Hello
I'm drawing a build in Solidworks 2016 with a timing belt of 9.52, a sprocket of 12 teeth and one of 42 teeth, I drank on this problem:
Is it possible to match the teeth of the belt on the two sprockets knowing that they do not have the same diameter, on the 12 tooth one no problem, but the 42 tooth one I don't see how to do it.
Thank you and have a good end of the year
Hello
You have to send the parts with it. Assembly alone is not enough.
Hello
If you knew how to do it on the 12-tooth side, it's the same construction on the 42-tooth side, then you have to have the right center distance.
Look at this site: https://mulco.net/plans-cao/?lang=fr
There is a module that will allow you to find the right center distance.
According to my logic the teeth cannot be identical, I think that the more the diameter increases the more the width of the teeth increases (since the belt teeth are earlier than this average line unlike a roller chain), on the other hand the shape of the hollows which is corresponding,
I can't find where the error is in your diagram but there is no difference between a toothed belt system, a chain system or a classic gear, except that the neutral fiber actually changes position.
On a belt system, this fiber is above the teeth: to put it very simply, the belt consists of a solid back reinforced with a steel or Kevlar cable (which makes it substantially inextensible) on which the teeth are molded to avoid the relative slippage between the belt and the pulley.
Attached is the documentation of Binder Magnetics: see page 10 paragraph 3.
To @soring you have to open in large design management to see with the unattached parts.
On the other hand it's better to join the pieces (pack and go to do this)
Otherwise in view of the assembly I guess you want to draw the belt with its teeth and make the teeth match on the 9dts sprockets and on the 42 teeth sprockets.
For your information there is not much interest except to row SW for not much but if you contravene the 1st teeth at the bottom on the sprocket (free rotation then up on the other sprocket it should work.
Then you can remove these 2 constraints and add driven belts, and a mechanical gear constraints between the 2 sprockets with the right ratio.
For my part, the belt remains smooth and the sprockets most of the time are just stuck in rotation, it's much less heavy and sufficient for plans and assembly.
Stefbeno, in the referenced paragraph, it is mentioned three types of carving, I guess that practically (most cases) the contact or reduced clearance types are enough, but the "0" pruning confirms my doubts at least theoretically,
Hello sbadenis,
It's true that there's not much point in pushing the drawing to this point, but I'd like to continue with a movement study
for a demonstration.
How to put the pinion in free rotation
Thank you
Hello
My interpretation of the question asked: how to constrain the assembly to obtain a realistic representation of the pulley/toothed belt transmission, and perhaps an animation ("motion study for a demonstration").
The first condition is technological: the two pulleys and the belt must be compatible in terms of pitch and shape of the gears, and must respect the relationship between belt length, pulley diameters and centre distance...
The easiest way to do this is to use a manufacturer's documentation and 3D models.
The second point concerns the positioning of the parts in the assembly.
Using a belt/chain assembly feature between the two pulleys forces the rotational speeds and angles to respect the transmission ratio defined by the radii of the selected entities at the time of creation. To orient the two pulleys separately so that the teeth coincide with those of the belt, it is necessary in order:
- inactivate the Belt/Chain function,
- apply the appropriate stresses for the coincidence of the teeth,
- then reactivate the Belt/Chain function.
Note that the transmission ratio is equal to 12/42... The rays used to create the function must respect this ratio for the study of motion to conform to reality. It is very likely that the different radii of the volume bodies do not allow this ratio to be respected.
Maybe circles should be used in specially created sketches...
As for hoping for a realistic animation of the belt during the movement, I don't see the solution...
A flat belt would make a better illusion than a toothed belt.
Hello
I'm going to stay on a flat belt, it's too complicated for not much.
Thank you all, and happy holiday