Material selection for Sliding material 1

[A Banerjee]

I am currently designing a structural bearing. The application of the component that I'm thinking must have

i) extremely low co-efficient of friction & abrasion (better than UHMWPE against steel grade 350 or Stainless Steel AISL 316)
ii)compressive strength greater than 200 MPa
iii) insulator and inert to environment and
iv) available and lower cost.

Can you guys suggest something please.

Thanks in advance.

 

[3DDave]

Better than UHMWPE? That would be a rocker bearing. If there was a sliding bearing material that met your requirements Google would find it on the first search.

 

[Pud]

There's PEEK and PAI (e.g. Torlon) which might do items 1-3.


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[TugboatEng]

Google up "composite bearing". There are hundreds of choices.

 

[dik]

My experience is that you can have a bearing that is inexpensive, or one that works.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[EdStainless]

You can get i-iii, but they effectively preclude low cost.
You are looking at filled composite/polymer systems to get these characteristics.
The way to control cost is to use a readily available form (no special shapes), and just have the bearing do the bearing job.
This usually means fairly thin pieces that are well supported by steel.


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P.E. Metallurgy, consulting work welcomed

 

[JohnRBaker]

Yes, I got feeling that those specs were for some sort of 'unicorn' material.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[dik]

I've not used it, but I understand that polyamide imide bearing material is incredible, but very pricey.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Tmoose]

Static or dynamic friction ?
Required/desired service life including wear rate ?
Misalignment tolerance?
Permissable deflection based on the rest of the system's requirments ?
Will the "bearing" be protected to ensure Good cleanliness, or subject to some level of contamination either unintentional or of necessity?
What's the "PV" of your application?

Compressive "strength" both yield and ultimate may require considering Hertzian stresses.

 

[drawoh]

A Banerjee,

Is this a dynamic bearing like for a shaft, or is this a structural pin connection?

I have a specification sheet here for glass filled Delrin. This material has a compressive strength of 100MPa at 10% strain, and 1MPa at 1% strain. I am guessing the 10% strain is mostly permanent.

If you need the 200MPa, you are looking at some form of bronze.

--
JHG

 

[Jboggs]

Have you checked PBC Linear, Igus, and GGB bearings?

 

[dvd]

A couple of suggestions -

https://www.daytonlamina.com/catalog-index/014

https://grmcp.com/fluorogold-slide-plates/

Make them electrically insulated, independently.

 

[Pud]

dik, You're correct. After injection moulding parts need a post mould heat curing cycle to cross link the stuff. Could take a week for 6mm thick sections. Ramping up/down temperature.


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[Tmoose]

I forgot to ask the length of motion required, IF this is even a linear bearing.

https://www.liveabout.com/thmb/NEFy.../onewayconfusion-5ab96a0ec06471003680e853.PNG

If only .01" then there are options not appropriate for 5" translation.

If you look closely here the end of each "trunnion" bearing support is hanging by a strip of spring steel.
Vertically stiff, but allowing a little bit of lubrication free axial motion and even some yawing alignment about a vertical axis.

https://www.allstates.com/balancer stewart warner end.JPG

 

[kjoiner]

Hello,

I recommend contacting Igus. They are experts in polymer bearings and have a wide variety of bearing materials to choose from. They can also custom fabricate bearings as well.

Kyle

 

[Tmoose]

OP A Banerjee was last here Dec 29 or so.