Patent Description:
Various types and configurations of actuation systems are known in the art for moving components of a thrust reverser system. While these known actuation systems have various benefits, there is still room for improvement, particularly as space / packaging constraints within aircraft propulsion systems increase. There is a need in the art therefore for an improved thrust reverser actuation system.

Documents <CIT>, <CIT> and <CIT> disclose linkage systems for thrust reverser mechanisms.

According to an aspect of the present invention, an assembly is provided for an aircraft propulsion system in accordance with claim <NUM>.

<FIG> illustrates an aircraft propulsion system <NUM> for an aircraft such as, but not limited to, a commercial airliner or cargo plane. The aircraft propulsion system <NUM> includes a nacelle <NUM> and a gas turbine engine. This gas turbine engine may be configured as a high-bypass turbofan engine. Alternatively, the gas turbine engine may be configured as any other type of gas turbine engine capable of propelling the aircraft during flight.

The nacelle <NUM> is configured to house and provide an aerodynamic cover for the gas turbine engine. An outer structure <NUM> of the nacelle <NUM> extends along an axial centerline <NUM> between a nacelle forward end <NUM> and a nacelle aft end <NUM>, which axial centerline <NUM> may also be a rotational axis of the aircraft propulsion system <NUM> and its gas turbine engine. The nacelle <NUM> of <FIG> includes a nacelle inlet structure <NUM>, one or more fan cowls <NUM> (one such cowl visible in <FIG>) and a nacelle aft structure <NUM>, which is configured as part of or includes a thrust reverser system <NUM>.

The inlet structure <NUM> is disposed at the nacelle forward end <NUM>. The inlet structure <NUM> is configured to direct a stream of air through an inlet opening at the nacelle forward end <NUM> and into a fan section of the gas turbine engine.

The fan cowls <NUM> are disposed axially between the inlet structure <NUM> and the aft structure <NUM>. Each fan cowl <NUM> of <FIG>, in particular, is disposed at an aft end <NUM> of a stationary portion <NUM> of the nacelle <NUM>, and extends axially forward along the axial centerline <NUM> to the inlet structure <NUM>. Each fan cowl <NUM> is generally axially aligned with a fan section of the gas turbine engine. The fan cowls <NUM> are configured to provide an aerodynamic covering for a fan case <NUM>. Briefly, this fan case <NUM> circumscribes the fan section and may partially form a forward outer peripheral boundary of a bypass flowpath of the aircraft propulsion system <NUM>.

The term "stationary portion" is used above to describe a portion of the nacelle <NUM> that is stationary during aircraft propulsion system <NUM> operation (e.g., during takeoff, aircraft flight and landing). However, the stationary portion <NUM> may be otherwise movable for aircraft propulsion system <NUM> inspection / maintenance; e.g., when the aircraft propulsion system <NUM> is non-operational. Each of the fan cowls <NUM>, for example, may be configured to provide access to components of the gas turbine engine such as the fan case <NUM> and/or peripheral equipment configured therewith for inspection, maintenance and/or otherwise. In particular, each of fan cowls <NUM> may be pivotally mounted with the aircraft propulsion system <NUM> by, for example, a pivoting hinge system. The present disclosure, however, is not limited to the foregoing fan cowl configurations and/or access schemes.

The aft structure <NUM> includes a translating sleeve <NUM> of the thrust reverser system <NUM>. The translating sleeve <NUM> of <FIG> is disposed at the nacelle aft end <NUM>. This translating sleeve <NUM> extends axially along the axial centerline <NUM> between a forward end <NUM> thereof and the nacelle aft end <NUM>. The translating sleeve <NUM> is configured to partially form an aft outer peripheral boundary of the bypass flowpath. The translating sleeve <NUM> may also be configured to form a bypass nozzle <NUM> for the bypass flowpath with an inner structure <NUM> of the nacelle <NUM> (e.g., an inner fixed structure (IFS)), which nacelle inner structure <NUM> houses a core of the gas turbine engine.

