drawing of a tree of a reducer

[J ax]

Hello everyone, I'm a mechanical engineering student.
We have, through input data, to be sized a shaft of a two-stage reduction gearbox characterized by toothed wheels to straight teeth, and then this tree we must also draw it:/ . in lesson we have been made a quick demonstration of how to dimensional the tree 3, the user, that is to be connected to the user. instead I have to size and draw the tree 1, that is the first, that to connect to the motor.
with regard to the real dimensioning (calculating of forces and moments, choosing of the material of the wheels, testing fatigue and pitting of the latter, static sizing and fatigue of the tree, choice of bearings and determination of the characteristics of the tabs) I should not have excessive problems.
the problem, at least for me, resides in the design, in the sense that the assistant made us a very quick sketch and absolutely not on the scale of the 3 tree that he did, and then said quickly that there will have to be seals and the case of the reducer, connected through screws. I didn't understand much. But if I could understand correctly how precisely this tree 3 should be done, then I could adapt it to my case (as I must make the tree 1).
So I was wondering if someone could help me, I don't know, maybe having a file of autocad or similar programs, or giving me suggestions.

I attach to the message two jpg files, which would practically be the tree in question designed by the assistant, resumed by two my companions (I saw that I did not see well until the board!)

In this case you had the 80 wide toothed wheel, then 180 is the distance between the center of the wheel and the center of the left bearing and 70 is the distance between the center of the wheel and the center of the right bearing (also here, from the sizing told us that the distance between the bearings was 250, but then tell us right, after the right bearing, how much you still have to do along the shaft). the tab is 14*9*60 and that toothed wheel had a radius primitive 144 mm. bearings are ball bearings with d=50 d=110 b=27

 

[MBT]

but the schools have recently become "reducer's festival" after the decree gelmini?
Anyway, let's talk about it after you showed up in the appropriate area and you conveniently used the proverbial "search" button. . .

 

[meccanicamg]

ciao j ax. per prima cosa ti consiglio as follows:

- read the rules well and introduce you- use the search button to find what has already been posted
- I recommend these links where I have already explained about trees and gearboxes 1 2 3 4.

then we discuss it.

 

[J ax]

the regulation I had read it, then since this forum is huge I tried to look for the topic where it turns out but I did not find it, so I made a brief presentation on the first post of this topic and this discussionhttp://www.cad3d.it/forum1/showthread.php?t=26351&highlight=riduttoreI had already seen it, I found answers to some of my doubts but not to those I reported on the first post, like how and where the seals and the case of the reducer must be

 

[meccanicamg]

read here! http://www.cad3d.it/forum1/showthread.php?t=26549the seals are foreseen the proximity of the shaft where the case ends to ensure the non contamination of the bearing by external agents and possibly not to let out the internal lubricant. for choice see skf in the section radial sealing rings for trees.

How should the reducer's case be? What does that mean? cast iron or aluminum or structural steel electro-welded. if the reducer is made up of 2 volumes because the first is a conical couple and then there is the second stage formed by straight or helical teeth wheels (cylindriche) it is necessary that the case of the first stage is applicable to the main case. all the mechanics must be mounted before and assemble everything on the main case. I've done many notes and corrections in the posts I've linked you, just read. if you read the link that you have also returned to the end, you will find the dislocation on the case, how to do it, why, the hole of passage etc.

Have you ever taken a reducer in your hand? never seen how they are made? searched in google? I'm talking to a student, but... What preparation do you have? Did you do technical school before? You come from high school, so I have to explain what a life is? to give you information dobbiam also understand what level you are. That's what it takes to show up.

 

[J ax]

So I'm in the third year of mechanics, and first I did the scientific high school. Let's say that of theory something I should know, but on practice I am absolutely lacking in the sense that, in this case, I have never seen or taken a reducer in hand. and also all these things between seals etc etc., drawing machines (for what little I remember) we did not do them, so practically I see them now for the first time.
so, for these things here, my problem is what I have to put around this tree and how to draw them, I hope I have clarified my "position"

 

[meccanicamg]

Okay, now your position is clearer.

I invite you to read qui if you have not yet looked that it is the reference to the skf, where there are all the seals.

in particular radial uppers are lincate in this link and there are illustrations on their operation and how they fit.

