Stator assembly for compressor in-plane rotor balancing and sealing in a gas turbine engine

Abstract

A stator assembly mounted about a rotor disk in a compressor of a gas turbine engine is accessed at mid-plane to enable access to the rotor disk (e.g., for trim balancing) via removable stator vanes without disassembly of the stator assembly and / or compressor casing. The stator assembly can include vane apertures aligned along a radial axis that retain removable stator vanes when inserted into the stator assembly and provide a radial path to the rotor disk when the removable stator vanes are removed. A casing access assembly can seal the removable stator vanes in place within the compressor casing when engaged and provide access to the removable stator vanes and a radial path through the compressor casing when disengaged. This enables trim balancing of a mid-plane compressor rotor assembly.

Description

TECHNICAL FIELD

[0001] Embodiments described herein relate generally to a stator assembly, and more particularly to a stator assembly that enables in-situ trim balancing and gas path flow sealing of a compressor rotor assembly at a midspan in a compressor in a gas turbine engine. BACKGROUND

[0002] In gas turbines, high vibration levels sometimes occur due to rotor imbalance, rotor fouling (e.g., dirt or other deposits on the rotor), blade and seal material defects due to rubbing, and foreign object damage (FOD). Typically, trim balancing of a midspan rotor assembly in a compressor requires at least partial disassembly (e.g., split) of the compressor case and removal of compressor blades to reach the balancing location below the blade platforms. As a result, the time, energy, and risk required for trim balancing of a midspan rotor assembly is high.

[0003] For example, U.S. Patent Publication No. 2008 / 0298970 discloses a shroud ring on a radially outer end of a rotating blade. U.S. Patent No. 2,972,441 discloses an adjustable stator vane with an inner shroud and an outer shroud. However, neither of these references provide a method of balancing and sealing a midspan rotor assembly in a compressor without disassembly of the compressor case. The present disclosure is intended to overcome one or more problems discovered by the inventors. SUMMARY

[0004] In embodiments, a stator assembly is disclosed that includes a seal ring including a seal ring aperture extending therethrough along a radial axis, wherein the seal ring is configured to be installed around a midspan trim balancing rotor disk, and wherein the seal ring aperture is configured to provide access to the midspan trim balancing rotor disk along the radial axis when the seal ring is installed around the midspan trim balancing rotor disk.

[0005] In an embodiment, a stator assembly is disclosed, comprising: an inner diameter ring assembly comprising a first vane aperture and a seal ring aperture aligned along a radial axis; an outer diameter ring assembly concentric with the inner diameter ring assembly and having a greater diameter than the inner diameter ring assembly, wherein the outer diameter ring assembly comprises a second vane aperture aligned with the seal ring aperture and the first vane aperture along the radial axis; a plurality of fixed stator vanes, each fixed stator vane comprising an airfoil extending between the inner diameter ring assembly and the outer diameter ring assembly; and a removable stator vane comprising a button configured to be seated within the first vane aperture, a platform configured to be seated within the second vane aperture, and an airfoil between the button and the platform, wherein, when the button is seated within the first vane aperture and the platform is seated within the second vane aperture, the airfoil extends along the radial axis between the inner diameter ring assembly and the outer diameter ring assembly, and wherein the removable stator vane is configured to be removed by pulling radially outward along the radial axis. BRIEF DESCRIPTION OF DRAWINGS

[0006] The details of an embodiment of the present disclosure, relating to its structure and operation, can be gleaned in part by studying the attached drawings, in which like reference numerals refer to like parts, and in which:

[0007] Figure 1 A view along a longitudinal axis of a stator assembly is shown in accordance with an embodiment;

[0008] Figure 2 A perspective view of a stator assembly is shown in accordance with an embodiment;

[0009] Figure 3 A perspective view of a removable stator vane is shown in accordance with an embodiment;

[0010] Figure 4 An exploded cross-sectional view of a portion of a stator assembly for receiving a removable stator vane is shown in accordance with an embodiment;

[0011] Figure 5 A close-up perspective view of a portion of a stator assembly with a mounted removable stator vane is shown in accordance with an embodiment;

[0012] Figure 6 A cross-sectional perspective view of an assembled housing passage assembly is shown in accordance with an embodiment;

