Bronze bush

[ukracer]

Just wondering apart from the self lubricating function of bronze bushes why they are used and what would be the possibility of using some mild steel as a temporary bush. 60mm ID and 50mm ID
The pin that fits the bush just rotates about half way round. The original bushes have grease nipples fitted anyway.

Just cant get any material till after xmas now apparently.

 

[Jackimus]

Oh matron...?

 

[BrokenBiker]

What sort of loads are involved? Is it just rotational or is there something hanging off the end?

What is the shaft made out of?

 

[bricol]

You answered your own question . . .

Oilite bushes retain oil - soak them in oil before installation. Bronze doesn't, so it needs proper lubrication. All sorts of bearing bronzes out there - gets very complicated.

As for a steel bush - depending on speed, how long you want it in there, how often you will lube it, and what is running in it.

Steel running in lubricated cast iron works well at quite high speed.

 

[tom2207]

one of the engineering plastics may get you by as a temp measure ,,, delrin or ptfe or the likes , easy to machine , depends on loads and speeds ,,, maybe 3d print something ,,,

 

[ukracer]

one of the engineering plastics may get you by as a temp measure ,,, delrin or ptfe or the likes , easy to machine , depends on loads and speeds ,,, maybe 3d print something ,,,

Sadly i dont have plastics in the sizes needed. Interesting if a 3D printed plastic would work. I have not seen the machine set up but i understand the pin moves in a rotational direction. Imagine holding both ends of the pin with your hands one on each end and twist your wrists forward and backwards. But as you can see from the pic its destroyed the bushes on one size.

 

[BrokenBiker]

But as you can see from the pic its destroyed the bushes on one size.

cant see any pic attached.

 

[ukracer]

He has managed to get a slug of bronze

What sort of loads are involved? Is it just rotational or is there something hanging off the end?

What is the shaft made out of?

I suspect its a press or bending machine. And my guess is high loads.

 

[Bornfree]

Apparently gold is just as good as bronze for making bushes

 

[ukracer]

You answered your own question . . .

Oilite bushes retain oil - soak them in oil before installation. Bronze doesn't, so it needs proper lubrication. All sorts of bearing bronzes out there - gets very complicated.

As for a steel bush - depending on speed, how long you want it in there, how often you will lube it, and what is running in it.

Steel running in lubricated cast iron works well at quite high speed.

I don't think its high speed but did think choosing a material might not be straight forward.

He got a slug already and managed to get another slug to collect tomorrow. I suspect they wil both be bronze. I intend to bore both of them to 50mm. And then turn a mandrel to hold each one while I turn the ID.
I am only doing it at home as he is ultra busy at work, although they do have a lathe they would usually use the job shop up the road. But they cant do it till after jan 5th and they need this machine running to get a job out before xmas.

 

[ukracer]

Apparently gold is just as good as bronze for making bushes

It costs almost as much.

 

[hotponyshoes]

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

 

[daleyd]

Some info on bronze and the properties and why it might be used in various applications here

https://www.ggbearings.com/en/resources/bearings-resources/faq/why-use-bronze-bushings

As said above it depends what type of bronze is currently used, it was presumably chosen for a reason (s).

 

[Richiew]

That lower one is nicely wallered. Just caught it in time.

 

[tom2207]

ah ,,, seen the pics ,,, bigger than I imagined ,,, forget plastics ,,,,

 

[Milkybars]

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

 

[Brad93]

You answered your own question . . .

Oilite bushes retain oil - soak them in oil before installation. Bronze doesn't, so it needs proper lubrication. All sorts of bearing bronzes out there - gets very complicated.

As for a steel bush - depending on speed, how long you want it in there, how often you will lube it, and what is running in it.

Steel running in lubricated cast iron works well at quite high speed.

Cast iron bearings perform better than Bronze in many applications.

Especially if there is a lack of lubrication.

 

[Dapph2]

Just wondering apart from the self lubricating function of bronze bushes why they are used and what would be the possibility of using some mild steel as a temporary bush. 60mm ID and 50mm ID
The pin that fits the bush just rotates about half way round. The original bushes have grease nipples fitted anyway.

Just cant get any material till after xmas now apparently.

There is porosity in sintered bronze use for bushes which allows tiny globules of oil to sit in the pores , so the microscopic film of oil produced causes the precision shaft to actually float in the oil which surrounds all of the shaft.

You have to keep such bearing lubricated with the recommended oil for the bearing . Some such bearing have been running for 50 years or more continuously so long at the oil feed is clean and constant
As a result you can get super accurate bearings for lathes , turbines & machinery .

 

[Brad93]

Just wondering apart from the self lubricating function of bronze bushes why they are used and what would be the possibility of using some mild steel as a temporary bush. 60mm ID and 50mm ID
The pin that fits the bush just rotates about half way round. The original bushes have grease nipples fitted anyway.

Just cant get any material till after xmas now apparently.

I've got some plastic that size. It's not self lubricating but it is bearing plastic. Very very low friction.

 

[Brad93]

There is porosity in sintered bronze use for bushes which allows tiny globules of oil to sit in the pores , so the microscopic film of oil produced causes the precision shaft to actually float in the oil which surrounds all of the shaft.

You have to keep such bearing lubricated with the recommended oil for the bearing . Some such bearing have been running for 50 years or more continuously so long at the oil feed is clean and constant
As a result you can get super accurate bearings for lathes , turbines & machinery .

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.