System for lubricating and cooling a mechanical assembly

• US 20020195296A1
• Filed: 06/14/2002
• Published: 12/26/2002
• Est. Priority Date: 06/15/2001
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Baixas, Andre, Maret, Pierre
• Granted Patent: US 6,817,448 B2
• Time in Patent Office: Days
• US Class Current: 184/6.22
• CPC Class Codes: B64C 27/14 Direct drive between power plant and rotor hub
• CPC Class Codes: F16H 57/0412 Cooling or heating; Control of temperature
• CPC Class Codes: F16N 17/00 Lubrication of machines or apparatus working under extreme conditions additives to lubricating oil or lubricating grease C10M
• CPC Class Codes: F16N 7/32 Mist lubrication splash lubrication F16N7/26
• CPC Class Codes: Y10T 74/2189 Cooling

Abstract

According to the invention, this system comprises a main device (2) and an auxiliary backup device (3), which comprises:

at least one reservoir (10) of lubricating and cooling liquid independent of the main device (2);

at least one source (11) of pressurized gas; and

at least one spray nozzle (17, 18) which is fed, on the one hand, with lubricating and cooling liquid at a pressure at most equal to 2 bar (2.10⁻⁵ pascal) from said reservoir (10) and, on the other hand, with pressurized gas from said source (11), said nozzle being able to spray a mist of lubricating and cooling liquid onto said mechanical assembly (1) so as temporarily to supplement the defective main device (2).

Claims

1. A system for lubricating and cooling a mechanical assembly such as a helicopter transmission gearbox, said system comprising:

a main lubricating and cooling device circulating a stream of lubricating and cooling liquid through said mechanical assembly at a relatively high pressure; and

an auxiliary backup device set in operation automatically or manually when said main device becomes defective, said backup device comprising;

at least one reservoir of lubricating and cooling liquid;

at least one source of pressurized gas;

at least one spray nozzle which is fed, on the one hand, with pressurized lubricating and cooling liquid from said reservoir and, on the other hand, with pressurized gas from said source, and which is able to spray a mist of lubricating and cooling liquid onto said mechanical assembly so as temporarily to supplement the defective main device,

wherein;

said reservoir of the auxiliary backup device is independent of said main device; and

said spray nozzle is fed with lubricating and cooling liquid from said reservoir at a pressure at most equal to 2 bar (2.10<sup>−

5</sup> pascal).

2. The system as claimed in claim 1, wherein said spray nozzle is fed with lubricating and cooling liquid at a pressure roughly equal to 1 bar (10⁻

5 pascal).

3. The system as claimed in claim 1, wherein said independent reservoir of lubricating and cooling liquid is arranged some distance away from said mechanical assembly so that said lubricating and cooling liquid it contains does not experience the effect of the heat given off by said mechanical assembly.

4. The system as claimed in claim 1, wherein the lubricating and cooling liquid contained in said reservoir is pressurized by said source of pressurized gas feeding said spray nozzle, and wherein a pressure and flow limiter is arranged between said reservoir and said spray nozzle.

5. The system as claimed in claim 1, wherein the lubricating and cooling liquid contained in said reservoir is pressurized by an auxiliary gas source independent of said pressurized gas source feeding said spray nozzle, and wherein a pressure and flow limiter is arranged between said reservoir and said spray nozzle.

6. The system as claimed in claim 1, wherein the lubricating and cooling liquid contained in said reservoir is pressurized by a pump the outlet of which is connected to said reservoir by a bypass comprising a calibrated valve that opens as soon as the outlet pressure of said pump becomes higher than said feed pressure of the spray nozzle.

7. The system as claimed in claim 1, in which said mechanical assembly is driven by an engine provided with at least one compressor stage, wherein said source of pressurized gas feeding said spray nozzle is formed by said compressor stage.

8. The system as claimed in claim 5, wherein said independent source of auxiliary gas consists of a pressurized gas container.

9. The system as claimed in claim 1, comprising a number of spray nozzles, wherein said nozzles are fed with pressurized gas and with lubricating and cooling liquid through a splitter.

10. The system as claimed in claim 9, wherein said nozzles are split into groups and all the nozzles in one group are fed with pressurized gas and with lubricating and cooling liquid by a common feed device, all said common feed devices themselves being fed with pressurized gas and with lubricating and cooling liquid by said splitter.