Patent Description:
Modern aircraft gas turbine engines may include thrust reversers configured to improve the braking ability of an aircraft by redirecting forward at least a part of the thrust generated by the gas turbine engine. The thrust reverser may include one or more doors configured to pivot from a stowed position to a deployed position so as to redirect gas turbine engine bypass air flow as well as to create additional drag on the exterior of the gas turbine engine.

Thrust reverser doors are complex parts that may require high stiffness, complex curvatures, and the ability to transfer load across the door. However, conventional methods of manufacturing suitable thrust reverser doors can be time consuming and expensive. Accordingly, what is needed are improved thrust reverser doors and methods of manufacturing which address one or more of the above-discussed concerns.

<CIT> discloses a push-pull shutter and method of making it.

<CIT> discloses monolithic thrust reverser components.

<CIT> discloses a blocker door assembly having a thermoplastic blocker door for use in a turbine engine.

<CIT> discloses a plastic core blocker door.

It should be understood that any or all of the features or embodiments described herein can be used or combined in any combination within the scope of the appended claims.

According to an aspect of the present invention, a thrust reverser door is provided in accordance with claim <NUM>.

Optionally, the grid structure has an orthogrid configuration.

Optionally, the grid structure has an isogrid configuration.

Optionally, the grid structure is formed on the second side of the cover plate body. The grid structure has a first grid side in contact with the second side of the cover plate body and a second grid side opposite the first grid side. The second grid side of the grid structure has a shape conforming to a corresponding shape of the interior surface of the backskin.

Optionally, the grid structure is formed on the interior surface of the backskin. The grid structure has a first grid side in contact with the interior surface of the backskin and a second grid side opposite the first grid side. The second grid side of the grid structure has a shape conforming to a corresponding shape of the second side of the cover plate body.

Optionally, the cover plate body and the backskin include a thermoplastic material.

Optionally, the grid structure is welded to the backskin.

According to another aspect of the present invention, a method for forming a thrust reverser door is provided in accordance with claim <NUM>.

Optionally, forming the grid structure includes forming the grid structure independent of the cover plate body and the backskin.

Optionally, forming the grid structure further includes overmolding the grid structure onto the second side of the cover plate body and forming the grid structure to conform to the interior surface of the backskin.

Optionally, mounting the second side of the cover plate body to the interior surface of the backskin with the grid structure includes induction welding the grid structure to one or both of the cover plate body and the backskin.

Optionally, overmolding the grid structure onto the second side of the cover plate body includes forming a plurality of nodes.

Optionally, mounting the second side of the cover plate body to the interior surface of the backskin with the grid structure includes mounting the grid structure to the interior surface of the backskin at the plurality of nodes.

According to another aspect of the present invention, a gas turbine engine is provided in accordance with claim <NUM>.

The present invention, and all its aspects, embodiments and advantages associated therewith will become more readily apparent in view of the detailed description provided below, including the accompanying drawings.

It is noted that various connections are set forth between elements in the following description and in the drawings. It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities. It is further noted that various method or process steps for embodiments of the present disclosure are described in the following description and drawings. It is further noted that various method or process steps for embodiments of the present disclosure are described in the following description and drawings. The description may present the method and/or process steps as a particular sequence. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the description should not be construed as a limitation.

Referring to <FIG>, an exemplary gas turbine engine <NUM> is schematically illustrated. The gas turbine engine <NUM> is disclosed herein as a two-spool turbofan engine that generally includes a fan section <NUM>, a compressor section <NUM>, a combustor section <NUM>, and a turbine section <NUM>. The fan section <NUM> drives air along a bypass flow path <NUM> while the compressor section <NUM> drives air along a core flow path <NUM> for compression and communication into the combustor section <NUM> and then expansion through the turbine section <NUM>. Although depicted as a turbofan gas turbine engine in the disclosed non-limiting embodiments, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines including those with three-spool architectures.