[0013] Figure 7 An exploded perspective view of a housing passage assembly is shown in accordance with an embodiment;

[0014] Figure 8 A perspective view of a compressor housing assembly is shown in accordance with an embodiment;

[0015] Figure 9 A close-up perspective view of a portion of a compressor housing assembly that houses a stator assembly and a compressor rotor assembly is shown, in accordance with an embodiment;

[0016] Figure 10 A perspective view of a compressor rotor assembly is shown, in accordance with an embodiment;

[0017] Figure 11 A cross-sectional perspective view of a portion of a compressor housing assembly is shown, in accordance with an embodiment, with a removable stator vane seated in a stator assembly;

[0018] Figure 12 A cross-sectional exploded perspective view of a portion of a compressor housing assembly is shown, in accordance with an embodiment, with a housing passage assembly removed from a portion of the compressor housing assembly and a removable stator vane removed from a stator assembly; and

[0019] Figure 13 A cross-sectional view of a portion of a compressor housing assembly is shown, in accordance with an embodiment, including a mounted housing passage assembly and a stator assembly with a removable stator vane installed. DETAILED DESCRIPTION

[0020] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various embodiments and is not intended to represent the only embodiments in which the disclosure can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that embodiments of the invention can be practiced without these specific details. In some instances, well-known structures and components are shown in simplified form in order to avoid obscuring the subject matter of the present disclosure.

[0021] In accordance with an embodiment, Figure 1 A view along a longitudinal axis L of the stator assembly 100 is shown, and Figure 2 A perspective view of the stator assembly 100 is shown. Figure 1 A central radial axis R of the removable stator vane 400 described herein is also established. As shown, the stator assembly 100 is generally circular in the view along the longitudinal axis L. The stator assembly 100 includes an inner diameter ring assembly 200 and an outer diameter ring assembly 300 that is concentric with the inner diameter ring assembly 200 and has an inner radius that is greater than an outer radius of the inner diameter ring assembly 200, thereby encircling the inner diameter ring assembly 200. Both the inner diameter ring assembly 200 and the outer diameter ring assembly 300 can include a plurality of segments. For example, each of the inner diameter ring assembly 200 and the outer diameter ring assembly 300 can include two semi-circular segments that are joined to form the respective assembly. Alternatively, the inner diameter ring assembly 200 and / or the outer diameter ring assembly 300 can consist of a single segment or can include three or more segments.

[0022] The stator assembly 100 also includes at least one removable stator vane 400 and a plurality of fixed stator vanes 500 (e.g., including fixed stator vanes 500A, 500B, and 500C as representative). The removable stator vane 400 and the fixed stator vanes 500 each include an airfoil extending radially between the inner diameter ring assembly 200 and the outer diameter ring assembly 300. As shown, a center of the removable stator vane 400 extends along the radial axis R. In embodiments, the stator assembly 100 consists of only a single removable stator vane 400. In general, the removable stator vane 400 and the fixed stator vanes 500 are equally spaced around an entire circumference of the stator assembly 100.

[0023] Figure 3 A perspective view of the removable stator vane 400 is shown, according to an embodiment. The removable stator vane 400 can include a button 410, an airfoil 420, a platform 430, a detent 440, a stem 450, and a knob 460. Each of these components of the removable stator vane 400 will be described in more detail below.

[0024] Figure 4 An exploded cross-sectional view of a portion of the stator assembly 100 receiving the removable stator vane 400 is shown, according to an embodiment. The inner diameter ring assembly 200 includes a seal ring 210 and a shroud ring 220. The outer diameter ring assembly 300 includes an inner ring 310 and an outer ring 320.

[0025] In embodiments, the seal ring 210 includes a seal ring aperture 212 through the seal ring 210 along the radial axis R. The seal ring aperture 212 can be sized and shaped to allow for trim balance or monitoring gaspath hardware health (e.g., balance weight hole manufacturing tools, balance weight insertion and / or extraction tools, borescopes, etc.) for trim balance pass-through. Similarly, the shroud ring 220 can include a shroud ring vane aperture 222 through the shroud ring 220 along the same radial axis R as the seal ring aperture 212. The shroud ring vane aperture 222 can be configured in size and shape to receive the button 410 of the removable stator vane 400. For example, a profile of the shroud ring vane aperture 222 can correspond to a profile of the button 410 to form an interference fit with the button 410. The profile of the shroud ring vane aperture 222 can also be configured in size and shape to completely enclose the profile of the seal ring aperture 212 therein, such that any object capable of passing through the seal ring aperture 212 is also capable of passing through the shroud ring vane aperture 222 when the removable stator vane 400 is removed. However, the profile of the seal ring aperture 212 can be sized and / or shaped to prevent unseated balance weights from passing to impact the shroud ring 220.

