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simulation of a planetary gear system


New member
I am trying to run a simulation of a planetary gear system consist of four planetary gears, one sun gear & a ring gear. The planet gears will be revolving around the sun & the ring gear. I am trying to run this simulation on Promotion but I am having problems. I already defined the gear connections, material & has made the sun gear as a driver & give it a certain angular velocity. Every time when I try to run the moton analysis on it, I got the message showing that engine is not connected. Can anybody help me in this problem?


New member
Which version are you using? In the Wildifire Mechaninsm you have that assemble the 4 planetary and the sun with pin, after

you assign the gear movement and every one, saying the relation between its. About this message I


New member
I m using ProE2001.

I think mechanism option is not gonna work coz there will be interferences in the gears if I'll use mechanism method. I tried the mechanism method with one sun & one planet gear & I was able to rotate both on their axes but there were interferences.

Promotion has the option of gears & gear pairs so that there will be no interferences between the gears.



What is it you are trying to simulate? I can imagine that with the simple use of parameters and relations one could simulate the rotational movement of a planetary gear-set in Pro/E 2001 quite easily.

Best regards,

Matthew Ian Loew

Luck is the residue of design.

Branch Rickey


New member
Thankx for replies

I m trying to rotate sun gear on its axis & the planetray gears around their axis as well as aorung the ring gear just like a planetary gear system. I dont know how we can do it by relations? I m realtively new in ProE.

I will really appreciate if anybody can help me in doing this simulation.



New member
Are the gears assembled using 'cylinder' surfaces at their pitch diameters?

There was an old ptc log about preventing 'slip' with the old pro mechanism.

Hope u can get a result .


New member
Out of the manual:

You can change the absolute tolerance by changing the relative tolerance or the characteristic length, or both.

1. Click Mechanism > Settings. The Settings dialog box opens.

2. If you want to change the Relative Tolerance setting for your assembly, deselect the check box and enter a value between 1e


New member
I cannot mail this file to u. Its a huge file. (reply to xcad)

I didnt use the cylinder connections infact I used the pin connections. I was able to rotate the sun gear & a planet gear on their own axis but with pin connection I could revolve the planet gear aound the sun gear. The planet has to be rotate on its own axis as well should revolve around the sun gear. What option u think I should use in order to do that? (reply to jbackl)

I m not running an analysis I just want to perform a simple simulation. (reply to donha)


New member
Thankx for giving the URL. I have never worked on the relations but I will try it not.

I was still wondering if somebody knows how to do this simulation by using mechanism or by using promotion.



New member
I believe MDO has an option called Cam-Follower connections. I'm not sure this would help, but you can get some ideas out of it.


New member
Hello Razza and others

I duno if this the problem is solved but, I wanted to write back because this is precisely, ( i mean rotating the planetary gear system ) the work we do a lot.

If you are using ProMech Motion, make cynlindircal surface (PCD as the dia.)on each gear and then cut the teeth. use these surfaces as gear surfaces and u can assign them some transparent colors.

Choose the SUN and Planet surafaces as Spur gear surfaces ( or even helical). But for RING gear, choose the Option Ring gear. Only then can u mesh the planet and sun.

A planetary stage needs a planet carrier, that will keep all the planets connected. Make some rough planet carrier and make it a seperate body. This PC has to be connected to the Groung using a Pin/Cylindrical joint.

put each Planet in seperate bodies ( 4 bodies in ur case). join planet bodies to the planet carrier body using four Pin/Cylindirical joints.

Make the ring gear as ground. join the sun to ground by another pin/cyl. joint.

make 8 gear connections ( 4 Pla-sun + 4 ring-sun).

totaly there must be6 gear surfaces ( 1 sun, 4 planets, 1 ring) ,6 pin/cyl. joints (1 gnd-sun, 1 gnd-PC and 4 PC-pla)and 8 gear connetions

now try running.