The translating sleeve <NUM> of <FIG> includes a pair of translating sleeve segments <NUM> (e.g., halves) arranged on opposing sides of the aircraft propulsion system <NUM> (one such sleeve segment visible in <FIG>). The present disclosure, however, is not limited to such an exemplary translating sleeve configuration. For example, the translating sleeve <NUM> may alternatively have a substantially tubular body. For example, the translating sleeve <NUM> may extend more than three-hundred and thirty degrees (<NUM>°) around the axial centerline <NUM>.

Referring to <FIG> and <FIG>, the translating sleeve <NUM> is an axially translatable structure. Each translating sleeve segment <NUM> of <FIG>, for example, may be slidably connected to one or more stationary structures (e.g., a pylon <NUM> and a lower bifurcation <NUM>) through one or more respective track assemblies <NUM> and <NUM>. Each track assembly <NUM>, <NUM> may include a rail mated with a track beam; however, the present disclosure is not limited to the foregoing exemplary sliding connection configuration.

With the foregoing configuration, the translating sleeve <NUM> may translate axially along the axial centerline <NUM> and relative to the stationary portion <NUM>. The translating sleeve <NUM> may thereby move axially between a forward stowed position (see <FIG>) and an aft deployed position (see <FIG>). In the forward stowed position, the translating sleeve <NUM> provides the functionality described above. In the aft deployed position, the translating sleeve <NUM> at least partially (or substantially completely) uncovers at least one or more other components of the thrust reverser system <NUM> such as, but not limited to, one or more (e.g., fixed or translating) cascade structures <NUM>. In addition, as the translating sleeve <NUM> moves from the stowed position to the deployed position, one or more blocker doors (not shown) arranged with the translating sleeve <NUM> may be deployed to divert bypass air from the bypass flowpath and through the cascade structures <NUM> to provide reverse thrust.

<FIG> and <FIG> schematically illustrate an actuation system <NUM> for the translating sleeve <NUM>. This actuation system <NUM> is configured to move (e.g., axially translate) the translating sleeve <NUM> and each of its segments <NUM> between the forward stowed position (see <FIG>) and the aft deployed position (see <FIG>). This actuation system <NUM> includes one or more actuators 68A-D (generally referred to as "<NUM>") and one or more linkage systems <NUM> and 72A-B (generally referred to as "<NUM>").

Each actuator <NUM> may be configured as a linear actuator. Examples of such a linear actuator include, but are not limited to, a lead screw actuator and a hydraulic cylinder actuator. The present disclosure, however, is not limited to such exemplary linear actuators not to any specific type of actuator.

Each actuator <NUM> of <FIG> extends along a respective actuator centerline <NUM> between an actuator forward end <NUM> (e.g., a stationary end) and an actuator aft end <NUM> (e.g., a translating end), which centerline <NUM> may be parallel with the axial centerline <NUM>. Each actuator <NUM> is mechanically fastened (e.g., pinned) or otherwise connected to a stationary structure <NUM> (e.g., a torque box) at (e.g., on, adjacent or proximate) its forward end <NUM>, which stationary structure <NUM> may be included as part of, housed within and/or attached to the stationary portion <NUM> (see <FIG>). Each actuator <NUM> is mechanically fastened (e.g., pinned) or otherwise connected to the translating sleeve <NUM> and a respective translating sleeve segment <NUM>. For example, each actuator <NUM> may be connected to the components <NUM>, <NUM> at (e.g., on, adjacent or proximate) its aft end <NUM>. Alternatively, each actuator <NUM> may include a moveable (e.g., translatable) component that moves longitudinally along the actuator <NUM>. Each actuator <NUM> of <FIG> includes a translating member <NUM> (e.g., a lead screw or a telescopic device) which enables the respective actuator <NUM> to move (e.g., translate) its aft end <NUM> (or its moveable component) relative to its forward end <NUM> along the respective actuator centerline <NUM>.

