Diagram Adaptation Slope Modification fHa

[[Is...]]

Noticed in the fHa drop down there is a Slope modification which can take leaning profile charts and make them line up with the nominal. Just wanted some clarification on when this would be used? I assume when a slope modification is provided in the gear data?

[[Ky...]]

I think I saw it once on a customer's print a few years back. The nominal helix angle was zero, but they wanted the tolerance for fHb to be around a different nominal angle. I could not tell you why they wanted that, though. I don't know much about the design of gears, I just measure them.

[[Ro...]]

One idea of profile or helix slope modifications is to optimize the running and noize behavior of gears. Very common especially at gears for electrical drive train solutions. Another usecase is to define a conical shape in helix direction via helix slope modification. Kyle mentioned this above, typical are spur gears with a +/- slope modification on left and right flank to create a conical shape.
If you have profile or helix slope modifications you´ll find them on the drawing. Depending from the gear designer some of them use the correct nomenclature for this modification which is CHalpha or CHbeta.

[[Is...]]

That makes sense, interested to utilize the modification. Thank You!