innovative chain

[unclehan]

Can you guys check out this chain?

http://tsubakimoto.com/products/chain/conveyor_chain/bearing_bush_chain.html

It uses actual needle bearings between the pin and the roller instead of bushing. So I'm guessing this chain would be a lot more longer lasting. But since it's not very widely used, I'm guessing it costs significantly more to produce. It seems it's only used on conveying applications where precise displacement is important.

Compared to a regular chain bushed chain, how much more costly will this "needle bearing chain" be in terms manufacturing cost? I'm guessing it's very expensive since it's not widely used, like the silent chain.

Thanks for the help.

 

[artmichalek]

It would be crazy expensive to make precision needle bearings small enough to work in a bike chain. Note that the Tsubaki chains only go down to 75mm pitch. That's about three times bigger than a bike chain.

 

[boudreaux]

It would be crazy expensive to make precision needle bearings small enough to work in a bike chain. Note that the Tsubaki chains only go down to 75mm pitch. That's about three times bigger than a bike chain.

And imagine how fragile the itty bitty rollers would be...

 

[serenaslu]

And imagine how fragile the itty bitty rollers would be...

And heavy.

 

[unclehan]

It would be crazy expensive to make precision needle bearings small enough to work in a bike chain. Note that the Tsubaki chains only go down to 75mm pitch. That's about three times bigger than a bike chain.

I think 75mm is about 6 times bigger than a bike chain. But anyway, let's say they scale it down.

How much more expensive do you think such a chain would be compared to a regular chain? It seems all it takes is to replace the bushing with the needles.

I'm not familiar with manufacturing.

Thanks.

 

[Don Shipp]

Conventional chains are something like 95% efficient. That's enough.

 

[artmichalek]

How much more expensive do you think such a chain would be compared to a regular chain? It seems all it takes is to replace the bushing with the needles.

I'm not familiar with manufacturing.

The bushings on a bike chain are on the order of ~5mm in diameter with ~2mm pin. That would make the rollers somewhere in the neighborhood of ~0.5mm. The dimensional requirements for precision bearings are on the order of +/- 0.01%, which works out to +/-0.0005mm. You pretty much have to be working in a high level clean room to even measure something to that resolution, let alone fabricate it. And that doesn't mean they're going to be strong enough either. To transmit the tensile loads that a bike chain is subjected to through such a small bearing, the contacting surfaces would have to be extremely hard. It would be cheaper to buy a new chain after every ride than it would be to try to extend it's life span by swapping out the bushings for needle bearings.

 

[unclehan]

The bushings on a bike chain are on the order of ~5mm in diameter with ~2mm pin. That would make the rollers somewhere in the neighborhood of ~0.5mm. The dimensional requirements for precision bearings are on the order of +/- 0.01%, which works out to +/-0.0005mm.

But does it have to be PRECISION? What if it's only +/- 1%? What would happen? Will it not roll properly? There are a lot of clearance between the bushing and the pin and the roller on a regular chain. So I don't see why the bearing version have to be that precise.

 

[boudreaux]

But does it have to be PRECISION? What if it's only +/- 1%? What would happen? Will it not roll properly? There are a lot of clearance between the bushing and the pin and the roller on a regular chain. So I don't see why the bearing version have to be that precise.

Are you just extra thick r what?

 

[wilmar13]

But does it have to be PRECISION? What if it's only +/- 1%? What would happen? Will it not roll properly?

Bingo!

Imagine you the bearing needles are different sizes how smooth do you think that would be?

FWIW high precision bearings are usually sorted, even though they are machined to incredible tolerances, and matched for as close to uniformity as possible.

 

[unclehan]

Bingo!

Imagine you the bearing needles are different sizes how smooth do you think that would be?

FWIW high precision bearings are usually sorted, even though they are machined to incredible tolerances, and matched for as close to uniformity as possible.

It doesn't have to be too smooth, but then again, you have to realize the situation is different for this chain than from a conventional needle bearing setup.

In conventional bearing, the needles are held in place by its axis and everything is rigid...the shafts, the housing ect... Therefore you need high precision needles for it to run smoothly.

But for such a chain, even if the needles are a little off, it might not roll perfectly, but with a big enough clearance between the pin and roller, the needles have a lot of room to "move" since they are not held in place. There are HUGE clearances between the pin, the bush, and the roller in a conventional chain.

Anyway, any kind of rolling should be better than the sliding between the bushing and the pin as in conventional chains.

You might think strength might be a problem, but a conventional needle bearing with OD of 1cm can take radial load of couple of hundred pounds, which is more than enough for a bike.

 

[meb]

Can you guys check out this chain?

http://tsubakimoto.com/products/chain/conveyor_chain/bearing_bush_chain.html

It uses actual needle bearings between the pin and the roller instead of bushing. So I'm guessing this chain would be a lot more longer lasting. But since it's not very widely used, I'm guessing it costs significantly more to produce. It seems it's only used on conveying applications where precise displacement is important.

Compared to a regular chain bushed chain, how much more costly will this "needle bearing chain" be in terms manufacturing cost? I'm guessing it's very expensive since it's not widely used, like the silent chain.

Thanks for the help.

Intended for low maintenance and minimizing difficult repairs including those at difficult access areas. On a conveyor, the weight penalty would be less significant than a bike as the conveyor is not usually mobile and is generally motorized. Imagine having to lube bushings or live with wear given greater chain use of a conveyor magnitudes more than a bike.

