Tension in Conveyor Belt due to weight placed on it

In summary: You need to also account for the weight of the belt and the weight of the material being transported.In summary, the equation for the tension in a belt conveyor transporting material is: (Wm+Wt)x g x μ.
  • #1
achan88
4
1
Hello,

I am trying to determine the tension in a belt conveyor transporting material to calculate the motor power required and also tensioning force needed on it. I wanted to know how the material weight that is being carried affects it. I considered the tension to be equal to the friction force due to material weight as well as the belt weight. So assuming the material wt. = Wm lbm and belt wt. = Wt lbm, the frictional resistance will be = (Wm+Wt)x g x μ. Is this correct? What other forces do I need to take into account?

I have attached a schematic diagram of the problem.

Thank you.
 

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  • #2
If the material is placed continuously along the belt then you have a catenary between supporting rollers.
As the sag allowed between rollers increases, the tension in the belt rapidly reduces to a reasonable value.
 
  • #3
A free body diagram will show that If the belt does not sag the tension due to the weight is infinite..
So clearly the belt will sag - And how much it sags will define the tension.

What friction are you trying to find? The bearing friction in the rollers? The belt-roller interface friction?
These may help for the former:
http://www.roymech.co.uk/Useful_Tables/Tribology/Bearing Friction.html
http://www.skf.com/group/products/b...ings/principles/friction/skf-model/index.html

For the latter, the belt-roller friction is really only important for the driven roller (assuming that's how it's driven), the belt-roller friction at the idler rollers should only become relevant during bearing failure - assuming your bearing selection is acceptable.
 
  • #4
If the material is placed continuously along the belt then you have a catenary between supporting rollers.

Oh, I forgot to mention that the belt is traveling over a 3"x3" mesh support grid of 1/8" SS rods. So the sag is pretty much negligible. The frictional force that I am considering is the resistance to the belt sliding over the mesh while carrying a constant layer of material. The speed is also pretty slow, about 2 ft/min.

I also found this webpage : http://www.brighthubengineering.com...nsite-calculations-for-conveyor-belt-systems/

Does this equation account for the friction resistance or do I need to add it to calculate the total effective tension?

Thanks.
 
  • #5
achan88 said:
Oh, I forgot to mention that the belt is traveling over a 3"x3" mesh support grid of 1/8" SS rods. So the sag is pretty much negligible.
That is a game changer.
achan88 said:
= (Wm+Wt)x g x μ.
That is enough to estimate the tension if the belt only moves material horizontally.
 
  • #6
A couple of things:
1. A conveyor belt that is allowed to sag is not being properly supported. They should never be allowed to sag.
2. Even if it did sag, that has nothing to do with the power needed to make it run because the sag tension is a constant force that is equal everywhere and is static: it exists whether the belt is moving or not and isn't affected by the motion.
 

FAQ: Tension in Conveyor Belt due to weight placed on it

1. How does weight placed on a conveyor belt affect tension?

When weight is placed on a conveyor belt, it increases the tension in the belt. This is because the weight creates a downward force, causing the belt to stretch and become tighter. The amount of tension will depend on the weight and the type of belt being used.

2. Can too much weight on a conveyor belt cause damage?

Yes, placing too much weight on a conveyor belt can cause damage. This is because the increased tension can lead to excessive stretching and strain on the belt, which can cause it to break or wear out faster. It is important to follow weight capacity guidelines to avoid damaging the conveyor belt.

3. How does the angle of incline affect the tension in a conveyor belt?

The angle of incline can greatly affect the tension in a conveyor belt. As the angle increases, so does the weight and force placed on the belt, which in turn increases the tension. It is important to consider the angle of incline when determining the weight capacity of a conveyor belt.

4. What is the maximum weight a conveyor belt can handle?

The maximum weight a conveyor belt can handle will depend on various factors such as the type of belt, its width and length, and the angle of incline. It is best to consult the manufacturer's guidelines to determine the maximum weight capacity for a specific conveyor belt.

5. How can tension in a conveyor belt be measured and adjusted?

Tension in a conveyor belt can be measured using a tension gauge or by manually applying weight and measuring the deflection of the belt. If the tension needs to be adjusted, it can be done by adjusting the tensioning device, such as a take-up pulley, or by adding or removing weight from the belt. It is important to regularly check and adjust tension to ensure optimal performance and prevent damage to the belt.

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