geometric tolerances

[Matricola99]

Good morning to all, I apologize for disturbing, I would need some tips regarding the geometric tolerances to put on a shaft for wheel drive of a chariot (low number of turns, high torque). the shaft is profiled for coupling with the gearbox, with two bearing surfaces type 22216e and at the center a surface for the wheel, stable stuck to the press. which geometric tolerances should I place on these 3 different surfaces? Thank you so much to all!

 

[@ndreaR]

Good morning to all, I apologize for disturbing, I would need some tips regarding the geometric tolerances to put on a shaft for wheel drive of a chariot (low number of turns, high torque). the shaft is profiled for coupling with the gearbox, with two bearing surfaces type 22216e and at the center a surface for the wheel, stable stuck to the press. which geometric tolerances should I place on these 3 different surfaces? Thank you so much to all!

With regard to tolerances to be applied on bearing seats, you can consult the skf catalog, available for free online. This will be a total oscillation (run out in English). What exactly do you mean by wheel?
if you can give more information about your project in my opinion you may receive more information from more experienced people than me

 

[meccanicamg]

With regard to tolerances to be applied on bearing seats, you can consult the skf catalog, available for free online. This will be a total oscillation (run out in English). What exactly do you mean by wheel?
if you can give more information about your project in my opinion you may receive more information from more experienced people than me

the wheel that he intends is the wheel of the carriage, the one that rotates on the track.

 

[@ndreaR]

the wheel that he intends is the wheel of the carriage, the one that rotates on the track.

Thank you! I thought he meant that but I wasn't sure

 

[Matricola99]

hello to all, thank you so much for your help and interest, I press that the dimensional tolerances on all surfaces have already defined them, as well as those on the bearing surfaces (following the skf catalog), but I would like to know more about the other surfaces, I attach the design to make you understand better, if you can give me an evaluation. Thank you.

 

[@ndreaR]

hello to all, thank you so much for your help and interest, I press that the dimensional tolerances on all surfaces have already defined them, as well as those on the bearing surfaces (following the skf catalog), but I would like to know more about the other surfaces, I attach the design to make you understand better, if you can give me an evaluation. Thank you.

on the drawing you sent I have the following doubts:
1) lack surface roughness
2) the elastic ring seat I would quote it from the shoulder rather, I link you a video about it (

)
3) As for bearings if they have to support axial loads I would also estimate a geometric tolerance of double oscillation on the shoulder where they go to a bar
4) I would also make a check, from skf catalog, if the minimum shoulder straps are respected
5) the datum a and b is better to place them referred to the diametral quotas
6) the s6 tolerance on the phi85 diamtero can go well, with h7 hole you have a link with interference
7) I personalmte (but I only speak to you with study experience and non-work) would not put any further geometric tolerances on the coupling diameter with the wheel
8) the channel I do not have the rules under hand but I think it can go well as indicated
9) the indications for the seat, wheel etc. do not serve according to me in the drawing of particular

 

[MassiVonWeizen]

beyond what written by @ndrearicci there are errors both of quotation and technological. then you have to try to put yourself in the shoes of who that tree will have to build it and who has no idea, must import it, where it will be mounted.

 

[Matricola99]

on the drawing you sent I have the following doubts:
1) lack surface roughness
2) the elastic ring seat I would quote it from the shoulder rather, I link you a video about it (

)
3) As for bearings if they have to support axial loads I would also estimate a geometric tolerance of double oscillation on the shoulder where they go to a bar
4) I would also make a check, from skf catalog, if the minimum shoulder straps are respected
5) the datum a and b is better to place them referred to the diametral quotas
6) the s6 tolerance on the phi85 diamtero can go well, with h7 hole you have a link with interference
7) I personalmte (but I only speak to you with study experience and non-work) would not put any further geometric tolerances on the coupling diameter with the wheel
8) the channel I do not have the rules under hand but I think it can go well as indicated
9) the indications for the seat, wheel etc. do not serve according to me in the drawing of particular

Thank you so much andrea you were super nice!
below my comments at your points:
1) you are perfectly right, I indicated them on board drawing and I did not include them in the cutout I placed you, I had doubts about the wheel coupling superifice: being a coupling with interference roughness should be more precise right? Can you give me directions?
2) interesting, I will certainly look at it to better understand
3) yes, I had already rated double oscillation but it was not necessary
4) from skf catalog are respected these shoulders, but recheck
5) You're right, I'll correct right away
6) correct with interference
7) I am very interested in this.. How come? or considering the application is sufficient a concentricity and linearity on the face of the grafted wheel?
8) yes, I compiled it by looking at the legislation
9) All right, you're right