The gas turbine engine <NUM> generally includes a low-pressure spool <NUM> and a high-pressure spool <NUM> mounted for rotation about a longitudinal centerline <NUM> of the gas turbine engine <NUM> relative to an engine static structure <NUM> via one or more bearing systems <NUM>. It should be understood that various bearing systems <NUM> at various locations may alternatively or additionally be provided.

The low-pressure spool <NUM> generally includes a first shaft <NUM> that interconnects a fan <NUM>, a low-pressure compressor <NUM>, and a low-pressure turbine <NUM>. The first shaft <NUM> may be connected to the fan <NUM> through a gear assembly of a fan drive gear system <NUM> to drive the fan <NUM> at a lower speed than the low-pressure spool <NUM>. The high-pressure spool <NUM> generally includes a second shaft <NUM> that interconnects a high-pressure compressor <NUM> and a high-pressure turbine <NUM>. It is to be understood that "low pressure" and "high pressure" or variations thereof as used herein are relative terms indicating that the high pressure is greater than the low pressure. An annular combustor <NUM> is disposed between the high-pressure compressor <NUM> and the high-pressure turbine <NUM> along the longitudinal centerline <NUM>. The first shaft <NUM> and the second shaft <NUM> are concentric and rotate via the one or more bearing systems <NUM> about the longitudinal centerline <NUM> which is collinear with respective longitudinal centerlines of the first and second shafts <NUM>, <NUM>.

Airflow along the core flow path <NUM> is compressed by the low-pressure compressor <NUM>, then the high-pressure compressor <NUM>, mixed and burned with fuel in the combustor <NUM>, and then expanded over the high-pressure turbine <NUM> and the low-pressure turbine <NUM>. The low-pressure turbine <NUM> and the high-pressure turbine <NUM> rotationally drive the low-pressure spool <NUM> and the high-pressure spool <NUM>, respectively, in response to the expansion.

Referring to <FIG>, <FIG>, the gas turbine engine <NUM> includes a nacelle <NUM> generally enclosing and forming an exterior housing of the gas turbine engine <NUM>. The nacelle <NUM> of the gas turbine engine <NUM> is mounted to a pylon <NUM>, which may, for example, mount the gas turbine engine <NUM> to a wing of an aircraft (not shown). The nacelle <NUM> may include a thrust reverser assembly <NUM> forming an aft portion of the nacelle <NUM>. The thrust reverser assembly <NUM> includes a plurality of doors <NUM> and a respective plurality of actuators <NUM>. Each door <NUM> may be pivotably mounted to the nacelle <NUM> and configured to pivot between a stowed position (see, e.g., <FIG>) and a deployed position (see, e.g., <FIG>). In the stowed position, an exterior loft surface <NUM> of the door <NUM> may be configured to form a portion of an outer surface <NUM> of the nacelle <NUM>. As used herein, terms such as "forward" and "aft" should be understood as positional terms in reference to the direction of airflow, such as airflow along the bypass flow path <NUM>, through the nacelle <NUM>.

In operation, each door <NUM> may be pivoted by a respective actuator <NUM> between the stowed position and the deployed position. When pivoted to the deployed position, the door <NUM> may reduce aircraft braking requirements and permit the use of shorter runways by reversing a substantial portion of engine thrust during landing. The thrust reverser assembly <NUM> may slow down the aircraft by preventing the gas turbine engine <NUM> from generating forward fan thrust and by generating reverse thrust to counteract primary thrust. For example, in the deployed position, the plurality of doors <NUM> may block all or a portion of the bypass flow path <NUM>, enclosed by the nacelle <NUM>, and direct the airflow of the bypass flow path <NUM> in a forward direction through recesses <NUM> within which the plurality of doors <NUM> are retained when in the stowed position. The door <NUM>, in the deployed position, may further contribute to slowing the aircraft by creating additional drag.

