Turbine casing jack

An apparatus for lifting an inner casing of a turbine includes a base, an arm, a guide roller, and an adjustment system. The arm has a first end and a second end, and is pivotally connected to the base intermediate the first end and the second end. The guide roller is operatively coupled to the first end of the arm to rotatably engage an exterior surface of the inner casing, and an adjustment system extending from the base and engaging the arm to change an angular position of the arm relative to the base and adjust a position of the guide roller relative to the exterior surface of the inner casing.

FIELD OF THE INVENTION

The subject matter disclosed herein relates to a jacking tool. More specifically, the subject matter disclosed herein relates to a roller jack for rotatably support, lifting, and aligning an inner turbine casing relative to a turbine rotor.

BACKGROUND OF THE INVENTION

A typical gas turbine includes a turbine section having alternating stages of fixed nozzles and rotating buckets, and a turbine casing assembly generally surrounding the turbine section. The turbine casing assembly includes an inner casing and an outer casing. Gas turbines are typically designed with a split in the inner and outer casings along a horizontal centerline of the unit, to enable the inner and outer casings to be separated into upper and lower halves. When a maintenance operation needs to be performed on a gas turbine, it is often necessary that one or more sections of the inner and outer casings be removed. For example, it is common to remove sections of the inner and outer casings to allow maintenance workers to inspect and/or replace nozzles/buckets and/or to perform various other scheduled maintenance operations. Reassembly of the inner and outer casings requires realigning the inner casing with an axis of a turbine rotor.

In the disassembly and/or reassembly of gas turbine casings, roller jacks may be employed to move sections of the casings. For example, a lower half of an inner casing may be supported on roller jacks after removal of the upper half of the inner and outer casings, for access to the interior of the gas turbine. The interior of the gas turbine can further be accessed by rolling the lower half of the inner casing on the roller jacks to rotate the inner casing upward to a position where its removal is not obstructed by internal components of the gas turbine. Further, when reassembling the casings, the casings must be repositioned and aligned to an appropriate or desirable position (e.g., centered around a turbine rotor). Roller jacks can support the inner casing and be adjusted to position the inner casing with respect to the outer casing and internal turbine components (e.g., a rotor).

Because typical inner and outer casing assemblies are very heavy, the roller jacks that are employed are usually hydraulic jacks, which can handle very large loads. However, fine tuning the positioning of a hydraulic jack can be difficult, which may lead to improper alignment and/or damage of tight assembly clearance parts of gas turbines with which they are used. For example, overshoot during extension of a hydraulic jack may cause a collision of the casing into a turbine blade tip. In addition, hydraulic jacks have a tendency to retract under load if left extended for a period of time so that repositioning may become necessary if a user leaves the jack to adjust another portion of the casing assembly. Furthermore, conventional roller jacks, while lighter and smaller than some alternative equipment used to dissemble/reassemble a turbine casing assembly, are still quite heavy for a person to lift and manipulate, and overly bulky for the tight working spaces in and around a turbine.

BRIEF DESCRIPTION OF THE INVENTION

A first aspect of the disclosure includes a roller jack for rotatably supporting an inner casing of a turbine. The roller jack includes a base, an arm, a guide roller, and an adjustment system. The base includes a mounting element configured to couple to an outer casing of the turbine. The arm is pivotally connected to the base, and the arm has a first end and a second end. The guide roller is rotatably positioned at the first end of the arm and configured to rotatably engage an exterior surface of the inner casing of the turbine. The adjustment system is configured to adjustably pivot the arm relative to the base to engage the guide roller with the exterior surface of the inner casing.

A second aspect of the disclosure includes a roller jack for lifting an inner casing of a turbine. The roller jack includes a base, an arm, a guide roller, and an adjustment element. The arm has a first end and a second end, and is pivotally connected to the base intermediate the first end and the second end. The guide roller is operatively coupled to the first end of the arm to rotatably engage an exterior surface of the inner casing. The adjustment system extends from the base and engages the arm to change an angular position of the arm relative to the base and engage the guide roller to rotatably engage the exterior surface of the inner casing.

