Ford Motor Company's maintenance used to have a PM (preventive maintenance) schedule that included lubricating overhead conveyor drive chains with grease.
They had a paint brush and a coffee can of grease at every drive unit. (a mfg facility could have hundreds of these drives)
The maintenance folks I work with at a couple of Ford facilities were changing out drive chains about once every six months. These drive chains are standard #120 roller chains with attachments that pull the overhead conveyor chain.
Just to let you know how big an issue this was, these chains were costing them about $600-700 a pop, and remember one plant has many of these items that were being changed out twice a year.
I showed the maintenance staffs how lubricating with grease was wasting their time, and costing them money. Lots of money.
Grease is oil whipped up into a thick paste by mixing the oil with a soap base, such as lithium, or calcium.
For the oil, that has been applied to the outside of a chain in the form of grease, to effectively lubricate it has to first seperate from the soap base, and then migrate to the friction points.
Problem is, it takes a loooong time for the grease to seperate from the soap base. Longer than the six months it took for the chain to wear and elongate...which in turn wore the drive side sprockets, which would also have to be changed out with the new drive chain. (~$200 a pop)
This was not counting the cost of the maintenance staff that took two men to change each drive chain and sprocket. Union labor aint cheap.
And in the case of the conveyor itself...if a drive chain is elongating at an accelerated rate, so does the conveyor chain it is meshing with. And endless circle of wear.
And depending on how long the line is...you could be talking in the six figures of accelerated wear happening.
A serious issue for the auto mfg that has to answer to stock holders.
I showed them how by simply changing their method and product, they could save literally thousands, and thousands of dollars each year.
I first had to convince them that the grease was doing absolutely no good at all. Which talk alone wasn't getting it done. (imagine that)
I had to have them physically break apart a working drive chain to show them that there was simply NO lubrication making it to the friction points...however the outside of the chain was NEVER going to rust.
After an automatic system that provides a periodic lube of dry-film lubricant to the drive chain, their chains were lasting and lasting.
The maintenance staff was convinced that a change in plan was needed.
But I was not the only one around the country helping them to smarten up...because soon all Ford plants had a manditory specification that requires automatic lubrication to all overhead drive chains with dry-film lubricant.
The results of changing method and product was amazing. Money was immediately saved.
However, I found that there were still conveyors in some areas that were still having drive chains wear out abnormally fast.
When I looked into the situatiuon, I found that some of the drive chains were being adjusted incorrrectly, which was causing pre-mature wear and failure. The particular drive I first encountered like this was having the drive chain changed out every 30 days, even with auto lube with dry-film!
I instructed the maintenance man responsible for that drive how to properly align and tension the chain....and 3 years later the very same chain was still on the drive and well within spec.
That line was actually torn out before the chain could wear to a point of needing replacement.
BTW...Ford now specifies dry-film lubrication on all of their overhead conveyor systems around the globe. as does GM, Crysler, and Toyota.
Many still don't have a clue...but the big boys paid attention.
