Reply to thread 406-282835 1

[Hooligooner]

Hello

I also am trying to find the maximum and minimum sizes over pins for an external DIN 5480 spline. I am using DIN 5480:2006 parts 1 and 2. In DIN 5480-1:2006 section 10.12 of this standard it talks about using DIN 5480-15 to calculate these sizes, this is not available to us. It also suggests that it can be done using the deviation factors as described in DIN 5480-2, however no explanation of how this is achieved is given.

In DIN 5480-1:2006 section 9.1 there is given an example of a W120x3x38x8f side fit spline. I have been trying to find M1[sub]max[/sub] and M1[sub]min[/sub] for this spline using the deviation factor. The target sizes from the example are Max 126.017, min 125.956.

DIN 5480-1:2006 section 10.12 tells us the deviation of the measurements over measuring circles is A[sub]M1[/sub]=A[sub]e[/sub]*A*[sub]M1[/sub] = -0.04256

Obviously this isn't enough on it's own. So far the closest I have managed to come is to apply A[sub]M1[/sub] to the f8 limit dimensions of the 120 shaft i.e. -0.036/-0.090. This gives an answer of max 126.016, min 125.962.

I don't believe this is right, where am I going wrong?

 

[Occupant]

I've attached page 24 of the standard. As you can see, this is not going to be easy. inv(alpha) should not be a problem, but angle "beta" could, because you have to calculate it from inv(beta). It can be calculated, they show a little Basic program to do it. What I don't have is the "Measuring Circle" for your spline to complete the calculation. But, at least, this may of some help to you.

 

[spigor]

W120x3x38xhf shaft. In the standard I read:
Dk=6 (pin dia.)
Mdk=126,095
A*=1,52
8f: -0,051/-0,091

The min measurement: 126,095-0,091*1,52=125,96
The max measurement: 126,095-0,051*1,52=126,02

The same for the span measurement:
7 (no of teeth)
M7=59,710
A*=0,866
8f: same

The min measurement: 59,710-0,091*0,866=59,63
The max measurement: 59,710-0,051*0,866=59,67

 

[Hooligooner]

spigor

Thank you, that looks like what I am trying to find. Please can you tell me, where did you get the values for 8f? Is it the DIN 5480-15:2006 that I have not got?

 

[spigor]

No, it comes form DIN 5480-1:2006-03 10.9 Deviations and tolerances, Table 7, I believe you have got it.

 

[Hooligooner]

Aha, so A[sub]s[/sub]+T[sub]eff[/sub] and A[sub]s[/sub]+T[sub]G[/sub] as per the example shown. Thank you.

Think I could have looked at this till the cows came home and never got it.