[0026] In Figure 4In the illustrated embodiment, the seal ring 210 and shroud ring 220 are generally U-shaped in cross-section. For example, the seal ring 210 can include a base 216 with a pair of sidewalls 218A and 218B extending radially outward from the base 216 on opposite sides of the base 216, and the shroud ring 220 can include a base 226 with a pair of sidewalls 228A and 228B extending radially inward from the base 226 on opposite sides of the base 226. The shroud ring 220 can have an inner width on an axis parallel to the longitudinal axis L that is equal to or greater than an outer width of the seal ring 210 on an axis parallel to the longitudinal axis L. Thus, the shroud ring 220 fits over the seal ring 210 to wrap the seal ring 210 therein. Additionally, the sidewalls 218A and 218B of the seal ring 210 can include fastener holes 214, and the sidewalls 228A and 228B of the shroud ring 220 can include corresponding fastener holes 224 configured to align with the fastener holes 214 when the seal ring 210 is wrapped by the shroud ring 220. Thus, a fastener 230 can be inserted through the aligned fastener holes 224 and 214 along an axis parallel to the longitudinal axis L, thereby mounting the shroud ring 220 to the seal ring 210 to secure the seal ring 210 within the shroud ring 220. Further, the shroud ring 220 can include a plurality of apertures (not shown) along the radial axis R that are sized and shaped to receive one end of each stationary stator vane 500 therethrough, thereby securing the radially inner end of each stationary stator vane 500 within the cavity between the shroud ring 220 and the seal ring 210.

[0027] In embodiments, the inner ring 310 and outer ring 320 are configured to be fastened to one another to form the outer diameter ring assembly 300. For example, the inner ring 310 can be generally U-shaped, and the outer ring 320 can be positioned (e.g., aligned with ring features, spot welded, brazed, etc.) on the inner side of the inner ring 310. The inner ring 310 can include inner ring vane apertures 312 (visible in Figure 12 FIG. 4), and the outer ring 320 can include outer ring vane apertures 322. The inner ring vane apertures 312 and the outer ring vane apertures 322 can be configured in size and shape to receive the platform 430, the airfoil 420, and the button 410 therethrough. Additionally, the outer ring vane apertures 322 can be configured in size and shape to prevent the stop 440 from passing therethrough. For example, the outer ring vane apertures 322 can have a profile that corresponds to a profile of the platform 430 to form an interference fit with the platform 430. The inner ring vane apertures 312 can be configured in size and shape to prevent the platform 430 from passing therethrough, or can have the same profile as the outer ring vane apertures 322 (e.g., to form an interference fit with the platform 430).

[0028] The profile of the inner ring vane aperture 312 can be configured in size and shape to completely encompass the profile of the shroud ring vane aperture 222 (and thus, the seal ring aperture 212) such that any object capable of passing through the shroud ring vane aperture 222 is also capable of passing through the inner ring vane aperture 312. Similarly, the profile of the outer ring vane aperture 322 can be configured in size and shape to completely encompass the profile of the inner ring vane aperture 312 (and thus, the shroud ring vane aperture 222 and the seal ring aperture 212) such that any object capable of passing through the inner ring vane aperture 312 is also capable of passing through the outer ring vane aperture 322. As used herein, a profile that “encompasses” another profile can be any profile that is equal to or larger than the other profile.

