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January 12, 2004
G'day Paul
I'm not certain why you would want to fit tapered roller bearings. This has been raised quite a number of times in the past (perhaps before you were on the list) and see below for one of the more recent comments.
avagoodday
Colin
We have had many discussions on the differences between the use of angular
contact ball bearings, as used originally in Spridgets, and the use of any
type of tapered roller bearing.
Without launching into a complex and boring diatribe on the rights and
wrongs of either type of bearing, the simple answer is that the original
axle and spacer set-up for Spridgets - using angular contact ball bearings -
was designed at a time when taper rollers (Timken and many other brands)
were used in other configurations and motor vehicle designs. So the original
designer had a choice of types of bearings. General Motors Holden in
Australia originally used taper rollers on their Holden motor car stub
axles, but now use angular contact bearings pretty well exclusively. As do
almost every major manufacturer in the world, and, coincidentally, every
Formula One team currently competing. The angular contact bearing design
obviously has some advantages.
The best advice that I can offer is to ask the simple question as to why you
would want to contradict such a major design decision without an engineering
evaluation conducted to determine the differences. If you ask anyone who
understands bearings about where the loads from a taper roller set-up fall,
as distinct from the loadings from an angular contact bearing arrangement,
then you might ask why taper rollers were ever used in any stub axle. And
when you see the inner races of a pair of opposed angular contact bearings
located by a spacer which when standard is 1.5 inches long in a Spridget,
you can see the additional support that the original angular contact
bearings and spacer give to the stub shaft that isn't available without the
spacer. Add to that the "stretching" load imposed upon the stub axle when
using taper rollers without a spacer, and the little common sense matters
add up. This is before we enter into the different widths discussions.
As an employee of SKF Bearings Supplies in Australia, I cannot offer a
complete technical evaluation without someone coming up with the necessary
cash to cover the huge costs (including the solicitors). So the above
opinions are to be taken as mine, not my employer.
If you are still in doubt, then just look at anyone who has a history of
breaking Spridget stub axles. Ask them what type of bearings they used - the
ones that the vehicles were designed for in preference to all other
alternatives? Or a quick fix without engineering support for the application
where it is sometimes pressed into service. The answer lies much deeper than
simple static and dynamic bearing capacities. Angular contact bearings were
designed with particular applications in mind, as were taper rollers. And I
have never seen any application where they were interchangeable.
I appreciate that many others will have a different opinion than mine, and
that is the beauty of this forum.
Steve Koen
"Colin@SpriteParts" < colin@... > 28170
Posted on January 12, 2004 07:18 AM
Posted to category(s) Cylinder Head | Drive Train | Engine (external) | Engine (internal) | Interior | International | Miscellaneous | Restoration