DETAILED DESCRIPTION OF THE INVENTION

As noted, the subject matter disclosed herein relates to a roller jack for rotatably supporting, lifting, and aligning a turbine inner casing relative to a turbine rotor. In contrast to conventional roller jacks, embodiments of the roller jack disclosed herein are simpler to operate, smaller, and lighter, all of which facilitates their relative ease of use in tight working spaces.

FIG. 1is a perspective view illustrating a roller jack100for rotatably supporting, lifting, and/or aligning, for example, an inner casing200(FIG. 2) of a turbine relative to a rotor of the turbine (not shown), according to various embodiments.FIG. 2is a cross-sectional, side view of roller jack100in use with an inner casing200and an outer casing210of a turbine. Referring toFIG. 1andFIG. 2, roller jack100can include a base102, an arm104, a guide roller106, and an adjustment system108.

Base102can be a rigid body to provide support and structure for roller jack100. Base102can take on a variety of shapes which provide for support and connection of other roller jack components. In the embodiment depicted byFIG. 1andFIG. 2, base102has a first wall112, a second wall114parallel to first wall112, and a connecting member116connecting first wall112and second wall114. First wall112and second wall114define a slot117in which arm104can fit.

A stop element201can be connected to or integrated with base102. Stop element102is configured to limit pivotal motion of arm104relative to base102. Stop element201is positioned or located in slot117adjacent base102.

A handle146can be connected to or integrated with base102. Handle146can include at least one support element148connected to or extending from base102, and a gripping element150connected to at least one support element148. Two support elements148are depicted inFIG. 1, but one is conceived, as are three or more. Roller jack100, while smaller and lighter than conventional jacks, might still be considered heavy for a person to lift and move. Handle146can facilitate easier lifting and moving of roller jack100.

A mounting element110can be connected to, or integrated with, base102. Mounting element110can include a flange138at least partly surrounding a portion of arm104. In some cases, flange138can define a central opening140through which arm104can extend. While flange138is shown as including an oblong hole, flange138can have any shape to accommodate fastening to outer casing210and appropriate passage/positioning of arm104and guide roller106. Flange138can also have a plurality of apertures144. Each aperture144can be configured to receive a fastener145for mounting or coupling roller jack100to an exterior surface212of outer casing210of the turbine.

FIG. 3illustrates a roller jack300having a mounting element310that includes a flange338. Flange338is smaller than flange138, with fewer apertures144, for mounting roller jack300in a smaller, more confined space, or on a smaller area of exterior surface212of outer casing210.

FIG. 4illustrates multiple roller jacks100,300coupled or mounted to exterior surface212of outer casing210of a turbine. As depicted inFIG. 4, in some embodiments, roller jack100is mounted at a forward location on outer casing210, while roller jack300is mounted at an aft location on outer casing210. In these cases, the forward location has more space to fit the larger mounting element110of roller jack100, while the aft location has less space and requires a smaller mounting element such as mounting element310of roller jack300.

Referring again toFIG. 1andFIG. 2, mounting element110can further include a shim142approximately matching the shape of flange138and configured to mate with flange138. Shim142can be fashioned with various widths W in order to adapt roller jack100for use with varying models or sizes of turbines and turbine casings, to adjust how far arm104and guide roller106need to extend beyond outer casing210to engage inner casing200. Different turbines might require roller jack100to extend through outer casing400to different lengths in order to engage inner casing200as desired. Referring toFIG. 3, roller jack300can also have a shim342approximately matching the shape of flange338and configured to mate with flange338.

