"Cydrome Leader" wrote in message
news
Gunner Asch wrote:
On Sat, 25 Mar 2017 20:52:23 +0000 (UTC), Cydrome Leader
wrote:

My new-old stock gast rotart vane pump just died. I though it broke
a
shear pin as only the motor was still spinning. I know, it makes no
sense
to have a have shear pin in a small tabletop style pressure/vacuum
pump.

Apparently the rotor was held to the motor shaft with some sort of
loctite, at least according to the manual and it broke free. The
shaft is
round and nearly polished, same for the bore of the rotor. The
service
manual says sent it to a repair depot and never mess with the
rotor.
Forget that.

What's the best loctite to attach the 1/2" shaft to the about 2.5"
diameter rotor? They will be wet at all times with light motor oil,
and
the runnning temp is too hot to touch for more than a few seconds.
I've
not used loctite under those conditions.

The stuff that broke free looks slightly yellow, like 5 minute
epoxy of
some type.

It just seems like real cheap, ****ty design to me. I've never seen
the
inside of pump held together with glue.


Drill it, loctite it and then push in a roll pin.

Of course after hitting post I did locate some henckel 243 which is
alleged to be the oil resistant blue stuff. I don't have any super
thin
skinny aircraft type bits to get in there unless the end bell of the
motor
comes off. This is a single casting that acts as the side of of the
pump
and holds the motor together. Not sure of they added some obnoxious
seals
in there so we'll just see if the blue stuff works.

Still baffled by the rotor glued to a shaft design. It's not even an
interference fit.

What's the name for installing a roll pin in the direction of a
shaft,
sort of like how a square key sits? That might be the lazy next
option.

Dutchman or Scotch key.
http://www.practicalmachinist.com/vb...62/index2.html

Good luck drilling straight along the seam between different
materials.

-jsw