren’t infinitely rigid – belts stretch, gears have backlash, and couplings are elastic – designers must decide what inertia ratio is acceptable for each specific application.

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How to Calculate Inertia of Load Reflected to Motor & Inertia Ratio

Before calculating your inertia ratio, you must first calculate your inertia of load reflected to the motor (JL below) by following the formula and variables below:

Formula for Calculating Inertia of Load Reflected to Motor

Once you calculate your inertia of load reflected to the motor (JL above and below), you can now calculate inertia ratio by following the following formula and variables:

Formula for Calculating Inertia Ratio

If you have questions, please contact our experts today! Also - please use our inertia ratio calculator below for your application.