Systems and methods for attaching a probe to a casing of a gas turbine engine

A system for attaching a probe to a casing of a gas turbine engine is disclosed. The system may include a probe receptacle attachable to the casing. The probe receptacle may include an internal bore, a bayonet slot, a spring disposed within the internal bore adjacent to the bayonet slot, and a sealing surface within the internal bore. The system also may include a probe attachment assembly disposed about the probe and configured to engage the probe receptacle. The probe attachment assembly may include at least one bayonet positionable within the bayonet slot and a seal positionable adjacent to the sealing surface within the internal bore.

FIELD OF THE DISCLOSURE

The disclosure generally relates to a probe and more particularly relates to systems and methods for attaching a probe to a casing of a gas turbine engine.

BACKGROUND

Attaching probes to a casing of a gas turbine engine can be problematic, particularly when threading the probe into the casing where limited space is available and/or the line of sight is obstructed. For example, threading a probe into a threaded probe receptacle can be very difficult to do if the probe is very long. Anytime a threaded connection is used, there is a possibility of cross-threading. If cross-threading occurs in the probe receptacle, it may not be accessible for repair. Similarly, there is a possibility of the threads seizing. If seizing occurs, the probe may be indefinitely stuck in the probe receptacle and may not be accessible for repair. Threaded connections can also back-out, causing structural issues and/or leaks. Moreover, with threaded connections, it is often difficult to precisely position the probe.

SUMMARY

Some or all of the above needs and/or problems may be addressed by certain embodiments disclosed herein. In one embodiment, a system for attaching a probe to a casing of a gas turbine engine is disclosed. The system may include a probe receptacle attachable to the casing. The probe receptacle may include an internal bore, a bayonet slot, a spring disposed within the internal bore, and a sealing surface within the internal bore. The system also may include a probe attachment assembly disposed about the probe and configured to engage the probe receptacle. The probe attachment assembly may include at least one bayonet positionable within the bayonet slot and a seal positionable adjacent to the sealing surface within the internal bore.

In another embodiment, a system for attaching one or more instruments to a casing of a gas turbine engine is disclosed. The system may include a probe. The system also may include a probe receptacle attachable to the casing. The probe receptacle may include an internal bore, a bayonet slot, a spring disposed within the internal bore, and a sealing surface within the internal bore. The system also may include a probe attachment assembly disposed about the probe and configured to engage the probe receptacle. The probe attachment assembly may include at least one bayonet positionable within the bayonet slot and a seal positionable adjacent to the sealing surface within the internal bore.

In another embodiment, a system for attaching a probe to a casing of a gas turbine engine is disclosed. The system may include a probe receptacle attachable to the casing. The probe receptacle may include a casing seal portion attachable to the casing, a main body attachable to the casing seal portion, and a cap attachable to the main body. The cap may include a bayonet slot and a spring. The main body may include a sealing surface. The system also may include a probe attachment assembly disposed about the probe and configured to engage the probe receptacle. The probe attachment assembly may include a busing and seal disposed about the probe. The bushing may include at least one bayonet positionable within the bayonet slot. The seal may be positionable adjacent to the sealing surface.

Other features and aspects of the systems and methods disclosed herein will be apparent or will become apparent to one with skill in the art upon examination of the following figures and the detailed description. All other features and aspects, as well as other system, method, and assembly embodiments, are intended to be included within the description and are intended to be within the scope of the accompanying claims.

DETAILED DESCRIPTION

FIGS. 1-9schematically depict various embodiments of a system100for attaching a probe102to a casing104of a gas turbine engine106. In some instances, the probe102may be positioned downstream of a combustor of the gas turbine engine106. The system100may be used at any location about the gas turbine engine106.

Generally speaking, the system100may include a probe receptacle108and a probe attachment assembly110. The probe receptacle108may be attached to the casing104of the gas turbine engine106. In some instances, the probe receptacle108may be embedded within the casing104. As depicted inFIGS. 2 and 3, the probe receptacle108may include a main body112, a casing seal portion114, and/or a cap116. The cap116may be attached to the main body112opposite the casing seal portion114. The cap116and casing seal portion114may be threaded or the like to the main body112. Moreover, the cap116, the main body112, and/or the casing seal portion114may be attached to the casing104of the gas turbine engine106. For example, the cap116, the main body112, and/or the casing seal portion114may be threaded into the casing104. In some instances, the probe receptacle108may be embedded within the casing104or formed as an integral component of the casing104. The casing seal portion114may form a seal between the probe receptacle108and the casing104of the gas turbine engine106.

