Problem bearing repair on 3 phase Hidria axial ventilation fan

[harry wall]

I plan to use this fan to ventilate fine dust from my shed but the bearings sound like they need replacing so that's what I'm doing - trying to disassemble it
The fan is a Rotomatika R13R-6330A-6T (630mm diameter, 3 ph, 240V AC, 6 pole) dated 2006. Also (I think) called a Hidria. Made in Slovenia.
Can't find any internet tips nor any exploded parts diagrams.

My problem is I cannot remove the rotor to get at the bearings. It is not rusted but I cannot move anything. A bearing puller cannot move one end which appears to be pressed onto the shaft and the other end has a large slot (about 25mm long and 3 mm wide) that also does not want to move clockwise or anticlockwise.

I'm stumped and hope someone here may have an idea. Here's a couple of photos....
518083
518084

[havabeer69]

have you tried seeing if that slot is a screw thread for a flat head screw driver or something?

[harry wall]

Sure have. Even tried "tapping" it with a hammer and flat headed punch to no avail. If you look carefully at the photo you'll see the dents I made in the slot.

[Picko]

Have you tried turning it the other way? It looks to me, by the way that fan's been running, like that should be a left hand thread.

[harry wall]

Yes, tried both ways as per my first post.
The fan can be wired to turn in both directions so that complicates the matter a little more because, as you also realize, the thread would normally be opposite to the direction of spinning.

[chambezio]

Is there a grub screw hiding under some camouflage in the bottom of a groove some where?
Here is another thought.....could the bearing have been pressed in with Loctite? Heat would soften it while you apply pressure from your bearing puller.