Are there any rules to determine exactly when to apply addendum modification to a DIN 5440 involute spline? How is the amount of modification determined? Is this normaly given on the drawing as part of te spline spec.?
Quickgear,
The more information that you provide to
a gear manufacturer, the better chance you
have of getting the right parts. The DIN
spec is important since it lists the major
and minor diameters as well as tooth thickness
and profile shift. As in gears, splines, to
allow more balanced loading, the external
splines have a profile shift toward the od
to strengthen them. I do not have the DIN
standard at home, so I will assume that the
profile shift is approximately 25 percent
time the addendum or module.
Quickgear,
the DIN splines use the profile shift for achieving the proper standardized main dimensions. One of them is the OD - the DIN standard splines allways create a small clearance for sliding - say - a standard ball bearing above them. Therefore the shift is different for differenf modules and OD's. I have a copy of DIN spline standard, please post here more data about your spline, I can help you to find more. By the way - DIN includes charts with ALL dimensions of the (finished) spline, you do not need to calculate anything unless you want to.
gearguru