As shown inFIG. 2, arm104includes a longitudinal section218extending from a first end120to a second end122. Arm108can be pivotally connected to base102, such that arm104can swing or pivot relative to base102, and change an angular position of arm104relative to base102. The pivotal connection can be facilitated by a pivot pin124connecting arm104to base102. Pivot pin224can be fixedly connected (or directly connected) or rotationally connected to either base102or arm104, such that arm104can pivot around an axis of pivot pin124relative to base102. Pivot pin124can extend through arm104and at least part of base102. The pivotal connection of pivot pin124can be between first end120and second end122. The pivotal connection can also be offset from a direct line or path between first end120and second end122. In other words, arm104can have a longitudinal axis220extending from first end120to second end122, and the pivot connection section226can be offset from longitudinal axis220where pivot pin124can connect to arm104. Pivot connection section226can protrude from longitudinal section218between first end120and second end122. The protruding shape of pivot connection section226can create a concavity in which stop element201can be located adjacent and between pivot connection section226and longitudinal section218, where it can limit motion of arm104in both clockwise and counter-clockwise directions.

Guide roller106is operatively positioned on first end120of arm104. Guide roller106can be any currently known or later developed part or device capable of rotatingly engaging and supporting an exterior surface202of inner casing200. In the embodiment depicted inFIG. 1andFIG. 2, guide roller106rotates around a roller pin128. First end120of arm104includes a first finger130spaced from a second finger132, and roller pin128spans the space, connecting from first finger130to second finger132. Guide roller106is positioned to rotate or roll on roller pin128in this space between first finger130and second finger232. Guide roller106is located such that guide roller106can contact exterior surface202of inner casing200of a turbine when roller jack100is in use mounted to exterior surface212of outer casing210of the turbine and rotatably support inner casing200(FIG. 2) relative to arm104. Because turbine casings are very heavy, guide roller106can be made of hardened material such as steel.

As seen inFIG. 2, adjustment system108is configured to adjustably pivot arm104and guide roller106relative to base102, e.g., such that guide roller106can be brought into and out of rotating engagement and support of inner casing200. To adjustably pivot arm104, adjustment system108can be engaged with, attached to, or connected to base102, and adjustment system108can include an adjustment member109extending from base102toward arm104, and being length-adjustable to change a position of arm104relative to base102. A contact head236can be pivotally attached to adjustment member109, configured to engage, couple with, or contact arm104, or to be engaged with, attached to, couple with, or connected to arm104. Contact head236can have a larger diameter or larger contact surface area (i.e., surface area configured to contact arm104) than adjustment member109would have without contact head236.

Adjustment system108can be located proximate second end122of arm104. “Proximate” second end122of arm104can mean any location toward second end122from pivot pin124or pivot connection section126, such that adjustment system108can engage arm104on an opposing side of arm104relative to guide roller106. The farther toward second end122from pivot pin124or pivot connection section126adjustment system108is located, the more leverage adjustment system108has to move arm104and guide roller106.

As depicted inFIG. 1andFIG. 2, adjustment member109can be a threaded shaft134threadably engaged or engage-able with base102, and which can extend from base102toward arm104. Threaded shaft134can be rotated relative to base102and arm104, to push second end122of arm104away from base102and/or pull second end122of arm104toward base102.

Alternatively to adjustment member109having threaded shaft134, adjustment system108can include other devices operable to push second end122of arm104away from base102and/or pull second end122of arm104toward base102. A hydraulic pancake cylinder500coupled with a fluid source502, as depicted inFIG. 5, is an example of another device that can operate to facilitate pivoting of arm104. Further, adjustment member109can be manually-operated or power-driven by a drive system. For example, in the embodiment depicted inFIG. 2, a manually-operated adjustment member109can have a manual adjustment interface111by which a human operator can more easily turn a threaded adjustment member109. Adjustment member109with threaded shaft134can instead be turned by a drive system600, including a motorized actuator602coupled with an internal or external power source604, as depicted inFIG. 6. Further, a power-driven embodiment, such as one including motorized actuator602inFIG. 6can be computerized, so that a control system606can be configured to control adjustment, with input from a human operator. The embodiment including a manually-operated threaded shaft134requires relatively little space and is relatively light in weight, as compared to conventionally used jacks. Ideally, the motorized actuator602and the hydraulic pancake cylinder500weigh less than conventionally used hydraulic equipment, and utilize less space as well.

