doubt about application, size, calculations and materials mechanical reducer

[salvia]

Hello everyone,
I apologize in advance for stupid questions, if they're too stupid, don't answer me, please answer me the same: I am a mechanical engineering student struggling with the design of a single-stage reducer, from the track I know the power to be transmitted to the user that is 320 kw, the rotation system of the motor that is 710 rpm, the transmission ratio that is 4 and the duration to be guaranteed is 25000 hours, and I know that the wheel teeth must be helicoidal, my questions are as follows:
1)Once found the transversal module by formula (l'ho da da da http://www.edutecnica.it/meccanica/heli/heli.htm ) Do I have to choose its table value or do this only for the normal module? is such a module that allows me to find the primitive diameter of the pinion while the nomal one serves to define addendum and dedendum of the tooth, right?
2) what is the formula to get the value of σt (of the formula I mentioned before)? (for now I took it from table http://www.edutecnica.it/meccanica/ingranaggi/ingranaggi.htm#sym)
3) what could be the application of such a reducer? from my research I realized that the power is high enough (or much?), right? is the number of laps high or low? Could an application be a crane?
3)From calculations my pinion has: number of teeth 19, transversal module equal to 8mm (out 7,34 and I approximated by excess), diameter equal to 152mm according to you are plausible size?
4) for now I have chosen the material 18 hinges 7-6 for the wheels (well?) and I am deciding that of the trees, would you have some advice to give me?

Thank you so much to whom will you answer?

 

[volaff]

there are many examples of gearboxes with formulas and sizes in the forum.
try searching using the "research" function.

 

[PIETRO2002]

Hello everyone,
I apologize in advance for stupid questions, if they're too stupid, don't answer me, please answer me the same: I am a mechanical engineering student struggling with the design of a single-stage reducer, from the track I know the power to be transmitted to the user that is 320 kw, the rotation system of the motor that is 710 rpm, the transmission ratio that is 4 and the duration to be guaranteed is 25000 hours, and I know that the wheel teeth must be helicoidal, my questions are as follows:
1)Once found the transversal module by formula View attachment 62485 (l'ho da da da http://www.edutecnica.it/meccanica/heli/heli.htm ) Do I have to choose its table value or do this only for the normal module? is such a module that allows me to find the primitive diameter of the pinion while the nomal one serves to define addendum and dedendum of the tooth, right?
2) what is the formula to get the value of σt (of the formula I mentioned before)? (for now I took it from table http://www.edutecnica.it/meccanica/ingranaggi/ingranaggi.htm#sym)
3) what could be the application of such a reducer? from my research I realized that the power is high enough (or much?), right? is the number of laps high or low? Could an application be a crane?
3)From calculations my pinion has: number of teeth 19, transversal module equal to 8mm (out 7,34 and I approximated by excess), diameter equal to 152mm according to you are plausible size?
4) for now I have chosen the material 18 hinges 7-6 for the wheels (well?) and I am deciding that of the trees, would you have some advice to give me?

Thank you so much to whom will you answer?

I would recommend you to do a search on the forum, where the subject has been treated specifically so many times! It will take you some time to put together the information, but I think it's worth it, it's definitely not a problem that you will solve by applying only the formula you posted above.

 

[salvia]

Thanks to the answers, I actually read a lot of discussion about it but I will be quite inexperienced with the forum and also the field, the thing that I just can't understand, among all, is how to imagine a possible application, however thanks again, I try better maybe?

 

[volaff]

see if you can find:
henriot- handbook of gears

 

[salvia]

All right, thank you very much ? I have studied the part of the dentate wheels by construction of r. johns machines, however maybe try to find this other one too!

 

[PIETRO2002]

All right, thank you very much ? I have studied the part of the dentate wheels by construction of r. johns machines, however maybe try to find this other one too!

if you are looking in the forum you can also find many references on the texts and sites where to deepen, henriot, niemann, manual bonfiglioli, site khk gear and who more's got more 'of it!

 

[salvia]

Thank you very much, I'm looking for more in depth and there's actually a lot of useful information I'm sorry?

 

[Bain]

Hi, I'd like to show you something:
- the formula you used is used for a low number of turns, you are beyond that threshold

 

[salvia]

Hi, I'd like to show you something:
- the formula you used is used for a low number of turns, you are beyond that threshold

thank you for making me notice! but what formula do I have to use then? also on the book (young people) reports me the same, specific that I subsequently performed the verification to wear

 

[PIETRO2002]

thank you for making me notice! but what formula do I have to use then? also on the book (young people) reports me the same, specific that I subsequently performed the verification to wear

do not look for the simple solution.. Unfortunately, we cannot do this! Surely with the information you'll find will open a world and you'll understand more. designing a reducer is not limited only to dentate wheels, but there are trees, bearings sealing systems, lubrication carter, calculations for thermal power etc etc.

