System and method for removing the cover from the generator enclosure

Abstract

A system and method for removing a cover from a generator enclosure is provided. [Solution] A system and method for removing a cover (10) from a generator enclosure (14) housing a stator and rotor (20) are disclosed. A cover axial pull tool (42) is configured to lift a section of the cover (10) upward and move the section of the cover axially away from the generator enclosure (14) to disengage it from the stator frame (84) of the stator. A cover vertical lift tool (88) works in cooperation with the generator enclosure (14) and the cover axial pull tool (42) to provide a path for the section of the cover (10) to navigate when the cover is lifted away from the cover axial pull tool using a hoist assembly (74) to avoid contact between the cover and the enclosure.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to industrial generators, and more specifically, to systems and methods for removing a cover from a generator enclosure.

Background Art

[0002] Generally, industrial generators include two main parts: a stator and a rotor. Both the stator and the rotor are surrounded by a generator enclosure. A cover for the generator enclosure, also called an end shield, closes an opening in the side of the enclosure around the end of the rotor. The cover can support the weight of the generator rotor bearing and contain hydrogen gas used to cool the generator at maximum pressure without excessive distortion. A cover for a generator typically includes two halves (e.g., an upper half and a lower half) coupled to the enclosure. The two halves of the cover may be bolted together by a joining plate positioned at any adjacent edge.

[0003] When maintenance is performed on a generator, at least one of the upper or lower halves of the cover is removed to allow the operator to access the generator's internal components. For example, each time the generator is shut down, at least a portion of the cover must be removed to allow access to the stator and rotor. Typically, in a shutdown scenario, the upper half of the cover is removed to allow the operator to access the stator and rotor. A typical cover, including both the upper and lower halves, can be large, heavy, and bulky, especially in the case of hydrogen-cooled generators. Furthermore, the cover may have a complex geometric shape due to protruding segments on the inner surface of the cover that, when used, would interfere with the stator frame of the stator housed in the enclosure. For example, the upper half of the cover on the inner surface covering the enclosure may have a conical or bell shape that makes it difficult to remove this portion of the cover from the enclosure. Another factor that adds to the challenge of removing the upper half of the cover is the limited space around the enclosure due to its proximity to a gas or steam turbine that may act as the prime mover to rotate the generator's rotor shaft. In addition, because there is only a limited amount of space between the enclosure and the motor, there are only a limited number of dedicated lifting points that can be used to facilitate the removal of the upper half of the cover.

[0004] Figure 1 shows an example schematic diagram illustrating the removal of a section of the cover 10, such as the upper half with its protruding inner surface 12, from the enclosure 14 of the generator 16, as well as the limited space and lifting points that the operator must face, making the removal of the cover a difficult attempt. As shown in Figure 1, a hoist assembly 18 can be used to lift the cover 10 vertically (i.e., up and down) from the enclosure 14 after the protruding inner surface 12 has been disengaged from the stator frame of the stator, which is housed by the enclosure along with the other components of the generator 16. In the cover removal operation illustrated in Figure 1, a beam 22, such as an I-beam, can be positioned above the generator 16 in the limited space between the generator and adjacent components of the prime mover 24 (e.g., a gas turbine or steam turbine). The beam 22, which the hoist assembly 18 can advance via a hoist trolley, can serve as a dedicated lifting point for lifting the cover 10 from the enclosure 14 of the generator 16. A sling (or tagline) 26 attached to the cover 10 is used by an operator 27 positioned around the limited space between the generator 16 and the prime mover 24 to control the movement of the cover as it is lifted from the enclosure 14 onto the beam 22 by the hoist assembly 18. For clarity, only one operator 27 is shown in the example illustrated in Figure 1, but it is understood that additional operators can be positioned in that location and elsewhere relative to the enclosure 14.