As depicted inFIG. 4, the probe receptacle108may include an internal bore118. The internal bore118may extend through the cap116, the main body112, and/or the casing seal portion114. The internal bore118may provide a passageway for the probe102and the probe attachment assembly110to move through the probe receptacle108. The size and shape of the internal bore118may correspond to the probe102and/or the probe attachment assembly110.

The probe receptacle108may include a bayonet slot120. In some instances, the bayonet slot120may be disposed within the cap116. The bayonet slot120may include multiple portions that form a path along the cap116. For example, as depicted inFIGS. 8 and 9, the bayonet slot120may include a first portion122extending from an opening124in a substantially axial direction relative to the probe102. At a bottom of the first portion122, the bayonet slot120may include a second portion126in the circumferential direction. The bayonet slot120also may include a third portion128, such as a notch, at and end of the second portion126that is oriented axially in the opposite direction of the first portion122. For example, the bayonet slot120may be generally J-shaped. The length of the third portion128may be equal to or less than a diameter of a bayonet. In other instances, the bayonet slot120may be generally L-shaped. The bayonet slot120may be any shape. In some instances, the third portion128may be omitted, and an external anti-rotation means may be used. For example, the probe102may be secured on the outside of the casing to prevent rotation.

Referring back toFIG. 4, the probe receptacle108may include a spring130disposed within the internal bore118adjacent to the bayonet slot120. In some instances, the spring130may be positioned within the cap116. A bottom portion132of the spring120may abut an upper lip134of the main body112. In some instances, a washer136may be disposed within the internal bore118adjacent to the spring130and the bayonet slot120. For example, the washer136may be positioned on a top portion138of the spring130. In some instances, the washer may be omitted. In some instances, the spring130may be omitted. As described below, the bellows seal150may act as a spring when compressed. In this manner, the bellows seal150may include enough spring stiffness to provided suitable resistance on the bayonet146.

The probe receptacle108may include a sealing surface140within the internal bore118. In some instances, the sealing surface140may be a lip142within the main body112.

As depicted inFIGS. 5-7, the probe attachment assembly110may be disposed about the probe102. That is, the various components of the probe attachment assembly110may be attached to the probe102. For example, the probe attachment assembly110may be threaded onto the probe102. The probe attachment assembly110may be inserted into the probe receptacle108via the internal bore118and rotated to secure the probe102in place.

The probe attachment assembly110may include a bushing144disposed about the probe102. The bushing144may include at least one bayonet146. The bayonet146may be a protrusion or the like extending outward from the bushing144. In some instances, the at least one bayonet146may include two bayonets spaced180degrees apart. Any number of bayonets may be used herein. The bayonet146may be positioned within the bayonet slot120. That is, for each bayonet146, there may be a corresponding bayonet slot120. The spring130may maintain the bayonet146within the bayonet slot120. Moreover, the bayonet slot120may be shaped to provide tactile responses based on one or more locations of the bayonet146within the bayonet slot120. For example, when the bayonet146enters the third portion128of the bayonet slot120(i.e., the notch), an operator may feel a tactile response due to the spring130applying force on the bayonet146and forcing the bayonet146into the notch. The spring130may maintain the bayonet146within the notch until a sufficient counter force is applied.

The probe attachment assembly110also may include and a seal148. The seal148may be positioned adjacent to the sealing surface140within the internal bore118. That is, the seal148may engage the lip142within the main body112. In this manner, the seal148may form a seal at the sealing surface140within the internal bore118. In some instances, the seal may be a bellows seal150. For example, the bellows seal150may be a corrugated sheet metal part that compresses under load forming a seal. Other types of seals may be used herein. As noted above, the bellows seal150may act as a spring to keep the bayonet146within the slot120.

