Oil tank for aircraft engine

Patent metadata

Field	Value
Publication number	US-12276202-B2
Application number	US-202117219171-A
Country	US
Kind code	B2
Filing date	Mar 31, 2021
Priority date	Mar 31, 2021
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

Aircraft engine oil tanks, lubrication systems, and associated methods are provided. The oil tank includes a first tank portion defining a first volume for holding oil and a second tank portion defining a second volume for holding oil, in fluid communication with the first volume. The first tank portion includes an oil outlet for delivering oil to a lubrication load via a pump. The first volume is in fluid communication with a vent opening for venting the oil tank. At least part of the second tank portion is disposed higher than the vent opening for retaining a quantity of oil inside the oil tank during a negative-g force flight condition and facilitate the recovery of the lubrication system following the negative-g force flight condition.

First claim

What is claimed is:

1. An aircraft engine comprising:
an aircraft engine oil tank including:
a first tank portion defining a first volume for holding oil, the first tank portion including an oil outlet for delivering oil to a lubrication load, the first volume being in fluid communication with a vent opening for venting the aircraft engine oil tank, the oil outlet being disposed lower than the vent opening relative to an upright orientation of the aircraft engine oil tank; and
a second tank portion defining a second volume in fluid communication with the first volume, at least part of the second volume being disposed higher than the vent opening relative to the upright orientation of the aircraft engine oil tank, the second tank portion being laterally separated from the vent opening relative to the upright orientation of the aircraft engine oil tank, an oil-holding capacity of the second volume being equal to or greater than a minimum quantity of oil required in the first volume for the oil outlet to be submerged in the oil in the upright orientation of the aircraft engine oil tank, the second tank portion holding oil in the second volume and preventing the oil in the second volume from flowing to the vent opening when an upward force acting on the oil in the second volume is greater than a downward force acting on the oil in the second volume relative to the upright orientation of the aircraft engine oil tank, the second tank portion being configured to prevent the oil in the second volume from draining from the aircraft engine oil tank when the upward force is greater than the downward force;

a lubrication load;
an oil pump in fluid communication with the oil tank and with the lubrication load, the oil pump driving oil from the oil tank toward the lubrication load; and
a scavenge pump in fluid communication with the oil tank and with the lubrication load, the scavenge pump driving oil from the lubrication load toward the oil tank for recirculation.

2. The aircraft engine as defined in claim 1 , wherein the oil-holding capacity of the second volume is between 1% and 25% of the oil-holding capacity of the first volume.

3. The aircraft engine as defined in claim 1 , wherein the oil-holding capacity of the second volume is between 1% and 10% of the oil-holding capacity of the first volume.

4. The aircraft engine as defined in claim 1 , wherein the first tank portion is devoid of baffles.

5. The aircraft engine as defined in claim 1 , wherein the second tank portion is devoid of baffles.

6. The aircraft engine as defined in claim 1 , wherein the vent opening is disposed in the first tank portion.

7. The aircraft engine as defined in claim 1 , wherein the second tank portion includes only one auxiliary chamber defining an entirety of the second volume.

8. The aircraft engine as defined in claim 1 , wherein an entirety of the second volume is disposed higher than the vent opening.

9. A lubrication system of an aircraft engine, the lubrication system comprising:
an oil pump in fluid communication with a lubrication load for driving oil toward the lubrication load; and
an oil tank in fluid communication with the oil pump for supplying oil to the oil pump, the oil tank including:
a main chamber including:
an oil outlet for delivering oil to the oil pump; and
a vent opening for venting the main chamber, the vent opening being located higher than the oil outlet relative to an upright orientation of the oil tank associated with a straight-and-level flight condition of the aircraft; and

an auxiliary chamber in fluid communication with the main chamber, at least part of the auxiliary chamber being disposed higher than the vent opening relative the upright orientation of the oil tank, the auxiliary chamber being laterally separated from the vent opening relative to the upright orientation of the oil tank, an oil-holding capacity of the auxiliary chamber being equal to or greater than a minimum quantity of oil required in the main chamber to cause priming of the oil pump, the auxiliary chamber holding oil in the auxiliary chamber and preventing the oil in the auxiliary chamber from flowing to the vent opening when an upward force acting on the oil in the auxiliary chamber is greater than a downward force acting on the oil in the auxiliary chamber relative to the upright orientation of the oil tank, the auxiliary chamber being devoid of an outlet that permits the oil in the auxiliary chamber to drain from the oil tank when the upward force is greater than the downward force; and

a scavenge pump in fluid communication with the oil tank and with the lubrication load, the scavenge pump driving oil from the lubrication load toward the oil tank for recirculation.

10. The lubrication system as defined in claim 9 , wherein the oil-holding capacity of the auxiliary chamber is equal to or greater than a minimum quantity of oil required for an inlet port of the pump to be submerged in the oil.

11. The lubrication system as defined in claim 10 , wherein the oil pump is disposed outside of the oil tank.

12. The lubrication system as defined in claim 11 , comprising a conduit establishing fluid communication between the oil outlet of the main chamber and the inlet port of the pump, the oil-holding capacity of the auxiliary chamber being equal to or greater than a minimum quantity of oil required to fill the conduit with the oil.

13. The lubrication system as defined in claim 9 , wherein the oil-holding capacity of the auxiliary chamber is equal to or greater than a minimum quantity of oil required for the oil outlet of the main chamber to be submerged in the oil.

14. The lubrication system as defined in claim 9 , wherein the oil-holding capacity of the auxiliary chamber is between 1% and 10% of an oil-holding capacity of the main chamber.

15. The lubrication system as defined in claim 9 , wherein an entirety of the auxiliary chamber is disposed higher than an oil inlet for receiving oil into the main chamber.

Assignees

• Pratt & Whitney Canada

Inventors

• Bergeron Sebastien
• Daniel Marion

Classifications

• F01M11/064

  Movement · CPC title

• F01M2011/0041

  for accommodating movement or position of engines · CPC title

• F01M11/0004

  Oilsumps · CPC title

• F16N19/00

  Lubricant containers for use in lubricators or lubrication systems · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title