Referring to <FIG>, the door <NUM> includes a backskin <NUM> having an interior surface <NUM> and the exterior loft surface <NUM> opposite the interior surface <NUM>. The backskin <NUM> may be a single-piece component formed of, for example, a thermoplastic material, a thermoset material, or any other suitable lightweight material such as aluminum. The backskin <NUM> may be pivotably mounted to the nacelle <NUM> by one or more hinges <NUM> and may be coupled to the actuator <NUM> at an actuator attachment point <NUM>.

The door <NUM> includes a cover plate <NUM> comprising a cover plate body <NUM> having a first side <NUM>, which defines an inner loft surface of the door <NUM>, and a second side <NUM> opposite the first side <NUM>. The door <NUM> further includes a grid structure <NUM> mounting the second side <NUM> of the cover plate to the interior surface <NUM> of the backskin <NUM>. In various embodiments, the grid structure <NUM> may be formed (e.g., overmolded or compression molded) on the cover plate <NUM> and may extend from the second side <NUM> of the cover plate body <NUM>. In various other embodiments, the grid structure <NUM> may be formed on the backskin <NUM> and may extend from the interior surface <NUM> of the backskin <NUM>. The grid structure <NUM> is defined by a plurality of intersecting ribs <NUM>. In various embodiments, the plurality of ribs <NUM> may be arranged such that the grid structure <NUM> has an orthogrid configuration (see, e.g., <FIG> and <FIG>). In various embodiments, the plurality of ribs <NUM> may be arranged such that the grid structure <NUM> has an isogrid configuration (see, e.g., <FIG>).

In various embodiments, where the grid structure <NUM> is formed on the cover plate <NUM>, the plurality of ribs <NUM> includes a first side <NUM> in contact with the second side <NUM> of the cover plate body <NUM> and a second side <NUM> mounted to the interior surface <NUM> of the backskin <NUM>. Similarly, in various embodiments, where the grid structure <NUM> is formed on the backskin <NUM>, the first side <NUM> of the plurality of ribs <NUM> is in contact with the interior surface <NUM> of the backskin <NUM> and the second side <NUM> of the plurality of ribs <NUM> is mounted to the second side <NUM> of the cover plate <NUM>. In various embodiments, the second side <NUM> of the plurality of ribs <NUM> of the grid structure <NUM> may conform to the respective interior surface <NUM> of the backskin <NUM> or second side <NUM> of the cover plate <NUM>. For example, the second side <NUM> of the plurality of ribs <NUM> may be shaped to conform to a corresponding shape of the interior surface <NUM>. Accordingly, a height H of the plurality of ribs <NUM> between the first side <NUM> and the second side <NUM> may vary throughout the grid structure <NUM>.

In various embodiments, the cover plate <NUM> may be formed from a thermoplastic material (e.g., polyether ether ketone (PEEK)). For example, the cover plate body <NUM> may be a stamped thermoplastic material with the grid structure <NUM> formed by overmolding a thermoplastic material onto the second side <NUM> of the cover plate body <NUM> or the interior surface <NUM> of the backskin <NUM>. In various embodiments, a material (e.g., a thermoplastic or a thermoset material) of one or more of the cover plate <NUM>, the grid structure <NUM>, and the backskin <NUM> may include fibers for reinforcing the thermoplastic or thermoset material. For example, the thermoplastic or thermoset material may include continuous, discontinuous, or chopped carbon fibers.

The grid structure <NUM> includes a plurality of nodes <NUM> formed at interfaces between intersecting ribs of the plurality of ribs <NUM> (see, e.g., <FIG> and <FIG>). The grid structure <NUM> is mounted to the interior surface <NUM> of the backskin <NUM> at the plurality of nodes <NUM>. The plurality of nodes <NUM> include a respective plurality of apertures <NUM> for the passage of fasteners <NUM> therethrough for mounting the cover plate <NUM> to the backskin <NUM>.

Referring to <FIG>, a method <NUM> for forming a thrust reverser door, such as the door <NUM>, is provided. In Step <NUM>, the backskin <NUM> including the interior surface <NUM> and the exterior loft surface <NUM> is provided. In Step <NUM>, the cover plate <NUM> is formed, for example, by stamping (e.g., with a heated press) or the cover plate <NUM> may be laid up with continuous fibers on a mold.

