Frequent belts damaged

[maypot]

Hi,

We are burning transmission belts on a conveyor like a hell. The conveyor is driven by a sensorless vector drive and the starting inertia is quite high. Previousy the drive was tripping on overload during start-up , so I have configured the drive for full torque at almost zero speed. The capacity of the drive is 75 k W.
They have used belt tensioner to adjust the belt but without much success.They assume they are using the right belts.
I would like to help the poor mechanical guys to solve their problem.
Grateful for any input .

Bob

 

[gwolf]

You could check:

Correct alignment of belt, rollers, and guides - if the belt is rubbing somewhere this will cause large loads.

Check also with the belt off that all of the rollers can be turned easily, also that there are no pieces of old broken belt jammed between the rollers and support structure.

Lastly: "They assume they are using the right belts" - assumption is the mother of all ****-ups.

Good Luck,

gwolf.

 

[TPL]

If possible, you might want to consider using a stroboscope to look at this belt when it is operating

 

[diamondjim]

What size, type of belt, operating temperature
and radius of the drive pulleys or sheaves.

 

[PeterCharles]

You don't say what type of conveyor, but you do say the inertia is high.

My ignorance, but I don't know what you mean by a "sensorless vector drive".

However, if it were a belt conveyor with a 75 kW drive I would be thinking of a fluid coupling to give give a 'soft start'.

When selecting conveyor drive components you need to know :-
the estimated absorbed power,
the estimated torque required to start acclerating the machine,
the inertia of the machine.

 

[minerk]

Have they checked the sheaves for wear? Are the belts a matched set? Are they tensioning properly?

 

[ischgl99]

Has this just started to happen? If so then look for something causing a higher load such as worn bearings or maybe a blockage in your conveyor.

With the VFD you can adjust the acceleration time to reduce the starting current for the high inertial load. This will certainly help with your belts if the problem is not mechanical and is related to a fast starting time.

 

[limct]

Bob,
These areas worth looking into;
- if it's a toothed belt, confirm that the belt matches with the pulley, also check the pulley condition, especially the teeth.
- if it's a v-belt, most of the belt problem is related to pulleys alignment, it's even more obvious for a micro-V type. also check the grooves condition.
- if any part come into contact with the belt during running, in most cases, the culprit is the cover itself, you open it up during check-up and always see nothing wrong!
- improper tensioning
- if the belt is a stretchable type, check the elasticity.

Best regards,
ct