The probe attachment assembly110further may include a handle152for installing the probe102into the probe receptacle108. The handle152may be attachable to the probe102. The handle152may be application specific. That is, the size and shape of the handle152may vary. For example, the handle152may be configured to pass through the outer casing of the gas turbine engine for attaching the probe to the inner casing of the gas turbine engine. The handle152may facilitate a user inserting and/or removing the probe102from the probe receptacle108. The handle152also may facilitate an operator rotating the probe102within the probe receptacle108. Moreover, the handle152can be locked in place, thereby preventing rotation of the probe102, if, for example, the third portion128of the slot120is omitted. Anti-rotation may prevent unintended disengagement of the probe102from the probe receptacle108.

In use, the probe102is inserted into the probe receptacle108and rotated to lock it in place. During the insertion and rotation of the probe102, the bellows seal150may engage the sealing surface140to prevent leakage around the probe102. The probe102may be removed by rotating it in the opposite direction and pulling it out.

As the probe102is inserted into the probe receptacle108, an operator may rotate the probe102until the bayonet146finds the opening124to the bayonet slot120so that the bayonet slot120may capture the bayonet146. This operation can be done blindly, i.e., strictly by feel. Once the bayonet146is initially positioned in the bayonet slot120, the operator may push down on the probe102in the axial direction to overcome the spring130in the probe receptacle108. In some instances, the spring rate of the spring130may be high enough to prevent accidental (or unintended) disengagement but also low enough that the operator can overcome the spring130during installation and removal.

The operator may push down on the probe102until the bayonet146bottoms out in the first portion122of the bayonet slot120. The operator may then turn the probe102until the bayonet146reaches the end of the second portion126of the bayonet slot120. The operator may then remove pressure on the probe handle152, allowing the spring130to drive the bayonet146into the third portion128(i.e., the notch) of the bayonet slot120. Once seated in the notch, the bayonet146is captured and the probe102cannot move axially or circumferentially (unless an external force on the probe102is sufficient to overcome the force applied by the spring130).

During installation, when the operator pushes on the probe102axially with the bayonet146in the first portion122of the bayonet slot120, the bellows seal150makes contact with sealing surface140. As a result, the bellows seal150forms a seal about the probe102within the probe receptacle108, preventing leakage of gas. Once the bayonet146is locked in the notch of the bayonet slot120, the bellows seal150remains in contact with the sealing surface140.

When removing the probe102, the operator reverses the order of operations discussed above. It is noted that if the probe receptacle108is threaded into a casing104, the direction in which the probe102is turned (clockwise or counterclockwise) is set such that the removal of the probe102may tighten the probe receptacle108into the casing104. This prevents accidental loosening of the probe receptacle108.

The system100disclosed herein is generally referred to as a “quick connect/disconnect” system. In some instances, the system100enables the probe102to be installed deep inside a cavity of the gas turbine engine106in which tools, such as wrenches or the like, cannot be used. In addition, the system100forms a seal about the probe102during installation. Moreover, the system100enables an operator to install and/or remove the probe102blindly. That is, installation and/or removal of the probe102can be completed by feel.

In some instances, gas turbine engines106may include multiple casing104. For example, some gas turbine engines106include an outer casing and an inner casing, which may be difficult to access due to space restrictions. The system100disclosed herein enables the installation and/or removal of the probe102in the inner casing. For example, the handle152may pass through a small access port in the outer casing so that the probe102may be inserted into and/or removed from the probe receptacle108attached to the inner casing.

The system100eliminates cross-threading and/or seizing of the probe102in the probe receptacle108. Also, the system100provides a positive locking mechanism that prevents the probe102from backing out. Further, the system100enables for precise positioning of the probe102in the axially direction. The probe102can be quickly removed for inspection and reinstalled.

Although specific embodiments of the disclosure have been described, numerous other modifications and alternative embodiments are within the scope of the disclosure. For example, any of the functionality described with respect to a particular device or component may be performed by another device or component. Further, while specific device characteristics have been described, embodiments of the disclosure may relate to numerous other device characteristics. Further, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments could include, while other embodiments may not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.