In addition to This link find the complete catalogue.
qui find examples of application.

the prappresentation can be in section effectively as they are or with simplified method (retangle with cross or rectangle with cross and tip on the direction of the estate).

But you don't have a drawing book? vademecum for designers and technicians? If you want to become ing... you must have manuals, otherwise you will never have knowledge or tools,

 

[J ax]

Okay thank you, after I try to understand something from those links.
In my case I inotre on the right jpg, between the 2 that I attached in the first post, all on the right there is attached to the bearing something indicated with a 3 circled. What is that there?
As for the case, since nothing is said in the exercise, I can try to reproduce it as it is in the jpg I have attached, or are there specific things to respect?

for the drawing book I have the backincasa chirone

 

[meccanicamg]

Okay thank you, after I try to understand something from those links.
In my case I inotre on the right jpg, between the 2 that I attached in the first post, all on the right there is attached to the bearing something indicated with a 3 circled. What is that there?
As for the case, since nothing is said in the exercise, I can try to reproduce it as it is in the jpg I have attached, or are there specific things to respect?

for the drawing book I have the backincasa chirone

reference (3) is a seeger. I didn't see any case in the attached pictures, except for two missing walls of the case. you have to make a complete design as if you were to send it to production, even better as if you were to do it in practice:

They all say the chirone is a good book... never browsed in my life, but seeing the questions that arise, rest of the idea that my 3 volumes "from project to product - paravia" are much more detailed, moreover with the collection uni m1 (general and mechanical volume) and with "vademecum for designers and technicians - hoepli" and other manuals also in English language there is a wide overview to understand regulations, representations, examples.

I repeat that in the links above mentioned there are the diesgni and explanations. So much so I also posted a design in the section of a single-stage gearbox with helical wheels made with two crates.

 

[PierArg]

reference (3) is a seeger. I didn't see any case in the attached pictures, except for two missing walls of the case. you have to make a complete design as if you were to send it to production, even better as if you were to do it in practice:

They all say the chirone is a good book... never browsed in my life, but seeing the questions that arise, rest of the idea that my 3 volumes "from project to product - paravia" are much more detailed, moreover with the collection uni m1 (general and mechanical volume) and with "vademecum for designers and technicians - hoepli" and other manuals also in English language there is a wide overview to understand regulations, representations, examples.

I repeat that in the links above mentioned there are the diesgni and explanations. So much so I also posted a design in the section of a single-stage gearbox with helical wheels made with two crates.

Hello, I confirm that the chirone is backincasa is done very well.

for the rest, as the good mechanicsmg says, you can not have the "vademecum for designers and technicians" of the baldassini. an engineer/designer/designer without vademecum of baldassini is like an apostle without the gospel. :biggrin:

 

[meccanicamg]

Hello, I confirm that the chirone is backincasa is done very well.

for the rest, as the good mechanicsmg says, you can not have the "vademecum for designers and technicians" of the baldassini. an engineer/designer/designer without vademecum of baldassini is like an apostle without the gospel. :biggrin:

you who have the return home.... how are the gearbox treated?
I have on my own: all mechanical organs (dened wheels, cuscientti, seals, seeger, wreaths etc. all). schematic representation of bearings. many drawings of albris with pinions of quotated piece, many axioms of gearboxes with their quotated parts, sections of gearboxes, parallel axes and orthogonal axes. drawings of the seals and lids, how to mount the bearings and lock etc. I think there's everything about the books I have.

instead for the questions that are asked by those who have the return home I ask myself: or do not know anything about drawing, or do not reason, or on the book there is not enough explanation material. I want to understand

 

[PierArg]

you who have the return home.... how are the gearbox treated?
I have on my own: all mechanical organs (dened wheels, cuscientti, seals, seeger, wreaths etc. all). schematic representation of bearings. many drawings of albris with pinions of quotated piece, many axioms of gearboxes with their quotated parts, sections of gearboxes, parallel axes and orthogonal axes. drawings of the seals and lids, how to mount the bearings and lock etc. I think there's everything about the books I have.

instead for the questions that are asked by those who have the return home I ask myself: or do not know anything about drawing, or do not reason, or on the book there is not enough explanation material. I want to understand

Now I don't have the book under my hand and I don't think there are sections that treat the gearboxes in a dedicated way. But there's no way.
for the rest is divided as you described your textbook.
the strong point is how it treats geometric tolerances: there really if you don't understand them then you have serious problems...:biggrin:

If it can be of help I can tell you that the book chirone backincasa treats the topics very simple with an elementary language. I also came out of high school and, having no preparation on the mechanical/industrial design, I found the book very "in my reach".

