Emergency lubrication device of simplified architecture for a power transmission main gearbox of an aircraft

Patent metadata

Field	Value
Publication number	US-10415692-B2
Application number	US-201615372634-A
Country	US
Kind code	B2
Filing date	Dec 8, 2016
Priority date	Dec 17, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

An emergency lubrication device of simplified architecture for a mechanical system. The emergency lubrication device has a tank, trigger means, at least one pipe, and at least one distribution means. The tank contains a lubrication liquid and it is arranged inside the mechanical system and above the pipes and the distribution means. Each distribution means includes at least one constriction means for limiting the flow rate of the lubrication liquid. The lubrication liquid is heated by the mechanical system, and the viscosity of the lubrication liquid decreases so that the flow rate of the lubrication liquid through each distribution means is substantially equal to or greater than a minimum flow rate so long as the tank contains the lubrication liquid.

First claim

What is claimed is:

1. An emergency lubrication device of simplified architecture for a mechanical system, the emergency lubrication device being provided with a tank, trigger means, at least one pipe, and at least one distribution means, the tank containing a lubrication liquid, and the trigger means enabling the lubrication liquid to flow between the tank and each of the at least one distribution means in the event of a malfunction of a main lubrication means of the mechanical system being detected, the tank being spaced from and not fluidly connected to the main lubrication means, wherein the tank is arranged above each of the at least one pipe and each of the at least one distribution means so that the lubrication liquid flows under the action of terrestrial gravity from the tank into each pipe and each distribution means, each distribution means including at least one constriction means in order to limit the flow rate of the lubrication liquid through each distribution means and being arranged inside the mechanical system, each pipe feeding each distribution means being arranged at least in part inside the mechanical system, the lubrication liquid flowing in each pipe and in each distribution means thus being heated by the mechanical system and the viscosity of the lubrication liquid decreasing following a malfunction of the main lubrication means so that a flow rate of the lubrication liquid through each distribution means is substantially equal to or greater than a minimum flow rate so long as the tank contains the lubrication liquid.

2. The emergency lubrication device of claim 1 , wherein the tank is arranged inside the mechanical system.

3. The emergency lubrication device of claim 1 , wherein the height H 1 of the lubrication liquid in the tank is less than the distance H 21 , H 22 between the tank and each distribution means, the height H 1 and the distance H 21 , H 22 being defined in the gravity direction measured from a bottom of the tank upward for H 1 and downward for H 21 and H 22 .

4. The emergency lubrication device of claim 3 , wherein the height H 1 and the distance H 21 , H 22 are initially defined so that the decrease in the height H 1 while the emergency lubrication device is lubricating the mechanical system, and the decrease in the viscosity of the lubrication liquid, make it possible for the flow rate of the lubrication liquid through each distribution means to be substantially equal to or greater than the minimum flow rate so long as the tank contains the lubrication liquid.

5. The emergency lubrication device of claim 1 , wherein the trigger means comprise a first valve enabling the tank to be put into communication with each pipe.

6. The emergency lubrication device of claim 1 , wherein the trigger means comprise a plurality of first valves positioned in association with each distribution means.

7. The emergency lubrication device of claim 1 , wherein the trigger means comprise a second valve for venting the tank, the tank being closed and leaktight.

8. The emergency lubrication device of claim 1 , wherein each constriction means includes an orifice having a first diameter that is greater than or equal to a second minimum value in order to avoid coking the lubrication liquid.

9. The emergency lubrication device of claim 8 , wherein the second minimum value lies in the range 0.3 mm to 1.0 mm.

10. The emergency lubrication device of claim 1 , wherein each pipe has a second diameter that is greater than or equal to a first minimum value so as to enable the lubrication liquid to be heated sufficiently.

11. The emergency lubrication device of claim 10 , wherein the first minimum value lies in the range 6 mm to 10 mm.

12. The emergency lubrication device of claim 1 , wherein the minimum flow rate is equal to the lowest flow rate of the lubrication liquid through each distribution means on starting the emergency lubrication device.

13. The emergency lubrication device of claim 1 , wherein the trigger means are under electrical control.

14. The emergency lubrication device of claim 1 , wherein the trigger means are under pyrotechnic control.

15. The emergency lubrication device of claim 14 , wherein the trigger means and the tank are located inside the mechanical system, and the pyrotechnic control is triggered thermally as soon as the temperature of the trigger means reaches a predetermined threshold.

16. A power transmission main gearbox for a rotary wing aircraft, wherein the main gearbox is provided with the emergency lubrication device of claim 1 , the mechanical system being the main gearbox.

17. An emergency lubrication system comprising:
a tank configured to hold lubrication liquid for a mechanical system, the tank being disposed at a first height, the tank being spaced from and not fluidly connected to a main lubricant system;
a distribution portion including a constricting section, the distribution portion located inside the mechanical system and disposed at a second height below the first height; and
a pipe connecting the tank to the distribution portion and capable of directing lubrication liquid from the tank to the distribution portion by gravity, at least part of the pipe being located inside the mechanical system; and
a trigger having a closed position where lubrication liquid is blocked from entering the pipe during operation of the main lubricant system, and an open position where upon malfunction of the main lubricant system, lubrication liquid flows from the tank through the pipe to the distribution portion by gravity to be supplied to the mechanical system,
wherein, the distribution portion and the pipe are positioned such that the lubricant liquid is heated by the mechanical system as it flows through the pipe and distribution portion so that a flow rate of the lubrication liquid through the distribution portion is substantially equal to or greater than a minimum flow rate.

18. The emergency lubrication system of claim 17 , wherein a height of the lubrication liquid in the tank, measured from the bottom of the tank upward toward a tank height, is less than a distance between the tank and the distribution portion.

19. The emergency lubrication system of claim 18 , wherein the height and the distance are initially defined based on the tank height so that a decrease in the height while the emergency lubrication system is lubricating the mechanical system, and a decrease in viscosity of the lubrication liquid, increases the flow rate of the lubrication liquid through the distribution portion to be substantially equal to or greater than the minimum flow rate so long as the tank contains the lubrication liquid.

20. An emergency lubrication system comprising:
a tank configured to hold lubrication liquid for a mechanical system, the tank being disposed at a first height, the tank being spaced from and not fluidly connected to a main lubrication system;
a distribution portion including a constricting section, the distribution portion located inside the mechanical system and disposed at a second height below the first height; and
a pipe connecting the tank to the distribution portion and capable of directing lubrication liquid from the tank to the distribution portion by gravity, at least part of the pipe being located inside the mechanical system; and
a trigger enabling lubrication liquid to flow from the tank through the pipe to the distribution portion to be supplied to the mechanical system in the event of a malfunction of the main lubrication system being detected,
wherein, the

Assignees

• Airbus Helicopters

Inventors

• Lapeyre Jean-Victor
• Eymard-Duvernay Gilles

Classifications

• F16N2260/24

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• F16H57/0456

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• F16H57/045

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• F16H57/0436

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