lifting board with toothed belt

[stefanobruno]

I made a small fork with a toothed pulley that climbs on a belt as from pdf attached.
My client expresses doubts about the possibility of straps to endure those alternating flexions.
I asked the supplier but, to get the answer, it will take a few days.
the fork makes 2 cycles per minute to 10 m/1' max and is driven by inverter.
I ask you if you have already faced a motorization like this or what you think.

Thanks, bye.

 

[gerod]

I did something in the past but I'm studying a similar problem with chains.
There are charts for choosing straps. I would say that, once you determine the forces at stake (inertials, pretension, etc.), take your service factor and then verify that the belt resists those loads with a certain margin.
the a-zeta had made a nice technical manual on the size of the straps.
I think it's still available even if I have the paper version.
What belt did you use?
but above all that forces you have to win?
then, 2 cycles per minute = 30 seconds to climb and 30 to get off? or are they less?

a greeting

 

[stefanobruno]

I don't have any problem with scope. I have a belt 8m50 door 8580n and has a breaking load of 33250n and I lift 1000n of peak ( 750n nominal).
the climb cycle ( 2500 mm to 10 m/1' max ) I do it in 20", idem downhill but with load 200n.
My problem is to understand whether to turn on the back of the belt on two 80 mm diameter mad rollers, whether acceptable or not.

I'm gonna go find me a-zeta.

with chains there would be no problem but they are in food and I would rather avoid.

Bye.

 

[cacciatorino]

is a very common application, all vertical axes with straps are made like this (eg: el.more).
But it checks well, besides shooting on the belt as gerod said: the belt performs a counter-fold on the smooth side, this usually reduces the permissible winding diameter to work safely. so when you go to see the minimum diameter of wrapping allowed, go to look for the note that says how to behave in case of counterfeit.

very often these lifters are accompanied by a pneumatic cylinder of weight compensation, so the gear motor must win only the inertia of the load and not also its weight. In these cases, however, it must be remembered to put on the cylinder a servolavola or a large storage tank to avoid dangerous (for the reducer) peaks of pressure.

 

[cacciatorino]

I've seen you've already understood the problem.

It is a food industry, perhaps better a polyurethane belt than a classic htd that tends to create rubber powder.

 

[sampom]

I made a small fork with a toothed pulley that climbs on a belt as from pdf attached.
My client expresses doubts about the possibility of straps to endure those alternating flexions.
I asked the supplier but, to get the answer, it will take a few days.
the fork makes 2 cycles per minute to 10 m/1' max and is driven by inverter.
I ask you if you have already faced a motorization like this or what you think.

Thanks, bye.

I understood that your doubt lies in the "inverse" winding around the 2 crazy wheels of reference.
It's still a planned application and choosing the right belt should be no problem. check in the catalogue which are the angles/rages of minimum winding (on the back, in the opposite).. Now I'm not underhanded, but if you asked the supplier, he'll be sure to advise you about it (they didn't answer you right away, it's not that great thing.. you will have spoken with a commercial:smile.
about the load with that boar silk pulls on other (only fix them well at the extremes with the appropriate tooth platelets).

if you still had "paura" you could within the limits of encumbrance adopt the mad wheels of greater diameter (it would be to say not smaller than the dense motor, if you are also 30-40% more) and remove them until you bring the 2 branches of parallel and orthogonal belt to the motion; if the motion wraps only half you already have enough.

greetings
Marco:smile:

 

[stefanobruno]

I found data here: http://mulco.gwj.de/it/it is not easy to know what is the minimum diameter in case of counterflation, not all specify it (in the link indicated the indication there is but not for the "my" belt ).

the fork is already counterweighted as far as possible, the indicated load is what remains from the empty / full situation.

the diameter of the crazy rollers is now obligated, the whole project is, as usual dictated by minimum dimensions, never that there is to be skied.

I wasn't afraid, they made me come:biggrin:.

Bye.

 

[Focus]

for these applications the best straps are those in metric step, polyurethane and steel cables with t or at profile (mulco so much to make a name).
on the catalog you will find all the data to size the recommended pulleys and minimum rays.

Hi.

 

[MFT]

I found data here: http://mulco.gwj.de/it/it is not easy to know what is the minimum diameter in case of counterflation, not all specify it (in the link indicated the indication there is but not for the "my" belt ).

the fork is already counterweighted as far as possible, the indicated load is what remains from the empty / full situation.

the diameter of the crazy rollers is now obligated, the whole project is, as usual dictated by minimum dimensions, never that there is to be skied.

I wasn't afraid, they made me come:biggrin:.

Bye.

Hi.

as already said there is no problem if you want to make a verification on the catalog of the poggi there is that scheme with all the calculations of the case, I attach you extract

Hi.

 

[stefanobruno]

there is that pattern with all the calculations of the case

I visited the site and downloaded the catalogs but, it seems, there is just that pattern without any other indications.
Did I miss something?

Bye.

 

[MFT]

there are those two following pages with example of calculation.

Mar

 

[stefanobruno]

It was resolved by using the manufacturer's u.t. that addressed me to this document: http://www.megadyne.it/ist/index.php?p=pr_macro_cat&macro_id=2&cat_id=4&famiglie=14&prodotto=80thanks to all participants.