System and method for detecting a lubricant-out condition in an aircraft gearbox

Patent metadata

Field	Value
Publication number	US-11512811-B2
Application number	US-201716316766-A
Country	US
Kind code	B2
Filing date	Jul 11, 2017
Priority date	Jul 12, 2016
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

A gearbox includes a housing including a lubricant reservoir, at least one gear system arranged in the housing, at least one lubricant delivery passage operable to direct a flow of lubricant from a lubricant reservoir onto the at least one gear system, at least one lubricant return passage operable to guide the flow of lubricant to the lubricant reservoir, and a lubricant-out sensor fluidically connected to the at least one lubricant return passage. The lubricant-out sensor is operable to detect a non-pressure based parameter of the lubricant.

First claim

What is claimed is:

1. A gearbox comprising:
a housing including a lubricant reservoir;
at least one gear system arranged in the housing;
at least one lubricant delivery passage operable to direct a flow of lubricant from the lubricant reservoir onto the at least one gear system;
at least one lubricant return passage defined completely within the housing and operable to guide the flow of lubricant from the at least one gear system to the lubricant reservoir; and
a lubricant-out sensor fluidically connected to the at least one lubricant return passage, the lubricant-out sensor being operable to detect a loss of lubricant based on a non-pressure based parameter of lubricant in the gearbox.

2. The gearbox according to claim 1 , wherein the lubricant-out sensor includes a sensing element extending into the at least one lubricant return passage.

3. The gearbox according to claim 1 , wherein the lubricant-out sensor comprises a temperature sensor, wherein the non-pressure based parameter of the lubricant in the gearbox comprises lubricant temperature.

4. The gearbox according to claim 1 , wherein the lubricant-out sensor comprises a conductivity sensor, wherein the non-pressure based parameter of the lubricant in the gearbox comprises lubricant conductivity.

5. The gearbox according to claim 1 , wherein the lubricant-out sensor comprises a combination sensor operable to sense at least two non-pressure based parameters of the lubricant in the gearbox.

6. The gearbox according to claim 5 , wherein the at least two non-pressure based parameters of the lubricant in the gearbox include temperature and conductivity.

7. The gearbox according to claim 1 , wherein the gearbox comprises a splash lubricated gearbox.

8. A rotary wing aircraft comprising:
an airframe including an extending tail;
at least one engine operatively supported to the airframe;
a main rotor assembly operatively coupled to the at least one engine;
a tail rotor assembly mounted at the extending tail;
at least one gearbox operatively connecting the at least one engine and the tail rotor assembly, the gearbox comprising:
a housing including a lubricant reservoir;
at least one gear system arranged in the housing;
at least one lubricant delivery passage operable to direct a flow of lubricant from a lubricant reservoir onto the at least one gear system;
at least one lubricant return passage defined completely within the housing and operable to guide the flow of lubricant from the at least one gear system to the lubricant reservoir; and
a lubricant-out sensor fluidically connected to the at least one lubricant return passage, the lubricant-out sensor being operable to detect a loss of lubricant based on a non-pressure based parameter of a lubricant in the gearbox.

9. The rotary wing aircraft according to claim 8 , wherein the lubricant-out sensor comprises a temperature sensor, wherein the non-pressure based parameter comprises a temperature parameter.

10. The rotary wing aircraft according to claim 8 , wherein the lubricant-out sensor comprises a conductivity sensor, wherein the non-pressure based parameter comprises a conductivity parameter.

11. The rotary wing aircraft according to claim 8 , wherein the lubricant-out sensor comprises a combination sensor operable to sense at least two non-pressure based parameters of the lubricant.

12. The rotary wing aircraft according to claim 11 , wherein the at least two non-pressure based parameters include temperature and conductivity.

13. The rotary wing aircraft according to claim 8 , wherein the gearbox comprises a splash lubricated gearbox.

14. The rotary wing aircraft according to claim 8 , further comprising a controller connected to the lubricant-out sensor and which sends an alert when the lubricant-out sensor detects a loss of lubricant based on the non-pressure based parameter of the lubricant in the gearbox, and a display which displays a lubricant out warning based on the alert sent from the controller.

15. The rotary wing aircraft according to claim 14 , wherein the non-pressure based parameter includes at least one of a temperature parameter and a conductivity parameter.

Assignees

• Sikorsky Aircraft Corp

Inventors

• Glasser Adam R
• Wint Dwaine
• Baldyga John J
• Mullen Michael F
• Lutian David M
• Mckan Lindsey

Classifications

• G01F23/246

  thermal devices · CPC title

• B64C27/14

  Direct drive between power plant and rotor hub · CPC title

• G01F23/24

  by measuring variations of resistance of resistors due to contact with conductor fluid · CPC title

• F16N2250/18

  Level · CPC title

• F16H57/0457

  Splash lubrication · CPC title