positioning tab in mast-mode coupling

[mafer78]

Hi.
I wanted to ask if there are rules to follow for the correct positioning of a tab in the hub.

I read from other posts that besides having a central position can also exit the hub to be anchored by a spacer with quarry and/or radial opening.

//mafer

 

[TECNOMODEL]

always depends on how everything is built. if you only have to "transcinate" a hub then you use a length equal to the thickness of the same and sizing the thickness according to the effort you have to support.

then nothing forbids you to make the seat coming out of the tree for processing, assembly etc.

 

[Kakisan]

Hi.
I would advise you to use all the useful length of the hub, so as to reduce the thickness and largeness of the tab (in this way the reduction of useful section on both tree and hub will be lower in the section at the correspondence of the tab).
then technologically you can get rid of, you can pass it on the hub, download the extremes, use the form b or the shape c...
Have a good day.

 

[meccanicamg]

the general thing is to find the least tongue that can transmit the bike. if you do not leave the hub it is better because you avoid building those absurd and expensive substantials with the broaching for the unloading of the tab.

then for various needs it is possible to make them longer or with the front opening in the seat on the tree, with screw fixings and many variants.

avoid on the hub that has the small diameter of getting the tab to the shouldering of the diameter change because there would be two components of sensitivity to the carving that could break the shaft itself.

then dimensional to cut and pressure specifies coupling shaft hub.

 

[mafer78]

Bye to all,
First of all thank you so much for the answers and then I wanted to ask you if there is a software/tool/excel to make the measurements and/or verifications that mensiona Meccamg.

//mafer

 

[meccanicamg]

I think an excel is on the net, but it must be searched. I'll put my dispensing dispenses here

.



otherwise you can use kisssoft or you make the excel sheet with the above formulas.






adversity: if the materials of the tree and hub are different from the material of the tab, it is necessary to check with the mechanical characteristics of the three components.



then you have to look at the catalog what is available as lengths.





I had already posted these formulas.


found excel sheet here http://www.tecnocentro.it/tables_ita/linguette_6604_(catalogue &calcolo_coppia).htm

 

[mafer78]

great..... excellent both the dispenses and the rest.....tool excel I found in the annex a calculation that I had made, but this did not calculate the check to cut and pressure that you asked me......

kisssoft I'd like to have it.... but it's not free.... I'm sure it would make me easier to live....

the length of the tab I chose it from 20mm and the depth of the hub is 25mm the material of the shaft is a reclaimed c40.

What do you think?
//mafer

 

[meccanicamg]

great..... excellent both the dispenses and the rest.....tool excel I found in the annex a calculation that I had made, but this did not calculate the check to cut and pressure that you asked me......



kisssoft I'd like to have it.... but it's not free.... I'm sure it would make me easier to live....



the length of the tab I chose it from 20mm and the depth of the hub is 25mm the material of the shaft is a reclaimed c40.



What do you think?

//mafer

I think you need to check, but I believe in spans and feel that it's enough.

 

[mafer78]

less bad....they are nights and nights I make formulas and study. . . .
Are there regulations and/or rules also dictated by experience?

I attach you a constructive way.....like overview so then maybe I can start drawings etc....... could you give me some advice or highlight some mistakes?

ah in the new scheme I put a washer braces before the seeger

Thank you very much
//mafer

 

[meccanicamg]

There are no rules for where to put the bearings, as long as it is dimensioned right and do not shove the trees.
It would be good for you to do a larger section of the axis because you don't understand much....especially that shouldering thing is and why it is so large in diameter.

 

[mafer78]

Okay perfect. I found another tool for the tab that also makes me the calculation of cutting and surface pressure sizing, is what you asked for right?

I attach the images hoping that is what you asked, the shoulder is of axial block of the last bearing, its diameter is not yet accurate, which rests on the inner ring of the bearing.

//mafer

 

[TECNOMODEL]

can you post the link of the tool you found?

 

[mafer78]

can you post the link of the tool you found?

http://www.tecnici.it/software/categoria/meccanica/page/1/are some, that of the tabs is called "calc ling 1.0", need registration for download.

//mafer

 

[mafer78]

meccanimg, just above I have inserted the pictures of the axis....what do you say?

I also attach cutting and pressure calculation of the tab, what do you think?

 

[meccanicamg]

meccanimg, just above I have inserted the pictures of the axis....what do you say?





I also attach cutting and pressure calculation of the tab, what do you think?

the sizing is ok for the tab.

 

[meccanicamg]

Okay perfect. I found another tool for the tab that also makes me the calculation of cutting and surface pressure sizing, is what you asked for right?





I attach the images hoping that is what you asked, the shoulder is of axial block of the last bearing, its diameter is not yet accurate, which rests on the inner ring of the bearing.





//mafer

All in all, the tree is fine. the discharge between its bearing seats the msx -0,5 mm doi on the diameter to make it more robust.
pay attention to the bevels of pads that will be 0.5x15 degrees and not 0.5x45 degrees.

 

[mafer78]

Okay.
Would you leave or change it with something else?

//mafer

 

[easymec]

Good evening,
One thing I can't find is the minimum external diameter of the hub.
Whereas it is not calettato, what is the value of (external diameter) minimum for the hub?

for simplicity do we consider how resistant section that highlighted in black in the image below and check torsion?
therefore apply the extra safe hypothesis for the hub, the resistant section to be considered is external diameter of and internal diameter equal to di+2xt2, correct?

 

[biz]

Good evening,
One thing I can't find is the minimum external diameter of the hub.
Whereas it is not calettato, what is the value of (external diameter) minimum for the hub?

for simplicity do we consider how resistant section that highlighted in black in the image below and check torsion?
therefore apply the extra safe hypothesis for the hub, the resistant section to be considered is external diameter of and internal diameter equal to di+2xt2, correct?

think of a hub made of a very soft material. thinking that the hub is stuck and the shaft in rotation, you would see the material flowing (sliding plan-cut-) in the inner part, the one you did not color. the cutting plane is just that black circular line inside the crown.
It is true that we must also consider a torque component for the colored area of black.
In that case, as you thought it was, great lines, correct. yields first to cut or torsion zone? Of course it is a very gross and unsuitable hypothesis to reality.

However, verification is important. when checking I would do a numerical analysis, considering the real geometry of the section.

 

[meccanicamg]

Calettato means stocked shaft in hub with third object that blocks.
the ring that must bring the pair is that formed from the outer diameter hub and equivalent diameter just larger than the tongue edge. That's the black field. certainly also the area below cooperates.
verifications are done as in my post with formulas mentioned above. specific cut and pressure are to be evaluated for all three elements: tree, hub, tab.