Patent Description:
Gas turbine engines, such as those that power modern commercial and military aircraft, generally include a compressor section to pressurize an airflow, a combustor section for burning a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases. The compressor section and the turbine section may each include rotatable blades and stationary vanes. Within a surrounding engine casing, the radial outermost tips of the blades are positioned in close proximity to blade outer air seals (BOAS). The BOAS may be parts of shroud assemblies mounted within the engine casing. Each BOAS may typically incorporate multiple segments that are annularly arranged within the engine casing, with the inner diameter surfaces of the segments being located closest to the blade tips.

Under certain circumstances, probes may be installed in the BOAS, for example, for use in a Non-intrusive Stress Measurement System (NSMS) or a tip-timing system for observation and management of various rotating blade parameters. However, installation of the probes may involve extensive modification and/or disassembly and reassembly of BOAS hardware. Modifications to the BOAS hardware (e.g., heat shields and BOAS support structures) may result in increased degradation of gas turbine engine components during a test program and may, therefore, result undesirable test program limitations. Further, available space proximate the BOAS may limit the locations where the probes can be installed, potentially resulting in non-ideal spacing (e.g., circumferential spacing) of probes. Accordingly, improved methods and systems the installation of probes are desirable. <CIT> and <CIT> disclose arrangements of the prior art.

According to an aspect of the present invention, a probe adapter is provided according to claim <NUM>.

Optionally, the adapter body is configured to be mounted to an outer radial side of a blade outer air seal (BOAS).

Optionally, the adapter body includes an inner adapter side and an outer adapter side extending between a first adapter end and a second adapter end and the probe aperture extends from the inner adapter side to the outer adapter side.

Optionally, the probe adapter further includes an adapter portion mounted to (e.g., to the second adapter end or side of) the adapter body. The adapter portion includes a threaded aperture configured to threadably retain the threaded fastener.

Optionally, the slot is oriented in a slot direction extending between the first adapter end and the second adapter end.

Optionally, at least a portion of the slot is disposed within the probe aperture.

According to another optional embodiment of the present invention, a gas turbine engine includes a blade outer air seal (BOAS) including an inner radial side and an outer radial side. The gas turbine engine includes a probe adapter according to the invention mounted to the outer radial side of the BOAS.

Optionally, the gas turbine engine further includes a probe including a probe assembly and a probe cable extending from the probe assembly. The probe assembly is retained within the probe aperture of the adapter body by the driver in the first position.

Optionally, the gas turbine engine further includes a plug retained within the probe aperture of the adapter body by the driver in the first position.

Optionally, the gas turbine engine further includes a heat shield in contact with the BOAS and disposed radially outside the probe adapter.

Optionally, the probe cable is disposed radially between the probe adapter and the heat shield along at least a portion of a length of the probe cable.

Optionally, the probe assembly includes a center axis and the center axis intersects the heat shield.

Optionally, the BOAS and the probe adapter form an integral component.

Optionally, the probe adapter further includes an adapter portion mounted to the adapter body. The adapter portion includes a threaded aperture configured to threadably retain the threaded fastener.

According to another aspect of the present invention, a method for installing a probe in a probe adapter for a blade outer air seal (BOAS) is provided according to claim <NUM>.

Optionally, the method further includes contacting a probe cable of the probe with the first end of the driver.

Optionally, the method further includes bending the probe cable subsequent to sliding the driver from the second position to the first position.

The present disclosure, 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. 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>, one or more sections of the gas turbine engine <NUM>, such as the compressor section <NUM> and the turbine section <NUM>, may include a plurality of airfoils, including, for example, one or more blades <NUM> and vanes <NUM>. The sections <NUM>, <NUM> may further include at least one blade outer air seal assembly (hereinafter "BOAS assembly") <NUM> located radially outward of the blades <NUM> with respect to the longitudinal centerline <NUM> of the gas turbine engine <NUM>. The BOAS assembly <NUM> includes at least one blade outer air seal (hereinafter "BOAS") <NUM>. The BOAS <NUM> may include a radial portion <NUM> and an axial portion <NUM>. The radial portion <NUM> may include a first axial side <NUM> and a second axial side <NUM> opposite the first axial side <NUM>. The axial portion <NUM> may include an inner radial side <NUM>, radially adjacent the blade tips 52T of the blades, and an outer radial side <NUM> opposite the inner radial side <NUM>.

