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Metric Spline Callout 4

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eagle156

Mechanical
May 3, 2004
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I've called out ANSI involute spline specifications in past designs. What is the minimum required for metric involute splines?
 
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It depends what metric standard spline you are using.
There is an international ISO 4156 standard, US standard ANSI B29.2M-1980 reaffirmed 1989, which is based on the ISO standard.
But I did not see yet any splines made by using these standards (it does not mean that they do not exist).
If you design new metric splines, I strongly recommend the German DIN 5480 standard. It is widely used, the design approach is very practical and many countries simply applied this standard in their national standards.
Per DIN 5480 the dimensions of all splines are precalculated in the standard, the part designer does not need to calculate them. (except the load/stresses). There is the English version of the standard available. It is really a valuable document. If you work with shafts, get a copy of it!
The spline specification looks like this:

120x3x30x38x9H/8f DIN5480

where 120 is a"reference dia"
3 is module
30 is pressure angle
38 is no. of teeth
9H is tolerance on the hub (internal) spline
8f is tolerance on the shaft (external) spline.
This spline is "side fit"; the OD or ID centered splines are described with more data.
The root shape (flat or full radius) can be also specified.

If only one spline is defined, the letter N or W are used before the reference diameter.
N means "Nabe" (Hub, internal) W means Welle (Shaft, external)


The "reference dia" is a theoretical diameter, slightly larger than major diameter on the shaft spline. The reason for this spline description is to give the designer the information, what size of part (most of the time bearing's bore) can be moved with some clearance ABOVE the spline.
In the example above, a bearing with nominal bore size 120mm will slide above the spline to its journal dia located behind the spline.
I hope I helped (or confused?) little bit; Ask if you need more info.
If you want the ANSI or ISO call out, ask!
 
gearguru,

I am also starring you, and e mailing this thread to myself in the unlikely event that it should 'disappear'.

Now, along the same lines, I deal with a european manufacturer of heavy duty automotive equipment who has used the SAE standard 1-1/2 10 spline since about 20 years ago, when it was the design of preference in the USA.

Current USA manufacturers who want to use this european product are asking for a (excuse me if my memory is not good, as I am not on the computer where all this info is contained, but I think you can still help with what I remember) 38 (or is it 28) SAE spline for currently equipment. I notice that the european mfg has a 39 (or is it 29) spline design for their domestic models. Close, but no cigar, as they say. (now that I am proof reading this, I think it is 38mm OD, 29 spline for over there, and 1-1/2" OD, 28 spline for over here.)

I would like to furnish the european mfg with a designation just as you listed out above for eagle156, but after exhaustive web searches, I cannot find even the SAE, or whatever I need, to start trying to convert it to a DIN or other european standard that they could understand. They don't have good english speakers, so I have to do the search, and give it to them in their language.

You got any ideas that might solve my problem, and also provide more info to eagle156, since I hijacked his thread??

rmw
 
Thanks for the star, rmw!
I have also seen the SAE splines made overseas and also used on vehicles built in "metric" countries. All of them were 45 degrees pressure angle splines, made by rolling.
DIN standard does not include the 45 degree splines, therefore the US spline standards for these splines were and still are used around the world. The new ISO and ANSI already include the 30, 37.5 and 45 degrees PA (45 degrees press. angle is easier to make by net forming/rolling than the 30 degrees, which is widely used for machined splines).
For your spline I need to know little bit more, to be sure that the ext. and int. splines will mesh properly.
Please try to find the following:
external/internal
No. of teeth
Diametral Pitch (usually as a fraction, like 16/32)
Pressure angle
OD, ID, tooth thickness,
side fit or OD fit and also backlash ( clearance between the teeth) if available.
To properly reengineer the splines, the data for both internal and external are necessary.
If you have the spline data from one spline only, I can calculate the other.
I would avoid the simple description similar as in DIN, it can create a lot of confusion.
 
Gearguru,

What you are asking is the information I am looking for to give to the manufacturer to produce a USA compatable product. I was hoping you could give me a source for a SAE standard for that spline. No method of searching that I have been able to come up with leads me to it.

Look at this link to see the sizes I am talking about,


Upon looking at this site, I think their standard is the 37 spline shaft which the listed slack adjuster would fit. The 1-1/2", 28 spline is what I am after.

rmw
 
rmw,
If you want to let them make both internal and external splines, I can give you the standard sizes.
If you need only one spline, then the data for the meshing one are necessary to verify if the spline is made by some standard and which one.
The web page which you posted does not give me enough information to do it.
Contact them (Dana, I believe) and ask for more. Otherwise you risk that the splines won't mesh.
 
I checked bot web pages mentioned above;
the Dana's page does not tell if it is an involute spline, there is no info about the pressure angle, they do not tell if the diameter is a pitch dia (probably) or OD;
The other page is good info if you want both splines made by that company. Sorry, I have to stress again: If you have one spline, for designing the meshing one more info is necessary.
gerguru
 
Gearguru,

That is why I think that there is a standard out there somewhere, and someone knows what it is. Otherwise, how could one manufacturer of the slack adjusters, make his female splines, be they 10 spline, or 28 or 37 spline, and another manufacturer make "S" cams, and they never see one another until the assembly floor and they fit without interference.

No amount of searching on the web has produced that standard, nor any reference to it for me.

I went to some other sites after I posted that last night, and saw lots more information, of a standard nature, but nothing that would give me enough information to fabricate either a female or male spline for this application.

Someone out there knows where it is.

rmw
 
rmw,
yes, there are standards. The problem is, that not everybody is using them. Even if he/she is doing it, there is always the option of different pressure angle, different fit and different centering (OD/side) within the same standard. Therefore if you have one spline, you need to know how it was designed, only then you can find the meshing one. I also work with different customer's splines - but they always give us the detailed spline data.


 
I am reopening this link because I have been working with the above spline standards a lot and have noticed what i believe is an error- i was wondering if anyone esle has noticed- or maybe someone can tell me if I am mistaken. Specifically thte error is:

the numerical tables with the 'precalculated' dimensions to which gearguru refers, have errors (imo) on the tables for modules 2.5 and 2.0, namely that the pitch diameter for the internal spline data is not the same as the pitch diameter for the external spline. The tables for all the other modules have identical pitch diameters for both internal and external splines (for a given module and tooth number), but not for modules 2.5 to 2.0.

The iso standard 4656 in particular has this, maybe the din as well, I don't know about the american.

Has anyone else noticed?
 
I think you mean ISO 4156 rather than
ISO 4656. Since it was just published
this year, I would not be surprised to
see some errors. The pitch diameter
must be the same for internal or external
threads unless they are talking about
modified pitch diameters or corrected
pitch diameters.
 
yes I made an error earlier , thank-you diamondjim
I am indeed referring to ISO4156 notISO 4656.
also i have only been referring so far to the 30deg pressure angle tables.

If anyone else is interested, I would advise users of this standard to be careful with tables 28 and 29, which you can find on pgs.51-52 of ISO4156-1981(E)
 
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