Inertia mismatch

The advantages of using direct drive motors

Inertia mismatch between the load and the motor is an essential area of concern, especially for servo motors- or other traditional motor solutions applications. It is of less concern for applications that implement direct drive motors.

Basics

Moment of inertia is a quantity that shows how much torque is needed for a specific angular acceleration. It is an additive quantity. Simple shapes can be added together to make a complex shape. Inertia mismatch is the difference between the moment of inertia of a motor and the load. Torque motors can tolerate a much higher mismatch due to the load being stiffly coupled.

This white paper briefly references the most important topics when dealing with inertia and inertia mismatch.