The Beauty of the Servo Motor and Drive

sprague trolleyServo motors and drives are a continual source of fascination.  What great inventions!  Where would modern manufacturing be without these amazing and powerful workhorses?  Electric motors were the key to revolutionizing industry.  Today, there are many servo manufacturers such as Allen Bradley, Siemens, Okuma, Yaskawa, Fanuc, and Cincinnati Milacron to name just a few.

DC motors, as we might recognize them, owe their existence to American inventor Thomas Davenport who developed the first commutator-type direct current electric motor for commercial use which he patented in 1837.  These motors ran at up to 600 rpm and powered machine tools and printing presses.  1837!  Can you believe it?!  Sadly, Davenport’s invention was too expensive to be commercially viable due to the cost of the primary battery power.  But the idea for this magnificent machine did not die.

More servo facts:
  • 1871 – Zenobe Gramme, a Belgian, invented the first commercially successful DC motor by developing the anchor ring dynamo solving the double-T armature pulsating DC problem.
  • 1886 –   American Frank Julian Sprague (who was once employed by Thomas Edison) invented the first practical DC motor that allowed power from electric motors to be returned to the electric grid and thus allowed Sprague to invent the first electric trolley system in Richmond, Virginia in 1887 and elevator controls in 1892.
  • 1824 – French physicist Francois Arago formulated the existence of rotating magnetic fields which spurred the effort to develop the AC motor which would bring the advantage of long distance high voltage transmission.
  • 1887 – Nikola Tesla developed the shorted-winding-rotor induction motor, among other motors;  George Westinghouse bought the Tesla’s patents and paid Tesla to develop them.
  • 1892-93 – Westinghouse developed the first practical induction motor and a line of polyphase 60 hertz induction motors
  • 3 operating principles are used to make electric motors today:  magnetic, electrostatic, and piezoelectric with the most common being magnetic.
  • Smallest Industrial Servo Motor (at least that I know of) –  weighs only 5 grams and is about the size of a dime
  • More than 70% of U.S. industrial electricity consumption involves motor-driven systems mostly for pumps, fans, blower systems, and air compression.
If you have a servo motor system, or two, or hundreds, here’s how to keep them running:
  • Buy the right motor for your application
  • Define your parameters to avoid overheating
  • Use insulated bearings or shaft ground bushings
  • Minimize the distance from the drive to the motor

If you find that you need servo motor repair, servo drive repair, or encoder repair and yours are no longer under warranty, you need to find a reliable industrial electronic repair company.   Choose a firm with lots of experience, free evaluations, and a good warranty.

Here are a couple of links for specific servo motor, drive or encoder repair services:  Allen Bradley servo motor repairs, Yaskawa servo motor repairs.