coning hinge and lead lag
Bugdevheli,
About a year ago I think, you posted a photo of a R-22 blade that was curved in the lead/lag plane. I thought maybe the reason for the bent blade was because the R-22 head lacks a lead/lag hinge. Without a lead/lag hinge the blade must bend in lead/lag when it moves about the coning (flapping) hinge.
My understanding is that any rotor that uses a flapping hinge must also incorporate a lead/lag hinge to relieve the strain caused by the imbalance in angular momentum. A teetering head doesn't need a lead/lag hinge because the two blades work together. And most teetering heads are very strong in lead/lag with wide chord and drag links. The Robinson has no drag links.
So its not clear to me how the Robinson head can survive strong turbulence without any lead lag hinges. (I assume the blades flap independently in a sharp edged gust)
Is this related to your question?
P.S. This may have come up before and I have tried to search but it is difficult to search on R-22 rotor head as you get about 400 hits.