Snow replacing sprockets and chain

[trlong]

Folks,

Never mind. I believe I have found the answer to my own question. The eccentric locking collar on the shaft for the large sprocket is snug against the bearings. Also, searching the web, I found an article on "timken.com" stating "...When assembled on the shaft, this eccentric recess engages, or mates, with an eccentric cam end of a bearing's inner ring. The collar is engaged on the inner cam of the bearing. This assembly grips the shaft tightly with a positive binding action that increases with use...". Hopefully, if anyone else with as little mechanic's experience as I have attempts this repair, this note may help.

 

[caseyvand]

Hey trlong.....does that Timken article say anything about which way to turn the collar? I would guess that the collar would tighten with use if the collar was tighted in the correct direction....it would depend on which direction the shaft turns.
Casey

 

[trlong]

casyvand,

If you search the web for "eccentric locking collar" you should get a hit on Timken and that article. If you look (physically) at the flange on the bearings and the inside of the eccentric locking collar you will see that each is thicker to thinner around the inner circumference. By Timken's description, I "assume" you face the hollow side of the locking collar to the bearing flange with the thickest section of the collar to the thinnest section of the flange and then "set" the collar with the "allen" set screw. As the shaft rotates (makes no difference in shaft rotation direction) the two parts are supposed to tighten against each other. Pretty slick and simple system, per Timken's 1923 patent. The set screw is simply to keep the collar lined up until the motion locks the two together. At least that's what I could glean from the description and diagrams. All is still to be proven when I get the assembly back on the blower, adjust the chain tension (still not sure about how tight) and then test it out. Hope this helps.

 

[caseyvand]

trlong....I read the Timken explanation but they do not make it very clear that you need to turn the collar tight on the inner eccentric bearing race in the same direction as the shaft turns and then tighten the set screw.
Casey