Angular Contact Bearings For Spindle

[Kakarott]

I am from India.I have CNC Turning wich has a Fanuc OT-D Control.The spindles max rpm is upto 4000.The spindle has 5 bearings in total.All are angular contact.Earlier bearings were of FAFNIR make wich came as a OE fitment.Now I have to replace them as the noise has increased.The question is suggest me a gud manufacturer of angular contact bearings.Here in India diff. makes r available such as RHP,FAFNIR etc.So for wich make shud I go.Also the wich type of preload shud be considered "Medium Preload" or "Light Preload" and wich grease shud be used while repalcing the bearings.

[svenakela]

I suggest you go to a local dealer with the old bearings and get some support directly from them, they should find replacement products for you.
I know SKF is present in India as I saw a couple of SKF signs last time I was there, depends were you are though.

[NC Cams]

The best option is to contact Fanuc and buy OEM bearings. Reason: they know EXACTLY what bearings to use and what to grease them with.

When it comes to AFTERMARKET servicing of spindle bearings, that can be a TOTALLY different situation. Reason: the factory often uses unique or special bearings in a spindle and the specs for the bearings are NOT universally known - nor published.

The amount of preload M, L or H, depends on the spindle design and operating requirements that the OEM established. These are NOT "guesstimates" but rather carefully calc'd values.

SOMETIMES, and I do mean sometimes, the bearings can be reverse engineered. However, this may be an exercise in futility if the spindle has been serviced by someone else and they have simply thrown whatever worked at the spindle. Your guess is as good as mine in this sort of situation.

Finally, this ultimately is NOT a simle "plug and play" service operation. It involve some research and some reverse engineering and/or re-engineering of the situation. It is DEFINITELY not a simple message board, talk you thru repair....

[Kakarott]

Actually the earlier make of bearings is FAFNIR and they are Medium preloaded.SKF Bearings are also available here.My friend replaced the OE Fafnir bearings (medium preload)with the RHP make light preload bcoz medium preload were not available tht time.The bearing seller recommended the Kluber Grease wich is a high rpm grease.But now a year has passed the RHP bearing have started making noise,he serviced and re-greased them but no use the sound remains.Is it the sound occured bcoz the bearings were replaced by light preload instead of medium preload.The fafnir bearings lasted for 5-6 years.But these RHP ones didnt lasted for a year.

[NC Cams]

If you already "knew" what worked in the lathe, why ask for an alteranate recommendation???

Spindle bearings are essentially NOT a "by guess"/"by golly" what do you think we ought to use or via a "message board opinion based" selection process.

A/C's for machine tools are selected/engineered SPECIFIALLY for the intended operating environment - this includes grease, preload, even other "not commonly published" specs that machine tool makers use/specify. I've seen guys use "generic bearings" both with and without success - and not know why for either result.

the use of "whatever is available" bearings (Example: light in place of medium preload) is something that the user takes big risks/on/with when they do that sort of thing. Sometimes, the assumption works. Sometimes it results in (very) short(er) service life. Sometimes, poor life and worse performance.

Again, grease and preloads are NOT "opinion" based things to recommend or mix haphazardly. High speed greases DON'T always work in low speed/grunt applicaitons - different lube requirements. Same thing goes for L vs M vs H preloads. This is where/why the OEM spec'd lube is/should always be used - that or a good proven "experience" based lube" of proper type and viscosity. Grease is simply NOT grease.

BTW, Kluber makes many, many types of grease for machine tool use!!!! Simply saying "Kluber grease" tells you NOTHING about which grease you should/must use.

Point is: you have enough information to get you both INTO and OUT OF of the predicament that you're currently in. BE CAREFUL.