Passive oil system for planetary bearings

1. A passive oil system, comprising:

a reservoir housing configured in operation to rotate around a rotational axis, the reservoir housing defining a reservoir between a top wall, a bottom wall, innermost side, and an outer sidewall;

an outlet positioned adjacent the outer sidewall to discharge a lubrication fluid contained in the reservoir in response to the reservoir housing rotating around the rotational axis;

a spillway wall located in the reservoir housing and separating the reservoir from the outlet;

a spillway opening adjacent the innermost side providing fluid communication between the reservoir and the outlet; and

an orifice adjacent the outer sidewall providing fluid communication between the reservoir and the outlet.

2. The passive oil system of claim 1 , wherein the innermost side is fully open between the top wall and the bottom wall.

3. The passive oil system of claim 1 , wherein the spillway opening permits a greater flow rate than the orifice of the lubrication fluid from the reservoir to the outlet.

4. The passive oil system of claim 1 , wherein the innermost side is fully open between the top wall and the bottom wall.

5. The passive oil system of claim 1 , wherein the reservoir is partially enclosed on the innermost side by a wall.

6. A gearbox, comprising:

a planetary carrier configured in operation to rotate a rotor shaft around a rotational axis;

a reservoir housing configured in operation to rotate around the rotational axis, the reservoir housing defining a reservoir between a top wall, a bottom wall, innermost side, and an outer sidewall, wherein the innermost side is generally parallel to the rotational axis and located between the rotational axis and the outer sidewall;

an outlet positioned adjacent the outer sidewall to discharge a lubrication fluid contained in the reservoir to a planetary bearing in response to rotation of the reservoir housing around the rotational axis;

a spillway wall located in the reservoir housing and separating the reservoir from the outlet;

a spillway opening adjacent the innermost side providing fluid communication between the reservoir and the outlet; and

an orifice adjacent the outer sidewall providing fluid communication between the reservoir and the outlet.

7. The gearbox of claim 6 , wherein the spillway opening permits a greater flow rate than the orifice of the lubrication fluid from the reservoir to the outlet.

8. The gearbox of claim 6 , wherein the innermost side is fully open between the top wall and the bottom wall.

9. The gearbox of claim 6 , wherein the reservoir is partially enclosed on the innermost side by a wall.

10. The gearbox of claim 6 , wherein the innermost side is fully open between the top wall and the bottom wall; and

the spillway opening permits a greater flow rate than the orifice of the lubrication fluid from the reservoir to the outlet.