In Step <NUM>, the grid structure <NUM> is formed. The grid structure <NUM> may be overmolded onto the second side <NUM> of the cover plate body <NUM>. The grid structure <NUM> may be overmolded onto the second side <NUM> of the cover plate body <NUM> such that the second side <NUM> of the plurality of ribs <NUM> of the grid structure <NUM> conforms to the interior surface <NUM> of the backskin <NUM>. In some embodiments, Step <NUM> include overmolding the grid structure <NUM> onto the second side <NUM> of the cover plate body <NUM> so as to include the plurality of nodes <NUM>, as previously discussed. In various embodiments, the grid structure <NUM> may be formed (e.g., molded) independent of the cover plate <NUM> and the backskin <NUM> and may be mounted to the cover plate <NUM> and the backskin <NUM> subsequent to the formation of the grid structure <NUM> (see Step <NUM>).

In Step <NUM>, the grid structure <NUM> of the cover plate <NUM> is mounted to the interior surface <NUM> of the backskin <NUM>. In various embodiments, mounting the grid structure <NUM> to the interior surface <NUM> may include welding the second side <NUM> of the plurality of ribs and/or the plurality of nodes <NUM> to the interior surface <NUM>. For example, the grid structure <NUM> may be induction welded to the interior surface <NUM> of the backskin <NUM>. Alternatively, in various embodiments, the grid structure <NUM> of the cover plate <NUM> may be bonded to the interior surface <NUM> of the backskin <NUM> with a suitable adhesive. Alternatively, in various embodiments, the grid structure <NUM> may be mounted to the interior surface <NUM> of the backskin <NUM> by the plurality of fasteners <NUM> extending through the plurality of apertures <NUM> of the plurality of nodes <NUM> or through alternative apertures disposed through the cover plate <NUM>, for example, along a perimeter of the cover plate <NUM>. While Steps <NUM> and <NUM> discuss overmolding the grid structure <NUM> onto the second side <NUM> of the cover plate body <NUM> and mounting the grid structure <NUM> to the interior surface <NUM> of the backskin <NUM>, it should be understood that the grid structure <NUM> can be similarly formed (e.g., overmolded) onto the interior surface <NUM> of the backskin <NUM> and mounted to the second side <NUM> of the cover plate body <NUM>.

In an embodiment not being part of the invention, the method <NUM> may include in Step <NUM>, subsequent to overmolding the grid structure <NUM> onto the second side <NUM> of the cover plate body <NUM>, overmolding the plurality of fasteners <NUM> onto the grid structure <NUM> or the interior surface <NUM> of the backskin <NUM>.

The cover plate <NUM> and backskin <NUM> of the present disclosure may provide a thrust reverser door, such as the door <NUM>, having substantially improved stiffness while reducing manufacturing time and cost.

Claim 1:
A thrust reverser door (<NUM>) comprising:
a backskin (<NUM>) comprising an interior surface (<NUM>) and an exterior loft surface (<NUM>);
a cover plate (<NUM>) comprising cover plate body (<NUM>), having a first side (<NUM>) and a second side (<NUM>) opposite the first side (<NUM>); and
a grid structure (<NUM>) mounted to the second side (<NUM>) of the cover plate body (<NUM>) and the interior surface (<NUM>) of the backskin (<NUM>), the grid structure (<NUM>) defined by a plurality of ribs (<NUM>);
wherein the grid structure (<NUM>) comprises a plurality of nodes (<NUM>) formed at interfaces between intersecting ribs of the plurality of ribs (<NUM>), the plurality of nodes (<NUM>) including a respective plurality of apertures (<NUM>) for the passage of a plurality of fasteners (<NUM>) therethrough for mounting the cover plate (<NUM>) to the backskin (<NUM>), and wherein the grid structure (<NUM>) is mounted to the interior surface (<NUM>) of the backskin (<NUM>) at the plurality of nodes (<NUM>).