chain lubrication 1

[autoguru]

The chain as we know it, needs a lot of lubrication.
Where is the lubrication most critical/important?

the pin/bushing interface? or the roller/bushing interface?

I would think the lubrication at the pin/bushing joint is a lot more important than the roller/bushing interface.

It seems sprocket-to-chain bushing is rolling contact (very efficient), but bushing-to-pin is sliding contact (under boundary lube conditions) and link-to-pin is sliding contact (under boundary lube conditions). Therefore I think the sliding action at the joints is the main reason why chain need so much attention when it comes to lubrication. And I would think it's also the most common reason for chain failure.

Is that right?

 

[Barry1961]

If we are only talking of standard roller drive chains I would agree. I am not aware of a method of lubricating one without the other though.

Some chains can be destroyed very quickly if lubricated. In particular if running in fine grit.

Barry1961

 

[MikeHalloran]

The best dirt bike chains (e.g. for running in fine grit) are factory- lubricated and o-ring sealed. The seals are preloaded so much that the chain is physically hard to flex, and at least a yard of it can be held out straight horizontally without bending. Forget efficiency.

In a place like an engine, roller chains are very durable, provided they actually get an oil spray. Hy-Vo chains have only rolling contact, and should be even more durable, but cost more.



Mike Halloran
Pembroke Pines, FL, USA

 

[autoguru]

"If we are only talking of standard roller drive chains I would agree. I am not aware of a method of lubricating one without the other though."

I thought it's easier to lubricate the roller/bush interface than the pin/bush? at least that's according to Tsubakimoto's website.

Also, since external lubrication is very easy, if the external side of the roller and the sprocket gets well lubed, I don't think lubrication between the roller/bush will matter as much.

 

[MintJulep]

Mike,

But on dirt bikes, the sprockets are essentially a consumable item.

Sprocket cheap, chain expensive.

 

[MikeHalloran]

Dirt bike chain is a consumable, too. It may make sense to use bulk industrial chain and throw it away with the sprockets, depending on the character of your local dirt/mud.



Mike Halloran
Pembroke Pines, FL, USA

 

[Barry1961]

Both the roller/bush and the pin/bush interface are lubricated at the same time on standard roller chain. At least that’s according to the Tsubakimoto's website.

http://tsubakimoto.com/products/chain/install/rs_chain_lubrication.html

I guess it is possible to lubricate the roller link without getting oil on the pin link but I have never seen it done. The lubrication path for the pin/bushing is longer and the area is smaller so it will get less oil.

When I mentioned chain running in fine grit I was thinking of reclaimer chain in a cement plant. There the lubrication will cause the dust to form a hard abrasive coating.

Most of the SS, WH, MRS, MXS, S, X, C, H, 400 thru 900 Class Pintle, DF, MD, Detachable and Rivetless are designed to be able to run dry. Of course the non-metalics and washbox chain run without lube.

Barry1961

 

[strokersix]

It has been observed in testing on multiple occasions in a dusty agrigultural environment that lubricated is better than dry for roller chain as well as spur gears. The argument that lube will combine with dirt to make a gritty paste and accelerate wear does not hold true, at least for the applications I'm familiar with.

 

[Barry1961]

Different types of chain and applications will require different lubrication or none at all.

Barry1961

 

[autoguru]

"The best dirt bike chains (e.g. for running in fine grit) are factory- lubricated and o-ring sealed. The seals are preloaded so much that the chain is physically hard to flex, and at least a yard of it can be held out straight horizontally without bending. Forget efficiency."

Mike, that preload is independent of the driving load right? So if the driving load is small, the efficiency is low. If the driving load is greater, the efficiency gets better? If the chain has to carry a heavy load, the "preload" due to the seals is negligible.

Are the O-ring chains significantly more expensive than a "regular" chain?

The O-ring seals will wear out with time right?

 

[tbuelna]

If you want to see a clever approach to minimizing mechanical loss at the pin/link interface, take a look a newer types of silent (inverted tooth) chain. The newer designs replace the traditional cylindrical pin with two "C" shaped pins, rolling back-to-back against each other. The rolling contact of the crescent shaped pins is much more efficient than the sliding contact of the cylindrical pin.

Take a look at U.S. patent 5,372,554.

Regards,
Terry

 

[MikeHalloran]

Yes, the o-ring chain is expensive relative to unsealed chain. Yes, the o-rings eventually wear, and the chain starts to get flexible.



Mike Halloran
Pembroke Pines, FL, USA

 

[autoguru]

"If you want to see a clever approach to minimizing mechanical loss at the pin/link interface, take a look a newer types of silent (inverted tooth) chain. The newer designs replace the traditional cylindrical pin with two "C" shaped pins, rolling back-to-back against each other. The rolling contact of the crescent shaped pins is much more efficient than the sliding contact of the cylindrical pin."

But those are for silent chains, which are 5 times as expensive as roller chains.

Does the C shaped pin significantly add to the cost of the chain?

 

[autoguru]

How does the "rocker pin joint" work? It seems to be a clever idea. They use 2 pins instead of one. But the 2 pins are shaped like "C"s that roll against each other. But so far it seems they are only used for silent chains.

I'm really curious how that work because when the "C" joint articulate, it elongates/shortens the pitch of the chain. And it seems they are limited only to the silent/inverted tooth chains.

It also probably add a lot to the cost of the chain.

Welcome any comments.
Thanks.