Dear Sir,

We are using Quadrature (A,B pulses) incremental pulse encoders for speed control for our stand motors in Bar Rolling mill. (Hubner Make, 500 ppm, Motor speed 1380 (max)). We are looking for non-contact type encoders to avoid problem with the encoder coupling. Could someone suggest a make and type which can replace the existing one? Also give the accuracy of the new type. I searched some website like (sick, hubner) but could not find a suitable non-contact. Thanks in advance.

Regards,
James

 

Hello,

Renishaw makes a stainless steel ring encoder that bolts to your load and has a non contact read head that looks at some gratings in the stainless steel ring. They are superior to motor coupled encoders because you don't have runout associated with motor couplings (some encoder manufacturers make very specialized couplings to try and avoid this error) and bearings in the encoder to fail, etc. They can also be had with very high encoder counts through interpolation built into the read head device.

~Ken

 

I have used Northstar encoders on large DC motors. They have since been bought by Danaher. These bolt onto the accessory flange of the motor and do not use couplings.

Check them out here...
http://www.danahercontrols.biz/north2.htm

Bill

 

Thanks for the reply.

could you please suggest some specifi model or details which will help in selecting a suitable model.

 

You should use a hollow shaft encoder, which allows for flex and doesn't break in flex situations as you describe. Try the HS 35 series from Northstar, Dynapar, both owned by Danaher or BEI.

B

 

I know this is a late reply to your post, but thought you'd be interested that BEI has just introduced a non-contacting version of their incremental encoders, they call the ES series. They use a magnetic coupling to synch the encoder to the shaft. You can find them on this link: http://www.beiied.com/encoders_harsh_environments.html