Closing out the right OT Rovatti PTO pump rebuild.....finished !
The more I've worked on this thing the more I'm impressed with its design features.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1150336)
Back when we were at this stage ^ the worry was how to get the impeller off the keyed taper without breaking it when in fact it's piss simple due to using Timken bearings on the pump shaft and having a grubscrew on one end to preload the bearings.
With one stuffed bearing there was just enough end float on the shaft to get a couple of screwdrivers behind the impeller however with new bearings there certainly is not.
![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
Had me wondering for a bit after partial reassembly how one might get the impeller off as there are no threaded puller holes in it and then it dawned on me.
Clearances behind the impeller are miniscule therefore when the bearing preload screw is wound back to allow shaft end play the impeller can be pressed back against the housing where just undoing the nut some and using a drift on the pump shaft pops it cleanly off the taper. Shit simple and clever design. Color me impressed.
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
Anyways all completed now after a real last 2hr battle with getting the 2 halves of the driveshaft to slide completely together.
Some monkey had previously decided to grind a small taper on the end of the 3 side lemon tube inner driveshaft which inhibits it scraping the rust, dirt and gunge from inside of the outer however after cutting it square again so a nice sharp edge could do it thing and then some time with hammers and in the washbath it's like a new'un again.
![Phew :phew:](https://www.eevblog.com/forum/Smileys/default/phew.gif)
Completed project minus a fitting to allow connection to our pipe work.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1152810)