Motor Drive Rec

[bigalow]

I have a motor/drive application. I need to replace old resolver Moog servo motor and drive on a Grinding machine. Servo motor controls th reg wheel.
Parameters:
RPM 100 to 400=oper range
3000oz/in max torque
1000oz/in cont
5000z/in starting torque
size= lots of room

Needs to be controlled with a pot/RPM
Needs feedback for constant RPM
RPM cant vary with load
480VAC machine
Must be free.......Kidding
Motor drives a pulley an I cant reduce the pulley size. No AC Vector?

Thanks

[bigalow]

Correction 500oz/in stating torque

[Al_The_Man]

Can you use the present servo motor by replacing the resolver with an encoder?
What is the ratio of the present motor to final drive?
I assume the 100-400 rpm is the final rpm?
You may be able to use a AC or DC servo motor with a Advanced Motion Drive in the encoder feedback mode with control pot.
Depends how stable you want the feedback to be.
Al.

[bigalow]

Its a 2.2KW servo motor so I guess im looking at 3HP. I need speed regulation of 1%. Top speed needed is 400RPM. I can,t reduce the size of the motor pulley or increase the size of the grinding wheel pulley.
I thought of using a vector drive with a 900 RPM AC motor but I would only have less than a 1HP at 200 RPM right? I would need a 10 hp, WEG has the inverter duty 900RPM motor,,
Im looking at about $2100 for a less popular Servo/motor combo

[Al_The_Man]

Using a VFD in the vector mode would not bring you close to 1% regulation, you would need the encoder option feedback to the VFD.
Incidentally WEG have a new motor/VFD line out that guarantee 100% torque down to 1 rpm.
If the present motor size is 2.2Kw, presumably a servo replacement of this size should work.
What is wrong with the present motor? is it DC brushed?
Al.

[bigalow]

Its a PWM motor with hall effect sensor feedback to the servo drive, Its an old drive with obsolete components, Manufacture printed thier part number on mosfets. Plus has a monster power supply. All the caps are dried out and values are ? Motor still runs good thouigh.

Be a fun experiment to try and drive the motor with another drive??
What do think? Be pretty hard I imagine matching the phasing and the correct modulation for the motor characteristics?
The motor runs continueus for 12hrs a day and only stops once at the end of the day

[Al_The_Man]

If an older motor it most likely has standard hall effect devices but it can still be used easily on such drives as Advanced Motion Control, I just picked up 3 100amp type on ebay for 10c on the $1. These have the P.S. built in.
The phase connections are fairly straight forward, it sometimes just involves going through the six combinations of the stator connections if it does not run right off the bat.
The drive commutates the motor based on the relationship between the halls and the stator winding, this is doen automatically once you have the right sequence.
Al.