Perhaps the weak point is that the arguments are treated in a very limited way, no examples, cases and analogies are made with other components or even cases in which they explain "the component in the axieme".


I hope I have given you exhaustive answers

@j ax: I would pray to confirm or deny what I said.
Thank you very much

 

[meccanicamg]

Now I don't have the book under my hand and I don't think there are sections that treat the gearboxes in a dedicated way. But there's no way.
for the rest is divided as you described your textbook.
the strong point is how it treats geometric tolerances: there really if you don't understand them then you have serious problems...:biggrin:

If it can be of help I can tell you that the book chirone backincasa treats the topics very simple with an elementary language. I also came out of high school and, having no preparation on the mechanical/industrial design, I found the book very "in my reach".

Perhaps the weak point is that the arguments are treated in a very limited way, no examples, cases and analogies are made with other components or even cases in which they explain "the component in the axieme".


I hope I have given you exhaustive answers

@j ax: I would pray to confirm or deny what I said.
Thank you very much

then confirm my doubts. I who have done mechanical expert I have not bought any drawing book for the university, inasmuch as the ones I have seen recommended (that now I do not remember) are volumes of not many pages, with so much talk and little technical spent at the end of learning.

thanks pierarg x l'info :finger: at least I know how to calibrate the answers

 

[PierArg]

then confirm my doubts. I who have done mechanical expert I have not bought any drawing book for the university, inasmuch as the ones I have seen recommended (that now I do not remember) are volumes of not many pages, with so much talk and little technical spent at the end of learning.

thanks pierarg x l'info :finger: at least I know how to calibrate the answers

I add something very important and that before I forgot to punctuate: if a person coming out of the industrial technician (of course done properly) studies on this book find nothing extra.

I believe that the chirone is the most used in universities for its approach: not all students who choose mechanical engineering come from technical institutes.
the problem is that, especially in the south (I am Calabrian), technical institutes have serious shortcomings. They do not have any laboratories (that, to say, not even at university:biggrin, nor qualified personnel to put us in.

You know why I chose science? because I was convinced that at least he would teach me to sit and study. and it doesn't rain on it. for the rest I didn't even know what a sigma or a tau was (the ones in fact because by curiosity I used to spray my older brother's books).

 

[meccanicamg]

for the rest I didn't even know what a sigma or a tau was (the ones in fact because by curiosity I used to spray my older brother's books).

That's what the older brothers need. Fortunately when I did the superiors to the technician we still had our beloved workshop with a 30 ina of parallel lathes, 4 universal milling machines, 30 rowing machines of which 5 mechanics and other hydraulics, special turning machines to copy or with automatic charger or other and the rest of the equipment. a fully equipped double laboratory of chemistry, 3 computer laboratories (unfortunately a little lacking), a multimedia laboratory for the English language.

At the university we also used the laboratories of measures, metrology and control (sitec) so we had the opportunity to touch things and work on it.

Unfortunately, over time things have to be changed and even the hours of workshop in high school have diminished them by strategy of the various ministers who have succeeded, but it is a sin and fortunately the danger of closing has been escaped.

the our technical institute, once occupied 1/4 of the city, had the internal railway, produced steel, had the workshops that built bridges and railway locomotors. in the evening he was studying and working day. those were training times. already when I was enacted there was not all this, but certainly much more than other institutions.

 

[PierArg]

That's what the older brothers need. Fortunately when I did the superiors to the technician we still had our beloved workshop with a 30 ina of parallel lathes, 4 universal milling machines, 30 rowing machines of which 5 mechanics and other hydraulics, special turning machines to copy or with automatic charger or other and the rest of the equipment. a fully equipped double laboratory of chemistry, 3 computer laboratories (unfortunately a little lacking), a multimedia laboratory for the English language.

At the university we also used the laboratories of measures, metrology and control (sitec) so we had the opportunity to touch things and work on it.