Referring to <FIG>, the actuators <NUM> are configured about the axial centerline <NUM> in an annular array. The actuators 68A-B may be arranged proximate a top end of the nacelle <NUM> on opposing sides of the nacelle <NUM>. The actuators 68C-D may be arranged proximate a bottom end of the nacelle <NUM> on opposing sides of the nacelle <NUM>.

The intermediate linkage system <NUM> is configured as or otherwise includes a cross-over shaft <NUM>. This cross-over shaft <NUM> is mechanically / rotationally coupled to and links respective elements 86A and 88B (e.g., input / output shafts, receptacles or other types of couplings) of the actuators 68A-B. The cross-over shaft <NUM> may thereby transfer toque between (e.g., time and/or drive) the actuators 68A-B, which may enable the actuators 68A-B to move simultaneously during thrust reverser system <NUM> operation.

The cross-over shaft <NUM> extends along its centerline <NUM> between the actuators 68A-B while, for example, projecting through and/or extending around one or more obstacles <NUM>. These obstacles <NUM> may be fixed structures of the aircraft propulsion system <NUM> such as, but not limited to, the pylon <NUM> for mounting the aircraft propulsion system <NUM> to an aircraft body member; e.g., an aircraft wing. An example of the cross-over shaft <NUM> is a flex shaft. The present disclosure, however, is not limited to such an exemplary cross-over shaft. In the specific embodiment of <FIG>, the cross-over shaft <NUM> lies in a (e.g., flat) cross-over shaft plane that is, for example, perpendicular to the axial centerline <NUM>.

Each of the side linkage systems 72A, 72B is mechanically / rotationally coupled to and links respective elements 88A and 86C, 86B and 86D (e.g., input / output shafts, receptacles or other types of couplings) of the actuators 68A and 68C, 68B and 68D. Each side linkage system 72A, 72B may thereby transfer torque between (e.g., time and/or drive) the actuators 68A and 68C, 68B and 68D, which may enable the actuators 68A-D to move simultaneously during thrust reverser operation. Each side linkage system 72A, 72B, for example, includes a plurality of linkage shafts 90A-C (generally referred to as "<NUM>") and one or more gearboxes 92A-B (generally referred to as "<NUM>").

Each linkage shaft 90A-C extends along a centerline 94A-C (generally referred to as "<NUM>") thereof between opposing linkage shaft ends. As each linkage shaft <NUM> extends longitudinally along its centerline <NUM>, that linkage shaft <NUM> also extends circumferentially about the axial centerline <NUM> such that, for example, the linkage shaft <NUM> has a generally arcuate shape. This arcuate shape may have a two-dimensional (2D) curvature. Each linkage shaft <NUM> of <FIG> and <FIG>, for example, lies in a respective (e.g., flat) side linkage shaft plane that is, for example, perpendicular to the axial centerline <NUM>. In the specific embodiment of <FIG>, the intermediate linkage shaft plane is offset from (e.g., non-coaxial with) the end linkage shaft planes. The intermediate linkage shaft centerline 94C of <FIG>, for example, is axially displaced from the end linkage shaft centerlines 94A-B along the axial centerline <NUM>. However, the end linkage shaft centerlines 94A-B may (or may not) lie in a common plane. The intermediate linkage shaft 90C may thereby enable the respective side linkage system <NUM> to avoid one or more obstacles <NUM> within the nacelle outer structure <NUM>.

The first (e.g., top) end linkage shaft 90A extends between and is coupled to the actuator 68A or 68B and the gearbox 92A. More particularly, one of the linkage shaft ends is coupled to the actuator element 88A or 86B and the other one of the linkage shaft ends is coupled to an element 98A (e.g., input / output shaft, receptacle or any other type of coupling) of the gearbox 92A.

The second (e.g., bottom) end linkage shaft 90B extends between and is coupled to the actuator 68C or 68D and the gearbox 92B. More particularly, one of the linkage shaft ends is coupled to the actuator element 86C or 86D and the other one of the linkage shaft ends is coupled to an element 100B (e.g., input / output shaft, receptacle or any other type of coupling) of the gearbox 92B.

