Fastener removal tools and methods

A fastener removal tool is provided. The fastener removal tool includes a body having a cylinder and a puller coupled to the body. The puller includes an arm for engaging an installed fastener and a piston inserted into the cylinder of the body such that, when the cylinder is pressurized, the piston is displaced within the cylinder to displace the arm relative to the body to cause removal of the fastener.

BACKGROUND

The field of this disclosure relates generally to fasteners and, more particularly, to tools and methods for use in removing fasteners from a turbine assembly.

Many known turbine assemblies include components that are secured in position using fasteners that are designed to be removed via a pulling action. For example, some components are assembled using dowel pins. However, fasteners of this type may only be accessible through small openings that may be difficult to reach. Moreover, the limited space may make it difficult to pull such fasteners outward.

Tools and methods for manually removing these types of fasteners are commonplace. For example, dowel pins have been known to be removed from turbine assemblies by coupling a bolt to the dowel pin and then manually turning a jacking nut on the bolt using a wrench, such that each turn of the nut results in an incremental pulling movement of the dowel pin. However, using these known tools and methods, it may be challenging, time consuming, and laborious to manually remove the fasteners that secure components in place.

BRIEF DESCRIPTION

In one aspect, a fastener removal tool is provided. The fastener removal tool includes a body having a cylinder and a puller coupled to the body. The puller includes an arm for engaging an installed fastener and a piston inserted into the cylinder of the body such that, when the cylinder is pressurized, the piston is displaced within the cylinder to displace the arm relative to the body to cause removal of the fastener.

In another aspect, a fastener removal method is provided. The method includes coupling a tool to an installed fastener, wherein the tool includes a puller having an arm that engages the fastener. The method also includes pressurizing a cylinder in a body of the tool such that a piston of the puller is displaced within the cylinder to remove the fastener via the arm of the puller.

In another aspect, a method of removing an installed fastener of a gas turbine assembly is provided. The method includes coupling a tool to the fastener within an interior space of an inner ring that supports a plurality of inlet guide vanes of the gas turbine assembly. The tool includes a puller having an arm that engages the fastener. The method also includes pressurizing a cylinder in a body of the tool such that a piston of the puller is displaced within the cylinder to remove the fastener via the arm of the puller.

DETAILED DESCRIPTION

The following detailed description illustrates fastener removal tools and methods by way of example and not by way of limitation. The description should enable one of ordinary skill in the art to make and use the tools, and practice the methods, and the description describes several embodiments of the tools and methods, including what are presently believed to be the best modes of making and using the tools, and practicing the methods. Exemplary tools are described herein as being useful when removing fasteners, such as dowel pins, from a turbine assembly. However, it is contemplated that the tools have general application to a broad range of systems in a variety of fields other than turbine assemblies.

FIG. 1illustrates an exemplary turbine assembly100. In the exemplary embodiment, turbine assembly100is a gas turbine assembly that includes a compressor102, a combustor104, and a turbine106coupled in serial flow communication with one another within a casing110and spaced along a centerline axis112. In operation, a flow of working gas114(e.g., ambient air) enters compressor102and is compressed. A flow of compressed gas116is then channeled into combustor104. Compressed gas116is mixed with fuel and ignited to generate a flow of combustion gases118. Combustion gases118are channeled through turbine106and discharged from turbine assembly100as exhaust gases120.

In the exemplary embodiment, turbine assembly100also includes a plurality of inlet guide vanes122that are circumferentially spaced about centerline axis112upstream from compressor102. In the exemplary embodiment, inlet guide vanes122direct working gas114into compressor102. In some embodiments, each inlet guide vane122may be rotatable to facilitate varying the direction of working gas114entering compressor102. Turbine assembly100may have any suitable quantity of inlet guide vanes122spaced in any suitable manner about centerline axis112.

