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SMOKES (Mechanical)
2 Feb 12 15:45
I have inheirited a Linear SIC bearing design.
The design was orignally based on using Fluroscint polymer. The Engineers before me changed the material specs to graphite impregnated Sintered SIC but I suspect none of the drawing tolerances have been changed to Suit the material.
Currently the Design is only stressed to 3%under the heaviest design load. I know there is way to much material on parts but I have to maintain reverse compatiblity with units that are still out in the field.
The bearing  design is lubricated by fluid the unit is pumping

The bearing design is great we have units with these bearings running continously for 20 years.   

My question is with out changing the shape of the parts if I reduced the geometrical tolerances from 0.02mm  ot 0.05mm  would this affect the reliablity of the parts. Or Changing from Sintered SIC to Reaction bonded SIC. The main concern is dry running and using a fluid with particulates in it to Lubricate the bearings.If the bearing fails due to due to dry runing or abrasion it will cause a very critial and expensive failure.   
Can someone point me in the right direction to any papers Regarding design tolerances  and specification of SIC linear bearings.

The other question is resourcing the manufacturing of this design to the Far east. has any one had any luck doing this?

by luck I mean Getting the supplier to manufacuter them to the drawing and material specification or using a loaclly branded Sintered SIC material. I suspect I have a lot of testing to do when I resource the supplier.



  
MikeHalloran (Mechanical)
4 Feb 12 13:26
If it ain't broke, why are you fixing it?

Re offshoring manufacture, you might as well just quit now.
If offshoring works, you won't be needed anymore.
If offshoring fails, you will be blamed.

 

Mike Halloran
Pembroke Pines, FL, USA

SMOKES (Mechanical)
7 Feb 12 3:14
Supplier Price went up by 50% and current suppliers got a contract with an OEM so they not interested in our small order quantities.
I need a good price and delivery times hence resourcing the parts.

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