A Question To What Goal
Dear sganesh,
perhaps this is a demonstration of applied physics? If n = constant = v / 2*PI*r, with a different radius one gets a different speed, so there shall be frictional effects at the tapered roller. Perhaps that's a design intended to steer the belt, improve centering etc.
There's knowledgable specialists on this forum who might say a word about effects on the belt.
Perhaps you will be so kind as to share the opinions of the presenter / person you met / operator, also, a picture would be very much appreciated.
Regards
R. ■
Re: Taper Idler As Trough Idlers
That is true for the surface velocity of the roll Roland but the surface area in contact with the belt remains constant and therefore no frictional effect. Imaging a line drawn on the surface of the roll parallel to the centerline of the roll axially, it will always contact the belt at the same time at each revolution. The end points of the line however travel at different speeds to get back there. Therefore this has no effect except to allow for a slight increase in carrying volume due to the cross section area increasing. This same effect can be applied by simply increasing the angle of the wing rolls. The one negative side of this is the smaller diameter end of the roll will wear faster than the larger end due to more contact with the belt surface.
I am of course assuming that the centerline of this tapered wing roll is perpendicular to the belt travel. Maybe this is not the case.
It is not a set up that I would recommend.
I would enjoy hearing other members comments. ■
Gary Blenkhorn
President - Bulk Handlng Technology Inc.
Email: garyblenkhorn@gmail.com
Linkedin Profile: http://www.linkedin.com/in/gary-blenkhorn-6286954b
Offering Conveyor Design Services, Conveyor Transfer Design Services and SolidWorks Design Services for equipment layouts.
Let It Roll
Dear Gary,
instead of news from the subcontinent it's once more me.
I'd really rather think the belt should sort of slip over that roller, but without a pic from the "threadmaker" it's still in the dark. I attached a sketch trying to make some comments, but then, if i take the dough rolling pin out of the kitchen, lathe it to a taper (don't know what familiy shall think 'bout it, or me, then...) and let it roll over the table --> it shall move in a circle. But, as the roller must be fixed in the idler, it cannot make that movement, and the belt shall slip over it.
Have a nice weekend!
and best regards
R.
P.S.: Dear Sganesh, over to you .
P.P.S: On second thought, it doesn't have to be the sacrifice of the dough rolling pin, a tapered roller out of a bearing will do the trick too. ■
Taper Roll Effect
Hi all..
If you were to flatten the trough out to be horizontal, the three rolls of the idler would have a very similar profile to that of an edge crowned pulley.
Belts on cones always tend to go up-hill towards the larger diameter end.
I suspect that the taper wing rolls are therefore for training, possibly instead of a slight forward tilt.
Seems a complicated thing to make though, so I can't see the point
Cheers
LSL Tekpro ■
To Learn In One Way
Dear Mr. Sganesh,
i also need to learn many things. Here some specific questions:
Details about the setup you encountered,
Difference in diameters of the rollers in question
A sketch
Some notes on the operators / manufacturers comments of the How that works? and To what purpose?
In wait for your kind & understanding reply
Regards
R. ■
Re: Taper Idler As Trough Idlers
Hello,
For belt conveyors; rollers are cylindrical in shape. In specialised case (if there is practical economy in totality considering price and inventory) then middle roll could be of bigger diameter to suit more load carried by middle roller. Tentatively 67% of material load for 3-equal roll trough idlers and around 50% of material load for 3-unequal roll trough idler. In such case, bigger diameter for middle roller is to keep belt stress / strain along thickness, within allowable limit.
Belt being single entity, it can move only at one linear velocity. Single roller of tapering diameter can also rotate at one value of rpm. So belt will be moving faster compared to roller periphery where diameter is less. It will be moving slower compared to roller periphery where diameter is bigger. So such idlers will result into faster wear of belt on such roller.
In spite of above, sometimes side rollers having tapering sleeve at their outer end are used to apply aligning action on belt. The outer roller periphery at its outer end being moving faster (m/s and not rpm), it will tend to push belt towards the conveyor centre, when belt has shifted on that side. Such type of idlers are used for tripper conveyor, etc. (not of very high speed or a significant application), accepting the faster wear of belt but to have aligning of the belt to avoid the ‘head ache’ due to belt misalignment.
The baggage / package handling conveyor can have tapering diameter roller for 90 degree turn unit, etc. with related constructional features. In this case the belt at outer radius has more m/s and so bigger diameter of roller at that location is matching to it.
Regards,
Ishwar G. Mulani
Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)
Author of Book : Belt Feeder Design And Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Re: Taper Idler As Trough Idlers
Hello,
For belt conveyors; rollers are cylindrical in shape. In specialised case (if there is practical economy in totality considering price and inventory) then middle roll could be of bigger diameter to suit more load carried by middle roller. Tentatively 67% of material load for 3-equal roll trough idlers and around 50% of material load for 3-unequal roll trough idler. In such case, bigger diameter for middle roller is to keep belt stress / strain along thickness, within allowable limit.
Belt being single entity, it can move only at one linear velocity. Single roller of tapering diameter can also rotate at one value of rpm. So belt will be moving faster compared to roller periphery where diameter is less. It will be moving slower compared to roller periphery where diameter is bigger. So such idlers will result into faster wear of belt on such roller.
In spite of above, sometimes side rollers having tapering sleeve at their outer end are used to apply aligning action on belt. The outer roller periphery at its outer end being moving faster (m/s and not rpm), it will tend to push belt towards the conveyor centre, when belt has shifted on that side. Such type of idlers are used for tripper conveyor, etc. (not of very high speed or a significant application), accepting the faster wear of belt but to have aligning of the belt to avoid the ‘head ache’ due to belt misalignment.
