Bronze bush

[ukracer]

Leeds Bronze ..try them. They will supply cored materials close to your dims ..to save on the expensive material

I can get it cored locally but not till Wednesday. But i will get a price though. Cheers

 

[ukracer]

Cast iron bearings perform better than Bronze in many applications.

Especially if there is a lack of lubrication.

Interesting..

 

[ukracer]

The interesting part about sintered bronze bearings (oilite) is that the SAE oil is actively released from the bush as the friction increases and heat is generated.
Low friction, less oil released.

The oilite bushes can last years in certain applications due to this self sustaining mechanism.

It doesn't happen but they can be recharged with oil by heating the oil and leaving the bush in there to soak. Although I think vacuum impregnating them is meant to be more successful.

These lasted 11 years..

 

[ukracer]

Looks like it's seen some load.
I'd be worried about a steel bush cold-welding itself to the shaft under those conditions..

I was not sure but decided there must be a reason they dont use steel. That said it wa only going to be a temp fix till the new year.

 

[Erie Fred]

For high-er loads we used Ampco-18.
One application where Ampco-18 was not holding up, I brought in Brush Wellman
for some IIRC aluminum Bronze.
Was pricey, but did the job.

 

[bricol]

Looking at the worn bush, I would expect the pin/shaft running in it to be worn too.

 

[oldbikedavey]

Apparently gold is just as good as bronze for making bushes

Might be cheaper....

 

[oldbikedavey]

Would casting something up in aluminium bronze be a valid solution ?

 

[Agroshield]

I intend to bore both of them to 50mm. And then turn a mandrel to hold each one while I turn the ID.

Without the pins that go in the bush, it may be difficult to make things fit well. Given the wear in the bush, it would be wise to check that the pin is not also worn, or similarly out of round. A bush which is sized to, and has to pass over, the unworn part of the pin will be loose on a worn part.

Any sloppiness in the connection is going to lead to premature failure. That sloppines could be between the pin and ID of the bush or the OD of the bush and the hole. Hence the bushes would normally go in the link with a slight press fit and then be bored insitu on a mill.

A simple 50 ID 60 OD item is a bit risky if anything other than a short term fix is required.

 

[Monkey Harris]

Re bronze type bushes on small motors,
fans on ovens and boilers..
Often getting hot,
when they get stuck I oil and free them seem to work well afterwards..
Is this common practice..

Why do they get stuck..?

 

[Seadog]

Why do they get stuck..?

The lubricant dries up and becomes more akin to a lacquer.

 

[Munkul]

Not sure if you can buy them in the sizes you need, but we've had some amazing success with the spotted graphite impregnated solid bronze bushes. In a horrible high torque, high side load, high impact application where regular oilite sintered bronze gave up quickly.

 

[bricol]

Cast iron, unlubricated works in some applications. We use them on oscillating rams in one of our machines - 12 per head, maybe 14 heads in a machine, heads rotating at around 260 rpm, the rams banging backwards and forwards at the same time, once per rev - it has a pretty complex lubrication system.

If the lubrication fails, it doesn't take long for things to pick up and wear.

In other parts of the same machines, we use some stupidly expensive plastic bearing material, runs dry and lasts years. But eye wateringly expensive.

 

[Dapph2]

Re bronze type bushes on small motors,
fans on ovens and boilers..
Often getting hot,
when they get stuck I oil and free them seem to work well afterwards..
Is this common practice..

Why do they get stuck..?

Not enough lube so the bush heats up & expands onto the hot shaft that will also have expanded ..even worse if there is a bit of scoring on either part , when you lube it , it will have lost a bit of heat so with luck it will act as a bearing once again ...for a while if it wasn't too damaged.
My antique 1943 back gear lathe had true sintered phosphor bronze bearings on the cross shaft mounting bushes , It never appeared to reach full speed in any ratio , one day I happened to rest my left hand on one of the bearing as I was about to change the drive belt ration . It was *%^$£ing hot I can tell you the motor wasn't that far behing either.


On stripping it down I found dozens of tiny scores in both bearing sets of the shaft .. Someone in its earlier life had been turning cast iron brake drums ???
I ended up putting in two new bushings with two high speed roller bearing in each bushing and also had a new precision drill rod as the cross shaft turned down a 1/2 thou so I could get a good push fit on assembly .

 

[Dapph2]

Cast iron, unlubricated works in some applications. We use them on oscillating rams in one of our machines - 12 per head, maybe 14 heads in a machine, heads rotating at around 260 rpm, the rams banging backwards and forwards at the same time, once per rev - it has a pretty complex lubrication system.

If the lubrication fails, it doesn't take long for things to pick up and wear.

In other parts of the same machines, we use some stupidly expensive plastic bearing material, runs dry and lasts years. But eye wateringly expensive.

For those with an enquiring mindset ....

There are two main types of graphited cast iron one is spheroidal or ductile good for bearings.
https://www.bing.com/search?q=What+...gEJMTg1NjhqMGoxqAIAsAIA&FORM=ANNTA1&PC=EDGEDB

And the other is flake cast iron which is good for compression & strength .

What is flake graphie cast iron used for ? - Bing

Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you.

www.bing.com

 

[oldbikedavey]

Aluminium bronze is quite hard. It doesn't make great bearings in many applications.

Babbited, its characteristics would change.

 

[Cobbler]

Babbited, its characteristics would change.

I thought Babbited was a cruel cut, named after that American caught playing away & his courting tackle removed.

 

[daleyd]

I thought Babbited was a cruel cut, named after that American caught playing away &his courting tackle removed.

John Wayne Babbitt!

 

[ukracer]

Without the pins that go in the bush, it may be difficult to make things fit well. Given the wear in the bush, it would be wise to check that the pin is not also worn, or similarly out of round. A bush which is sized to, and has to pass over, the unworn part of the pin will be loose on a worn part.

Any sloppiness in the connection is going to lead to premature failure. That sloppines could be between the pin and ID of the bush or the OD of the bush and the hole. Hence the bushes would normally go in the link with a slight press fit and then be bored insitu on a mill.

A simple 50 ID 60 OD item is a bit risky if anything other than a short term fix is required.

You are spot on. The pin is well hammered. I have put it in a four jaw and got it back to round bit I am also making a new pin. I will try and photo it all when finished but i only got the second slug of Bronze at 6pm and I feel under the weather today..
It is actually a short term fix to get a bender working before xmas. My son has a meeting to discuss pay and grades, on Tuesday as they have asked him to put his name on the O Licence they just got approved for.
Getting this machine up and running is another arrow in his bow as they have a long term contract to supply the product this machine produces.

 

[Agroshield]

...they have a long term contract to supply the product this machine produces.

While it is in bits, draw up the link, bushes and pins. Then you could make a complete spare set at your leisure for next time it wears out or starts to wear out and minimum downtime.