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Oil Supply through a Shaft

Oil Supply through a Shaft

Oil Supply through a Shaft

Hey everyone,

I have a constant oil supply to a shaft that I need to turn off/on purely mechanically. The oil supply on one side to the shaft never stops. I want to control the oil exiting the other side. Moreover, I want this control to occur when the shaft rotates and stops.
That is, I am looking for a purely passive device that can do the following:
a) The shaft is stopped. No Oil can get through the shaft. Oil is at <1pisg.
b) The shaft starts spinning. Oil can now flow through the shaft somehow.

I can't put any externally controlled valves etc. The oil must be able to pass only via the shafts rotation (and whatever other passive components we can fit inside it to accomplish this).
Any thoughts would be appreciated. I'm unaware of a device like this.


RE: Oil Supply through a Shaft

Would probably help to have at least a sketch, preferrably some dimensions too, of the setup. What is the inlet oil pressurized to (hard to imagine much flow if only 1 psig).

Can you do something to ensure the shaft always stops in one position when the unit is stopped? If so, one local zone of the oil slot on the outlet could be narrowed (or an elastomeric seal included in it) to reduce flow when the bleed hold in the shaft is in that location (assuming the oil is bleeding out thru a radial port in the shaft).

RE: Oil Supply through a Shaft

Copy the centrifugal switch used to start single phase capacitor start electric motors. Just use it to activate a rubber plug in the end of the shaft.

RE: Oil Supply through a Shaft

Thanks guys.
btrueblood, the pressure can be up to 1 bar, but should work with pressure close to atm as well.
It's a small shaft (30mm) and is mounted to a performance engine. The shaft can be stopped int he same location every time but it is subject to inertial loads from driving conditions.

Compositepro, I initially looked at a centrifugal design. I concluded that the mass I needed was very high and couldn't fit it within the 30x30mm package.
I am not familiar with a phase capacitor switch. I'll have a look.

RE: Oil Supply through a Shaft

Or an even simpler centrifugal design. The oil port into the side of the shaft (end plugged), and then just a leaf spring valve. If it needs to open at low speed it will have to be a very thin leaf and be fitted with a stop to keep it from opening too far and bending.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Oil Supply through a Shaft

Thanks EdStanless.
I considered something similar. Trick may be to provide a method of operation that doesn't allow it to open with the oil pressure and only centrifugal force.
I may only have <70g at 10mm to utilize also. Imagine the mass at the end of the leaf likely will have to be at most a cylinder or block 15mm by 15mm.

RE: Oil Supply through a Shaft

We used these on 1.375" shafts running 3600rpm.
We used spring steel leaf about 1.5" long and added a small blob of solder on end.
Make sure to use thin enough material, like a reed valve.
The stop tab was just a "Z" of steel strip tacked to the shaft.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Oil Supply through a Shaft

Hmm I'll have to think about adapting. I need it to work at 400rpm.
This leaves me with <1N of force if I use a mass within my constraints.

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