 

[waxbytes]

Can you guys check out this chain?

http://tsubakimoto.com/products/chain/conveyor_chain/bearing_bush_chain.html

It uses actual needle bearings between the pin and the roller instead of bushing. So I'm guessing this chain would be a lot more longer lasting. But since it's not very widely used, I'm guessing it costs significantly more to produce. It seems it's only used on conveying applications where precise displacement is important.

Compared to a regular chain bushed chain, how much more costly will this "needle bearing chain" be in terms manufacturing cost? I'm guessing it's very expensive since it's not widely used, like the silent chain.

Thanks for the help.

Even if one could make such a chain for a bicycle road grit and deraileur gearing (mis)alignment would chew it up in no time.

 

[Induray]

Even if one could make such a chain for a bicycle road grit and deraileur gearing (mis)alignment would chew it up in no time.

I know...design chainrings and cassette cogs that would accept 75mm pitch chain!.

BIG MOMMA JAMA!

 

[artmichalek]

But for such a chain, even if the needles are a little off, it might not roll perfectly, but with a big enough clearance between the pin and roller, the needles have a lot of room to "move" since they are not held in place. There are HUGE clearances between the pin, the bush, and the roller in a conventional chain.

It doesn't matter what your application is, precision matters for more than smoothness. A needle bearing has an inner race, an outer race, and a cage of rollers in between them. If all of the rollers aren't contacting both races at all times, the assembly with wear out very quickly.

 

[unclehan]

I don't think the needle bearings are worth it for its cost. Even though it may decrease the pin wear rate, (by a lot?), the chain will still die when its fatigue life ends.

Usually a normal chain has a life of 15000 hours under ideal lubrication condition and installation. They needs to be replaced once the elongation reaches a certain limit. But this "needle bearing" design should increase the wear life drammatically so the chain will be limited by its fatigue life.

Anyone ever had their chains "pulled apart"?

Thanks

 

[Induray]

I don't think the needle bearings are worth it for its cost. Even though it may decrease the pin wear rate, (by a lot?), the chain will still die when its fatigue life ends.

Usually a normal chain has a life of 15000 hours under ideal lubrication condition and installation. They needs to be replaced once the elongation reaches a certain limit. But this "needle bearing" design should increase the wear life drammatically so the chain will be limited by its fatigue life.

Anyone ever had their chains "pulled apart"?

Thanks

There is a forum thread here with the subject of breaking chains. Most attributed to the new 10 Spd drive trains. One cause of failure as mentioned in the forum is premature separation of a link due to bending forces created when shifting gears under high loads. The chain is locally twisted by the derailleur during the shifting process causing distortion of the chain. The forces created causes excessive tension forces on the pin (pins are made to resist shear not tension) as thus separates the pin fm the link. This appears to be a design flaw of the 10 spd systems. No fatigue failures were mentioned. I have a 9 spd shimano and so far no chain breakage. Where exactly have you experience fatigue failure? Within the links itself? Two places I can see it happening are at the neck-down of the link body, or the bore of the hole where the pin attaches. However, Prior to this happening(fatigue failure) the chain link material will yield plastically causing the chain to stretch. This is an indicator of "it is time to change the chain". Proper maintenance should prevent your chain form failing due to fatigue. And that is where I am having problems with this new 10 spd system. The chain is designed thinner to accomodated for that extra cog on the same dropout spacing as 8/9 spd. This in turn reduces the life of the chain significantly, forcing to change chains more frequently (and the are about $10 pricier the 9 spd), and in addition , it will not guarantee fm premature failure of the chain as I stated above!

 

[unclehan]

Usually chain wear and needs to get replaced because of the pin/bushing wear.

What about the roller/bushing wear? Is that important to check?

 

[alienator]

There is a forum thread here with the subject of breaking chains. Most attributed to the new 10 Spd drive trains. One cause of failure as mentioned in the forum is premature separation of a link due to bending forces created when shifting gears under high loads. ......more stuff.......This in turn reduces the life of the chain significantly, forcing to change chains more frequently (and the are about $10 pricier the 9 spd), and in addition , it will not guarantee fm premature failure of the chain as I stated above!

I think you're over-stating the failure rate of chains. I haven't seen that many failures posted anywhere. Most of the failures have been with Wippermans. The expense of a chain w/ roller bearings would be nasty, and it would be completely unneeded. Motorcycle final drive chains rely on bushings, and their stresses are much greater, with way bigger impulses to handle.

I would wager that even if a chain w/ roller bearings lasted twice as long as a bushing chain, it would cost more than twice as much. So not only would it be mechanically unneccessary, but it would be an economic non-starter. It'd be a matter of fixing something that ain't broken.

 

[alienator]

There is a forum thread here with the subject of breaking chains. Most attributed to the new 10 Spd drive trains. One cause of failure as mentioned in the forum is premature separation of a link due to bending forces created when shifting gears under high loads. ......more stuff.......This in turn reduces the life of the chain significantly, forcing to change chains more frequently (and the are about $10 pricier the 9 spd), and in addition , it will not guarantee fm premature failure of the chain as I stated above!

I think you're over-stating the failure rate of chains. I haven't seen that many failures posted anywhere. Most of the failures have been with Wippermans. The expense of a chain w/ roller bearings would be nasty, and it would be completely unneeded. Motorcycle final drive chains rely on bushings, and their stresses are much greater, with way bigger impulses to handle.

I would wager that even if a chain w/ roller bearings lasted twice as long as a bushing chain, it would cost more than twice as much. So not only would it be mechanically unneccessary, but it would be an economic non-starter. It'd be a matter of fixing something that ain't broken.