Slip Ring Problem

[rjbrownley]

We are using a slip ring assemble on the end of a shaft. Inside the shaft is a cartige heater that is powered by the slip ring. The problem we are seeing is the the brushes are grinding a groove into the slip ring. Does anyone know what may cause this problem?

 

[itsmoked]

Brush material too hard.
Ring material too soft.
Brush springs too stiff.
Current density too high.

Are the brushes taking forever to wear out?


Keith Cress
kcress -

http://www.flaminsystems.com

 

[jraef]

Couldn't have said it better.

Are you sure that is a cartridge heater? Seems odd. Slip rings on motors are typically either for Synchronous Motors or for Wound Rotor Induction Motors. Sounds to me as though you might have a WRIM and what you interpret as a cartridge heater is a rotor resistor used to alter the torque speed curve of that motor. Some WRIMs are not designed to be run continuously with rotor resistors in place, the resistors are just for soft starting and are supposed to be stepped out by shorting the rotor once you get to full speed. If you are not sure, I would try to find out what it is doing and why it is acting this way before you go changing any parts.

 

[powerjunx]

in addition to, AC Variable speed machine were fitted with slip rings too..yet cartridge heaters were not use in anyway. Better check the functional installation of such device.





"..the more, the merrier" Genghis Khan