Is this spindle missing a bearing?

[pinstripe]

Seems strange to have those two bearings right next to each other at the spindle nose, then no bearing at the back for support. It's a small surface grinder spindle from 1960-something.

[MrFluffy]

With two bearings up front, wouldnt it normally have a double row bearing at the front, maybe taper or plain depending on speed, and a single plain or roller bearing at the rear to allow the spindle to slide along the shaft for axial expansion?
I'd think yes too, but I wait to see what others say...

[Noitoen]

If it's directly coupled to a motor, it does not need another bearing.

[pinstripe]

If it's directly coupled to a motor, it does not need another bearing.

It's driven by a belt.

[MattiJ]

definitely missing a bearing

[Mark Rand]

It's got the pre-load springs at the back, so they should be working against a bearing or bearing carrier. What were they up against when you dissasembled it?

[pinstripe]

... and a single plain or roller bearing at the rear to allow the spindle to slide along the shaft for axial expansion?

Now you've got me wondering. I didn't take this photo (or pull the spindle apart). Maybe there is a plain bearing still in the housing. This grinder takes small wheels, so it spins at almost 5,000 RPM. Would they use a plain bearing for those speeds? There is a label saying not to oil the spindle, but it's not original.

[MrFluffy]

I've got a spare J&S wheelhead from someone as a rebuilder that I'm going to frankenstein onto my burdette surface grinder to give me J&S wheel hub sizes and fresh bearings. There's some play in the rear plain bearing on that, so I'm entirely expecting to find the same arrangement when it comes apart. I believe it will spin slower as its for larger diameter od wheels than what you have which looks like a id spindle.
Also my internal id toolpost grinder is very high rpm, and also uses plain bearing but is clearly marked with points to add the oil.
Hydrodynamic bearings are fine for higher speed, provided they have lubrication and the surface area to support the load and have been made from a appropriate material.

[rohart]

That layout is almost identical to the design of the Quorn spindle. Two up front, one at the back preloaded with a spring box. The spindle slides in the inner of the missing bearing. I would want a plain bearing to have a felt oiler from a small feed receptacle.