US 6,212,974 B1Granted

Variable stiffness positioning link for a gearbox

AssigneeUnited Technologies Corporation

InventorKeven G. Van Duyn

Life of this patent

Estimating the term…

Loading patent…

Abstract

A gearbox mounting arrangement for a gas turbine engine includes a plurality of variable stiffness positioning links that attach the gearbox housing to the engine case. The links include a first portion that is connected to the engine case, a second portion connected to the gearbox and the first and second portion releasably connected by an isolation mechanism having a lower stiffness than the first and second portions. During a high rotor imbalance condition such as a fan blade loss condition, the links yield to a lower stiffness level than during normal operation as the isolation mechanism becomes operational in response to the application of high axial loads and the first and second portions partially disengage. The partial disengagement of the portions of the links of the present invention results in partially isolating the gearbox from the deflections experienced by the engine case. Thus, only a percentage of engine case imbalance loads are transmitted through the links to the gearbox. Alternate embodiments for the isolation mechanism are disclosed.

Claims5

Dependent claims

A variable stiffness positioning link for securing a gearbox to a gas turbine engine case, said link characterized by having a first spring rate in a first direction during normal operation, said link comprising:

a first link portion having one end adapted to be connected to a gas turbine engine case;
a second link portion having one end adapted to be connected to a gearbox;
and
release means connecting said first and second link portions to prevent relative movement between said link portions in said first direction during normal operation and adapted to release and allow relative movement between said link portions in said first direction upon said link being subjected to an abnormally high load in said first direction, said link portions being constructed and arranged to define an isolation mechanism wherein upon release of said release means said link portions reconnect through said isolation mechanism, said isolation mechanism having a spring rate in said first direction lower than said first spring rate to decrease loads transmitted between said link portions in said first direction upon the release of said release means.

1 more element

Dependencies are inferred from the claim text.