IP Library Granted Patent US 9,561,872
Granted Patent B2
US 9,561,872 · App. 14/789,314 · Granted Feb 7, 2017

Method of detecting a leak past a dynamic seal in aircraft landing gear

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Quick Facts
Patent No.
US 9,561,872
App. No.
14/789,314
Granted
Feb 7, 2017
Kind
B2
Abstract

A leak detection method for detecting a leak past a dynamic seal in aircraft landing gear ( 100 ) comprising: a strut ( 10 ); a rod ( 20 ) slidably mounted in the strut; and a bearing ( 70 ) fitted to an end ( 11 ) of the strut to guide the rod ( 20 ). The bearing includes a bushing ( 50 ) having a seal ( 62 ) arranged to rub against the rod ( 20 ) to provide sealing between the strut and the rod, defines a fluid chamber ( 2 ), and a stop nut ( 40 ) for preventing the bushing from moving relative to the strut. The method includes a step of installing a test nut ( 3 ) without a wiper seal in the place of the stop nut ( 40 ), the step of putting the hydraulic fluid in the landing gear under pressure, and the step of verifying the existence of a leak of hydraulic fluid on the outside surface ( 22 ) of the rod ( 20 ).

Claims (10)

1. A leak detection method for detecting a leak past a dynamic seal in aircraft landing gear ( 100 ) comprising at least:

a strut ( 10 );

a rod ( 20 ) slidably mounted in the strut; and

a bearing ( 70 ) fitted to an end ( 11 ) of the strut to guide the rod ( 20 ), said bearing including at least one bushing ( 50 ) having at least one dynamic seal ( 62 ) arranged to rub against the rod ( 20 ) in order to provide sealing between the strut and the rod, thereby defining a chamber ( 2 ) filled with hydraulic fluid between the strut and the rod, and a stop nut ( 40 ) for preventing the bushing from moving in translation relative to the strut and provided with at least one wiper seal ( 64 ) arranged to wipe hydraulic fluid on the rod;

the method being characterized in that it includes a step of installing a test nut ( 3 ) without a wiper seal in the place of the stop nut ( 40 ), a step of putting the hydraulic fluid in the landing gear under pressure, and a step of verifying the existence of a leak, if any, of hydraulic fluid on an outside surface ( 22 ) of the rod.

2. A method according to claim 1 for detecting a leak in aircraft landing gear ( 100 ), wherein, if a leak is detected, the dynamic seal ( 62 ) is replaced.

3. A method according to claim 1 for detecting a leak in aircraft landing gear ( 100 ), wherein, if no leak is detected, the test nut ( 3 ) is replaced by the stop nut ( 40 ) for preventing movement in translation.

4. A method according to claim 1 for detecting a leak in aircraft landing gear ( 100 ), wherein the stop nut ( 40 ) for preventing movement in translation is previously positioned on the rod ( 20 ) and needs only to be mounted to the end ( 11 ) of the strut in order to take the place of the test nut ( 3 ).

5. A method according to claim 1 for detecting a leak in aircraft landing gear ( 100 ), wherein the test nut ( 3 ) can be fitted and removed independently of the other parts of the aircraft landing gear.

6. A method according to claim 1 for detecting a leak in aircraft landing gear ( 100 ), wherein the test nut ( 3 ) is subdivided into two half-cylinders ( 3 a , 3 b ) that are arranged to be assembled together.

Assignments (2)
CHANGE OF NAME Recorded Mar 8, 2018
From: MESSIER-BUGATTI-DOWTY
To: SAFRAN LANDING SYSTEMS
Reel/Frame 046335/0267 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 11, 2015
From: STEEL, GRAEME
To: MESSIER-BUGATTI-DOWTY
Reel/Frame 036543/0896 →