Spindle bearings

Surface grinders do not have purely radial loading, mostly perhaps, but not all. Ever heard of side wheeling? In addition, when you use radial bearings with side loading, even if only for the end thrust to axially locate and support the spindle and grinding wheel and resist deflection of the grinding wheel, the bearings will not be in their best loading orientation against the races and will fail early. Radial bearings should not be end loaded, and the grinder spindle preload does exactly that.
 
Thank you tinmuk that's an very generous offer I want to replace them with what ever will give me the best possible results. with zero invested in the machine I don't mind spending some money although if the alternative to your suggestion is going to be $400 a piece in bearings well the machine probably isn't worth it.... as far as setting preload is that measured axially for example if there .010 movement with no shims I proceed to add ..10 plus some for preload or do you take a rotational measurement with a low reading torque wrench like you would for setting up pinion bearings in a differential for car/truck? Again thanks to all for the help and suggestions! In the mean time I will see if I can remove the outter races for which ever direction I go
 
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I got it out....
 
So now you have numbers. I see Fafnir but can't see numbers, what are they? And how did it come out?
 
The numbers are 204WI.... I used my fingers and reached in there it didn't feel like it moved but the shims loosened up so I got a soft punch and tapped against the shim very light and worked out it really came out easily
 
Nate,
That is the basics of setting axial preload, the last little bit of how much to add after the play is gone is critical. You may want to just take out the play and see how well it grinds after operating temp is reached. If it performs well then just leave it.

Bob,
You obivously understand bearings well. However all bearing sets should be preloaded to increase life and axial stiffness, including deep groove radial bearings.

Angular contact bearings have a slightly higher shoulder on the thrust side, to allow the balls to ride up higer during preload, typicall 15 degrees instead of about 10 degrees. Other than that they are made identically.

I have designed angular contact versions of deep groove bearings where our customer needed more thrust load and the raceway curvature, number of balls, retainer did not change.
 
Its now called a 7204WN . I thought they weren't in there that tight See page 218, 4th bearing number down.
Timken will stock them.
 

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Wow that's great thanks for your help I'm going to order a pair! Just out of curiosity where did you get that part number I checked out the link and could not find that number referenced on the page
 
In the header, its the same brg, even the dimensions are displayed.

New Fafnir Angular Contact Ball Bearing, 20mm Bore, 47mm OD, 14mm Width, 7204W

Did you just buy them, there was 3 left an hour ago?
 
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