[0005] In the scenario illustrated in Figure 1, removing the upper half of the cover 10 from the enclosure 14 of the generator 16 typically involves an operator 27 attaching links and rings from the hoist assembly 18 to various connection points on the cover. The operator 27 also adds additional chain hoist / traction systems to other mounting points around the enclosure 14. In this way, these additional chain hoist / traction systems can be used to pull the upper half of the cover 10 into a horizontal position and disengage it from the stator frame, while the main hoist assembly 18 is used to pull the cover 10 vertically toward the beam 22.

[0006] To facilitate the horizontal movement of the cover 10 and the disengagement of the protruding inner surface 12 of the upper half of the cover from the stator frame, in addition to operator 27 located near the lower end of the enclosure 14 and horizontally away from the enclosure, other operators are typically positioned above and at the same level as the operator, but in different locations (e.g., near the cover removal / installation space). These operators 27 can also use a sling (or tagline) 26 to control the movement of the cover 10 as the hoist assembly 18 lifts the cover 10 vertically toward the beam 22, in order to prevent contact between the cover 10 and the enclosure 14.

[0007] This cover removal process is complex and time-consuming for the operator involved in removing the cover 10 from the enclosure 14. For example, due to the limited space around the generator 16, multiple operations by the hoist assembly 18, an additional chain hoist / traction system, and the operator 27 are required to disengage the protruding inner surface 12 of the upper half of the cover 10 from the stator frame, and then, once disengaged, navigate the cover toward the beam 22 to avoid contact between the cover and the enclosure 14, as well as other components of the generator 16 housed in the enclosure. The shape of the protruding inner surface 12 of the upper half of the cover, which can be bell-shaped or conical as described above, is another factor contributing to the complexity of removing the cover 10 from the enclosure 14. Due to the limited space around the generator 16 and the fixed position of the beam relative to the cover 10 and enclosure 14, an offset exists between the center of gravity of the cover and the beam 22 when the hoist assembly 18 lifts the cover perpendicularly upwards toward the beam. This offset causes the center of gravity of the cover 10 to invert or swing, resulting in a tendency for it to be directed towards the enclosure 14.

[0008] Operator 27 uses a sling (or tagline) 26 to counteract the tendency of the enclosure's center of gravity to move the cover toward the enclosure, in order to prevent the cover 10 from contacting the enclosure and damaging one or more of the enclosure, the generator 16, and the cover 12. Manipulating the cover 12 and its protruding sections outside the enclosure 14 while resisting its tendency to swing or reverse, while avoiding collision with the enclosure, is extremely difficult as it is labor-intensive and time-consuming. The countermeasures taken by Operator 27 to counteract the tendency of the cover 10 to return to the enclosure and be positioned below the beam 22 are not only very laborious, but also make the cover removal process a dangerous attempt for the operator as the operator may get in the way of the cover because they may be positioned under a heavy load (i.e., the cover). [Overview of the project]

[0009] The following provides a simplified overview of the disclosed subject matter to give a basic understanding of some aspects of the various embodiments described herein. This overview is not a comprehensive overview of the various embodiments. This overview is not intended to exclusively identify any important or essential features of the claimed subject matter as described in the claims, nor is it intended to assist in determining the scope of the claimed subject matter. Its sole purpose is to present some of the concepts of this disclosure in a streamlined form as a prelude to the more detailed descriptions that will be presented later.

[0010] In light of the aforementioned complexities and challenges associated with removing a section of the cover (e.g., the upper half) from a generator enclosure in a confined space, a better method is needed. Specifically, this method should be less complex and time-consuming, require fewer operators to facilitate the cover removal process, and enhance the safety of the operators involved in the process. Furthermore, the method should ensure that contact between the cover, enclosure, and generator components is avoided to prevent damage to these items.

[0011] Embodiments described herein provide solutions to address problems associated with the complexity and challenges of current methods deployed for safely and controlledly removing covers from generator enclosures. These solutions include systems and methods that reduce the number of operators required to facilitate the removal of covers from generator enclosures, enhance the safety of operators involved in the removal process, are less labor-intensive and substantially hands-free with respect to disengaging the covers from the stator frame and enclosure, and ensure that all contact between the cover, enclosure, and generator components is avoided when the disengaged cover is operated by a hoist assembly to a fixed position located above the generator enclosure space around the enclosure and generator, while navigating the confined space around the generator.