 

[MassiVonWeizen]

beyond what written by @ndrearicci there are errors both of quotation and technological. then you have to try to put yourself in the shoes of who that tree will have to build it and who has no idea, must import it, where it will be mounted.

quotation errors:
- the bevel before the diameter ø75 is not listed in that way, but with length and angle; because it is not possible to verify the diameter ø67 that you inserted and because in the process phase it is more practical to have the angle of inclination. the angle must be inserted as a separate quota and not as a suffix of the length.
- the length 35 of the bearing seat on the left is wrong because it is not quoted from the resulting angle; when you work you first shoulder and then bevels, also a bevel can be wrong and compromise the quotated size (35), finally that 35 is not verifiable correctly.
- the arrow tip of the grooved shaft goes on the primitive diameter
- the position of the seeger should always be placed starting from the bearing support shouldering.

technological errors:
- the bevel to insert a bearing must be 10/20° (see skf); with 45° the risk of impurity is high.
-The bevel for the wheel's calettation, considering the assembly type is absolutely necessary; Moreover it is preferable to make an invitation, in addition to the bevel, lowering of a few tenths (0.2/0.5 diametrali) the diameter for a length of at least a dozen millimeters without worrying if this length will go slightly under the wheel as the surface of calettamento will be almost total.
- lacks a geometric tolerance on the wheel that will have to be coaxial to the bearing seats
- looking at the tolerance between the bearing seats and that the diameter of the wheel, given the type of coupling, must necessarily have a fine roughness it is deduced that a grinding phase will be necessary; consequently a center tip is missing.
-The roughness on board design only serves to indicate what kind of roughness are required to make the shaft, but the operator should not invent where to apply them.

margin advice:
considered the automatisms of all cads it is advisable to insert in addition to the degree of tolerance also the shocks so that the operator has under the look what measure it has to get and above all check without going to browse tables in an environment not always convenient like that of an office.

 

[MassiVonWeizen]

on the above, as it serves the rectification lacking the exhaust gorges

 

[@ndreaR]

quotation errors:
- the bevel before the diameter ø75 is not listed in that way, but with length and angle; because it is not possible to verify the diameter ø67 that you inserted and because in the process phase it is more practical to have the angle of inclination. the angle must be inserted as a separate quota and not as a suffix of the length.
- the length 35 of the bearing seat on the left is wrong because it is not quoted from the resulting angle; when you work you first shoulder and then bevels, also a bevel can be wrong and compromise the quotated size (35), finally that 35 is not verifiable correctly.
- the arrow tip of the grooved shaft goes on the primitive diameter
- the position of the seeger should always be placed starting from the bearing support shouldering.

technological errors:
- the bevel to insert a bearing must be 10/20° (see skf); with 45° the risk of impurity is high.
-The bevel for the wheel's calettation, considering the assembly type is absolutely necessary; Moreover it is preferable to make an invitation, in addition to the bevel, lowering of a few tenths (0.2/0.5 diametrali) the diameter for a length of at least a dozen millimeters without worrying if this length will go slightly under the wheel as the surface of calettamento will be almost total.
- lacks a geometric tolerance on the wheel that will have to be coaxial to the bearing seats
- looking at the tolerance between the bearing seats and that the diameter of the wheel, given the type of coupling, must necessarily have a fine roughness it is deduced that a grinding phase will be necessary; consequently a center tip is missing.
-The roughness on board design only serves to indicate what kind of roughness are required to make the shaft, but the operator should not invent where to apply them.

margin advice:
considered the automatisms of all cads it is advisable to insert in addition to the degree of tolerance also the shocks so that the operator has under the look what measure it has to get and above all check without going to browse tables in an environment not always convenient like that of an office.

Thanks massive!
with regard to the diameter of the wheel drop (the phi 85 s6, to mean us), proponi quinidi una rectification of the same? I would have left a roughness of 1.6.
Then excuse me the silly question (it is right to be sure hahah) when you say that the diameter phi 67 cannot be verified you mean that the operator cannot make a measure with the caliber on that diameter, right?