The intermediate linkage shaft 90C extends between and is coupled to the gearboxes <NUM>. More particularly, one of the linkage shaft ends is coupled to an element 98B (e.g., input / output shaft, receptacle or any other type of coupling) of the gearbox 92A and the other one of the linkage shaft ends is coupled to an element 100A (e.g., input / output shaft, receptacle or any other type of coupling) of the gearbox 92B.

Each linkage shaft <NUM> may be a flex shaft. Alternatively, any one or more of the linkage shafts <NUM> may be configured as a flexible coupling such as, for example, an elastomeric shaft. The present disclosure, however, is not limited to such an exemplary linkage shaft configuration.

Each of the gearboxes <NUM> is configured to enable respective ones of the linkage shafts <NUM> to be offset from one another, for example, along the axial centerline <NUM>. Each of the gearboxes <NUM> is further configured to mechanically / rotationally couple the respective linkage shafts <NUM>. Each of the gearboxes <NUM> may thereby transfer torque between the respective linkage shafts <NUM>. Various types and configurations of gearboxes are known in the art, and the present disclosure is not limited to any particular ones thereof.

Each of the actuators <NUM> is configured as a self-driven actuator. Each of the actuators <NUM>, for example, may be a hydraulically driven actuator. Thus, each actuator <NUM> may be configured to receive hydraulic fluid that causes movement of its respective aft end <NUM> (or its moveable component) and, thus, the respective coupling to the translating sleeve <NUM>. In such embodiments, the linkage systems <NUM> and <NUM> enable timing of the actuators <NUM>. For example, if one of the actuators <NUM> had a tendency to move faster than another one of the actuators <NUM> (if discretely arranged), the tying together of those actuators <NUM> through the linkage system(s) <NUM>, <NUM> would prevent disproportional movement. In other words, the fastener actuator <NUM> may pull the slower actuator <NUM> along through the linkage system(s) <NUM>, <NUM> and/or the slower actuator <NUM> may hold the faster actuator <NUM> back through the linkage system(s) <NUM>, <NUM>.

In some embodiments, referring to <FIG>, the actuation system <NUM> may also include a (e.g., central, common) drive device <NUM>; e.g., an electric motor. This drive device <NUM> is configured to drive operation of any one or more or each of the actuators <NUM> through the respective linkage systems <NUM>, <NUM>.

In some embodiments, referring to <FIG>, any one or more of the linkage shafts <NUM> may each be configured with a respective internal (e.g., fluid, lubricant) flow passage <NUM>. This flow passage <NUM> may be formed between an outer housing <NUM> (tubular sheath) of the linkage shaft and an inner shaft member <NUM> of the linkage shaft <NUM>. The flow passage <NUM> is operable to flow fluid (e.g., lubricant, oil) therethrough, which fluid may cool and/or lubricant the inner shaft member <NUM> as the member <NUM> rotates within the outer housing <NUM>.

In some embodiments, referring to <FIG>, the flow passages <NUM> within neighboring linkage shafts <NUM> may be fluidly coupled together through a respective one of the gearboxes <NUM>. Each respective flow passage <NUM>, for example, may be fluidly coupled with an internal cavity <NUM> of the gearbox <NUM>. Thus, the fluid flowing through the flow passages <NUM> may also cool and/or lubricant gears within the gearbox <NUM>.

In some embodiments, such as the one of <FIG>, any one or some or each of the gearboxes <NUM> may be configured as a wet gearbox. However, in other embodiments, any one or some or each of the gearboxes <NUM> may be configured as a dry gearbox.

In some embodiments, referring to <FIG>, any one or some or each of the gearboxes <NUM> may each include a housing <NUM> and a plurality of internal gears 114A-C (generally referred to as "<NUM>") arranged within the internal cavity <NUM> of the housing <NUM>. The internal gears may include a plurality of input / output (I/O) gears 114A and 114B and at least one idler gear 114C. The idler gear 114C of <FIG> is meshed with and between the input / output gears 114A and 114B. The idler gear 114C thereby is configured to motively couple the input / output gears 114A and 114B. The input / output gear 114A is coupled to an end of one of the linkage shafts 90A, 90B; e.g., via an inner shaft member receptacle. The input / output gear 114B is coupled to an end of one of the linkage shafts 90C; e.g., via an inner shaft member receptacle.

