How do maintenance of DC Motors so that Machine can run smoothly if there thirteen motors connected.?

Question

In this machine we process dying to rope form of yarns for dennim cloth.Its speed is costant while running, if any break down occoures,arround thousend meters yarns or roape westage. These motors speed regulate by Dancer so that motor mainteined speed slow/fast so that tention also maintened.

Answer 1

as far as the dc motor is concerned,
clean commutator segments at regular intervals with spirit / petrol, after dis-engaging the carbon brushes
check that all carbon brushes have same depth & equal wear
wipe the carbon brushes too
use compressed air to blow off the dust / dirt from armature / field & housing

thirteen motors is fine

sure some plc controls in place
some or one motor is fixed speed
rest are variable speed / tension ... dancer controlled as u said
guess winding / spooling application too
impossible to guess without circuit diagram as also understanding application

so i'm guessing u wanted to know how to keep your motors in good shape

< i'm open to any & every help i can extend u., let me know if u need further detailed help >

Answer 2

This sounds like a process control problem. I imagine each DC motor is driven by its own controller and that the 13 controllers are themselves controlled by one device called "Dancer." If this is so, then Dancer is the key to a fast and controlled shut-down when a yarn breaks. I'd probably start by reading the operator's manual for Dancer and see what I could discover.

It's also possible my assumption is wrong and each of the 13 motors has its own Dancer to regulate the tension of each yarn. If this is the case, I'd still read the Dancer manual and see if there is a stop/start input that might be used to quickly stop all 13 motors simultaneously. This seems very likely because DC motor controllers often have logic-level inputs that allow remote control.

Unless you're a process control engineer or a very skilled electronics technician, I suggest that you don't actually tamper with the machine's electronics. Instead, study the manual and see if you can figure out if there's a better way to control this machine. If you do come up with an idea, take your suggestion to management and let them either assign you the task or bring in qualified technical help. It's far better to be the genius who figured out a better way, than the fool who destroyed 13 motor controllers and shut-down production!!!

Answer 3

This is a process that isn't really any different from a paper mill (processing pulp into finished paper), metal rolling (processing either hot or cold material through several reduction stands into a final coil or shape), or a conveyor system.

Proactively maintaining the DC machines driving the process (keeping them in good shape, commutating well, and reacting well to speed/voltage control inputs) is a good thing in that it should allow you to pick up on discrepancies and plan a controlled shutdown of the process - which in turn should limit the wastage of ruined material.

To maintain the DC machine:
- keep an eye on thermal loading (hot motor windings may be due for trouble; hot bearings are certainly a cause for alarm!).
- observe commutation regularly (sparking is detrimental to brush life and commutator life and shoudl be avoided). Change out brushes and clean up/monitor commutator film as required.
- monitor machine vibration (too much sahking means there's likely something wrong with the bearings ... and the torsional transients are going to make it much harder for you to maintain the required tension in the yarn).
- verify that the controllers (digital or analog - I'm unsure what Dancer is) are working as they should, particularly in response to specific 'test' inputs.

If you have to take one motor out for servicing (in a planned fashion) ... shut down the line first, or at least take the driven spindle out of service and allow the neighboring machines/spindles to take up the slack and maintain yarn tension. With the type of process you're describing, this shoudl be a fairly easy task. Most of the machine rating is not required to actually 'run' the process; the motors are more likely sized to be able to accelerate the process from a standstill.

Also make sure your sensors (speed feedback devices in particular) are reading correctly.

If you want to discuss something specific, email me directly with your questions and I'll do what I can to help you out.

Answer 4

My guess would be the only way to accurately do this is by having feedback from the motors (tachos). This signal then used to control the motors. Seems like an application more suited to using servos than dc motors.

A break in your product needs to be detected by something monitoring the tension or by photo cells.