The BOAS assembly <NUM> may further include a support <NUM> in contact with or mounted to the radial portion <NUM> of the BOAS <NUM>, for example, along the second axial side <NUM>. The support <NUM> may be configured to mount the BOAS <NUM>, for example, to a case (e.g., a turbine case, diffuser case, etc.) of the turbine section <NUM> or to an actuator configured to move the BOAS <NUM> between various radial positions so as to control a distance between the inner radial side <NUM> of the BOAS and the blade tips 52T.

The BOAS assembly <NUM> may further include a heat shield <NUM> in contact with or mounted to one or both of the BOAS <NUM> and the support <NUM>. The heat shield <NUM> may be generally disposed radially outside BOAS <NUM> and axially adjacent the support <NUM>. For example, as shown in <FIG> and <FIG>, the heat shield may include a first end <NUM> in contact with the first axial side <NUM> of the radial portion <NUM> of the BOAS <NUM> and a second end <NUM> in contact with the support <NUM>. In various embodiments, the heat shield <NUM> may be mounted to one or both of the BOAS <NUM> and the support <NUM> at one or both of the first end <NUM> and the second end <NUM> by any suitable attachment means such as, for example, fasteners, welds, etc. The heat shield <NUM> may include a middle portion <NUM> axially spaced from both the first end <NUM> and the second end <NUM> such that the heat shield <NUM> forms a shielded region <NUM> bounded by the heat shield <NUM>, the support <NUM>, and the BOAS <NUM>. The heat shield <NUM> and the outer radial side <NUM> may define a radial gap <NUM> therebetween. In various embodiments, one or more of the BOAS <NUM>, the support <NUM>, and the heat shield <NUM> may be annularly oriented with respect to the longitudinal centerline <NUM>.

Referring to <FIG>, the BOAS assembly <NUM> includes at least one probe adapter <NUM> mounted to the BOAS <NUM>. The probe adapter <NUM> may be mounted to the outer radial side <NUM> of the BOAS <NUM> and disposed in the radial gap <NUM>. As will be discussed in further detail, the probe adapter <NUM> is configured to position a probe <NUM> (e.g., an optical probe) relative to the BOAS <NUM>. The probe adapter <NUM> may include an adapter body <NUM> including an inner side <NUM> and an outer side <NUM> extending between a first adapter end <NUM> and a second adapter end <NUM> opposite the first adapter end <NUM>. In various embodiments, the BOAS assembly <NUM> may include more than one probe adapter <NUM>. For example, the BOAS assembly <NUM> may include a plurality of the probe adapters <NUM> circumferentially spaced about the BOAS <NUM>. The plurality of the probe adapters <NUM> may have a uniform or a non-uniform spacing about the BOAS <NUM> as required by the particular application. In various embodiments, at least a portion of the probe adapter <NUM> may be disposed in a recess <NUM> of the BOAS <NUM>. The BOAS <NUM> may include a probe port <NUM> formed through the BOAS <NUM> and aligned with the probe <NUM> to enable the probe <NUM> to observe the blade tips 52T. For example, the probe portion <NUM> may extend between the recess <NUM> and inner radial side <NUM>. In various embodiments, the probe adapter <NUM> may be integrally formed with the BOAS <NUM>.

The adapter body <NUM> may further include a probe aperture <NUM> extending from the inner side <NUM> to the outer side <NUM> of the adapter body <NUM>. The adapter body <NUM> may further include a slot <NUM> generally oriented in a direction extending between the first adapter end <NUM> and the second adapter end <NUM>. The slot <NUM> may include a first end <NUM> and a second end <NUM> opposite the first end <NUM>. At least a portion of the slot <NUM> between the first end <NUM> and the second end <NUM> may be disposed within the probe aperture <NUM>.

