trac. contr.

[Greg Hermann]

>On Sun, 15 Nov 1998, Greg Hermann wrote:
>
>> Once was in charge of a bunch of wear testing on that type of Chain
>> (Hy-Vo). The test machine was set up to run Toro/Eldo chains, but no big
>> deal.  FWIW, ATF gave 100% better chain wear than any type of conventional
>> gear oil. Synthetic gear oils (then pretty new stuff) did even worse. Note
>> that the Torp/Eldo used a 3/8" pitch chain, 2" wide between the converter
>> and tranny--an excellent application, which rarely wore out. Transfer cases
>> apply the chain between the tranny and the axle, also after the low range
>> gear, still use 3/8" pitch, sometimes 1/2" pitch chain, varying (I think)
>> from 1-1/2" to 2-1/2" wide, depending on application, and about the same
>> size sprockets. It does not take a rocket scientist to figure out that
>> these chains are loaded a lot more heavily, and do wear out, pretty
>> regularly.
>> >
>> >You're right about it being sensitive to the oil.
>>
>Hy-Vo chain was/is used for lotsa industrial apps too and in their catalog
>they have [or had...] a chart showing acceptable power loading for various
>pitches\widths depending on viscosity and type of lubrication system. Use
>gear 90 and the rating tanks. Pressure lube with 10-30 or ATF and the
>rating goes up, way up.
>
>The old NP 203 used to eat chains with gear 90. Never a problem with
>reccomended oils [ignoring the idiot factor here]

All true--I knew, liked, and took some courses from, later worked with, the
guy who had his name on the Hy-Vo chain patent--Prof. J. O. Jeffrey,
P.E.--better known to his students as "Jominy Joe". Quite a character.

What goes on inside the chain is that the EP additives in the hypoid type
oils eat up the surface of the chain pins chemically where they roll
against each other, because of the high contact pressure. The beauty of
this chain design is that there is no rubbing contact (under load) either
inside the chain or where the chain meshes the sprockets. Meshing of chain
and sprocket is exactly like a straight rack and a gear -rolling tooth
contact only, but then the chain folds around the sprocket, and there is NO
rise and fall of the chain onto the sprocket with each tooth, like what
happens with a roller chain or a silent chain. That is what makes the "High
Velocity" possible--no chain to sprocket tooth impact. Also why the
Toro/Eldo app was a LOT better and more durable than the NP203 app--ran the
chain faster, with less chain tension load--took better advantage of its
capabilities.