Gearbox with passive lubrication system

Patent metadata

Field	Value
Publication number	US-9458923-B2
Application number	US-201213426789-A
Country	US
Kind code	B2
Filing date	Mar 22, 2012
Priority date	Mar 31, 2011
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

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.

First claim

The invention claimed is:

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 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 coupled to the reserve housing adjacent the overflow tube being configured to allow the lubrication fluid to flow from the reserve housing onto a component in the gearbox at a predetermined rate, the metering jet metering the flow of lubrication fluid through at least one orifice, the metering jet filtering contaminants from the lubrication fluid and providing passive filtration and flow of lubrication fluid;
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;
wherein the metering jet includes an exit port on a lowest surface of the metering jet relative to the predefined level in the reserve housing, the exit port being configured to allow the lubrication fluid to exit the metering jet;
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 overflow tube is configured to act as a vent to allow air to exchange between an interior of a gearbox housing and the interior of the reserve housing.

2. The lubrication system according to claim 1 , wherein the reserve housing is integral with the gearbox housing.

3. The lubrication system according to claim 1 , wherein the reserve housing is a separate member attached to the gearbox housing.

4. 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.

5. The lubrication system according to claim 1 , wherein the metering jet is removable from the reserve housing.

6. The lubrication system according to claim 1 , wherein the overflow tube is removable from the reserve housing.

7. The lubrication system according to claim 1 , wherein the component is at least one of:
a bearing; and
a gear.

8. The lubrication system according to claim 1 , wherein the supply line is associated with an upper portion of the reserve housing.

9. 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 lubrication fluid being filtered within the gearbox;
a supply line in fluid communication with the reserve housing, the supply line configured to provide pressurized lubrication fluid to the reserve housing;
an overflow tube directly coupled between the gearbox housing and the reserve housing, the overflow tube having an overflow port, the overflow tube being configured to prevent a volume of the lubrication fluid in the reserve housing from exceeding a predefined level;
the overflow tube further comprising;
an overflow exit port in fluid communication with the 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 port into the gearbox housing; and

a metering jet coupled to the reserve housing adjacent the overflow tube being 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 metering jet includes an exit port on a lowest surface of the metering jet relative to the predefined level in the reserve housing, the exit port being configured to allow the lubrication fluid to exit the metering jet;
wherein the metering jet provides passive 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;
wherein the overflow exit port is lower than the overflow port; and
wherein the bearing is located in the gearbox housing.

10. The gearbox according to claim 9 , wherein the overflow port is a cutout in the overflow tube.

11. The gearbox according to claim 9 , wherein the period of time is at least thirty minutes.

12. The gearbox according to claim 9 , wherein the plurality of components in the gearbox are moveable objects that require lubrication to minimize friction.

13. The gearbox according to claim 9 , wherein the lubrication fluid is filtered within the metering jet.

14. The gearbox according to claim 9 , wherein the lubrication fluid is filtered within the overflow tube.

15. The gearbox according to claim 9 , 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.

Assignees

• Poster Scott D
• Elliott David A
• Cope Gary A
• Textron Innovations Inc

Inventors

• Poster Scott D
• Elliott David A
• Cope Gary A

Classifications

• F16H57/0471 Primary

  Bearing · CPC title

• B64C27/12

  Rotor drives · CPC title

• F16H57/0442

  for supply in case of failure, i.e. auxiliary supply · CPC title

• F16H57/045

  Lubricant storage reservoirs, e.g. reservoirs in addition to a gear sump for collecting lubricant in the upper part of a gear case · CPC title

• B64D35/00

  Transmitting power from power plants to propellers or rotors; Arrangements of transmissions · CPC title