Rotor Windings and Slip Ring Motors

Is it a two ring, three ring or four ring rotor?

commutator or collector?

"Slip Ring" by itself can mean Wound Rotor Induction Motors or Synchronous Motors.

In either kind it can be caused by bad rings, bad brushes,or a combination. But beyond that you would have to specify which type of Slip Ring motor you are talking about.

Okay engineers, here's one I've never heard of before. A contactless, wireless slip ring?

"PowerbyProxi recently completed the commercial launch of the Proxi-RingTM, a completely contactless slip ring which is used to transfer power across 360 degree rotating joints. The new technology replaces mechanical slip rings which have a reputation for failure and high associated maintenance costs."

Am I reading and understanding this right that you can generate and transfer electrical current from a rotating shaft without any contact of brushes or commutators? Here's the website-http://www.powerbyproxi.com/news.html

If true wouldn't that be revolutionary in that there would be no drag on the shaft when supplying current to a load?

This way of contactless power transfer exist longer. In professional Generator sets, the exitation of the rotor is done this way.

A second small auxiliary armature winding is mounted in the length of the main armature winding. This auxiliary armature winding is rotated in its own auxiliary stator. The AC voltage in the auxiliary armature winding is rectified and feeds the main armature winding.

If you controle the magnetical flux of the auxiliary stator,you can also control the DC current in the main armature winding.

This system is used to control the output voltage of a generator.

google at Brushless excitation systems or rotating excitating

Yes, in fact I would venture to say that almost all new Synchronous motors sold now are brushless. All that is different is that the rectifier is rotating on the rotor, so by using inductive coupling (transformer effect) you have no need to touch the rotor with brushes any longer. It WAS revolutionary in that industry, but it has been around now for 20+ years that I know of.

Guest,

After you check that the exciter voltages are correct for this rotor, you might want to check for a short or a ground in the rotor winding.

Luther M