External oil pump for gearbox
External oil pump for gearbox
(OP)
I am designing a custom gearbox for an aerospace application. It will only be run for a few hours of testing on the ground.
It is a high performance assembly, very small and tight due to space constraints, with relatively high power going through it. We will pumping gear oil to and from the gearbox provide spray for the gear mesh and to provide active cooling.
The suction or drain port is at the lowest part in the gearbox, however there won't be a maintained oil level due to lack of space ( one of the gears is just a fraction of an inch away from the suction hole).
So if you can imagine the conditions inside the gearbox will be very turbulent, oil and air could likely mix at times at the suction port.
My question is, would a gear pump be ok for this application? If not are there suitable options? All input is highly appreciated.
-John
It is a high performance assembly, very small and tight due to space constraints, with relatively high power going through it. We will pumping gear oil to and from the gearbox provide spray for the gear mesh and to provide active cooling.
The suction or drain port is at the lowest part in the gearbox, however there won't be a maintained oil level due to lack of space ( one of the gears is just a fraction of an inch away from the suction hole).
So if you can imagine the conditions inside the gearbox will be very turbulent, oil and air could likely mix at times at the suction port.
My question is, would a gear pump be ok for this application? If not are there suitable options? All input is highly appreciated.
-John





RE: External oil pump for gearbox
Mike Halloran
Pembroke Pines, FL, USA
RE: External oil pump for gearbox
Your gear housing is already designed, right? If not you could perhaps add a small sump at the bottom of the housing. Or a small tank in front of the gear pump? Dry running is indeed bad for a gear pump but for the alternative (vane pump), too. Pumps with dry running capability are not used for that and most probably much too big. Try an oversized gear pump (slow running) with big inlet pipes. That's my only advise.
RE: External oil pump for gearbox
A gear pump will work.
Ted
RE: External oil pump for gearbox
Johnny Pellin
RE: External oil pump for gearbox
Mike Halloran
Pembroke Pines, FL, USA
RE: External oil pump for gearbox
I will plan for a larger scavenger pump, and upsize the suction ports.
Thank you all for the great advice.