FIG. 2illustrates an enlarged portion of turbine assembly100taken within area2ofFIG. 1. In the exemplary embodiment, inlet guide vanes122are coupled to an inner ring124that extends circumferentially about centerline axis112. Inner ring124includes a plurality of circumferentially arranged segments126that each include a mounting flange128coupled to a wall130of casing110such that mounting flange128extends generally radially relative to centerline axis112. Segments126also include a support flange132extending from mounting flange128, and a lip134extending generally radially inward from support flange132. Each inlet guide vane122is seated in an opening136that extends through a support flange132of a respective segment126. Accordingly, each segment126of inner ring124supports a plurality of inlet guide vanes122in the exemplary embodiment. In other embodiments, inner ring124may have any suitable cross-sectional shape, any suitable quantity of segments126, and/or any suitable quantity of inlet guide vanes122per segment126.

In the exemplary embodiment, each segment126is coupled to casing wall130via at least one fastener138that extends through mounting flange128and is installed in wall130. By selectively removing fasteners138from casing wall130, segments126are individually detachable from casing110(and from each other) to facilitate removing inlet guide vanes122when servicing inlet guide vanes122and/or compressor102, for example. Notably, the exemplary fasteners138are removable from casing wall130via a pulling action, and are likewise insertable into casing wall130via a pushing action. In one embodiment, fasteners138may include dowel pins. In other embodiments, fasteners138may be of any suitable type that is insertable and/or removable in the manner described herein.

In the exemplary embodiment, each fastener138has a body (e.g., a dowel pin140) that defines a threaded bore142therein, and a head (e.g., a shoulder head screw144) selectively coupled within bore142. However, because a support flange132and a lip134of a respective segment126extend partly around fastener138, segment126defines an interior space146that somewhat confines fastener138in a manner that makes fastener138difficult to access. It may, therefore, be difficult to align and operate some tools such as wrenches, for example, within interior space146to manually remove a fastener138from casing110using, for example, a jacking nut assembly.

FIG. 3is a perspective view of an exemplary tool200that may be used to remove fasteners138from casing110.FIGS. 4 and 5are perspective and schematic cross-sectional views, respectively, of tool200during the removal of a fastener138from casing110. In the exemplary embodiment, tool200includes a body202, a puller204slidably coupled to body202, and a shield206(e.g., a finger guard) coupled to body202such that shield206at least partially surrounds puller204. In other embodiments, tool200may include any suitable quantity of components assembled in any suitable manner that facilitates enabling tool200to function as described herein.

In the exemplary embodiment, puller204includes a plate210, an arm212extending from plate210, and a pair of plunger assemblies214extending from plate210on opposing sides of arm212. As such, each plunger assembly214is oriented substantially parallel to arm212. Arm212has a proximal end216that is formed integrally with plate210, and a distal end218that defines an open-ended slot220that is sized to receive and engage shoulder head screw144when shoulder head screw144is coupled to dowel pin140. In other embodiments, puller204may include any suitable structure for engaging fastener shoulder head screw144and/or dowel pin140.

In the exemplary embodiment, each plunger assembly214includes a piston222, a plate screw224, and a stop screw226. Piston222has a proximal end228that defines a threaded bore230, and a distal end232that defines a threaded bore234. Each plate screw224is coupled within a threaded bore230of a respective piston222to secure the respective piston222to plate210. Moreover, each stop screw226is coupled within a threaded bore234of a respective piston222. Notably, each stop screw226includes a plurality of peripherally spaced-apart notches236that facilitate fluid flow across stop screw226as described in more detail below. In other embodiments, each plunger assembly214may have any suitable configuration that facilitates enabling puller204to function as described herein. For example, each plunger assembly214may be a single-piece, integrally-molded structure, rather than having separate piston222and screws224and226as described above.

