Tommy Cookers wrote: ↑
Sun Apr 01, 2018 4:49 pm
the tensile load will determine whether the small end eye can be designed for strength only ....
or whether stiffness (to avoid excessive contact loadings from pinch of the small end bearing) is the dominant design factor
Wright's Cyclone 18 c.1941 seems to have been a pioneer of H section rods
but maybe that was for the master rod only (and for master rod specific reasons)
or was it said that there some reason, from gas load distribution ?
I agree, rod stiffness is very important, not only for small end and big end bearings but for the rod bolts too (the higher the bolt turret stiffness, the smaller the bolt load). It is one of the many reasons titanium rods are so hard to design right as its young's modulus is half that of steel.
I suppose that in the case of radial engines having a H section master rod makes for a tidier transition to the flange that holds the other rods ?