However taper rollers are possibly used for 90 degree bend belt conveyor unit for handling baggage and packages, with appropriate constructional features to keep the belt in position. In this case belt velocity at outer edge is more and there diameter is also more. So it does not have mismatch of belt velocity and roller peripheral velocity.
Regards,
Ishwar G. Mulani
Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)
Author of Book : Belt Feeder Design And Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Re: Taper Idler As Trough Idlers
Hello,
For belt conveyors; rollers are cylindrical in shape. In specialised case (if there is practical economy in totality considering price and inventory) then middle roll could be of bigger diameter to suit more load carried by middle roller. Tentatively 67% of material load for 3-equal roll trough idlers and around 50% of material load for 3-unequal roll trough idler. In such case, bigger diameter for middle roller is to keep belt stress / strain along thickness, within allowable limit.
Belt being single entity, it can move only at one linear velocity. Single roller of tapering diameter can also rotate at one value of rpm. So belt will be moving faster compared to roller periphery where diameter is less. It will be moving slower compared to roller periphery where diameter is bigger. So such idlers will result into faster wear of belt on such roller.
In spite of above, sometimes side rollers having tapering sleeve at their outer end are used to apply aligning action on belt. The outer roller periphery at its outer end being moving faster (m/s and not rpm), it will tend to push belt towards the conveyor centre, when belt has shifted on that side. Such type of idlers are used for tripper conveyor, etc. (not of very high speed or a significant application), accepting the faster wear of belt but to have aligning of the belt to avoid the ‘head ache’ due to belt misalignment.
However taper rollers are possibly used for 90 degree bend belt conveyor unit for handling baggage and packages, with appropriate constructional features to keep the belt in position. In this case belt velocity at outer edge is more and there diameter is also more. So it does not have mismatch of belt velocity and roller peripheral velocity.
Regards,
Ishwar G. Mulani
Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)
Author of Book : Belt Feeder Design And Hopper Bin Silo
Advisor / Consultant for Bulk Material Handling System & Issues.
Pune, India.
Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com ■
Photos Attached
Originally Posted by Roland Heilmann
i also need to learn many things. Here some specific questions:
Details about the setup you encountered,
Difference in diameters of the rollers in question
A sketch
Some notes on the operators / manufacturers comments of the How that works? and To what purpose?
In wait for your kind & understanding reply
Regards
R.
Dear Mr.Ronald Heilmann,
Kindly find the photos attached.
Thank you Mr.Mulani, for clearing our doubts.
Regards,
Attachments
taper trough idler north (JPG)
taper trough idler south (JPG)
■
Taper Idler As Trough Idlers
I find Graham's comment (and I G Mulani) very interesting. If this is a training means, instead of a forward tilt, then it will train the belt equally when running in either direction. This makes such a system effective at training reversing belts.
Joe Dos Santos ■
Are These Taper Rollers Installed Correctly ?
Dear experts,
In these types of taper rollers, which diameter should be nearer to belt edge ? Bigger diameter or smaller diameter of the taper roller ?
I think bigger diameter should be nearer to belt edge. Mr.I.G.Mulani's post also advices the same.
Regards, ■
Taper Idler As Trough Idlers
It really depends on what is the purpose of the taper. If the smaller part is on the inside it will have a tendency to miss-align the belt by pulling to the inside rather then crowding it towards the center.
Joe Dos Santos ■
Some More From The Tapered Roller
Dear Mr. Sganesh,
first of all thank you very much for those pictures.
It is on their content that i would like to underline the following: I think that this design of training idler is not to be approved as it is. I follow Gary's opinion.
Pls. compare pic 1 vs. pic. 2: When in pic. 1 everything seems in order, in pic. 2 the tapered roller seems much more used, and especially the small finger roller is not only well used, its support is also bent out of place. Meaning, that the belt did make its way up and touched over the edge. Pls. also look at the belt edge in this vicinity. Such finger rollers are quite an ambiguous piece of equipment, in my opinion.
The tapered idler design as such is based on friction, at that depending on belt and idler surface conditions. Here it seems to be steel rollers, surface which is affected by moisture, material buildup and so on. Parameters to not to be neglected even if the conveyor is located in a gallery or similar. The physical effect however is drawn from the tilted roller / idler principle, but there it is a lot of rollers adding up small amounts towards greater effect.
Perhaps others may give more insight on practical experiences and theoretical background? At least: here on this occasion, a more stringent and more broadbased belt training job has to be done rather than trying to heal symptoms, and just locally, at that.
Regards
R. ■
Taper Wing Rolls For Reversibles
Morning Joe..
I am never too old to learn, and I think you have hit the nail on the head!
I have always used garland idlers on my reversible conveyors, but the concept of using the taper wing rolls concept, make very good sense.
I will ask Melco, our local idler supplier, for an indication of the feasibility of the supply of such rolls here in South Africa.
(If I used taper wing rolls on garland idlers, reversible conveyors should then become really simple)
Cheers
LSL Tekpro ■
Taper Idler as Trough Idlers
Dear Experts,
Today I saw a set of carrying rollers. It has 3 idlers in a frame. The centre ( Load carrying ) idler is a normal , cylindrical in shape.
But the side idlers are taper in shape. Bigger diameter is nearer to the centre roller and smaller diameter near the belt edge.
What is the benefit of this design ?
Regards, ■