Re: Fluctuation Of Conveyor Speed During Starting
Is this variation something you have seen at the drive pulley or something you have seen at the belt itself? ■
Rfi
Dear Mr. sganesh,
could you please provide information about the drive configuration (motor - coupling - gear - coupling), the control spec of the drive and the configuration of the conveyor with position of the effect you observed?
Regards ■
Its A Kind Of Magic
Originally Posted by sganesh
Have you noticed the fluctuation of conveyor speed for few seconds only at the starting? i.e. Conveyor starts with speed, slows down, again picks up, again slow down then becomes normal.
The above phenomenon is at the carrying side. What could be the reason?
I feel this could make ill-effects on the belt and other mechanical components.
Your valuable comments please!
Regards,
Your description of the problem is quite inadequate and misleading, without proper conveyor belt data. 
You imply that the phenomenon only occurs at the carrying side. So we are to assume that there is a magic head & snub pulley arrangement which restores uniform speed to the return strand. 
Come on lad; read some books; do some homework. ■
Re: Fluctuation Of Conveyor Speed During Starting
Sounds like normal behavior at start-up, where the belt is stretched, perhaps some slip/creep at the drive, the whole belt starts to move, counterweight moves up and down and then the whole thing stabilizes. Seems very unlikely this speed variation is not also on the return. ■
Re: Fluctuation Of Conveyor Speed During Starting
Hi sganesh,..
This phenomenon is absolutely typical of the requirements of the Funke Ramp not being met during the initial start period.
In other words, the rate of application of the initial break-away torque is too quick.
The best way to illustrate this is to imagine a car being towed.
If the towing car pulls away too quickly the tow rope goes very tight and then goes slack. It then goes tight again (and often snaps).
If however, it pulls away gently and slowly, this does not happen.
Cheers
LSL Tekpro ■
Re: Fluctuation Of Conveyor Speed During Starting
Originally Posted by Graham SpriggsIn other words, the rate of application of the initial break-away torque is too quick.
Cheers
LSL Tekpro
Thanks a lot for all. The phenomenon I have seen as explained is at many conveyors. Hence I had not posted all the details.
Thank you Mr.Graham. How to eliminate the above reason.
Obvious recommenadtion is VVVF drive or soft drives.
Can there be any other solutions? Should we reduce fluid coupling oil?
The above fluctuation may affect the joints badly.
It affects the time delay of speed sensor also.
Kindly reply.
Regards, ■
Re: Fluctuation Of Conveyor Speed During Starting
Reducing oil in the fluid coupling will soften the start, but you need sufficient oil to transmit the necessary torque without overheating.
As far as the speed sensor is concerned an over-ride is normally included to allow the driven machine to reach normal running speed. ■
Answer Got?
The reason why one takes care and asks for details is that one phenomenon can have different causes. And be essentially dependant from said details, not to speak about a weighing of possible cures.
There's such thing as a guess (read: shot) in the dark, who knows whom you'll hit and where...
Is it a too demanding demand demanding some detail and / or too demanding demand to provide them?
I personally would be the first who'd like to learn, even in reducing information demands...
Regards
Roland ■
Re: Fluctuation Of Conveyor Speed During Starting
Hi Sganesh..
I assume you have a single drive on your conveyor.
If so, I often find that people put too larger drive unit on the conveyor, thus producing too much pre- break-away torque, especially with oil fill matched to the size of drive/motor.
So.. put on the correct size drive unit.
If multiple drives are fitted, then stagger the starts by 3 seconds each.
Cheers
LSL Tekpro ■
Re: Fluctuation Of Conveyor Speed During Starting
This doesn't sound abnormal to me.
■
Re: Fluctuation Of Conveyor Speed During Starting
Originally Posted by henrysorenI suppose it depends on your experience with belt conveyors in the field.............. ■
Fluctuation of Conveyor Speed during Starting
Dear experts,
Have you noticed the fluctuation of conveyor speed for few seconds only at the starting? i.e. Conveyor starts with speed, slows down, again picks up, again slow down then becomes normal.
The above phenomenon is at the carrying side. What could be the reason?
I feel this could make ill-effects on the belt and other mechanical components.
Your valuable comments please!
Regards, ■