new grinder, bearings getting hot

Ok @ stacy , here what SKF say for bearing type he use ...
Data for 6205 bearing ..it is relative big bearing
25x52x15mm
Basic dynamic load rating, C, 14.8, kN. Basic static load rating, C0, 7.8, kN. Fatigue load limit, Pu, 0.335, kN. Limiting speed, 8500, r/min.
Edited to add...........

Data for 6201 32x12x10 bearing ...Limiting speed is 26.000 RPM - 17.000 RPM - 32.000 RPM , depends which kind of seal they have !
And here is calculator if someone want to play .
https://www.amroll.com/speed-limits.html
 
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Natlek said:
No , I m not Volf .I m in Macedonia :)
Can you take another one picture ?Take it from other side of small wheel if you want ? Is there another two Seeger ring ? How they are attached to plate I want to see ?That grinder looks good to me ....:thumbsup:
Click to expand...
No need for other picture , I found one on his site .Looks to me that everything is done right with small wheels .Of course we can not know other things , I mean on tolerance ..I like this grinder :thumbsup:
Xa3t5Sg.jpg
 
All the bearing data that I've seen is based on the outer surface of the bearing (race) being held station and the inner section next to the shaft spinning. This minimized the forces trying to throw the lubricant away from the bearings (ball or roller, etc). With the outer race rotating and the Inner race. stationary, you also get additional loading forces between the ball or rollers and the outer race. The cage holding the rollers or balls is also loaded differently. Let's not forget the seals, unless specified otherwise they are made to contain the lubricant based on the outer race being stationary.
 
What I don t understand is why he use such a big masive bearings ? It s weight 130 grams for god sake? For comparison 6201 weight only 37 grams ....Maybe from there come heat .....It is used in gearbox :)
 
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Well,
Got to spend some time with the machine this weekend and here are my impredsions.
First, the machine itself is pretty nice, no vibration, adjustable belt tension and speed and I love the 450mm (18inch) wheel that comes with it. Very nice, almost flattish hollow grinds.

However, the rollers on the flat platten and the traking wheel get hot. The temp seems to remain stabile "hot to toutch, but not burning hot" when the speed is <10 m/s. Running it like so for an extended periods of time (40+ minute runs) the temperature did not seem to change. If running 2/3 of max speed (20 m/s) the heat quickly gets way too hot to touch. Luckily the traking wheel seems to be the loosest of the wheels so i can still run the grinder with high speed with big wheel, but not the flat platten. Next time i am gonna get some dry ice (to cool down the center shaft) i will try to remove the problematic bearings and see if can sand the shaft or the id of the roller a bit looser. Currently when i removed the rings that hold the bearings in place the bearings did not want to come off easily so i figure it would be better to use temperature to get it open.
 
Stacy, while the OP mentioned "small wheel", I think he's talking about the 2" diameter platen wheels, not what we think of as "small wheels" of 1" or less in diameter.
 
Probably no spacer between the bearings. Maybe loosen the bolt to see if that helps.
 
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