DIN 5480 Spline Addendum Modifications 1

[TEguy]

This question was asked in an similar thread (thread406-36822) which is now closed.
The question was:
Are there any rules to determine exactly when to apply addendum modification to a DIN 5440 involute spline? How is the amount of modification determined? Is this normally given on the drawing as part of the spline spec.?

The answer by gearguru was:
the DIN splines use the profile shift for achieving the proper standardized main dimensions. One of them is the OD - the DIN standard splines allways create a small clearance for sliding - say - a standard ball bearing above them. Therefore the shift is different for differenf modules and OD's. I have a copy of DIN spline standard, please post here more data about your spline, I can help you to find more. By the way - DIN includes charts with ALL dimensions of the (finished) spline, you do not need to calculate anything unless you want to.


So I am having the same issue as the originator of this thread.
We have purchased a hydraulic motor from a reputable manufacturer, the motor shaft is specified as W40x2x18x9g.
We need to manufacture a hub to fit on this shaft.

The only information we have about the shaft spline is W40x2x18x9g.
How can we tell from this if any addendum modification was used in the calculation of tip circle diameter and root circle diameter?
This will determine the calculation for the diameters of out hub will it not?

All help is appreciated.

Regards
TEguy

 

[gearcutter]

Nice to see another Aussie on here
Here you go -

 

[TEguy]

Thanks gearcutter!
Just want to confirm - when the shaft designation states 9g, that means the profile reference line is shifted 0.9mm (profile shift)?

 

[gearcutter]

when the shaft designation states 9g, that means the profile reference line is shifted 0.9mm (profile shift)?

9g & 9H are tolerances derived from the ISO Limits & Fits.
They are specs used to determine the type of fit called-for between the mating parts.

 

[TEguy]

Thanks mate, so the 9g and 9H are not really the driving parameters for the profile shift?
So how is it determined in the table above that the profile shift should be +0.9 for external and -0.9 for internal?
Thanks for the help!

 

[gearcutter]

It's as gearguru says above.
But if you want to learn more about DIN-5480 then I would highly recommend you download it. It's available in English from just about all of the sites that make standards available.

 

[TEguy]

Gearcutter, I have gone through the standard several times now. It doesn't explain very well how the value of x is determined (profile shift coefficient).
How did your program come up with x.m = +0.9? What calculation was done to determine that x = 0.45?

 

[RolMec]

x = 0.45 is the max. profile shift as per standard out of a range of -0.05 to + 0.45. This parameter is for involute splines coupled to the number of teeth and the pressure angle alpha V, calculations as per the standard or else as per common involute gear parameters.
However, as gearcutter proposes, it seems appropriate that you obtain at least a copy of the DIN standard, as there's still more to know about required manufacturing specifics of such spline. Or else, why not involve some company who knows how to do it? You have just one hub ... this just cries ;-) for outsourcing...
Regards

Feedback is most welcome, thank you in advance!

 

[spigor]

The DIN 5480 uses standard nominal diameters. The values for x have been chosen so the external diameters line up nicely with the bearing shaft diameters.
W40x2x18x9g means W=shaft, dn=40(nominal dia.), m=2(module), z=18(teeth), shaft fit 9g (hubs typically use fit 9H).

You can calculate the value of x from the equation:

x=(dn-mz-1.1m)/(2m)=(40-2x18-1.1x2)/(2x2)=0.45

 

[TEguy]

Thank you Spigor.
This is what I was looking for!
I wish they wrote this equation black on white in DIN5480, it would have made things easier.
Thanks again!