doubt about initial conditions

[biz]

Good morning.
I'm thinking about how to set up a simulation. In practice I have to simulate the work of the white band, which you see in the image, full load. the doubt is about the assignment of forces. I do not know if to think of the system as a carrucola, that is, known fb, fc reacts on the pin and is equal to fb, while it does is equal to fb+fc. I'm not convinced.

to understand: it is a wrapper. the band descends until it arrives near the bottom (full load).

 

[meccanicamg]

but is the belt fed on the right side? Isn't the load in the middle of the band between the two white and down?
If so, you only have vertical forces. possibly the break-off for the extreme left pin which is fixed.

 

[Marco F inox]

It is not clear how the mechanism works.
because the band is bound to left down and is tense to right down, the only resistance point is at the top or divided center on the width of the two pulleys.
what is it and how does it work?

 

[cacciatorino]

Good morning.
I'm thinking about how to set up a simulation. In practice I have to simulate the work of the white band, which you see in the image, full load. the doubt is about the assignment of forces. I do not know if to think of the system as a carrucola, that is, known fb, fc reacts on the pin and is equal to fb, while it does is equal to fb+fc. I'm not convinced.

to understand: it is a wrapper. the band descends until it arrives near the bottom (full load).

I believe your assumption is a great correct way, as long as the sums you make are vectoral and not scalar. Is it a pipe bundle machine after cutting?

 

[biz]

I believe your assumption is a great correct way, as long as the sums you make are vectoral and not scalar. Is it a pipe bundle machine after cutting?

Clearly

but is the belt fed on the right side?

si

Isn't the load in the middle of the band between the two white and down?

si

If so, you only have vertical forces. possibly the break-off for the extreme left pin which is fixed.

not really, but the problem is not the breakdown of forces, that is banal. I get the doubt about setting the loads properly. I see it as a carbide system. when I implement the boundary conditions I will have to load the pin to with 2 times the fract 2 weight force? while the pin will be loaded with only fract 2 weight force?

for @marco ferraroni : just know that the load is centered compared to the two upper pins, facing downward and that it affects the belt, bound as a drawing, that is on the lower left pin (the visible one) and on the lower right pin (low - you can not see-).

 

[biz]

I believe your assumption is a great correct way, as long as the sums you make are vectoral and not scalar. Is it a pipe bundle machine after cutting?

si

 

[Marco F inox]

then the motor that is right, pulls down the band or belt and lifts the load.
If so, you must know that when the load is totally down, the upward thrust,
will be maximum, little speed up, but great strength.
when the load will be up, the thrust will be low.
Depending on the position of the load, you have to track the diagram of the forces with the angles that form and you will see that at the top the thrust will be really little. the engine will have to use all its power to keep the load lifted.

 

[cacciatorino]

second.me do well to consider straps as carrucole.

each belt branch will take 1/4 of the total weight of the pipe bundle, as well as the 4 anchor points of the two straps (the two fixed points and the two windings).

Finally, each carbide pin will have to endure a double effort compared to the strap shooting (you can understand it by making the balance of moments compared to one of the two points where the strap wraps on the pulley: the moment motor is given by the force on the belt for the diameter of the carbide, the resistant one, of the pin, by the reaction of the pin for the radius of the carbide).

 

[biz]

second.me do well to consider straps as carrucole.

each belt branch will take 1/4 of the total weight of the pipe bundle, as well as the 4 anchor points of the two straps (the two fixed points and the two windings).

Finally, each carbide pin will have to endure a double effort compared to the strap shooting (you can understand it by making the balance of moments compared to one of the two points where the strap wraps on the pulley: the moment motor is given by the force on the belt for the diameter of the carbide, the resistant one, of the pin, by the reaction of the pin for the radius of the carbide).

However, simplifying, making a scheme:so it is like a carrucole system

 

[cacciatorino]

However, simplifying, making a scheme:View attachment 68407so it is like a carrucole system

Yes, but you have two straps, which have to support each half of the weight of the beam. from which each branch of each belt takes half the middle, i.e. 1/4.

 

[meccanicamg]

However, simplifying, making a scheme:View attachment 68407so it is like a carrucole system

the scheme so is right provided f= total weight/2 being two straps.

 

[biz]

Yes, of course, 1/4 for each belt. Sorry, I lost myself in a glass of water. Thank you.

