Spline Selection

[Baheej]

How do I size and a select the right spline for a certain application? I know the torque, rpm and a starting shaft size. Any design books you can recommend? Thanks.

 

[jbthiel]

I can't recommend any books, but there are two suggestions.
1. If you need to connect with an off-the-shelf part, like a coupler or yoke, look at whats already available. If this is going to be a production part, find out what profiles your suppllier normally deals with.
2. Generally the spline count goes up with load and/or rpm's. I'm not sure what the exact reason is, but it probably has to do with having a larger rood diameter for strength and more area to transmit torque.

 

[patprimmer]

A fine spline leaves a larger root diameter for the shaft while still retaining bearing area, but is more subject to grit, dirt and damage.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Fabrico]

Automotive splines are fairly standardized by diameter/tooth count, not fine or course.

If the spline is to be cut, the minor diameter needs to be at least the shaft diameter for 100% strength. If it is rolled it can be formed in the shaft diameter and provide up to about 85%-90% of shaft strength.

 

[Baheej]

We ended up subcontracting the spline design to a designer who provided us with final drawings including dimensions, spline details and heat treatment. Thanks for your replies.

 

[Tmoose]

Is the transition between the spline and main shaft among the details?

http://www.pirate4x4.com/tech/billavista/PR-shaft/FAG fractured spline.jpg

http://www.pirate4x4.com/tech/billavista/PR-BV60/Materials/7.jpg