Gearbox with passive lubrication system
A lubrication system includes a reserve housing configured to retain a lubrication fluid. A supply line in fluid communication with the reserve housing is configured to provide pressurized lubrication fluid to the reserve housing. An overflow tube has an overflow port, the overflow tube being configured to prevent the volume of the lubrication fluid from exceeding a certain amount. A metering jet is configured to allow the lubrication fluid to flow from the reserve housing onto a component, such as a bearing, in the gearbox at a predetermined rate. The metering jet provides flow of the lubrication fluid onto the bearing even when the supply line no longer provides pressurized lubrication fluid to the reserve housing.
1. A lubrication system for a gearbox, the lubrication system comprising:
a reserve housing configured to retain a lubrication fluid;
a supply line in fluid communication with the reserve housing, the supply line configured to provide pressurized lubrication fluid directly to the reserve housing;
an overflow tube directly coupled between the reserve housing and the gearbox, the overflow tube having an overflow entry port and an overflow exit port, the overflow tube being configured to prevent a volume of the lubrication fluid in the reserve housing from exceeding a predefined level; and
a metering jet configured to allow the lubrication fluid to flow from the reserve housing onto a component in the gearbox at a predetermined rate;
wherein the reserve housing is closed to atmospheric conditions;
wherein the overflow exit port is located below the overflow entry port;
wherein the overflow exit port is configured to allow the lubrication fluid to flow from the reserve housing directly into the gearbox; and
wherein the metering jet provides flow of the lubrication fluid onto the component for a period of time subsequent to a cessation of flow of the lubrication from the supply line to the reserve housing.
2. The lubrication system according to claim 1 , wherein the reserve housing is integral with a gearbox housing.
3. The lubrication system according to claim 1 , wherein the reserve housing is a separate member attached to a gearbox housing.
4. The lubrication system according to claim 1 , wherein the metering jet is retained in the gearbox housing by a fastener.
5. The lubrication system according to claim 4 , wherein the overflow tube is removable from the reserve housing.
6. The lubrication system according to claim 1 , wherein the metering jet includes a plurality of orifices configured to allow the lubrication fluid to enter an interior of the metering jet.
7. The lubrication system according to claim 1 , wherein the metering jet includes an exit port on a lower portion of the metering jet, the exit port being configured to allow the lubrication fluid to exit the metering jet.
8. The lubrication system according to claim 1 , wherein the metering jet is removable from the reserve housing.
9. The lubrication system according to claim 1 , wherein the component is at least one of:
a bearing; and
a gear.
10. The lubrication system according to claim 1 , wherein the supply line is associated with an upper portion of the reserve housing.
11. A gearbox for an aircraft, the gearbox comprising:
a gearbox housing for housing a plurality of components;
a reserve housing configured to retain a lubrication fluid, the reserve housing mounted to the gearbox housing;
a supply line in fluid communication with the reserve housing, the supply line configured to provide pressurized lubrication fluid directly to the reserve housing; and
a metering jet configured to allow the lubrication fluid to flow from the reserve housing onto at least one of the plurality of components in the gearbox at a predetermined rate;
wherein the reserve housing is closed to atmospheric conditions;
wherein the metering jet is retained in the gearbox housing by a fastener; and
wherein the metering jet provides flow of the lubrication fluid onto a bearing for a period of time subsequent to a cessation of flow of the lubrication from the supply line to the reserve housing.
12. The gearbox according to claim 11 , further comprising:
an overflow tube, the overflow tube being configured to prevent a volume of the lubrication fluid in the reserve housing from exceeding a certain amount.
13. The gearbox according to claim 12 , further comprising:
a filter located in the overflow tube for removing contaminants from the lubrication fluid.
14. The gearbox according to claim 12 , the overflow tube comprising an overflow exit port in fluid communication with an overflow port so that the lubrication fluid can flow from the overflow port, through an interior of the overflow tube, and out the overflow exit into the gearbox housing.
15. The gearbox according to claim 12 , wherein the overflow tube is configured to act as a vent to allow air to exchange between the interior of the gearbox housing and the interior of the reserve housing.
16. The gearbox according to claim 11 , wherein the metering jet is removable from the gearbox housing.
17. The gearbox according to claim 11 , wherein the period of time corresponds with an amount of time that provides an operator of the aircraft sufficient time to land the aircraft.
18. The gearbox according to claim 11 , wherein the plurality of components in the gearbox are moveable objects that require lubrication to minimize friction.
19. The gearbox according to claim 11 , further comprising a filter to remove contaminants from the lubrication fluid.
20. The gearbox according to claim 19 , wherein the filter is located in the metering jet.