Torque allowed in spline connection

[bpick]

I am designing a slip shaft with a spline connection between a pipe and a solid shaft. I need to transmit torque and am looking for a standard spline. The highest number of teeth I see in the Machinery's Handbook is 16. this connection on a 3-1/2" shaft can transmit 8426 in*lbs per inch of spline length. I would like to go with more splines but can't seem to find much info on it. Is there a good resouce that is availabe for spline connection design?

 

[CoryPad]

You have stumbled onto a bit of a mess - the USA standard for splines is inactive. This specification, ANSI B92.1 for involute splines, is available from IHS:

http://www.global.ihs.com

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[tbuelna]

bpick,

You can make a spline with virtually any whole number of teeth you would like. ANSI B92.1 gives data from about 6 teeth up through 60 teeth, for various types of fits and pressure angles.

You can easily fit a 36T, 12/24DP, 30deg involute spline within a 3.5" diameter shaft and still have more than adequate rim thickness. At 8426 in-lb/in of spline length, the tooth contact stress (P/A) for this spline would be about 1880 psi, which is fairly modest for most alloy steels. The tooth shear stress is well below 2000 psi, and would also not be a concern.

The above only holds true as long as the length/diameter (L/D) of the spline is less than 1.0, it is accurately machined and mounted, and properly lubricated. If the L/D is greater than 1.0, torsional wind-up can cause unequal tooth loads along the length. So lead correction must be used, or the spline capacity should be de-rated.

Good luck.
Terry