Bearing Material

[Alan Worland 1Participant @alanworland1]

In the new year I shall be looking forward to starting my new project, a horizontal steam engine of 1.5 in bore and 2.5 in stroke.

Viewing the drawings it appears that the steel crankshaft will be running in cast iron – is this a good combination? or does it sound a good idea to incorporate a bronze sleeve in the cast iron?

Any experiences gladly received!

 

Alan

[Alan Worland 1Participant @alanworland1]

[GoCreateParticipant @gocreate]

Hi Alan

Cast Iron bearings with mild steel shafts is a very traditional combination, the graphite in cast iron helps provide lower friction. Cast Iron is also good when used with hardened steel shafts.

Cast iron will tend to ‘glaze over’ considerably reducing ware.

 

If you wanted to use bronze then leaded bronze is good with mild steel shafts and lower surface speeds as will be the case with your model. Many other bronzes are more suitable for use with higher surface speeds and hardened shafts such as phosphor bronze grades. Leaded bronze is very easy to machine, the lead content providing free machining qualities.

 

There would be little point in having a cast iron housing and fitting a bronze sleeve bearing, just stay with the cast iron on its own. Only if the housing is steel for example would you want to fit a cast iron or bronze bearing sleeve.

 

It won’t apply here but FYI most bronzes are not suitable for high loads, the bronze can become deposited on the shaft due to the load, aluminium bronzes with hardened shafts are more suitable for heavy duty applications. Aluminium bronze is difficult to machine.

 

Nigel

 

 

[Alan Worland 1Participant @alanworland1]

Thanks for the info Nigel, sounds like the design I have (originating from about 1890) is based on traditional methods of the period – I suppose if it wore I could introduce bushes at a later date.

 

Alan

[Tony MartyrParticipant @tonymartyr14488]

Alan

I have successfully used silver-steel shafts running in cast-irom bearings but I made sure that I used centrifugally cast iron bar as the bearing material and (occasionally fed) oil lubrication into the top of the bearings. After 20 odd years of intermittent use both components are ‘as new’

Tony

[Ian S CParticipant @iansc]

My little Super Adept lathe manages quite well with an unhardened shaft running in cast iron bearings. Ian S C

[Engine BuilderParticipant @enginebuilder]

The mandrel of my Myford ML 10 runs in the cast iron headstock with no additional bearings or bushes, no sign of wear after many years of use.

David

 

[Richard ParsonsParticipant @richardparsons61721]

In one place I worked we had ‘a large number of ‘Singer’ sewing machines. These worked some 8 hours per day 5 to 6 days a week doing all sorts of tasks ranging from hemming mattress tops to sewing complicated feather quits. The seldom went wrong. Their shafts were slightly hardened shafts in Meechnite cast iron bearings. All of their drivers (machinists oiled them religiously before they went home. Some dated from the late thirties and some were supplied under lease-lend. They were all destroyed in a fire one night set off by an arsonist.
Rdgs

Dick

[Alan Worland 1Participant @alanworland1]

Sounds like cast iron gets the vote!

Thanks guys

 

Alan

[Author]

Posts