[0029] The removable stator vane 400 can be inserted along the radial axis R through the outer ring vane aperture 322, the inner ring vane aperture 312, and the shroud ring vane aperture 222 such that the button 410 is disposed within the shroud ring 220 and the platform 430 is disposed within the outer ring 320 and the inner ring 310. The removable stator vane 400 is prevented from moving radially inward beyond the seal ring 210 at least because the button 410 cannot pass through the seal ring aperture 212 and / or the stop 440 cannot pass through the outer ring vane aperture 322. The profile of the button 410 can be sized and shaped to match the profile of the shroud ring aperture 222 such that the button 410 completely fills the shroud ring aperture 222 when the removable stator vane 400 is disposed within the stator assembly 100. Fluid passing along the radial axis R from one side of the seal ring 210 to the other side of the seal ring 210 is restricted by the button 410 covering the seal ring aperture 222.

[0030] The removable stator vane 400 can be removed from the stator assembly 100 by pulling it outward along the radial axis R. For example, a technician can grasp the knob 460 of the removable stator vane 400 and pull the removable stator vane 400 completely out such that the button 410 passes through the shroud ring vane aperture 222, the inner ring vane aperture 312, and the outer ring vane aperture 322, thereby exposing these apertures. Thus, when the removable stator vane 400 has been removed from the stator assembly 100, there is a radial path P to the interior space of the stator assembly 100 through the outer ring vane aperture 322, the inner ring vane aperture 312, the shroud ring vane aperture 222, and the seal ring aperture 212. Thus, by removing the removable stator vane 400, components of larger assemblies within the space can be accessed through the stator assembly 100 via the radial path P.

[0031] One end of each of the plurality of stationary stator vanes 500 can protrude through a respective vane aperture in the shroud ring 220, and an opposite end of each of the plurality of stationary stator vanes 500 can protrude through a respective vane aperture in the inner ring 310 and the outer ring 320 of the outer diameter ring assembly 300. Thus, one end of each stationary stator vane 500 is seated within the cavity of the inner diameter ring assembly 200, and the other end of each stationary stator vane 500 is seated within the cavity of the outer diameter ring assembly 300. It should be appreciated that each vane aperture is sized and shaped to receive a respective end of each stationary stator vane 500 therethrough, and each stationary stator vane 500 and its respective vane aperture can be identical to one another. Additionally, the airfoil of each stationary stator vane 500 can be identical to the airfoil 420 of the removable stator vane 400. The stationary stator vanes 500 can differ from the removable stator vane 400 in that they do not have the button 410, the platform 430, the detent 440, the stem 450, and the knob 460. The stationary stator vanes 500 can be fixed within the stator assembly 100 so long as the stator assembly 100 is assembled. In other words, the stationary stator vanes 500 can be removable, but only by disassembling the stator assembly 100. Thus, it should be appreciated that as used herein, the term “stationary” in the phrase “stationary stator vane” means fixed in place so long as the stator assembly 100 is fully assembled, and the term “removable” in the phrase “removable stator vane” means removable even when the stator assembly 100 remains fully assembled.

[0032] Figure 5 A close-up perspective view of a portion of the stator assembly 100 that houses the removable stator vane 400 is shown, according to an embodiment. As shown, when the removable stator vane 400 is seated within the stator assembly 100 (i.e., the airfoil 420 is positioned between the inner diameter ring assembly 200 and the outer diameter ring assembly 300), the button 410 of the removable stator vane 400 is seated within the shroud ring vane aperture 222. The shroud ring vane aperture 222 can be sized and shaped to precisely match the outer profile of the button 410, thereby forming an interference fit with the button 410 such that fluid communication through the shroud ring vane aperture 222 is minimal or nonexistent (e.g., into the cavity between the shroud ring 220 and the seal ring 210) when the button 410 is seated within the shroud ring vane aperture 222. Additionally, when the removable stator vane 400 is seated within the stator assembly 100, the platform 430 (not visible in FIG. 4) is seated in the outer diameter ring assembly 300 within the cavity between the inner ring 310 and the outer ring 320, and the detent 440 rests on the radially outer surface of the outer ring 320 of the outer diameter ring assembly 300. Installation of the removable stator vane 400 along the radial path P can be controlled by the detent 440 located on the outer ring 320. Figure 5

[0033] According to an embodiment, Figure 6 ​A cross-sectional perspective view of the housing pass-through assembly 600 is shown, and Figure 7 An exploded perspective view of the housing pass-through assembly 600 is shown. As shown, the housing pass-through assembly 600 has a proximal end and a distal end, and includes a cap 610, a neck 620, a spring 630, an impact plate 640, and a retaining ring 650. The housing pass-through assembly 600 can fit over the knob 460 of the removable stator vane 400 to hold it in place while the removable stator vane 400 is seated in the stator assembly 100. Accordingly, the housing pass-through assembly 600 should be sized and shaped to receive the knob 460 therein. For example, the inner diameter and profile of the open end of the neck 620 should be configured to encompass the outer diameter and profile of the knob 460.