 

[Bain]

to me it has always been taught that with a number of laps as in your case you perform the wear design and then it happens to break, consider that 720rpm is the value of the user; the module is always calculated on the pinion that in your case is the driving wheel.
Then I'm still a student, if there's someone more expert who has something to correct me do it as well

 

[salvia]

ah yes, there is much more to do, here I reported the doubts about the things that didn't come back, I didn't want to ask for everything, however thank you really

 

[salvia]

to me it has always been taught that with a number of laps as in your case you perform the wear design and then it happens to break, consider that 720rpm is the value of the user; the module is always calculated on the pinion that in your case is the driving wheel.
Then I'm still a student, if there's someone more expert who has something to correct me do it as well

Thank you! to us the professor said to do otherwise then: first with bending and then wear, however it is 710 rpm/minute the inbound rotation regimen counting the transmission ratio of 4, should I not have 177,5 rpm?

 

[Bain]

Excuse me, the professor is right, from how the delivery was written it seemed that 710rpm were the turns of the user

 

[TETRASTORE]

to make it easier I place some of the discussions of this forum where you can find both the calculation, verification, materials and also many tips on drawing details, of course where it comes to multi-stage parallel axle gears you will have to refer to only one pair of cylindrical gears to helical toothing.
some of the discussions that may interest you are:

generico:quiquiresources:quispecifications on monostage gearboxes:quiquiquiquiobserving the discussions I have indicated to you the links, you will see that the design includes the calculation, verification and sizing of various organs (enrangements, trees, bearings, etc.), so it is advisable that you prepare a ladder with calculations, choice of materials, verifications, etc. by completing it with what you can do, obviously after having first analyzed the discussions that I have listed you as many as possible others you could find.
you need to create a mental order to analyze issues and the various users of the forum to help you where you will need more information to proceed.

as application, high power and as relatively high output speed, it is not very frequent; I think it could be the motorization of a pump or impeller of a surface aerator (cleaning system).
a crane (edile) normally has one (or more) motorization for rotation, one for the translation of the cart that carries the load and one for the lifting rod. for these applications are generally used multi-stage gearboxes and, in some cases for limited loads, endless screw-reducers for carriage translation, the output turns are almost always below 100.

 

[salvia]

to make it easier I place some of the discussions of this forum where you can find both the calculation, verification, materials and also many tips on drawing details, of course where it comes to multi-stage parallel axle gears you will have to refer to only one pair of cylindrical gears to helical toothing.
some of the discussions that may interest you are:

generico:quiquiresources:quispecifications on monostage gearboxes:quiquiquiquiobserving the discussions I have indicated to you the links, you will see that the design includes the calculation, verification and sizing of various organs (enrangements, trees, bearings, etc.), so it is advisable that you prepare a ladder with calculations, choice of materials, verifications, etc. by completing it with what you can do, obviously after having first analyzed the discussions that I have listed you as many as possible others you could find.
you need to create a mental order to analyze issues and the various users of the forum to help you where you will need more information to proceed.

as application, high power and as relatively high output speed, it is not very frequent; I think it could be the motorization of a pump or impeller of a surface aerator (cleaning system).
a crane (edile) normally has one (or more) motorization for rotation, one for the translation of the cart that carries the load and one for the lifting rod. for these applications are generally used multi-stage gearboxes and, in some cases for limited loads, endless screw-reducers for carriage translation, the output turns are almost always below 100.

thanks I will analyze all the links! and thank you for clarifying my dilemma about the application, really! ?

 

[TETRASTORE]

sage, I attach an extract from a catalog of an Italian manufacturer (stm) where you can see the dimensional and performance characteristics of a monostage industrial reducer similar to your (814).
The speeds shown include performance for electric motors at 1400, 1000, 500 rpm, while the data referring to the speed of 750 rpm can be obtained for interpolation.
generally the builders do not declare the duration in the catalog but should be about 10000 - 15000 hours; to have the required duration of 25000 hours, probably it will be necessary to pass to the higher magnitude (816).
legend:
No [min-1]: turn into the reducer (in your case 710)
r: real reduction ratio (z2/z1, or n1/n2))
No [min-1]: output turns to the reducer (n1/ir)
p [kW]: it is the power in input to the reducer (in your case 320 kw)
♪ [kNm]: output to the gear shaft
♪ [kN]: Allowable radial load at half protruding of the output shaft

 

[salvia]

sage, I attach an extract from a catalog of an Italian manufacturer (stm) where you can see the dimensional and performance characteristics of a monostage industrial reducer similar to your (814).
The speeds shown include performance for electric motors at 1400, 1000, 500 rpm, while the data referring to the speed of 750 rpm can be obtained for interpolation.
generally the builders do not declare the duration in the catalog but should be about 10000 - 15000 hours; to have the required duration of 25000 hours, probably it will be necessary to pass to the higher magnitude (816).
legend:
No [min-1]: turn into the reducer (in your case 710)
r: real reduction ratio (z2/z1, or n1/n2))
No [min-1]: output turns to the reducer (n1/ir)
p [kW]: it is the power in input to the reducer (in your case 320 kw)
♪ [kNm]: output to the gear shaft
♪ [kN]: Allowable radial load at half protruding of the output shaft

Very kind, really! a question (very trivial probably), but this in the file is the type of modular reducer, right?

 

[TETRASTORE]

but this in the file is the type of modular reducer, right?

Yes, in your case for example, the pair of gears and the relative shaft output could constitute the final stage of other gears to 2, 3, 4.. stages both to parallel axes and to orthogonal axes, as you can see in the attached image (pair gears highlighted in yellow).
to the below link you can see the explosive components of a 2-stage modular axle reducer, in your case you only care about the final stage.