Lubrication of journal bearing during clockwise and counter-clockwise rotation

Patent metadata

Field	Value
Publication number	US-10577974-B2
Application number	US-201414905528-A
Country	US
Kind code	B2
Filing date	Jul 10, 2014
Priority date	Jul 15, 2013
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

The present disclosure is applicable to all gear trains using a journal bearing as a means of supporting gear shaft rotation. It is related in some embodiments to a system and method for supplying lubricant to the journal bearings of a gear-turbofan engine gear train when the fan rotor is subjected to a wind-milling condition in both directions, either clockwise or counterclockwise.

First claim

What is claimed:

1. A lubrication system for a gear-turbofan engine, the lubrication system comprising:
a gear including a gear bearing surface, the gear operatively coupled to a shaft; and
a bi-directional auxiliary pump operatively coupled to the gear, the bi-directional auxiliary pump including a first pump port and a second pump port;
wherein rotation of the gear below a predetermined operational speed range of the gear-turbofan engine in a first direction causes the bi-directional auxiliary pump to transfer lubricant outwardly from the first pump port to the gear bearing surface and wherein rotation of the gear below the predetermined operational speed range of the gear-turbofan engine in a second direction, which is opposite to the first direction, causes the bi-directional auxiliary pump to transfer lubricant outwardly from the second pump port to the gear bearing surface.

2. The lubrication system of claim 1 , wherein the gear comprises:
an idler gear directly driven by the shaft; and
a driving gear driven by the idler gear, the driving gear being operatively coupled to the bi-directional auxiliary pump for rotation of the bi-directional auxiliary pump when the driving gear is caused to rotate.

3. The lubrication system of claim 1 , wherein the bi-directional auxiliary pump is a positive displacement pump.

4. The lubrication system of claim 3 , wherein the positive displacement pump comprises:
a first plurality of check valves operatively coupled to the first pump port; and a second plurality of check valves operatively coupled to the second pump port.

5. The lubrication system of claim 4 , wherein:
the first plurality of check valves comprises:
a first check valve comprising:
a first valve inlet; and
a first valve outlet;
wherein the first valve outlet is operatively coupled to the first pump port; a second check valve comprising:
a second valve inlet; and
a second valve outlet;
wherein the second valve inlet is operatively coupled to the first pump port;
the second plurality of check valves comprises:
a third check valve comprising:
a third valve inlet; and
a third valve outlet;
wherein the third valve inlet is operatively coupled to the second pump port; and
a fourth check valve comprising:
a fourth valve inlet; and
a fourth valve outlet;
wherein the fourth valve outlet is operatively coupled to the second pump port.

6. The lubrication system of claim 5 , further comprising:
a pump inlet operatively coupled to the first valve inlet and to the fourth valve inlet; and a pump outlet operatively coupled to the second valve outlet and to the third valve outlet.

7. The lubrication system of claim 4 , further comprising:
a pump housing;
wherein the first plurality of check valves and the second plurality of check valves are disposed in the pump housing.

8. The lubrication system of claim 1 , wherein the lubricant comprises oil.

9. A turbofan engine, comprising:
a fan;
a fan shaft operably coupled to the fan;
a gear including a gear bearing surface, the gear operatively driven by the fan shaft; and
a bi-directional auxiliary pump operatively driven by the gear, the bi-directional auxiliary pump including a pump inlet and a pump outlet;
wherein rotation of the fan shaft in a first direction when the engine is in a non-operational mode causes the bi-directional auxiliary pump to transfer lubricant to the gear bearing surface by creating pressure at the pump outlet and by creating suction at the pump inlet and wherein rotation of the fan shaft in a second direction, which is opposite to the first direction, when the engine is in a non-operational mode causes the bi-directional auxiliary pump to transfer lubricant to the gear bearing surface by creating pressure at the pump outlet and by creating suction at the pump inlet.

10. The turbofan engine of claim 9 , wherein the gear comprises:
an idler gear directly driven by the fan shaft; and
a driving gear driven by the idler gear, the driving gear being operatively coupled to the bi-directional auxiliary pump for rotation of the bi-directional auxiliary pump when the driving gear is caused to rotate.

11. The turbofan engine of claim 9 , wherein the bi-directional auxiliary pump further comprises a first pump port and a second pump port and wherein the bi-directional auxiliary pump is a positive displacement pump.

12. The turbofan engine of claim 11 , wherein the positive displacement pump comprises:
a first plurality of check valves operatively coupled to the first pump port; and a second plurality of check valves operatively coupled to the second pump port.

13. The turbofan engine of claim 12 , wherein:
the first plurality of check valves comprises:
a first check valve comprising:
a first valve inlet; and
a first valve outlet;
wherein the first valve outlet is operatively coupled to the first pump port; a second check valve comprising:
a second valve inlet; and
a second valve outlet;
wherein the second valve inlet is operatively coupled to the first pump port;
wherein the second plurality of check valves comprises:
a third check valve comprising:
a third valve inlet; and
a third valve outlet;
wherein the third valve inlet is operatively coupled to the second pump port; and
a fourth check valve comprising:
a fourth valve inlet; and
a fourth valve outlet;
wherein the fourth valve outlet is operatively coupled to the second pump port.

14. The turbofan engine of claim 13 , further comprising:
a pump inlet operatively coupled to the first valve inlet and to the fourth valve inlet; and
a pump outlet operatively coupled to the second valve outlet and to the third valve outlet.

15. The turbofan engine of claim 12 , further comprising:
a pump housing;
wherein the first plurality of check valves and the second plurality of check valves are disposed in the pump housing.

16. The turbofan engine of claim 9 , wherein the lubricant comprises oil.

17. The turbofan engine of claim 9 , wherein the non-operational mode comprises the engine not being in a running state and not producing power.

18. The turbofan engine of claim 9 , wherein the non-operational mode comprises the engine not running within a predetermined operational speed range.

19. A method of providing lubricant to a gear bearing surface of a turbofan engine, comprising:
rotating a fan of the turbofan engine in a first direction when the turbofan engine is in a non-operational mode;
pumping lubricant to the gear bearing surface from a first pump port of a bi-directional auxiliary pump operatively coupled to the fan, by creating pressure at a pump outlet of the bi-directional auxiliary pump and by creating suction at a pump inlet of the bi-directional auxiliary pump, when the fan rotates in the first direction when the turbofan engine is in the non-operational mode;
rotating the fan of the turbofan engine in a second direction when the turbofan engine is in the non-operational mode, the second direction being opposite to the first direction; and
pumping lubricant to the gear bearing surface from a second pump port of the bi-directional auxiliary pump, by creating pressure at the pump outlet of the bi-directional auxiliary pump and by creating suction at the pump inlet of the bi-directional auxiliary pump, when the fan rotates in the second direction when the turbofan engine is in the non-operational mode.

20. The method as in claim 19 , further comprising:
disengaging the bidirectional auxiliary pump from an engine fan shaft

Assignees

• United Technologies Corp

Inventors

• Valva Christopher M
• Cigal Brian P

Classifications

• F02C7/06

  Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) · CPC title

• F02C7/32

  Arrangement, mounting, or driving, of auxiliaries · CPC title

• F01M2001/0238

  Rotary pumps · CPC title

• F16H57/0441

  Arrangements of pumps · CPC title

• F16H57/0495

  with fixed gear ratio · CPC title