[0034] The cap 610 can be hexagonal or other polygonal in profile to facilitate gripping by a tool (e.g., a wrench, fingers, etc.) for rotation (e.g., to tighten and loosen the housing pass-through assembly 600). The cap 610 can be integral with the neck 620, e.g., as a single unitary piece of material. The spring 630 is seated at the proximal end of the internal cavity 622 in the cap 610 and the neck 620. The impact plate 640 is seated on the spring 630, closer to the distal end of the internal cavity 622 than the spring 630. The impact plate 640 can have a diameter that is equal to or greater than the diameter of the spring 630, such that it completely covers the spring 630 from the distal end of the neck 620. When a force that exceeds the force of the spring 630 is applied to the impact plate 640, the spring 630 is compressed in the proximal direction. The retaining ring 650 can fit within a groove in the inner wall of the neck 620, near the distal end of the internal cavity 622 of the neck 620. The inner diameter of the retaining ring 650 is less than the inner diameter of the groove and less than the diameter of the impact plate 640, such that the retaining ring 650 protrudes out of the groove, thereby preventing the impact plate 640 from sliding out of the internal cavity 622 of the housing pass-through assembly 600.

[0035] In use, the housing pass-through assembly 600 fits over the knob 460 of the removable stator vane 400. Accordingly, when the housing pass-through assembly 600 is secured to the housing (e.g., by rotation that engages corresponding threads, thereby mating the housing pass-through assembly 600 with the housing) around the stator assembly 100, the top of the knob 460 pushes against the impact plate 640, thereby compressing the spring 630. In turn, the force of the compressed spring 630 is transmitted through the impact plate 640 to the knob 460 of the removable stator vane 400, thereby sealing the removable stator vane 400 in place within the stator assembly 100 to prevent the removable stator vane 400 from moving in the radial direction.

[0036] Industrial applicability

[0037] According to embodiments, Figure 8 A perspective view of the compressor housing assembly 700 is shown, and Figure 9A close-up perspective view of a portion of the compressor housing assembly 700 that houses the stator assembly 100 is shown. As shown, the compressor housing assembly 700 includes the intermediate compressor housing 710 shown in perspective view in Figure 9 The housing passage assembly 600 is engaged with a housing boss 720 that defines a housing orifice (e.g., the housing orifice 722 shown in Figure 11 ) through the intermediate compressor housing 710 along the radial axis R, thereby sealing the housing orifice from the external environment of the intermediate compressor housing 710. The housing passage assembly 600 can be engaged with the housing boss 720 by any releasable engagement means. For example, threads around the exterior of the neck 620 can be engaged with threads around the interior of the housing orifice (e.g., the housing orifice 722) of the housing boss 720.

[0038] Figure 10 A perspective view of a compressor rotor assembly 800 according to an embodiment is shown. As shown, the mid-plane trim balance rotor disk 810 is positioned near the middle portion of the compressor rotor assembly 800 between two rows of rotating blades 820 (e.g., a forward row of rotating blades 820A and a rearward row of rotating blades 820B are shown). In embodiments, the stator assembly 100 is mounted around the mid-plane trim balance rotor disk 810 and provides access to the mid-plane trim balance rotor disk 810 via a radial path P (see Figure 4 ).

[0039] Figure 11 Both 12 show cross-sectional perspective views of a portion of the intermediate compressor housing 710 that houses the stator assembly 100 according to an embodiment. In Figure 11 , the removable stator vane 400 is seated within the stator assembly 100 and the housing passage assembly 600 is engaged with the housing boss 720 of the intermediate compressor housing 710. In Figure 12 , the removable stator vane 400 has been removed from the stator assembly 100 and the housing passage assembly 600 has been disengaged from the housing boss 720 of the intermediate compressor housing 710.

