number of epicicloidal satellites.

[leonardo-037]

Hi, I press that before opening this new discussion I have displayed a lot of posts about epicyclical rotisms also using the "search" function but I couldn't find the answer to my question.

I have to carry out a project for the examination of mechanical design i specifically it is to design an epicycloidal reducer for a transmission of a truck.
After banging my head on several books, dispenses and notes I have to entrust myself to someone who knows how to respond precisely.
the question is as follows: "How do I determine the number of satellites to be inserted in the reducer at one stage? "

design data are:


cin=c1= 950000 nmm applied to solar
#1= 1400 rpm
♪
zsat=z2=20 (exit portatreno)
zcor=z3=2*20+22=62 fixes to the rear frame.

I found on the books that if the number of teeth of the satellites is equal then the solar and the crown must be arranged so that a tooth of the solar gear on the satellite must correspond a tooth of the crown on the satellite.
I also know that in a rotism it is preferable to start from the design of the most stressed wheel that should be the solar in my case (if you give me confirmation on this point I would be grateful)

as I said before on all the posts I found around, the number of satellites was fixed a priori or however on some dispenses I found short hints but of geometric character while I knew that through an analysis of the forces it is possible to determine it in order to have values of tensions on the tooth minors of that limit.

If all my reasoning was wrong, please tell me a procedure to dimensional the rotism?
I hope you can help me.

 

[meccanicamg]

you can use kisssoft for sizing and checking and seeing going up with the number of satellites what happens.

In theory, instead, you have a certain factor of replenishment between solar and gear delivery. If you increase the number of satellites increases the number of teeth intake and therefore the equivalent cover therefore decrease the efforts provided that there is not too much game that would make more satellites useless.
Usually the gears are made with a number of teeth first or at least odd to use all the trick well and not to make the same hips of the teeth work

 

[leonardo-037]

Hello mecanicamg,
first of all thank you for being interested in the question.... unfortunately I do not know the software you mentioned but I will research on it.... As for the project being at university level I should know how to calculate all the parameters from me....

I have continued my research into this report (simple for other) which concerns the optimal condition for the installation of satellites, i.e.:

(solar teeth + crown teeth number) / number of satellites = full number

It seems at last to answer my question if it was not for having found an explanation entirely in contrast with that report. consulting the mechanical design book (juvinall I don't know if someone knows it) is reported as an example an epicloidal reducer with:

♪
zcor = 70
♪

and here we are. Then he says: being the number of teeth of the satellite odd, to a tooth in correspondence of the solar must correspond a void in correspondence of the crown (or better if I consider a tooth on the satellite after 180° always on the satellite there must be a void if z odd or another tooth if zpari). and still here I've come to understand the problem.
immediately after to calculate the number of satellites always the juvinall says: for the first described geometries you can have only 2 or 5 satellites you leave to the reader the task to demonstrate why.
I have armed myself with so much patience and I have come to the conclusion that the book considers an acceptable number of satellites if both following reports are met:

zcor/nsat=integer number
zsol/nsat=full number

and I actually find myself with satellite number 2 or 5.

All this goes in contrast with the report I wrote at the beginning of my message.
If I had to follow your advice to put on the solar a first number of teeth type 13 then doing 13/nsat I would never get a whole number so all the speech goes to that country.....
Would you give me more precise indication? Where am I wrong? What reasoning is more right?