Gehl 1870 Tdc Owners Manual
My uncle has a Gehl 1870 baler that has started acting up. Pardon if I don't use correct terms for the pieces/parts.
The big (12-14” diameter) roller in the bottom of the chamber is chain driven on the left side of the machine with a 60 series chain. The roller turns clockwise when looking at the left side; the drive sprocket is in front of the roll's driven sprocket. The “pull” side of the chain is on the bottom and the slack side is on top; the idler sprocket is also on top.on the slack side. That all makes sense to me, but the pull side of the chain becomes slack and the slack side becomes taut when there is a bale in the chamber. It's acting like the belts are turning the bale faster than the roller is turning the bale.
To me it appears that the bottom roller is being driven by the bale instead of the other way around. It became noticeable when a banging (started yesterday) came from the baler as the drive sprocket was getting chain pushed to it from the roller; this allowed the sprocket to climb a tooth, tighten the tensioner/idler, then when the jumped link made it around the sprocket the idler would slam back down. I cannot see where there was ever a wooden block or idler on the taut side to take the slack. With little pressure, I can use a screwdriver and hold the pull side (which should be taut but is slack) of the chain up and remove the slack.
When I do this, the baler runs fine. The chain is new (tried that first) and has the correct number of links. The drive sprocket is worn some, but not sharp on top of teeth nor are the teeth curled on top. This baler has been used by them for a few years and worked fine last year.
It seems like the barn gremlins have been busy. I may resort to redneck ingenuity an put a tensioner/idler on the taut side to, but that's just a work around for a problem that I would like to fix correctly if anyone has ideas/experience that could lend an idea? Most dangerous game literary analysis guide answer of el. Thanks and 73, Mark. If I can remember this had a strange tensioner on it hopefully the parts manual will help you. It is a weird tensioner. The baler has been 'fixed' in that they took another link out and put a half link in it. To me, it merely masks the problem instead of 'fixing' it.
The drive sprocket is still being driven causing slack on the pull-side of the chain, but there is not enough length in the chain to let it climb the tooth. I admonished them that it thought it would cause excessive wear on the sprockets/chains, but in the end, it's their baler 73, Mark. How many drive rollers does the baler have? Deere balers have one on top and one near bottom.
Both have a rubber coating on them to help grip belts. Rubber coating can become excessively worn on or even come off of one. Resulting in drive rollers with different diameters spinning the same speed but trying to drive belts different distances. Ends up putting a lot of pressure on chains or belt slippage on a drive roller. Not sure if that would apply on the Gehl, but if it does I could see mismatched drive rollers causing the symptoms you describe. How many drive rollers does the baler have?
Deere balers have one on top and one near bottom. Both have a rubber coating on them to help grip belts. Rubber coating can become excessively worn on or even come off of one. Resulting in drive rollers with different diameters spinning the same speed but trying to drive belts different distances. Ends up putting a lot of pressure on chains or belt slippage on a drive roller. Not sure if that would apply on the Gehl, but if it does I could see mismatched drive rollers causing the symptoms you describe.
I agree with JMT on possible different drive roller diameters. OR could belts have been relaced several times and are too short which could affect the roller drive geometry??? If I recall, there is only one drive roller to drive the belts and I agree that the belts are driven in a different speed than the large roller under the bale. I don't think that shorter belts could change belt speed as they are driven by a roller of constant diameter.but like me, grasping at straws is my only recourse. With no bale in the chamber, everything runs quiet and smooth.both the belts and the roller underneath. The idler on that chain is mounted on an arm with a spring attatched to put tension on the chain.the spring can break or get knocked off from trash buildup this happen to our 1870 a few times The idler is fine as well as a new spring was placed on it in case it was weak. We've had all the sprockets off on that side trying to figure it out, so, although a little worn, everything should be in order The parts calls for xx links, a master link, and a 1/2 link on that particular chain.
Gehl 1870 Tdc Owners Manual Pdf
It's sort of a bear to get in on as it's fairly snug with that combination, but that's what we put on. I've arrived at the conclusion that it is just a poor design and the taut chain was a remedy. Since the belts and roller are not in perfect feet-per-minute unison, one is bound to try to drive the other once a bale is in the chamber. IN this occasion, the belts are driving the bale faster than the bottom roller is, therefore, the bottom roller becomes driven by the bale.
Gehl 1870 Tdc Owners Manual
The top of the chain (the idler side) becomes taut when a bale is formed and slack develops on the bottom side of the chain (the side that is taut when no bale is driving the bale). I understand that near-impossibility of getting both the bottom roll and belts to move at identical FPMs therefore causing slack on the pull-side of a chain.
I guess Gehl decided to address this by a short chain with little slack; I think a better remedy would be to have a idler on top and bottom that way the chain would be in correct relationship with the sprocket. As it is, the slack is being pushed to the drive sprocket and the chain is riding on the back of the tooth as the sprocket picks it up; too much slack and it jumps a tooth. I give up.poor design, I guess.