In some embodiments, referring to <FIG>, any one or some or each of the gearboxes <NUM> may each include a ring gear 114C' rather than the idler gear 114C of <FIG>. This ring gear 114C' circumscribes and is meshed with the input / output gears 114A and 114B.

In some embodiments, referring to <FIG> and <FIG>, any one or some or each of the gearboxes <NUM> is configured such that the inner shaft members <NUM> of the linkage shafts <NUM> rotate in a common direction.

Each gearbox <NUM> is described above where an input to the gearbox <NUM> (e.g., via 114A or 114B) rotates in a common direction as an output from the gearbox <NUM> (e.g., via 114B or 114A). The present disclosure, however, is not limited to such a common rotation configuration. For example, referring to <FIG>, the input / output gears 114A and 114B may be meshed with one another directly without, for example, an intermediate gear meshed therebetween (e.g., gears 114C, 114C').

Each of the gearboxes <NUM> is described above as enabling respective ones of the linkage shafts <NUM> to be offset from one another along the axial centerline <NUM>. One, some or each of the gearboxes <NUM>, however, may also or alternatively enable the respective ones of the linkage shafts <NUM> to also or alternatively be offset from one another radially relative to the axial centerline. The gearbox <NUM> in <FIG>, for example, enables the linkage shafts <NUM> to be radially offset from one another, which linkage shafts <NUM> may lie in different axial planes as described above or in a common axial plane along the axial centerline <NUM>.

The actuation system <NUM> is described above as driving movement (e.g., translation) of the translating sleeve <NUM> and its translating sleeve segments <NUM>. However, in other embodiments, the actuation system <NUM> may also or alternatively drive movement (e.g., translation) of one or more other components of the thrust reverser system <NUM> and/or one or more non-thrust reverser components. For example, in other embodiments, component <NUM> in <FIG> may alternatively be configured as a translating cascade structure (e.g., <NUM> of <FIG>) or another translating member to which the blocker doors are coupled, for example. In another example, the component <NUM> in <FIG> may alternatively be configured as a component of a variable area nozzle (VAN) such as, but not limited to, a variable area fan nozzle (VAFN). In still another example, the component <NUM> of <FIG> may alternatively be configured as a translating inlet structure (e.g., a translating body that includes element <NUM> and/or <NUM> of <FIG>) of the nacelle <NUM> or any other component(s) of the aircraft propulsion system <NUM> and/or the associated aircraft. The present disclosure therefore is not limited to any particular actuation system application.

Claim 1:
An assembly (<NUM>) for an aircraft propulsion system (<NUM>), comprising:
a first actuator (<NUM>), for example a linear actuator;
a second actuator (<NUM>); and
a linkage system (<NUM>, <NUM>) configured to transfer torque between the first actuator (<NUM>) and the second actuator (<NUM>), the linkage system (<NUM>, <NUM>) including a first linkage shaft (<NUM>), a second linkage shaft (<NUM>) and a gearbox (<NUM>), the first linkage shaft (<NUM>) having a first centerline (<NUM>), the second linkage shaft (<NUM>) having a second centerline (<NUM>) offset from the first centerline (<NUM>), and the gearbox (<NUM>) coupled to and between the first linkage shaft (<NUM>) and the second linkage shaft (<NUM>),
wherein the first actuator (<NUM>) and the second actuator (<NUM>) are each configured as a self-driven actuator;
wherein the linkage system (<NUM>, <NUM>) extends circumferentially about a rotational axis (<NUM>) of the aircraft propulsion system (<NUM>) from the first actuator (<NUM>) to the second actuator (<NUM>), characterised in that:
the first linkage shaft (<NUM>) and the second linkage shaft (<NUM>) extend circumferentially about the rotational axis (<NUM>) of the aircraft propulsion system (<NUM>).