[0040] As Figure 11As shown in FIG. 6, the neck 620 of the housing passage assembly 600 can be releasably secured within the housing orifice 722 of the housing boss 720. The spring 630 applies a force through the impact plate 640 to the knob 460 of the removable stator vane 400 to prevent radial movement of the removable stator vane 400. In other words, when installed, the removable stator vane 400 is prevented from moving radially outward from the outer ring 320 by the load created by the installed housing passage assembly 600. As a result, the button 410 remains seated within the shroud ring vane orifice 222, thereby covering the seal ring orifice 212 and preventing fluid flowing over the airfoil 420 from leaking through the seal ring orifice 212 to the mid-plane trim balance rotor disk 810. Similarly, the platform 430 remains seated within the outer diameter ring assembly 300, including the inner ring vane orifice 312 and the outer ring vane orifice 322. Notably, the stop 440 can prevent the removable stator vane 400 from being pushed too far radially inward into the radial path P.

[0041] As shown in FIG. 6, the neck 620 of the housing passage assembly 600 can be releasably secured within the housing orifice 722 of the housing boss 720. The spring 630 applies a force through the impact plate 640 to the knob 460 of the removable stator vane 400 to prevent radial movement of the removable stator vane 400. In other words, when installed, the removable stator vane 400 is prevented from moving radially outward from the outer ring 320 by the load created by the installed housing passage assembly 600. As a result, the button 410 remains seated within the shroud ring vane orifice 222, thereby covering the seal ring orifice 212 and preventing fluid flowing over the airfoil 420 from leaking through the seal ring orifice 212 to the mid-plane trim balance rotor disk 810. Similarly, the platform 430 remains seated within the outer diameter ring assembly 300, including the inner ring vane orifice 312 and the outer ring vane orifice 322. Notably, the stop 440 can prevent the removable stator vane 400 from being pushed too far radially inward into the radial path P. Figure 12 Figure 1 As shown in FIG. 6, the neck 620 of the housing passage assembly 600 can be releasably secured within the housing orifice 722 of the housing boss 720. The spring 630 applies a force through the impact plate 640 to the knob 460 of the removable stator vane 400 to prevent radial movement of the removable stator vane 400. In other words, when installed, the removable stator vane 400 is prevented from moving radially outward from the outer ring 320 by the load created by the installed housing passage assembly 600. As a result, the button 410 remains seated within the shroud ring vane orifice 222, thereby covering the seal ring orifice 212 and preventing fluid flowing over the airfoil 420 from leaking through the seal ring orifice 212 to the mid-plane trim balance rotor disk 810. Similarly, the platform 430 remains seated within the outer diameter ring assembly 300, including the inner ring vane orifice 312 and the outer ring vane orifice 322. Notably, the stop 440 can prevent the removable stator vane 400 from being pushed too far radially inward into the radial path P. Figure 4

[0042] Figure 13 ​​A cross-sectional view of a portion of a compressor including a stator assembly 100 is shown in accordance with an embodiment. As shown, the seal ring aperture 212 provides access to the mid-plane trim balance rotor disk 810. This access enables one or more trim balance weight holes 812 to be created (e.g., drilled) through the circumference of the mid-plane trim balance rotor disk 810 along the radial axis R. The trim balance weight holes 812 can be threaded to mate with corresponding threads on a trim balance solution (e.g., a weight). It should be appreciated that, typically, when the mid-plane trim balance rotor disk 810 is first installed, it will not include the trim balance weight holes 812. After installation and without the need to disassemble the compressor housing assembly 700, one or more trim balance weight holes 812 can be created via the radial path P, thereby enabling the installation of a trim balance solution in situ. In other words, the radial path P provides line-of-sight access to the mid-plane trim balance rotor disk 810, which enables the application of a rotor assembly trim solution to restore balance to the compressor rotor assembly 800, for example, after a gas turbine rotor assembly has been balanced during installation and the gas turbine has begun operation.

[0043] In an embodiment, the labyrinth seal 814 prevents fluid communication between the external environment of the stator assembly 100 and the trim balance weight holes 812. In other words, the labyrinth seal 814 prevents fluid from passing from one side of the seal ring 210 to the other side of the seal ring 210 along the longitudinal axis L of the stator assembly 100.