 

[@ndreaR]

quotation errors:
- the bevel before the diameter ø75 is not listed in that way, but with length and angle; because it is not possible to verify the diameter ø67 that you inserted and because in the process phase it is more practical to have the angle of inclination. the angle must be inserted as a separate quota and not as a suffix of the length.
- the length 35 of the bearing seat on the left is wrong because it is not quoted from the resulting angle; when you work you first shoulder and then bevels, also a bevel can be wrong and compromise the quotated size (35), finally that 35 is not verifiable correctly.
- the arrow tip of the grooved shaft goes on the primitive diameter
- the position of the seeger should always be placed starting from the bearing support shouldering.

technological errors:
- the bevel to insert a bearing must be 10/20° (see skf); with 45° the risk of impurity is high.
-The bevel for the wheel's calettation, considering the assembly type is absolutely necessary; Moreover it is preferable to make an invitation, in addition to the bevel, lowering of a few tenths (0.2/0.5 diametrali) the diameter for a length of at least a dozen millimeters without worrying if this length will go slightly under the wheel as the surface of calettamento will be almost total.
- lacks a geometric tolerance on the wheel that will have to be coaxial to the bearing seats
- looking at the tolerance between the bearing seats and that the diameter of the wheel, given the type of coupling, must necessarily have a fine roughness it is deduced that a grinding phase will be necessary; consequently a center tip is missing.
-The roughness on board design only serves to indicate what kind of roughness are required to make the shaft, but the operator should not invent where to apply them.

margin advice:
considered the automatisms of all cads it is advisable to insert in addition to the degree of tolerance also the shocks so that the operator has under the look what measure it has to get and above all check without going to browse tables in an environment not always convenient like that of an office.

another thing, the arrow for the groove should not be corrected on the outer diameter, as you say goes on the primitive diameter. I am consulting one iso 6413.

 

[MassiVonWeizen]

but who is the project? Yours or yours99?

as it is a calettamento with an important interference (hitting a h7) that can get to the tenth more precise millimeter is the surface better manages the assembly; then it is not that it warms up with the dropper and probably warms up by dilating the hole beyond the tenth, but however considering the oscillation set of 0.01 the grinding is to be done in any case and so it is worth doing also on the seat of the wheel (which must however be tolerated compared to the bearings)

diameter 67 you can measure it with the caliber, but it will be an imprecise measure; take a caliber and measure a conicity and you will see that casino is

 

[@ndreaR]

but who is the project? Yours or yours99?

I don't understand the sense of answering myself like this, I'm a student and I was taking advantage of the discussion of freshman99 to clarify my doubt and perplexity. Besides, I feel like I've always been educated in asking. Thank you for your last answer but I would say you don't care any further.

 

[MassiVonWeizen]

another thing, the arrow for the groove should not be corrected on the outer diameter, as you say goes on the primitive diameter. I am consulting one iso 6413.

It's a fineness I saw on a couple of slides, I might have said a shit

 

[Matricola99]

Thank you so much for the advices are very pricey!
I'll fix the drawing right away.
I hope I can help you in the future!

 

[Matricola99]

Thanks massive!
with regard to the diameter of the wheel drop (the phi 85 s6, to mean us), proponi quinidi una rectification of the same? I would have left a roughness of 1.6.
Then excuse me the silly question (it is right to be sure hahah) when you say that the diameter phi 67 cannot be verified you mean that the operator cannot make a measure with the caliber on that diameter, right?

hi andrea, from normative tables (I don't remember which but if you look for it immediately) the couplings with forced interference to the press, impose arithmetic roughness at least 0.4, the grinding becomes indispensable.

 

[MassiVonWeizen]

hi andrea, from normative tables (I don't remember which but if you look for it immediately) the couplings with forced interference to the press, impose arithmetic roughness at least 0.4, the grinding becomes indispensable.

be careful that a h7/s6 do not do it with the simple press, but it also requires a preheat of the hole that will be as much as the interference is. therefore the measurements of the hole and the tree will be thoroughly verified to know how effective interference will be. the preheat can also result in deformations on the wheel that are to be evaluated in case the rolling diameter should be extremely precise

 

[Matricola99]

You're perfectly right, my mistake not to specify it! However, once the wheel is calettata, the rolling surface must have a linearity and concentric tolerance with the shaft