Interesting spline

[priitj]

Hello,

I have a shaft that has spline which differs from these that I have seen and used when designing transmissions. It's profile is too round to be an involute spline. Can somebody please tell how such type of spline is called and maybe even point out some standard which applies to that spline?

Thank you!

 

[CoryPad]

It looks like the non-proprietary hexalobular shape that GM created to avoid the Torx patents from Camcar/Textron/Acument. I do not know of any standards for the shape.

 

[tbuelna]

Looks like a cycloidal geometry tooth form.

Here's a patent for something similar:

https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US8690473.pdf