I was reading through Peter William's book again this morning and I saw what he had to say about the shape of these bearings. When I read it I wished it had been quoted at the time on this forum.
Peter being the competent Norton engineer he was, I repeat his words as an illustration of the valid use of the various terms.
"Eventually, I understood the principle of the new 'Superblend' roller bearings. The slight curvature, or barrelling, on each roller obviates any tendency for the end corners of the rollers to dig into the races due to misalignment through crankcase and crankshaft distortion under extreme load conditions. They were quite capable of longitudinal location because the loads on our crankshaft were minimal, and theoretically non-existent, in that direction. It was interesting in the following decades to observe the development of roller bearings from the roller 'barrelling' to a hyperbolic function, through a sinusoidal function, to the current logarithmic curvature." p168, Peter Williams, Designed to Race.
I think you have omitted t…
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Les, you seem to overlook…
Les, you seem to overlook the effect of the elasticity of the surfaces, so a ball bearing will give a horseshoe shaped contact area under the loads experienced in main bearings, a plain roller will give a wider than expected rectangular contact area and a crowned roller gives an eliptical contact area.
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I think you have omitted the "definition" Norman. Your bit above is simply saying that Peter Williams thinks he knows what a "Superblend" bearing is.
Funny how the roller shapeis alwaysdescribed but no one mentions the shape of the tracks....:
Note the parallel track and the flat sided rollers:
http://simplybearings.co.uk/shop/p501834/NU305-Budget-Single-Row-Cylindrical-Roller-Bearing-25x62x17mm/product_info.html
Note:...If the rollers havethe tiniest deviation from a parallel shapeIE:straight sides and they are installed to work within a flat track the contact patch is reduced to anear theoretical zero widthline contact which would destroy thebearing in a very short time. It would also possesa far lower load capacity than a normal ball bearing which hasmatching ball and track profiles (inner and outer)to spread the load somewhat. If you use barrel shaped rollers you need a matching barrel shaped track profile....which the NU305 bearing does not have. Rollers are very hard steel with no deformation...Note the rounded ends of the rollers to prevent scuffing....Les