In the exemplary embodiment, body202is generally U-shaped and has a first leg member240, a second leg member242, and a bridge member244extending between first leg member240and second leg member242such that a passage246is defined between first leg member240and second leg member242. Body202includes a contact face248, a puller face250opposite contact face248, and a side surface252extending from contact face248to puller face250. A cylinder254and an adjacent sleeve256extend into each leg member240and242from puller face250in a substantially parallel orientation relative to passage246. Additionally, a hose socket258defined in side surface252is in flow communication with cylinders254via a suitable network of internal fluid conduits260within body202. Moreover, body202also includes a pair of bushings262that are each fitted (e.g., threaded) into a counterbore264defined about a respective one of cylinders254. A seal266(e.g., an0-ring or other suitable hydraulic seal) is positioned at the interface of each bushing262and its associated leg member240or242.

In other embodiments, body202may have any suitable configuration that facilitates enabling tool200to function as described herein. For example, body202may have any suitable shape (e.g., body202may not be generally U-shaped), body202may have any suitable quantity of cylinders254(e.g., body202may have only one cylinder254), and/or body202may have any suitable quantity of sleeves256(e.g., body202may not have any sleeves256). Moreover, in some embodiments, puller204may have any suitable quantity of plunger assemblies214(e.g., puller204may have only one plunger assembly214if, for example, body202has only one cylinder254).

In the exemplary embodiment, puller204is coupled to body202such that arm212extends into passage246between leg members240and242, with each piston222extending through a respective bushing262and into a respective cylinder254. As such, each corresponding stop screw226slides in a tight tolerance within an internal surface268of its respective cylinder254, with a seal269(e.g., an0-ring or other suitable hydraulic seal) positioned at the interface of each piston222and its associated bushing262. Optionally, as shown in the exemplary embodiment, each bushing262may be split into segments to facilitate coupling seal269to bushing262(e.g., by inserting seal269between split segments of bushing262).

Additionally, puller204is also coupled to body202via a pair of return springs270that each extend from plate210into a respective sleeve256. Return springs270bias plate210towards puller face250of body202in a biasing direction280such that plate210is seated against face250. With plate210seated against face250(as shown inFIG. 3), tool200is said to be in its inactivated (or resting) state such that distal end218(i.e., slot220) is substantially aligned with contact face248of body202. Although in the exemplary embodiment each return spring270is coupled to body202and plate210via a hook282and stake284engagement, return springs270may be coupled to body202and plate210in any suitable manner in other embodiments. Moreover, in some embodiments, puller204may also be pivotably (or hingedly) coupled to body202(e.g., if body202has only one cylinder254, puller204may have a pivot-type connection to body202). Other suitable mechanisms for coupling puller204to body202are also contemplated.

To detach a segment126of inner ring124from casing110, tool200is initially inserted into interior space146. More specifically, initially tool200is in its inactivated state (as shown inFIG. 3), such that contact face248slides towards support flange132along mounting flange128until slot220slidably engages shoulder head screw144. After shoulder head screw144has been seated in slot220, in the exemplary embodiment, a hydraulic or pneumatic pump (not shown) coupled to socket258is actuated to deliver a suitable working fluid (e.g., oil) through the network of internal conduits260and into cylinders254. The working fluid fills (or pressurizes) cylinders254to displace pistons222(and, therefore, plate210and arm212) of puller204away from puller face250of body202in a pulling direction286that is opposite biasing direction280. As such, the fastener138engaged by arm212is pulled from wall130of casing110, in which position tool200is said to be in its activated state (as shown inFIGS. 4 and 5).

As tool200transitions from its inactivated state to its activated state, the tension in return springs270increases such that the applied biasing force of return springs270on puller204likewise increases. After removing fastener138from wall130in the manner set forth above, the working fluid within cylinders254is evacuated via the pump, and return springs270are again permitted to automatically return puller plate210to being seated against body puller face250, thereby automatically returning tool200to its inactivated state. With tool200back in its inactivated state, tool200is removable from interior space146, and the fastener removal process can be repeated for other fasteners138as desired.