Adjustment of adjustment member109includes adjusting a length of adjustment member109between base102and arm104, to either move second end122of arm104from base102and pivot first end120of arm104toward base102or move second end122of arm104toward base and pivot first end130of arm away from base102. To move second end122of arm104from base102, adjustment member109can be adjusted to lengthen the distance of adjustment member109between arm104and base102. To move second end122of arm104toward base102, adjustment member109can be adjusted to shorten the distance of adjustment member109between arm104and base102, and weight or force on first end120, such as the weight of inner casing200, can be relied upon to press first end120of arm104away from base104and pivot second end122of arm104toward adjustment system108and base102. Alternatively, adjustment system108can be connected to arm104such that adjustment of adjustment member109draws second end122of arm104toward base102and pivots first end120of arm104away from base102.

During adjustment of adjustment member109and/or support of inner casing200, the larger diameter or contact surface area of contact head236disperses force on the surface of arm104over a larger area, reducing or preventing damage to inner casing200. The pivotal connection of contact head236on adjustment member109facilitates mating contact between contact head236and arm104during adjustment of adjustment system108, as adjustment member109moves linearly and the angle between arm104and adjustment member109changes.

Referring toFIG. 4, typically, a set of four roller jacks (e.g., two forward roller jacks100and two aft roller jacks300) are positioned symmetrically around the outer casing210to provide stable support of inner casing200. One roller jack100,300can be adjusted manually at a time, multiple people can manually adjust two or more roller jacks100,300simultaneously, or the set of roller jacks100,300can be power-driven and adjusted singly or simultaneously. When a guide roller106rotatably supports inner casing200, the pivoting of a single arm104and a guide roller106relative to base104moves inner casing200at a point of contact with guide roller106relative to an axis of the rotor (not shown). The casing200at the point of contact can be moved up or down, or laterally, depending on the direction of adjustment of adjustment system108, the angle of orientation of longitudinal section218relative to inner casing200, and the location around a circumference of inner casing200that guide roller106engages exterior surface202of inner casing200. The angle of orientation and location around the circumference of inner casing200can be set or adjusted as desired. Adjusting one roller jack100,300changes the angle of a center axis402of inner casing, while adjusting two roller jacks (e.g., one forward jack100and one aft jack300) on a same side of inner casing200an equal amount maintains the angle of center axis402and pivots inner casing200upward or downward relative to the center axis of the rotor. Adjusting all four roller jacks100,300an equal amount lifts or lowers inner casing200while maintaining existing lateral alignment and angle of center axis402.

Adjustment member109, arm104, guide roller106, and the pivotal connection between arm104and base102, can be configured such that adjustment member109can be adjusted in length a predetermined amount to achieve a predetermined movement of guide roller106, which knowing the positional relationships between inner casing200and outer casing210, and the mounting location of roller jack100on outer casing210, can translate to a known or predetermined movement of inner casing200. For example, roller jack100can be configured such that 0.254 millimeters (approximately 0.01 inches) of axial movement of adjustment member109, when inner casing200is directly supported on guide roller106, can vertically lift inner casing200at the point of contact between guide roller106and inner casing2000.254 millimeters (approximately 0.01 inches). Such a configuration facilitates relative ease of manual operation in positioning and aligning inner casing200relative to the turbine rotor (not shown). Further, adjustment system108has a relatively small footprint, further facilitating the ability of roller jack100to be used in small working spaces.

A method of rotating and positioning an inner casing of a turbine relative to a rotor of the turbine is described with reference, but is not intended to be limited, to the apparatuses and components shown inFIGS. 1-4. The method can include coupling at least one jack100,300to exterior surface212of outer casing210of a turbine, and adjusting adjustment system108to pivot arm104relative to base102, to rotatably support inner casing202of the turbine, and to move a center axis of inner casing202. In operation, the method can include rotating adjustment member109to move adjustment member109toward or away from arm104. In some cases, the method can include actuating a drive system600to adjust adjustment system108. In some cases, the drive system can be electrically-powered, computerized, and/or automated to rotate adjustment member109.