Gear efficiency modeling in a simulation model of a DC gearmotor

This paper presents how to build a simple simulation model of a DC gearmotor based on available datasheet parameters. The energy loss caused by the gearhead is broken down to inertia, viscous friction and coulomb friction. The gearhead inertia is transferred to the motor inertia, while the losses caused by the two frictions are calculated and added to the motor load torque. The coulomb friction is simulated as a constant, speed-independent efficiency - based on the datasheet's efficiency. The viscous friction is implemented as a speed dependent loss, for which the damping coefficient is estimated from other available parameters. The constructed model is tested and validated through constant voltage and constant speed tests. The plotted torque graphs illustrate the motor, gear and gearmotor efficiency.