Diameter of splined shaft

[RUFUS2K]

I am designing a splined shaft that will be driven by an accessory drive pad on an aircraft engine. The drive pad has a 12 tooth internal spline (SAE AS 972B). According to that SAE spec, the driven shaft should have an O.D. of 18.49-18.54 mm. I am having a hard time finding a readily available bearing with that I.D. If I am not concerned with transmitting maximum power, is there a reason that I can't make the shaft 17 mm to get to a standard bearing size?

 

[NickB]

None. Make sure the transition between the diameters isn't a square corner. A taper or radii is best.

Are you sure that diameter spec isn't just for the OD of the spline section?

 

[RUFUS2K]

NickB,

Thanks, that is what I thought. And no, the spline details are called out in a different section of the spec.