In order to observe the blades <NUM>, for example, to facilitate operations of a Non-intrusive Stress Measurement System (NSMS) or a tip-timing system, the BOAS assembly <NUM> may include one or more of the probe <NUM> positioned within one or more of the probe adapter <NUM>, as discussed above. For example, by comparing a theoretical time of arrival of the blade tips 52T to an actual time of arrival provided by the probe <NUM>, a deflection of the blades <NUM> may be determined. The deflection of the blades <NUM> may be used to calculate a stress/strain measurement of the blades <NUM>. It should be appreciated, however, that other measurements may be performed with the probe <NUM> such as, for example, temperature measurements.

The probe <NUM> may include a probe assembly <NUM> and a probe cable <NUM> extending from the probe assembly <NUM>. The probe assembly <NUM> may be configured to be retained within the probe aperture <NUM> of the adapter body <NUM>. In various embodiments, the probe assembly <NUM> may include an optical head <NUM> surrounding and retaining a fiber <NUM> of the probe cable <NUM>. The probe assembly <NUM> may additionally include a collar <NUM> coupling the probe assembly <NUM> and the probe cable <NUM> together, for example, with a set screw <NUM>. The probe assembly <NUM> may define a center axis <NUM> corresponding to the orientation of the fiber <NUM> within the probe assembly <NUM>. As shown, for example, in <FIG>, the probe cable <NUM> may include one or both of an inner hypo tube <NUM> and an outer hypo tube <NUM> configured to house and support the fiber <NUM>.

In various embodiments, the probe adapter <NUM> may include an adapter portion <NUM>, for example, an adapter portion <NUM> having a dovetail configuration as shown in <FIG>. The adapter portion <NUM> may include a first side <NUM> and a second side <NUM> opposite the first side <NUM>. The first side <NUM> of the adapter portion <NUM> may define the second end <NUM> of the slot <NUM>. The adapter portion <NUM> may be welded or otherwise attached to the adapter body <NUM> by any suitable method. The adapter portion <NUM> may include a threaded aperture <NUM> extending through the adapter portion <NUM> from the first side <NUM> to the second side <NUM>. As will be discussed in greater detail, the threaded aperture <NUM> of the adapter portion <NUM> may accommodate the insertion and removal of a corresponding threaded fastener <NUM> (e.g., a threaded bolt or screw) and may be configured to threadably retain the fastener <NUM>.

The probe adapter <NUM> may include a driver <NUM> slidably mounted within the slot <NUM> and slidable between a first position and a second position. The driver <NUM> includes a first end <NUM> and a second end <NUM> opposite the first end. The driver <NUM> further includes a top portion <NUM> defining a top side <NUM> and a bottom portion <NUM> defining a bottom side <NUM>. The bottom portion <NUM> may have a width W1 that is greater than a width W2 of the top portion <NUM> such that the bottom portion <NUM> is configured to be retained in the slot <NUM>. The first end <NUM> of the driver <NUM> may include a ramped recess <NUM> extending in a direction from the first end <NUM> to the second end <NUM> of the driver <NUM>. The ramped recess <NUM> may be shaped to substantially correspond to an exterior surface <NUM> of the probe cable <NUM>. The ramped recess <NUM> may additionally be shaped (e.g., curved) to substantially correspond to a bend orientation of the probe cable <NUM>. For example, in a direction from the bottom side <NUM> to the top side <NUM> of the driver <NUM>, the ramped recess <NUM> may increasingly extend a greater distance from the first end <NUM> to the second end <NUM>.

As noted above, the driver <NUM> may be slidable between a first position (see, e.g., <FIG>) and a second position (see, e.g., <FIG> and <FIG>) within the slot <NUM>. In the first position, the first end <NUM> of the driver <NUM> may be disposed proximate or may contact the first end <NUM> of the slot <NUM> and/or may be in contact with the probe <NUM> (e.g., the probe cable <NUM>). In the first position, the driver <NUM> may additionally cover at least a portion of the probe assembly <NUM> such that the bottom side <NUM> of the driver <NUM> fixes and retains the probe assembly <NUM> within the probe aperture <NUM>. In the second position, the second end <NUM> of the driver <NUM> may be disposed proximate or may contact the second end <NUM> of the slot <NUM>. In the second position, the driver <NUM> is substantially withdrawn from the probe aperture <NUM> so as to permit removal of the probe assembly <NUM> from the probe aperture <NUM>.

