Steel Plain Bearing
Steel Plain Bearing
(OP)
I have an application in which a .5 dia steel shaft carrying an 1800 pound radial load is supported by two steel bushings. Each bushing is .5 inch long. This bearing/shaft combination must operate at about 1 rev/sec with little or no lubrication. What should the shaft and bushing hardnesses be in order to have max bearing life? Will zinc plating on the shaft accelerate the wearing that takes place? Can any type of case hardening be used?
Tom P.
Tom P.





RE: Steel Plain Bearing
I want to say that a it was around $200 for a small basket of parts.
There are some very tough and thin plane bearing out there, Garlock makes some that may work for you. The DU series are self lube and good for around 50,000 psi-fpm. With you speed being so slow it might work.
Barry1961
RE: Steel Plain Bearing
The railroads used to call these type of bearings of (journals running with no lubrication) "hot boxes". The firemen would walk the length of the train when it was temporarily on a siding and pull the burning, smoking, packing out of the boxes, replace the packing and replinish the oil. Later the railroads replaced the journal bearings with anti-friction roller element bearings on all their rolling stock. Timken made a fortune and no more hot boxes. Practically any kind of roller element bearing would be better than a steel-on-steel journal running with "..no lubrication.." as you describe.
RE: Steel Plain Bearing
RE: Steel Plain Bearing
http://www.connexusa.com/HTML/principle.html
RE: Steel Plain Bearing
Tom P.
RE: Steel Plain Bearing
Could a high lead bronze be used?
RE: Steel Plain Bearing
I maybe wrong but I don't think railroads ever used plain steel bearings unless it was very early on. I seen pictures of my grandfather taken in the early 1880's standing beside a railcar with brass or babbitt bearings. The bearings were essentiall a half bearing supported in the trucks and setting on top of the axle. The bearings had an arrangement where there was a reservoir on the outside that contained a wicking material Oakum that helped keep the bearing lubricated. I still have one of the very long neck oil cans that allowed the trainman to oil the bearing while he remained standing.
One of the oils they used in the 30's until the end of the bearing, was an oil made by Sharvannia. This was highly sulfurized, high temperature oil, that I ran into again in the late 50's as we used a Sharvania steam cylinder oil.
RE: Steel Plain Bearing
You are correct as far as I remember. I told the story to emphasize the result of metal on metal journal with "no lubrication" as was stated in lever57's original post and to recall the advantage of rolling element antifriction bearings which can continue to function with no lubrication. Most heavy loaded journals I have experience with do not work well without the lubrication film with some exceptions like graphite.
What was the purpose of the soft babbit or brass inserts vs. some other material?
RE: Steel Plain Bearing
The bearing essentially actually sat on top the axle journal restrained in a housing so that with a railroad jack two men could change the bearing in about 2 hrs by simply jacking up the trucks. In a shop you could pick up the car and put new set of wheels in few minutes.
An interesting note about the RR tapered roller bearing is in the early 80's NASA was able to get over 1,000,000 dN out of a heavily loaded standard RR bearing simply by drilling small radial holes in the outer race.
RE: Steel Plain Bearing
If you are looking for plain bearings or teflon coated check out INAs permaglides, I have used them in the past under extreme loads and low RPM.
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