US 12,729,743 B1Granted

Reduction of geometric stress concentration of landing gear shock absorber bearing seal grooves

AssigneesSafran Landing Systems, Velizy-Villacoublay, Safran Landing Systems Canada Inc.

InventorsNicolas Antoni, Randy Lee, Zoran Pasic

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Abstract

The present disclosure includes features configured to reduce geometric stress concentration of landing gear shock absorber bearing seal grooves. The stress-reducing features are configured to provide a more gradual section area change as stresses approach a central seal groove axially from either side. The auxiliary stress-reduction grooves can have outwardly sloped surfaces for gradual section area change that increase in diameter approaching the central seal groove. As a result, the geometric stress concentration of the central seal groove can be significantly reduced within the corner radii of the rectangular groove by redirecting stress flow lines around the central seal groove, such as in axial loading and pressure loading from the central chamber during use of the shock-absorbing strut.

Claims20

Dependent claims

A stress-reducing bearing seal groove configuration for a landing gear shock absorber having a cylindrical bearing surface defining a central axis, the bearing seal groove configuration comprising:

a central seal groove extending circumferentially around the bearing surface to a central groove radial depth with respect to the central axis and configured to receive a seal member;
a first auxiliary stress-reduction groove extending circumferentially around the bearing surface and positioned spaced axially apart from a first side of the central seal groove, the first auxiliary stress-reduction groove having:
a first sloped surface having a radial first depth with respect to the central axis that increases approaching the central seal groove;
and a first end wall adjacent to the central seal groove and defining a first tooth between the first end wall and the central seal groove;
and a second auxiliary stress-reduction groove extending circumferentially around the bearing surface and positioned spaced axially apart from a second side of the central seal groove opposite the first side, the second auxiliary stress-reduction groove having:
a second sloped surface having a radial second depth with respect to the central axis that increases approaching the central seal groove;
and a second end wall adjacent to the central seal groove and defining a second tooth between the second end wall and the central seal groove, wherein the first and second auxiliary stress-reduction grooves are configured to redirect stress flow lines around the central seal groove during operation of the landing gear shock absorber.

4 more elements

A bearing for a landing gear shock absorber having a main fitting defining a central axis, a piston axially movable within the main fitting, and a central chamber, the bearing comprising:

a central seal groove extending circumferentially around the bearing to a central groove radial depth with respect to the central axis;
a seal member positioned in the central seal groove and configured to abut the main fitting and the piston to seal the central chamber internally;
a first auxiliary stress-reduction groove extending circumferentially around the bearing and positioned spaced axially apart from a first side of the central seal groove, the first auxiliary stress-reduction groove having:
a first sloped surface having a radial first depth with respect to the central axis that increases approaching the central seal groove;
and a first end wall adjacent to the central seal groove and defining a first tooth between the first end wall and the central seal groove;
and a second auxiliary stress-reduction groove extending circumferentially around the bearing and positioned spaced axially apart from a second side of the central seal groove opposite the first side, the second auxiliary stress-reduction groove having:
a second sloped surface having a radial second depth with respect to the central axis that increases approaching the central seal groove;
and a second end wall adjacent to the central seal groove and defining a second tooth between the second end wall and the central seal groove, wherein the first and second auxiliary stress-reduction grooves are configured to redirect stress flow lines around the central seal groove during operation of the landing gear shock absorber.

5 more elements

Dependencies are inferred from the claim text.