The threaded fastener <NUM> may be inserted into the threaded aperture <NUM> of the adapter portion <NUM> so as to contact the second end <NUM> of the driver <NUM>. Accordingly, the threaded fastener <NUM>, in contact with the second end <NUM> of the driver <NUM>, may fix the driver <NUM> in the first position so as to retain the probe assembly <NUM> within the probe aperture <NUM>. The threaded fastener <NUM> may additionally be used to slide the driver <NUM> from the second position to the first position by threadably inserting the threaded fastener <NUM> into the threaded aperture <NUM> to achieve the desired position of the driver <NUM>.

Referring to <FIG>, in various embodiments, the probe adapter <NUM> may not include the adapter portion <NUM>. For example, the adapter body <NUM> may include one or more structural features of the adapter portion <NUM>. For example, the adapter body <NUM> may include the threaded aperture <NUM>. Additionally, the adapter body <NUM> may define the second end <NUM> of the slot <NUM>. In various embodiments, adapter body <NUM> may be formed by an additive manufacturing process (e.g., direct metal laser sintering (DMLS)), for example, to reduce manufacturing time and cost. In various embodiments, the driver <NUM> may be additively manufactured within the slot <NUM> during additive manufacturing of the adapter body <NUM>. Accordingly, the additively manufactured adapter body <NUM> may reduce the risk of foreign object damage (FOD) by capturing the driver <NUM>. In various embodiments, during additive manufacturing of the adapter body <NUM> and the driver <NUM>, additively manufactured supports (not shown) may be formed between the adapter body <NUM> and the driver <NUM>. These additively manufactured supports may be broken subsequent to the additive manufacture of the probe adapter <NUM>, for example, during an initial operation of the driver <NUM> with the threaded fastener <NUM>.

As previously discussed, the probe adapter <NUM> may be disposed in the radial gap <NUM> with the heat shield <NUM> disposed radially outside the probe adapter <NUM>. In various embodiments, the center axis <NUM> of the probe assembly <NUM> may intersect the heat shield <NUM>. The probe cable <NUM> may additionally be disposed within the radial gap <NUM> along at least a portion of a length of the probe cable <NUM>. The low-profile configuration of the probe adapter <NUM> may permit introduction and removal of the probe <NUM> from the probe adapter <NUM> without modification or removal of the heat shield <NUM> or the surrounding structure of the BOAS assembly <NUM>. For example, the substantially axial orientation of the threaded fastener <NUM> load path may reduce a radial height of the probe adapter <NUM> while simplifying installation and removal of the probe <NUM> within the minimal space of the radial gap <NUM>. The probe adapter <NUM> can remain within the BOAS assembly <NUM> thereby permitting relatively rapid installation and removal of test equipment (e.g., probe <NUM>) in the event of a test program.

Referring to <FIG>, <FIG>, and <FIG>, a method <NUM> for installing a probe <NUM> in the probe adapter <NUM> is provided. In Step <NUM>, the threaded fastener <NUM> is at least partially withdrawn from the probe adapter <NUM> so as to allow the driver <NUM> to slide freely within the slot <NUM>. In Step <NUM>, the driver <NUM> is positioned in the second position (see, e.g., <FIG>) so as to provide access to the probe aperture <NUM>.

In various embodiments, for example, when the probe <NUM> is not installed in the probe adapter <NUM>, a plug <NUM> may be installed in the probe aperture <NUM> (see, e.g., <FIG>). The plug <NUM> may substantially correspond in shape and/or size to one or both of the probe assembly <NUM> and the probe aperture <NUM>. Accordingly, in Step <NUM>, the plug <NUM> may be removed from the probe aperture <NUM>, if necessary (e.g., if the plug <NUM> is installed in the probe adapter <NUM>).