Moreover, as tool200transitions between its inactivated state and its activated state, working fluid within cylinders254flows across stop screws226via notches236to facilitate enabling stop screws226to travel more freely along their respective cylinders254during pressurization and depressurization events. Moreover, as tool200transitions between its inactivated state and its activated state within interior space146, shield206facilitates preventing the operator's fingers from being placed on puller face250or plate210, and preventing the operator's fingers from being caught between plate210and body202, and/or between plate210and nearby structure(s) (e.g., lip134of inner ring124), when cylinders254are pressurized and depressurized. In some embodiments, puller plate210may also include a slot (not shown) for engaging a shoulder head screw144such that tool200may be inserted into interior space146to engage and re-install an already-pulled fastener138via plate210. For example, when tool200is in its inactivated state and is inverted, puller plate210may be capable of engaging and pushing (or re-inserting) an already-pulled fastener138back into wall130of casing110upon pressurization of cylinders254. As such, tool200may be useful for both pulling installed fasteners138, and for installing pulled fasteners138, in some embodiments.

In the exemplary embodiment, tool200is sized for handheld operation (i.e., tool200can be coupled to, and decoupled from, an associated fastener138in an elevated position using only one hand). In some embodiments, tool200is sized for handheld operation in the sense that tool200can be activated (either by the operator that is holding tool200or by another operator) while tool200is being held in the elevated position using only one hand. In one embodiment, tool200may be sized such that, in its activated state, tool200has a height288of about two inches (as measured, for example, from body contact face248to an outer face292of plate210), and a length290of about four inches (as measured, for example, from a first extent294of side surface252to a second extent296of side surface252). As such, tool200is sized for easier handling when removing fasteners from elevated locations, and is sized to fit within smaller spaces (e.g., interior space146) for pulling harder-to-reach fasteners (e.g., fasteners138). In other embodiments, tool200may not be sized for handheld operation as set forth above (i.e., some embodiments of tool200may be sized such that tool200cannot be coupled to, and decoupled from, an associated fastener138in an elevated position using only one hand).

Because tool200has such a small size in the exemplary embodiment (e.g., because cylinders254are sized smaller), the pump connected to tool200may be a hand-actuated pump, not an electrically actuated pump, to facilitate enabling more precise control over the amount of working fluid supplied to cylinders254, thereby inhibiting the over-pressurization of cylinders254. For example, in one embodiment, tool200may be operable only with a pump having a pressure rating of less than about seven hundred bars. Suitably, the operator holding tool200may actuate the associated pump, or another operator may actuate the associated pump. For example, one operator may repeatedly insert tool200into, and remove tool200from, interior space146for pulling one fastener138after the next, while another operator selectively hand-actuates the associated pump, thereby facilitating a more rapid process by which fasteners138are pulled from wall130of casing110about inner ring124in a shorter period of time. In other embodiments, the pump may be any suitable pump, including an electrically actuated pump. Moreover, in lieu of utilizing a pneumatic or hydraulic mechanism for displacing puller204relative to body202as set forth above, other embodiments of tool200may utilize a suitable arrangement of gears/levers that facilitates displacing puller204relative to body202when removing and/or inserting fasteners138.

The methods and systems described herein facilitate the removal of fasteners in a less laborious and less time-consuming manner. The methods and systems also facilitate removing fasteners that are accessible only in smaller openings that are more difficult to reach. For example, the methods and systems facilitate minimizing the amount of time needed to pull dowel pins that retain inlet guide vanes in a turbine assembly. As such, the methods and systems facilitate reducing the amount of time needed to conduct an inspection, or to perform routine service, on the compressor of a turbine assembly. The methods and systems thereby facilitate reducing the amount of time that a turbine assembly is offline during inspection and/or servicing, which in turn facilitates reducing the overall cost associated with inspecting and/or servicing the turbine assembly.

Exemplary embodiments of methods and systems for removing fasteners are described above in detail. The methods and systems described herein are not limited to the specific embodiments described herein, but rather, components of the systems and steps of the methods may be utilized independently and separately from other components and steps described herein. For example, the methods and systems described herein may have other applications not limited to practice with turbine assemblies, as described herein. Rather, the methods and systems described herein can be implemented and utilized in connection with various other industries.