[0044] In an embodiment, the stator assembly 100 is used in a compressor in combination with the housing access assembly 600. In an operational state of the compressor, the removable stator vane 400 is held in place in the stator assembly 100 by the housing access assembly 600 (e.g., prevents or reduces at least radial outward movement), the interaction of the stop 440 with the outer ring 320 (e.g., prevents or reduces at least radial inward movement), the interaction of the platform 430 with the outer ring aperture 322 and the inner ring aperture 312 (e.g., prevents or reduces at least longitudinal movement), and the interaction of the button 410 with the shroud ring aperture 222 (e.g., at least prevents or reduces longitudinal movement). The housing aperture 722, the outer ring vane aperture 322, the inner ring vane aperture 312, the shroud ring vane aperture 222, and the seal ring aperture 212 are sealed by these interactions to prevent fluid communication therethrough.

[0045] During trim balancing of the compressor, the housing access assembly 600 can be removed to expose the removable stator vane 400. The removable stator vane 400 can then be pulled radially outward from the stator assembly 100 via the radial path P through the housing aperture 722, the outer ring vane aperture 322, the inner ring vane aperture 312, the shroud ring vane aperture 222, and the seal ring aperture 212 to expose the mid-plane trim balance rotor disk 810.

[0046] Accordingly, a technician can create one or more trim balance weight holes 812 around the circumference of the mid-plane trim balance rotor disk 810 to facilitate trim balancing of the compressor rotor assembly 800. The compressor rotor assembly 800 can be rotated or “whirled” while the stator assembly 100 remains stationary to align a plurality of positions around the circumference of the mid-plane trim balance rotor disk 810 with the radial axis R. The trim balance weight holes 812 can be created at each of these positions around the circumference of the mid-plane trim balance rotor disk via the line-of-sight access provided via the radial path P, and trim balance weights can be inserted into each of the created trim balance weight holes 812. Each trim balance weight hole 812 can be threaded to engage with corresponding threads on a respective trim balance weight. The number of trim balance weight holes 812 can be determined according to any relevant trim balancing objectives or requirements.

[0047] Notably, the space between the inner diameter ring assembly 200 and the outer diameter ring assembly 300, including the airfoils of the removable stator vane 400 and the fixed stator vane 500, is protected from intrusion by foreign objects, such as unseated balance weights from the mid-plane trim balance rotor disk 810. For example, an unseated balance weight that does not enter the seal ring aperture 212 will be captured between the seal ring 210 and the mid-plane trim balance rotor disk 810. An unseated balance weight that enters the seal ring aperture 212 will be captured between the seal ring 210 and the shroud ring 220. The presence of the button 410 of the removable stator vane 400 within the shroud ring aperture 222 will prevent such objects from passing through the shroud ring aperture 222. In other words, the inner diameter ring assembly 200 provides access to the mid-plane trim balance rotor disk 810 while also providing a gas path flow seal and foreign object damage (FOD) protection.

[0048] It will be appreciated that the materials for the various components of the various embodiments described herein can be selected for the particular application for which the components or embodiments are used. Those of ordinary skill in the art will appreciate how to select these materials. As an illustrative, non-limiting example, the components can be made from various forms of steel. For example, the seal ring 210, the shroud ring 220, the outer diameter ring assembly 300, the removable stator vane 400, the fixed stator vane 500, the mid-plane trim balance rotor disk 810, and / or the labyrinth seal 814 can be made from 410-grade stainless steel. The fastener 230 can be made from alloy steel. The cap 610 can be made from 316-grade stainless steel, and the spring 630, the impact plate 640, and the retaining ring 650 can be made from 302-grade stainless steel. The intermediate compressor housing 710 can be made from CA6NM stainless steel, and the rotating vane row 820 can be made from 17-4 stainless steel.

[0049] The disclosed embodiments enable a gas turbine engine to be balanced in situ with the compressor case. Access to the rotating components from outside the compressor case through a radial path P can be very efficient and less costly. Trim balancing can be achieved by adding and / or removing trim weights to the mid-plane trim balance of the rotor disk 810 to reduce unwanted vibrations, thereby increasing the reliability and service life of engine components (e.g., blades, bearings, seals, etc.).

