Locking pump rotor to shafting
Locking pump rotor to shafting
(OP)
I have a problem. I need to lock an oil pump rotor to a shaft. Rotor is of the normal design and is driven via the through shaft. This in turn drives the second meshing rotor as can be seen in many oil pumps over the years.
The Rotor is hardened steel and has been taken from an oem oil pump. In the original pump the rotor was an interference fit onto its driver shaft. The new shaft it now sits on has to have a clearance fit for other design reasons. So I need to know how Ill go about locking the rotor to my new driven shaft given that its a clearance fit. The shaft is 14mm in diameter and the rotor approx 30mm in diameter. The pump is NOT a pressure pump but a scavenge pump, so the only pressure the pump will see is the head height to oil tank from sump,and I suppose accelerating/decelerating torsion at the point of clearance fit(hardly any to worry about at that diameter)
As for the clearance fit tolerance Im not too sure as yet, but its a snug fit and can be slid onto shaft by hand and will stay there if held vertically. Rotor material is nothing fancy, plain old oem rotors, shafting is 316 stainless.
Should I bore the rotor and fit a spring pin? Could be hard to bore and I may have to remove hardness and re-quench to drill(dont really want to do that)
Or> I have been onto a few 'famous' chemical bond companies and they assure me that there products will work, or at least, the data sheets says they will. I need convincing, 'glueing' a rotor onto a shaft scares me a little. Operating temp is at a guess -5 to 140c.
Any help folks? Convince me that chemicals will work, or not.
Thanks in advance, Brian.
The Rotor is hardened steel and has been taken from an oem oil pump. In the original pump the rotor was an interference fit onto its driver shaft. The new shaft it now sits on has to have a clearance fit for other design reasons. So I need to know how Ill go about locking the rotor to my new driven shaft given that its a clearance fit. The shaft is 14mm in diameter and the rotor approx 30mm in diameter. The pump is NOT a pressure pump but a scavenge pump, so the only pressure the pump will see is the head height to oil tank from sump,and I suppose accelerating/decelerating torsion at the point of clearance fit(hardly any to worry about at that diameter)
As for the clearance fit tolerance Im not too sure as yet, but its a snug fit and can be slid onto shaft by hand and will stay there if held vertically. Rotor material is nothing fancy, plain old oem rotors, shafting is 316 stainless.
Should I bore the rotor and fit a spring pin? Could be hard to bore and I may have to remove hardness and re-quench to drill(dont really want to do that)
Or> I have been onto a few 'famous' chemical bond companies and they assure me that there products will work, or at least, the data sheets says they will. I need convincing, 'glueing' a rotor onto a shaft scares me a little. Operating temp is at a guess -5 to 140c.
Any help folks? Convince me that chemicals will work, or not.
Thanks in advance, Brian.





RE: Locking pump rotor to shafting
What is the bore of the rotor or do you mean its a 30mm bore?
Assuming the clearence isn't that great what about a keyway.
desertfox
RE: Locking pump rotor to shafting
I had thought of a key and I guess it would not need to be that deep into rotor but Im worried about broaching, will a normal arbor style saw tooth broach cut the rotor without relieving the heat treatment first?
Thanks for the reply.
Brian.
RE: Locking pump rotor to shafting
Not sure whether the broach would cut or not, what about sleeving the bore using an intereference fit and then boring the sleeve to interference fit with the shaft, if your torques are low it might work.
desertfox
RE: Locking pump rotor to shafting
Thanks again,
RE: Locking pump rotor to shafting
Well pinning might work, but doing it the way I said in my last post you won't need to machine the rotor.
desertfox
RE: Locking pump rotor to shafting
Many thanks for your replies, Im very grateful.
RE: Locking pump rotor to shafting
Your welcome, why would you need to machine the shaft?
measure the shaft before you start, so machine the sleeve and force fit, then force fit the shaft after.
desertfox
RE: Locking pump rotor to shafting
RE: Locking pump rotor to shafting
No you got it right and I got it wrong, yes your going to have to machine the shaft sorry!
desertfox
RE: Locking pump rotor to shafting
RE: Locking pump rotor to shafting
RE: Locking pump rotor to shafting
Maybe spark eroding might be feasible if the gear is so hard that a tungsten carbide tool won't cut it.
Regards
Pat
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RE: Locking pump rotor to shafting
Thanks to all.