In Step <NUM>, the probe <NUM> is installed in the probe adapter <NUM> by positioning the probe assembly <NUM> within the probe aperture <NUM> (see, e.g., <FIG>). In Step <NUM>, the driver <NUM> is slid from the second position to the first position so as to retain the probe assembly <NUM> within the probe aperture <NUM>. The driver <NUM> may contact one or both of the probe assembly <NUM> and the probe cable <NUM> in the first position. The threaded fastener <NUM> may then be inserted into the probe adapter <NUM>, via the threaded aperture <NUM>, so as to contact the second end <NUM> of the driver <NUM> fixing the driver <NUM> in place (see, e.g., <FIG>). Optionally, the threaded fastener <NUM> may be tightened to provide a desired torque to the threaded fastener <NUM>. Step <NUM> may alternatively be performed by inserted the threaded fastener <NUM> into the probe adapter <NUM> and contacting the second end <NUM> of the driver <NUM> with the threaded fastener <NUM> so as to slide the driver <NUM> from the second position to the first position to retain the probe assembly <NUM> within the probe aperture <NUM>. As one of ordinary skill in the art will understand, the Steps <NUM>-<NUM>, discussed above, for installing the probe <NUM> in the probe adapter <NUM>, may be used in reverse order to uninstall the probe <NUM> from the probe adapter <NUM>.

In Step <NUM>, the probe cable <NUM> may be bent subsequent to sliding the driver <NUM> from the second position to the first position to secure the probe adapter <NUM> within the probe aperture <NUM>, in order to provide clearance for installation of the heat shield <NUM> (see, e.g., <FIG>). Bending of the probe cable <NUM> subsequent to installation of the probe <NUM> within the probe adapter <NUM> may be performed, for example, during initial assembly of the BOAS assembly <NUM> or where portions of the BOAS assembly <NUM> (e.g., the heat shield <NUM>) have been removed. To accomplish installation of the probe <NUM> within the probe adapter <NUM> with the BOAS assembly <NUM> in a fully-assembled condition, for example, the probe cable <NUM> may be bent prior to installation of the probe <NUM> within the probe adapter <NUM>.

While the probe adapter <NUM> is described herein with respect to the BOAS assembly <NUM>, it should be understood that the probe adapter <NUM> may be used in connection with other structural components of the gas turbine engine <NUM> and for other data collection purposes. For example, the probe adapter <NUM> may be mounted to a case (e.g., a turbine case), a flow separator wall (e.g., a wall separating the core flow path <NUM> and the bypass flow path <NUM>), or another structure of the gas turbine engine <NUM> for the purpose of collecting NSMS or other data. For further example, the probe adapter <NUM> may be mounted to a structure of the gas turbine engine <NUM> along the core flow path <NUM>, for example, a combustor wall assembly of the combustor <NUM>, for the purpose of collecting core flow path fluid, combustion, and/or exhaust data.

Claim 1:
A probe adapter, comprising:
an adapter body (<NUM>) comprising a probe aperture (<NUM>) and a slot (<NUM>); characterised by
a driver (<NUM>) slidably mounted within the slot (<NUM>) and slidable between a first position and a second position substantially withdrawn from the probe aperture (<NUM>), the driver (<NUM>) comprising a first end (<NUM>) and a second end (<NUM>) opposite the first end (<NUM>), the first end (<NUM>) comprising a ramped recess (<NUM>) extending in a direction from the first end (<NUM>) toward the second end (<NUM>); and
a threaded fastener (<NUM>) configured to contact the second end (<NUM>) of the driver (<NUM>) so as to retain the driver (<NUM>) in the first position;
wherein, in the first position, the driver (<NUM>) is configured to retain a probe assembly (<NUM>) of a probe (<NUM>) within the probe aperture (<NUM>) and, in the second position, the driver (<NUM>) is configured to permit removal of the probe assembly (<NUM>) from the probe aperture (<NUM>).