Example for horizontal travel drive

The task

A travel drive is to be accelerated and decelerated twice within a total cycle time of 50 s. Calculate the brake resistor to be used for an AX5112 servo drive.

Default values

• Speed 3000 rpm
• Acceleration and braking time 0.5 s
• Moment of inertia reduced to the motor shaft 0.02 kgm²
• Motor moment of inertia 0.0024 kgm²

Procedure

1. Calculation of the angular velocity



2. Calculation of the required braking torque



3. Calculation of the mean braking power for each braking process



4. Calculation of the required continuous power

Since the internal brake resistor already offers a continuous power of 90 W, it is sufficient for this application.

If the result is calculated for ten braking operations, it corrects itself as follows:

Required continuous power for ten braking operations

For this value it is recommended to use an external brake resistor AX2090-BW50-0300 with 300 W continuous power.