R_O_M
Guest
Bloody h...l ! what a mess! and I guess that is the least that can be said! Thanks for the kind compliments but we have only written about things that a lot of other people have come up with as well and like you "bob" we had to make our own way for many years. Now the business end of things! You were harvesting at the rate of about 20 tonnes _ hr or for Americans around the 700 to 750 bus plus per hour. This should be well within the capacity of the elevator which I think has a capacity of around the 1500 to 2000 bus _ hr on the R50's but I will stand correction there. If you have been harvesting in damp conditions for many years and have had a lot of rumbling and heavy thumping from the rotor, metal fatigue could have played a part in the thresher spiders coming apart or a thresher bar bolt breaking or coming out allowing the bar to let go. My own guess would be a problem that a lot of the earlier Gleaner rotaries had. The cogs that drove and timed the seperator rolls will sometimes strip their teeth. On the R 62, 72 series, the later ones came out with a much wider set of cogs to increase the capability of the cogs to take the drive loads of the rolls. We had a couple of teeth go out on the narrow cogs of our R62 but found them during the daily inspection before starting and saved our selves some grief. At a guess there were problems here. The rollers slipped from their timing as some teeth broke out. The material from the thresher which was perhaps a lot more going down to the sieves than normal due to possible crop conditions, was not cleared from the cage area fast enough by the now out of time and momentarily jamming rollers. The material built up, blocked a fair bit of the concave and _ or cage and was rammed and packed against the concave internally by the bars until something gave. Having harvested aerial seeded clovers, this would be particularly likely if the material was a little green and tough. The rollers also may have jammed and triggered all of this plus maybe as you say, a slipping drive belt which might have been caused by the broken gears, again jamming and causing momentary belt slippage. The loading on the sieves may have been partly due to the slipping and jamming rollers which were failing to sling the material smoothly down onto the sieves allowing the fan blast to do the precleaning job. As well of course the sieves may not have been throwing regularly due to belt slippage and jamming. If this is what happened then more and more teeth on the timing gears may have been steadily stripped over some time which also seems to happen. All of this is just guessing from this distance but there is likely to be chain of events that just started with one small failure. Have a look at those gears and see if the teeth were all stripped suddenly or were they torn off one or two at a time which you should be able to see from the dulling of any breakage marks. The broken shaft and maybe that was also the initial failed component, can easily be checked by seeing if it has a more or less straight through break with fatigue crystallization in the break or the long tapered and twisted break of a torque or twist off type breakage. A straight through break means the shaft has fatigued and broken and precipitated the trouble. A twisted off shaft means look elsewhere for the problem area and it also means a very sudden shock and stop from jamming somewhere. If the combine engine started to load a few seconds before the breakage then it is even more likely there was a build up of material somewhere until something gave. You have my sympathy as the damage sounds pretty serious but it is only metal and can be repaired unlike a human being being seriously injured. Best of luck and we really envy you with those yields after about 3 droughts, one frost wipe out and the remaining years in our last 10 year run being semi drought. A really bad time for everybody around here. There are many around here who are about at the end of their stress levels and finance and just want out. Cheers!