[0050] It is to be understood that the benefits and advantages described above can relate to one embodiment or can relate to several embodiments. Features described in connection with one embodiment can be used in conjunction with other embodiments. Any

[0051] The foregoing detailed description has been presented for purposes of clarity and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and the description was selected and presented in order to explain the premises of the described embodiments and the principles that they embody. The described embodiments are not limited to use in conjunction with a specific type of rotor assembly. Thus, although the present embodiments are depicted and described as being implemented in a compressor, it is appreciated that it can be implemented in a variety of other types of machines and in a variety of other systems and environments. Moreover, there is no intent to be bound by any theory presented in any preceding section. It is also to be understood that the illustrations can include exaggerated dimensions and graphical representations to better illustrate the referenced items shown, and are not to be considered limiting unless so explicitly stated.

Claims

1. A stator assembly for use in a gas turbine engine having a mid-plane counterbalanced rotor disk, the stator assembly comprising: an inner diameter ring assembly including a seal ring and a shroud ring, the seal ring including a seal ring aperture extending therethrough along a radial axis, the shroud ring mounted about the seal ring, wherein the shroud ring includes a shroud ring vane aperture aligned with the seal ring aperture along the radial axis, an outer diameter ring assembly concentric with the inner diameter ring assembly and having a greater diameter than the inner diameter ring assembly, wherein the outer diameter ring assembly includes a vane aperture aligned with the shroud ring vane aperture and the seal ring aperture along the radial axis; a plurality of stationary stator vanes, each stationary stator vane including an airfoil extending between the inner diameter ring assembly and the outer diameter ring assembly; and a removable stator vane configured to be seated within the shroud ring vane aperture in the shroud ring and the vane aperture in the outer diameter ring assembly such that an airfoil of the removable stator vane extends between the inner diameter ring assembly and the outer diameter ring assembly along the radial axis, wherein the removable stator vane is configured to be removed by pulling radially outward along the radial axis; wherein the seal ring is configured to be mounted about the mid-plane counterbalanced rotor disk, and wherein the seal ring aperture is configured to provide access to the mid-plane counterbalanced rotor disk along the radial axis when the seal ring is mounted about the mid-plane counterbalanced rotor disk.

2. The stator assembly of claim 1, wherein a profile of the shroud ring vane aperture encompasses a profile of the seal ring aperture.

3. The stator assembly of claim 1, wherein the outer diameter ring assembly includes an inner ring and an outer ring, wherein the inner ring includes an inner ring vane aperture aligned with the shroud ring vane aperture and the seal ring aperture along the radial axis, and wherein the outer ring includes an outer ring vane aperture aligned with the inner ring vane aperture, the shroud ring vane aperture, and the seal ring aperture along the radial axis.

4. The stator assembly of claim 3, wherein a profile of the inner ring vane aperture encompasses a profile of the shroud ring vane aperture, and wherein a profile of the outer ring vane aperture encompasses a profile of the inner ring vane aperture.

5. The stator assembly of claim 1, wherein the removable stator vane includes: a button configured to be seated within the shroud ring vane aperture and to prevent fluid communication through the shroud ring vane aperture; and a platform configured to be seated within a vane aperture in the outer diameter ring assembly when the button is seated within the shroud ring vane aperture. ​ 6. The stator assembly of claim 5, wherein the removable stator vane further comprises a stop positioned radially outward of the platform and having a larger profile than a vane aperture of the outer diameter ring assembly, thereby preventing any portion of the removable stator vane radially outward of the platform from being inserted through a vane aperture in the outer diameter ring assembly.

7. The stator assembly of claim 6, wherein the removable stator vane further comprises: a stem positioned radially outward of the stop; and a knob positioned radially outward of the stem.

8. The stator assembly of claim 7, further comprising a housing passage assembly configured to be installed around the knob of the removable stator vane, wherein the housing passage assembly comprises a spring in an inner cavity of the housing passage assembly, wherein the inner cavity of the housing passage assembly is configured to receive the knob of the removable stator vane therein, and wherein the spring is configured to exert a radially inward force on the knob of the removable stator vane when the knob of the removable stator vane is received within the inner cavity of the housing passage assembly upon installation of the housing passage assembly. ​

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