Here’s a great introduction to servo motors. While we have some fine articles on the history and care of servo motors, this is a great starting point for people who don’t know what a servo motor is.
If your interest in servos is not academic, if for example you need support for Indramat or Indradrive servos, give us a call. We specialize in legacy and new Rexroth Indramat motion control. We can help with phone support, emergency replacement units, and factory repair.