Unfortunately, over time things have to be changed and even the hours of workshop in high school have diminished them by strategy of the various ministers who have succeeded, but it is a sin and fortunately the danger of closing has been escaped.

the our technical institute, once occupied 1/4 of the city, had the internal railway, produced steel, had the workshops that built bridges and railway locomotors. in the evening he was studying and working day. those were training times. already when I was enacted there was not all this, but certainly much more than other institutions.

all these machines together I have never seen them!!!



You know what my university lab was?
I went back from university on Friday and went to my friend who has a mechanical workshop. I explained to him the theoretical piece and he explained it to me from a practical point of view.:smile:


Do you know how many times I've been in the lab at unification? two/three for a maximum of 4 hours in 5 years.

What a shame! !
the laboratories are actually there, but they are "monopolized" by professors to do the facts to them.

only one professor made us do 2 lessons in the lab (among others one of the best professors I've ever had). ..this case had come out of the mit.

 

[meccanicamg]

all these machines together I have never seen them!!!

You know what my university lab was?
I went back from university on Friday and went to my friend who has a mechanical workshop. I explained to him the theoretical piece and he explained it to me from a practical point of view.:smile:

Do you know how many times I've been in the lab at unification? two/three for a maximum of 4 hours in 5 years.

What a shame! !
the laboratories are actually there, but they are "monopolized" by professors to do the facts to them.

only one professor made us do 2 lessons in the lab (among others one of the best professors I've ever had). ..this case had come out of the mit.

It is shameful yes, then we complain that young graduates can't do their job, that companies exploit, that salaries are low. I struggle to keep my figure high curse:

 

[linch]

It is shameful yes, then we complain that young graduates can't do their job, that companies exploit, that salaries are low. I struggle to keep my figure high curse:

In a certain period I gave some work to a young ing.meccanico graduated from a university in the north, the work consisted of editing some details already carried out, to adapt them to a new machine.
I tried to explain several times what it was necessary to do, but there was no direction, he couldn't handle a whole design with its views, quotas, tolerances, prisms, etc.
after several attempts I had to give up.

 

[meccanicamg]

In a certain period I gave some work to a young ing.meccanico graduated from a university in the north, the work consisted of editing some details already carried out, to adapt them to a new machine.
I tried to explain several times what it was necessary to do, but there was no direction, he couldn't handle a whole design with its views, quotas, tolerances, prisms, etc.
after several attempts I had to give up.

Unfortunately, it happens. My personal experience leads to the following: me and other 4 or 5 college colleagues have always given us a lot to do, regardless of university specialization. So much so that one is very good in heat treatment and metallurgical field, the other is a magician of the car industry and I in the part of automations, mechanical dimensioning, thermal fluid dynamic simulations, the other is more attentive to the regulations. often we happen to find ourselves for clarifications, consults and we are technically prepared (everyone in his field). we all come from technical institutes and we had the opportunity to experiment at home, make small investments, buy equipment, dirty hands, build, weld, turn back etc. someone had the family company and breathed the good air.

our other "colleges" as well as "friends from beer" have lived the university experience as a right step to have in hand a sheet of paper. in fact they have no expectations, they are not motivated, they have no interest and even the most obvious things turn out to them unknown. Unfortunately they lower the level of the figure of the engineer. Here is also the low pay.

I often went to the workshop to repair machine tools, build equipment and everything else out of the expected hours. in the drawing hours, since I was doing well the prof let me go to the workshop, sometimes it gave me to correct the exercises of the previous class. I always had the chance to emerge and grow.

I still sleep little now, I keep updated and since I am looking for a job as you must, I hope that companies (although not put well) have an eye to assess my skills and want to invest.

 

[snaroz]

you who have the return home.... how are the gearbox treated?
I have on my own: all mechanical organs (dened wheels, cuscientti, seals, seeger, wreaths etc. all). schematic representation of bearings. many drawings of albris with pinions of quotated piece, many axioms of gearboxes with their quotated parts, sections of gearboxes, parallel axes and orthogonal axes. drawings of the seals and lids, how to mount the bearings and lock etc. I think there's everything about the books I have.

instead for the questions that are asked by those who have the return home I ask myself: or do not know anything about drawing, or do not reason, or on the book there is not enough explanation material. I want to understand

on the chirone-tornincasa about the gearboxes (and much more) there is only a miserable split... and not another word