Ceramic Bearings?????

[HELSEL]

Well we thought they was a great thing but one let go at the Chardon show. It totally ruined the engine!! We called the place where we got them and the guy said that they are not recommended for use on the power take off side!! That is not the same story that was told when we was buying them.

They claim they are good for 30.000 rpms and take the heat better and are stronger than the steel bearings.


Rick

 

[klickitatsacket]

who did you get yours from? I have not had any problems with mine yet.

 

[e.j. mcnamara]

waste of money

i seen the motor that the bearings where in totaly destroyed the bearings let go

 

[BobL]

Just couple of anecdotal experiences regarding bearing longevity in an extreme situation. In our lab we use turbomolecular vacuum pumps. They spin at about 50,000 rpm 24/7/365. When the bearings fail the resulting noise and damage is nothing short of spectacular so apart from losing our vacuum we don't like our bearings to fail. After going through 3 pumps with steel bearings in about 3 years we switched to ceramic bearings with no significant detectable change in life time. We now use electromagnetic bearings - no failure in the last 12 years - that's 315 billion trouble free revs!

 

[sILlogger]

Just couple of anecdotal experiences regarding bearing longevity in an extreme situation. In our lab we use turbomolecular vacuum pumps. They spin at about 50,000 rpm 24/7/365. When the bearings fail the resulting noise and damage is nothing short of spectacular so apart from losing our vacuum we don't like our bearings to fail. After going through 3 pumps with steel bearings in about 3 years we switched to ceramic bearings with no significant detectable change in life time. We now use electromagnetic bearings - no failure in the last 12 years - that's 315 billion trouble free revs!

what do you do and where can i get one!!! don't know what they are but they sound cool.....kind of expense tho i bet...good info. thanks

 

[sILlogger]

Just couple of anecdotal experiences regarding bearing longevity in an extreme situation. In our lab we use turbomolecular vacuum pumps. They spin at about 50,000 rpm 24/7/365. When the bearings fail the resulting noise and damage is nothing short of spectacular so apart from losing our vacuum we don't like our bearings to fail. After going through 3 pumps with steel bearings in about 3 years we switched to ceramic bearings with no significant detectable change in life time. We now use electromagnetic bearings - no failure in the last 12 years - that's 315 billion trouble free revs!

what do you do and where can i get one!!! don't know what they are but they sound cool.....kind of expensive tho i bet...good info. thanks

 

[BobL]

what do you do and where can i get one!!! don't know what they are but they sound cool.....kind of expense tho i bet...good info. thanks

Regarding E/M bearings I think you need to bear in mind the physical load/forces (especially the sideways forces) on turbo pumps are small compared to what are typical for CS bearings. The E/M bearings are a secondary bearing. AT low speed a steel bearing provides the load but as the pump spinns up the EM bearing takes over and is fully operational at full speed. I think eventually someone will come up with a versatile high load E/M bearing for all manner of machinery, maybe when room temp superconductors become a reality?

BTW Ceramic bearings for turbo pumps are readily available. EG see specs at http://www.alpinebearing.com/turbo-pump-bearings.asp

 

[Jacob J.]

There's an ongoing debate among saw builders as to the suitability of ceramic bearings in chainsaws. In the bigger saws, there's a number of factors in the engine working against itself and the bearing component is a very small part of that.

 

[Crofter]

A big cause of bearing failure is vibration. It does not even have to be rolling to have contact point damage to balls and races. A saw is surely a vibration prone environment if there ever was one. I wonder whether the extreme hardness of ceramics is a complete plus in this regard. Is the claimed longevity of ceramics more apparent in a steady load state.

 

[Lakeside53]

What happens when they fail? - do they shatter? Most failures I see in deep groove steel ball bearings - the cage disintergrates, the balls move, then the crank is jambed.

 

[bwalker]

What happens when they fail? - do they shatter?

When ceramics fail they tend to do so in a spectacular way.
Yake a ceramic ball and a stell ball and strike both with a hammer...The ceramic ball is crushed and the stell ball might be deformed a bit. But Cermic is harder....

 

[Big Woody]

You might say ceramics generally have no ductility or that they are a brittle material like glass.

I'm waiting for deano to come up with something in a saw he can market as "Nano". Its been the scientific buzzword for the past 10 years. Maybe Nano Boost Tubes (takes a pretty small drill bit though).

Remember it takes a pretty small mind to work on Nano Technology.

 

[klickitatsacket]

When ceramics fail they tend to do so in a spectacular way.
Yake a ceramic ball and a stell ball and strike both with a hammer...The ceramic ball is crushed and the stell ball might be deformed a bit. But Cermic is harder....

Hey ben When have you ever done this and with what bearings. How about some video with that. The reason I am saying this is because you are talking about something you nothing about. Here is a couple of pictures that I just took to show every one what I am talking about.

I just put a ball out of a 088 bearing (new) and a ceramic bearing of the same size on a quality anvil (Peter Wright) and smacked them with a 2 # hammer. The 088 ball was hit 1 time and it split in half. The silicon nitride bearing was hit twice and all it did is dent the anvil. The 088 ball did dent the hammer but not the anvil and it broke.

notice the 3 dents in the 2# hammer and the broken steel bearings.

notice dent lower right corner from the silicon nitride ball in the anvil when it was struck. ( the 088 ball did not leave a dent)

 

[Big Woody]

Why do you suppose the steel ball split in half as opposed to breaking in some other way?

 

[klickitatsacket]

Why do you suppose the steel ball split in half as opposed to breaking in some other way?

What are you trying to infer; I cut it in half with my hacksaw

 

[Big Woody]

Just testing your knowledge of stress analysis.:rockn:

 

[sILlogger]

What are you trying to infer; I cut it in half with my hacksaw

i'd be impressed if u did. thought would take as much skill as building a modded saw

 

[Lakeside53]

I just went out and pounded a couple of 1/4+ inch balls. Lost one (I think it's embeded in the wall); the other dented the anvil...

 

[klickitatsacket]

seeings how you did not offer an explination for this I will for those that want to know. the hammer dented and there fore was softer than the ball. The anvil did not so was harder than the ball in question. The anvil being harder caused the energy of the blow not absorbed by the hammer to feed back into the ball and left a flat spot where it contacted the anvil. The stresses that the now flattened metal being pushed into a hardened sphere caused it litterally to be pushed apart from the flat up.

 

[RiverRat2]

I just went out and pounded a couple of 1/4+ inch balls. Lost one (I think it's embeded in the wall); the other dented the anvil...

Smackin yer balls on an Anvil??? Sheesh yall must be Nuts????????????:monkey: