transfer same rotation in graph editor and 3d view When I change the rotation of a certain bone (e.g. the bone of an upper-arm) in 3d view on only one axis (e.g. ' X '), all three curves in the graph editor are automatically changed when I set a keyframe and not only one curve.

Therefore, changing the rotation in the graph editor by changing the keyframes would be easier than to work in 3d view where all 3 axes are automatically changed. But since I work with Quaternion I would like to avoid using the graph editor to adjust the rotation of a bone because the W rotation wouldn't be automatically adjusted.

Is there a way to have the same effect when changing the rotation of one axis in 3d view as it is in the graph editor?
I think you are referring to inserting a keyframe for a single channel. Of course with quaternions the minimum number of axis are two (because how quaternions works)