 

[Marco F inox]

There is a little confusion, we make clarity and simplicity.
because it is not an elastic but a belt that does not stretch, it is influent that this is bound to a lower pin to the left, or directly to the fixed pulley (high to the left).
It is therefore necessary to consider the belt as one, pulled down thanks to the top-right reference pulley to lift the load. .
It is a mechanism that determines a shot of a quota a and the lifting of the load of a quota to/2, as an advantageous lever.
you lose moving, but you gain in the load, because it is the equivalence between two moments,
force by arm.

 

[biz]

There is a little confusion, we make clarity and simplicity.
because it is not an elastic but a belt that does not stretch, it is influent that this is bound to a lower pin to the left, or directly to the fixed pulley (high to the left).
It is therefore necessary to consider the belt as one, pulled down thanks to the top-right reference pulley to lift the load. .
It is a mechanism that determines a shot of a quota a and the lifting of the load of a quota to/2, as an advantageous lever.
you lose moving, but you gain in the load, because it is the equivalence between two moments,
force by arm.

so in your opinion that forces act on the upper and lower pin?
I am not entirely convinced of such reasoning. I do not fully understand the balance of the system because, thinking about it, it seems that the upper pin feels as much as the lower one, but if we treat this system as a carrucola, we know that the upper pin feels twice the lower one.

 

[Marco F inox]

There is a little confusion, we make clarity and simplicity.
because it is not an elastic but a belt that does not stretch, it is influent that this is bound to a lower pin to the left, or directly to the fixed pulley (high to the left).
It is therefore necessary to consider the belt as one, pulled down thanks to the top-right reference pulley to lift the load. .
It is a mechanism that determines a shot of a quota a and the lifting of the load of a quota to/2, as an advantageous lever.
you lose moving, but you gain in the load, because it is the equivalence between two moments,
force by arm.

the scheme so is right provided f= total weight/2 being two straps.

so in your opinion that forces act on the upper and lower pin?
I am not entirely convinced of such reasoning. I do not fully understand the balance of the system because, thinking about it, it seems that the upper pin feels as much as the lower one, but if we treat this system as a carrucola, we know that the upper pin feels twice the lower one.

Yes, but you have two straps, which have to support each half of the weight of the beam. from which each branch of each belt takes half the middle, i.e. 1/4.

hunter, it is not so, we have to treat the mechanism as a carrucole system where there is
only one belt, one fixed hook that is the lower left pin, a force down to the right made by a motor, more different load losses, due to friction, rolling of the load and possibly to the divergence that can have the belt on the two sides of ascent from the load.
I attach a schematic design with numerical example.

 

[cacciatorino]

hunter, it is not so, we have to treat the mechanism as a carrucole system where there is
only one belt, one fixed hook that is the lower left pin, a force down to the right made by a motor, more different load losses, due to friction, rolling of the load and possibly to the divergence that can have the belt on the two sides of ascent from the load.
I attach a schematic design with numerical example.

I invite you to read what you respond to before responding. The straps are two.

 

[Marco F inox]

I invite you to read what you respond to before responding. The straps are two.

I always think much before answering, but among the many different considerations present in the forum, you must accept mine too, which can also be subject to corrections. It cannot be considered an offense, but only a contribution to solving a problem.
I wanted to answer biz with the drawing, but I didn't do it in time, I had problems even with the annex, I thought to override it and answer you.
Now I want to know, where they start and where the two straps you see end.

 

[cacciatorino]

We are not talking about offenses, but only an invitation to give centered answers, because otherwise it only increases the noise and you get away from the goal you would like to reach by intervening on the forum. here are the two straps:

 

[Marco F inox]

We are not talking about offenses, but only an invitation to give centered answers, because otherwise it only increases the noise and you get away from the goal you would like to reach by intervening on the forum. here are the two straps:
View attachment 68414

the two straps can be considered united, only from the tree at the bottom moved by the motor,
but the effect of their operation is totally independent and you do not know that
produced by belt 1.
because you were only evaluating belt 2, with effects on the pins of the pulleys, I consider valid the considerations and calculations made with my previous attachment.

 

[meccanicamg]

hunter, it is not so, we have to treat the mechanism as a carrucole system where there is
only one belt, one fixed hook that is the lower left pin, a force down to the right made by a motor, more different load losses, due to friction, rolling of the load and possibly to the divergence that can have the belt on the two sides of ascent from the load.
I attach a schematic design with numerical example.

but p is half total load to be lifted to the machine.