Power transmission gearbox and an aircraft

Patent metadata

Field	Value
Publication number	US-10012305-B2
Application number	US-201615173879-A
Country	US
Kind code	B2
Filing date	Jun 6, 2016
Priority date	Jun 11, 2015
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A power transmission gearbox provided with at least one lubrication system including a lubrication pump. The lubrication pump is in fluid flow communication with a fluid flow circuit leading to at least one spray means. The gearbox includes an emergency tank suitable for containing a lubrication fluid, the emergency tank being in fluid flow communication with the fluid flow circuit, the emergency tank being connected by at least one pipe to the fluid flow circuit upstream from each spray means, the lubrication fluid being moved in the fluid flow circuit to each spray means by a gas that is set into motion by the lubrication pump in the event of a leak of the lubrication liquid.

First claim

What is claimed is:

1. A power transmission gearbox having at least one lubrication system, the lubrication system including a lubrication pump that is arranged in a sump containing a lubrication liquid, the lubrication pump being in fluid flow communication with a fluid flow circuit leading to at least one spray means directed towards an internal space of a casing of the gearbox, the lubrication liquid being drawn from the sump by the lubrication pump in order to flow in the fluid flow circuit and be sprayed into the internal space by each spray means, wherein the gearbox includes an emergency tank suitable for containing a lubrication fluid, the emergency tank being in fluid flow communication with the fluid flow circuit, the emergency tank being connected by at least one pipe to the fluid flow circuit upstream from each spray means, the lubrication fluid being moved in the fluid flow circuit to each spray means by a gas that is set into motion by the lubrication pump in the event of a leak of the lubrication liquid.

2. A gearbox according to claim 1 , wherein the gearbox includes two lubrication systems.

3. A gearbox according to claim 1 , wherein the emergency tank is located above the fluid flow circuit.

4. A gearbox according to claim 1 , wherein the emergency tank includes a movable divider dividing the emergency tank into a pressurized volume that does not receive a lubrication fluid and a volume that receives the lubrication fluid.

5. A gearbox according to claim 1 , wherein in the absence of a leak of the lubrication liquid, the lubrication pump pressurizes the lubrication liquid to a pressure greater than or equal to 1.5 bars, the lubrication pump entraining the gas in the fluid flow circuit at a pressure of 1.05 bars following a leak of the lubrication liquid.

6. A gearbox according to claim 1 , wherein the emergency tank is connected to the fluid flow circuit by at least one pipe referred to as “outlet” pipe that leads to a duct of the fluid flow circuit.

7. A gearbox according to claim 1 , wherein the emergency tank is connected to the fluid flow circuit by at least one pipe referred to as “outlet” pipe, the outlet pipe having an end provided with a converging nozzle that is arranged within a duct of the fluid flow circuit.

8. A gearbox according to claim 1 , wherein the emergency tank is filled by the fluid flow circuit in the absence of a leak of the lubrication liquid, the fraction of the lubrication liquid that fills the emergency tank representing the lubrication fluid.

9. A gearbox according to claim 8 , wherein the emergency tank is connected to the fluid flow circuit by at least one pipe referred to as “inlet” pipe, the inlet pipe being a one-way connection enabling a fluid to flow solely from the fluid flow circuit towards the emergency tank.

10. A gearbox according to claim 1 , wherein the emergency tank is connected to the fluid flow circuit by a pipe referred to as “inlet” pipe in order to be filled by the fluid flow circuit in the absence of a leak of the lubrication liquid, the emergency tank being connected to the fluid flow circuit by an outlet pipe in order to transfer a lubrication fluid to the fluid flow circuit, the outlet pipe presenting a minimum diameter that is smaller than a minimum diameter of the inlet pipe.

11. A gearbox according to claim 7 , wherein the emergency tank is connected to the fluid flow circuit solely by an outlet pipe, the lubrication fluid being distinct from the lubrication liquid.

12. A gearbox according to claim 1 , wherein the emergency tank is connected to the fluid flow circuit by a pipe provided with a valve.

13. A gearbox according to claim 11 , wherein the valve is controlled by a manual control operable by a pilot.

14. A gearbox according to claim 12 , wherein the valve is connected to at least one pressure sensor measuring a pressure in the fluid flow circuit.

15. A gearbox according to claim 12 , wherein the valve is connected to at least one temperature sensor measuring a temperature in the internal space, the valve opening when the temperature becomes higher than a temperature threshold.

16. A gearbox according to claim 1 , wherein the emergency tank is independent of the sump and arranged outside the casing.

17. An aircraft, wherein the aircraft includes a power transmission gearbox according to claim 1 .

Assignees

• Airbus Helicopters

Inventors

• Louis Charles

Classifications

• F16N2260/24

  using accumulator · CPC title

• F16H57/046 Primary

  Oil-mist or spray lubrication · CPC title

• F16N2260/50

  After-lubrication · CPC title

• B64C27/12 Primary

  Rotor drives · CPC title

• F16H57/0442

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