If you search online, you will find numerous arrangements illustrated:

This one is quite a good start: **LINK**

https://www.researchgate.net/figure/The-coupling-dynamic-model-of-spindle-bearing-system-supported-by-both-angular-contact_fig13_321688545

In quick summary … You need some controlled longitudinal ‘float’ to maintain the bearing characteristics when temperatures change.

MichaelG.

The left hand bearing is not prevented from moving to the left along the shaft. Probably an oversight in the schematic.

.

Sorry ..it was just meant to be illustrative of the sort of information you should be able to find using Google

Obviously you will have a better idea of what you are looking for

I simply searched for “grinding spindle bearing arrangement” [without the quotation marks] and set it to display images … then chose the one that I thought might help.

Hopefully you will recognise some version that looks more familiar.

MichaelG.

Lee,

I have just had a look in the parts manual for the 540 machines and the cross-sectional diagrams here show the spindle supported on two angular contact brgs, one at each end. The spring box arrangement is there to maintain a constant preload through the outer rings, regardless of thermal differentials.

You must have a bigger machine ?

Two bearings at one end is the sort of arrangement one might use if axial positioning of the shaft was critical. In theory since the use of a paired unit is there to provide preload, then only one of the bearings needs to have the shaft going through it in order to get the required radial support. This arrangement 'might' also save one having to worry about some aspects of matching the two bearings, but I have to say I have never seen such an arrangement in my life so I am intrigued. Inner rings should normally be clamped to the shaft by a nut. I cant see how this would be compatible with your arrangement though.

Can you make some kind of sketch ?

Gerry.

Dont worry too much by the use of radial ball bearings. Essentially radial ball bearings and angular contact are same internally. When an axial load is put on radial ball bearings them they become angular contact. The size of the angle simply depends on the radial clearance within them. Typically for a 'C3' clearance bearing you will get 10 degrees or so of contact angle and this will increase depending on the load. When preloaded they run at about 15 degs contact angle. So provided these radial bearings are 'precision' made, they are just a lower cost arrangement than an angular contact set-up. But since radial bearings have fewer balls that ACs, they have a lower load capacity. This isnt a problem on a surface grinder though.

Gerry