JIS Internal Spline 1

[mdracing17]

I am looking to gather some information on an internal JIS spline. I have attached the specs on the external spline from the print of the shaft. I need to create the matching spline for a rotor the shaft will be turning. Not sure were to gather this information. I need a dxf file to create a solid model for casting. Any information would be greatly appreciated.

Mickey

 

[gearguru]

mdracing,
JIS splines are very similar, sometimes identical with the ISO (international) and DIN (German) splines. Find the spline data from your drawing with splines in DIN or ISO standard and then locate corresponding internal spline.

 

[mdracing17]

Gearguru,
I have not had much luck with this yet. I am a marketing major trying to do this stuff. I have a good working knowledge of it just not able to get it to paper. I do have some information on the internal spline. Do you know of anyone that has a program that can create a .dxf file of the spline. The info is as follow.

Number of teeth: 14
Module: .75
Pressure Angle: 30
Outside Diamter: 12mm
Inside Diameter: 10.5mm
Pitch diameter: 11.2mm

Thanks for the help,
mdracing17

 

[gearguru]

mdracing17,
You have there something wrong. The pitch diameter on both external and internal splines has to be the same. (Pitch dia = no of teeth * module), in your case it is 14 * 0.75 = 10.5mm
Search within this forum, there was a lisp program which creates the Autocad drawing of a gear/spline posted here. I did not use it, I can not tell you how it works. And I think it was created for diametral pitch (inch) based gears. You can still use it if you convert your data and calculate the diametral pitch (=25.4/module). These data should then satisfy the program's entry.
I believe that this lisp only creates the external gear/spline tooth. If it is so, and you want to use it to draw an internal spline, you have to use the tooth space as the entry for program's tooth thickness.
Check the drawing carefully, if it really created exactly what you need.
Be aware that the tooth thickness/space is measured as an arc length, always on the pitch diameter.
The pitch obviously equals the pitch diameter circumference divided by no. of teeth (and consists of a tooth space and a tooth thickness).
Confused enough?
Good luck! ;-)

 

[gearguru]

I looked again on the external spline data. I realized that they do not show the tooth thickness, only the size over pins and pin dia. (and also the span - measurement over teeth). You should first calculate the tooth thickness (min and max) and then select (from a standard) such internal spline, that there won't be interference.
All of it can be done using the known external spline data.
But I recommend that you hire someone familiar with these calculations and let him/her design your internal spline.

 

[mdracing17]

Gearguru,
Thank you for your help. That all actually makes since. I do think we are better getting a service to draw this out. A company that does reverse enginering should be able to accomplish this correct? Thanks again for your help and clarification.

 

[gearguru]

mdracing17,
I compared your external spline with splines in DIN5840 (I have the 1991 version). I do not have the JIS standard.
The spline corresponds with DIN spline with ref. diameter 12mm, module 0.75, 30 degrees pres. angle.
In the DIN standard there are dimensions for the internal spline.
FYI - in DIN the splines are designed by the "ref. diameter". It is a minimum diameter of the hub which can slide over the external spline with small clearance. In your case you can slide bushig/bearing with the hole 12.00 mm over your spline, which has the outside diameter 11.85 mm max.

 

[Trukker]

mdracing 17,
You have most likely taken care of this by now.
If you still need the info please let me know.

Trukker