System for lubricating an aeronautical engine

Patent metadata

Field	Value
Publication number	US-11867076-B2
Application number	US-202017595473-A
Country	US
Kind code	B2
Filing date	May 18, 2020
Priority date	May 24, 2019
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

The invention relates to a system ( 1 ) for lubricating an aeronautical engine ( 5 ) and a reduction gearbox ( 4 ) associated with the engine ( 5 ), the system ( 1 ) comprising an oil reservoir ( 2 ) feeding at least one first supply pump ( 3 ) supplying a first circuit ( 6 ) of the gearbox ( 4 ) opening into at least one chamber ( 4 a ) of the gearbox ( 4 ) and, in parallel, a second circuit ( 7 ) of the engine ( 5 ) opening into chambers ( 5 a ) of the engine ( 5 ). The second circuit ( 7 ) comprises a jet pump ( 9 ) of variable cross section supplied at least by the first supply pump ( 3 ), bypassing the first circuit ( 6 ), a second driven supply pump ( 10 ) being integrated into the second circuit ( 7 ) downstream of the jet pump ( 9 ), a portion of a flow (Qp) in the first circuit ( 6 ) being drawn off by the jet pump ( 9 ) to supply the second circuit ( 7 ).

First claim

The invention claimed is:

1. A system for lubricating an aeronautical engine and a reduction gearbox associated with the aeronautical engine, the system comprising a lubricating oil reservoir feeding at least a first oil supply pump supplying a first lubrication circuit of the reduction gearbox opening into at least one lubrication enclosure of the reduction gearbox and in parallel a second lubrication circuit of the aeronautical engine opening into lubrication enclosures of the aeronautical engine, recirculation pumps at the exit of the aeronautical engine and of the reduction gearbox returning the oil to the oil reservoir, wherein the second circuit comprises a variable-section jet pump supplied at least by said at least one first supply pump bypassing the first circuit, a second driven supply pump being integrated into the second circuit downstream of the variable-section jet pump, a part of a flow rate in the first circuit being collected by the variable-section jet pump to supply the second circuit.

2. The system according to claim 1 , wherein the variable-section jet pump is also supplied from the oil reservoir, a flow rate (Q 2 ) in the second circuit at the exit of the variable-section jet pump being the sum of the part of the flow rate (Qp) collected from the first circuit by the variable-section jet pump with a flow rate (Qr) coming from the oil reservoir via the variable-section jet pump.

3. The system according to claim 2 , wherein the variable-section jet pump has a first chamber of truncated conical shape at the top, narrowing away from a mouth of the variable-section jet pump and receiving in its interior the part of the flow rate (Qp) collected from the mouth, the first chamber being surrounded by a second chamber into which the oil from the oil reservoir opens, the first chamber opening into the second chamber via an outlet, internally housing a needle carried by one end of a rod movable along a length of the first chamber, a longitudinal displacement of the rod being controlled by an actuator, the needle obstructing to a greater or lesser extent the outlet of the first chamber depending on its position along the length of the first chamber.

4. The system according to claim 1 , wherein the first and second lubrication circuits directly supply the aeronautical engine and the reduction gearbox respectively without merging.

5. The system according to claim 1 , wherein the first and second lubrication circuits merge downstream of the variable-section jet pump and then separate again at the level of a three-way valve with an inlet way common to the first and second circuits, a first exit on an extension of the second circuit to the aeronautical engine and a second exit on an extension of the first circuit to the reduction gearbox.

6. The system according to claim 1 , wherein said at least one first supply pump is arranged on a shaft driven directly or indirectly by the reduction gearbox as first motorization means.

7. The system according to claim 6 , wherein the recirculation pumps at the exit of the aeronautical engine are arranged and driven on the shaft of said at least one first supply pump.

8. An assembly of an electronic control unit and a system for lubricating an aeronautical engine and a reduction gearbox associated with the aeronautical engine, wherein the system is according to any of the preceding claims, the electronic control unit incorporating means for calculating a respective oil flow rate in the second circuit to the aeronautical engine and in the first circuit to the reduction gearbox,
the electronic control unit comprising means for controlling the opening of the variable-section jet pump so that the flow rate (Q 1 -Qp) in the first circuit, after the variable-section jet pump has collected the part of the flow rate (Qp) in the first circuit in order to supply the second circuit is equal to the calculated oil flow rate to the reduction gearbox and, the second pump being driven by second motorization means, the control unit comprising means for controlling a speed of rotation of the second motorization means of the second pump in order to ensure the calculated oil flow rate in the second circuit, or
the electronic control unit incorporating means for controlling the three-way valve in order to ensure the calculated oil flow rate in the second circuit to the aeronautical engine and the calculated oil flow rate in the first circuit to the reduction gearbox.

9. A turbomachine as an aeronautical engine comprising an assembly of an electronic control unit and a lubrication system according to claim 8 .

10. A method for regulating a flow rate of lubricating oil in a turbomachine according to claim 9 , wherein the method performed a calculation of the respective flow rates to the aeronautical engine and the reduction gearbox, the method implementing laws for controlling the variable-section jet pump and, where appropriate, the three-way valve so that the actual flow rates to the aeronautical engine and the reduction gearbox are respectively equal to the respective calculated flow rates.

Assignees

• Safran Aircraft Engines

Inventors

• Pora Loic
• De Wergifosse Huguette

Classifications

• F01D25/18 Primary

  Lubricating arrangements (of machines or engines in general F01M) · CPC title

• F01M1/02

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title

• F01M1/12

  Closed-circuit lubricating systems not provided for in groups F01M1/02 - F01M1/10 · CPC title

• F01M1/16

  Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) · CPC title

• F16H57/0475

  Engine and gearing, i.e. joint lubrication or cooling or heating thereof · CPC title