Old 610, seized driven sheave

[cmyles]

Working on an old 610 (serial 206837) with seized up variable pitch sheaves, drive and driven. I'm pretty clear on disassembling the drive sheave but removing the driven sheave from the machine is not as clear. I get the jackshafts joined in the center with the split block, no mystery there. Out in the left chaincase the opposite end of the shaft has a 3/8" bolt in it which came right out. It appears that the small chain sprocket is locked to the shaft with two (maybe 1/4") set-screws about 90 degrees apart and I assume that, after removing those set-screws, it will have to be drawn off the shaft with a jaw puller before I can slide the shaft through the pillow block bearing and get the sheave and shaft on my workbench. That's how it looks to me, tell me if I'm seeing it wrong. Couldn't get any size allen wrench to grip in either of the set-screws (if that's what those holes even are, can't quite see in there) so they are either rounded out or missing or ? Am I on the right track?

 

[cmyles]

Figured it out. Bolt in the end of the shaft holds the sprocket on and there's a woodruff key. The set-screws are in a collar that's behind the sprocket and one of the screws was trashed so I split the collar to get it off, available new for about $20.

 

[Tazza]

Figured it out. Bolt in the end of the shaft holds the sprocket on and there's a woodruff key. The set-screws are in a collar that's behind the sprocket and one of the screws was trashed so I split the collar to get it off, available new for about $20.

Glad you got it worked out. I assume there is no other damage? i know they can be a little fiddly.

 

[6brnorma]

Glad you got it worked out. I assume there is no other damage? i know they can be a little fiddly.

The collar you split was a concentric locking collar. It had two holes......one housed a set screw, the other (shallow) hole was for the use of a spanner wrench to lock the collar (or a punch if you don't have a spanner wrench).

 

[6brnorma]

The collar you split was a concentric locking collar. It had two holes......one housed a set screw, the other (shallow) hole was for the use of a spanner wrench to lock the collar (or a punch if you don't have a spanner wrench).

On a side note. I have seen many of the pillow blocks and locking collars replaced. The bearing house computers often give different bearing numbers that will work.....problem is......in many cases the bearing is several thousands wider and does not allow the play necessary in this design and the locking collar is not concentric but rather uses two set screws. You'll have to tell me what you have. I have made sure that each of our machines have the original after we broke a "jackshaft" shaft due to the incorrect bearing........that was a 'hairball'.