[0012] Systems and methods in various embodiments allow for the removal of sections of a cover, such as the upper half of a cover having an inner surface with a protruding section that, when used, would cause interference with the stator, by utilizing a cover axial pull tool and a cover vertical lift tool. The cover axial pull tool allows for the nearly hands-free pulling of the cover half from the stator frame. Excessive rigging and repetitive movements are not required to safely disengage the cover from the stator frame. The cover vertical lift tool allows for rapid and fully guided removal and lifting of the cover half, functioning regardless of the cover's center of gravity and the position of the overhead lift point. In particular, both the cover axial pull tool and the cover vertical lift tool allow for the offsetting of the cover's center of gravity relative to the available lift point, thereby resolving many of the safety concerns regarding the operation present in current methods.

[0013] In one embodiment, the cover axial pull tool may include a cover mounting plate configured to be attached to a section of the cover (e.g., the upper half) and a portion of the enclosure. The cover axial pull tool may further include a vertical lift assembly coupled to the cover mounting plate and configured to vertically lift the section of the cover after the cover mounting plate has been attached to the cover and portion of the enclosure. The cover axial pull tool may also include a mechanical linear actuator assembly configured to disengage the section of the cover from the stator frame and move the cover mounting plate and vertical lift assembly axially relative to the enclosure.

[0014] In one embodiment, the vertical lift assembly of a cover axial pull tool can utilize a hydraulic cylinder to vertically lift the upper half of the cover, thereby creating a horizontal gap between the cover and the stator portion. In this way, the cover half can be disengaged from the stator frame by using a mechanical linear actuator assembly to move the cover axially away from the enclosure. Because of the horizontal gap created by utilizing the hydraulic cylinder, the risk of damaging the cover, the enclosure, and the stator portion housed within the enclosure is eliminated when the mechanical linear actuator assembly moves the cover axially away from the enclosure.

[0015] In one embodiment, the mechanical linear actuator assembly of the cover axial pull tool can utilize a lead screw handwheel that can be rotated by an operator, allowing the tool to move the cover axially away from the generator on a linear bearing operably coupled to the screw handwheel. In another embodiment, the mechanical linear actuator assembly can utilize an electrically operated screw wheel, as opposed to a handwheel rotated by an operator, to move the cover axially away from the enclosure in conjunction with the linear bearing. Regardless of the type of screw wheel used, the cover axial pull tool ensures that no contact occurs between the cover and the stator enclosure portion (e.g., no damage to any gasket surface). In addition, at mounting locations where a cover mounting plate is provided, the cover axial pull tool eliminates the risk of cover center of gravity offset relative to a dedicated lifting point (i.e., a beam above the generator enclosure space), such as tilting or swinging of the cover and, in some cases, contact with the enclosure. Instead, the cover axial pull tool allows the cover removal operation to be performed in a smooth and controlled manner without the need for rigging.

[0016] In one embodiment, the cover vertical lift tool may include a vertical guide rail assembly and a trolley lift assembly that work in cooperation with the enclosure, generator, and cover axial pull tool, facilitating the rapid and fully guided removal and lifting of the cover half from the cover axial pull tool via the vertical guide rail assembly, trolley lift assembly, and hoist assembly. The vertical guide rail assembly and trolley lift assembly of the cover vertical lift tool not only expedite the removal and lifting of the cover half, but these operations can also be performed in a controlled manner, regardless of the cover's center of gravity and the overhead lift point position of the beam relative to the generator enclosure space. By disregarding the cover shape and lift point location, the cover vertical lift tool can lift and remove the cover in a single continuous motion without the multiple iterative motions and altered rigging positions required in current methods to ensure there is no collision with the generator enclosure.

[0017] This eliminates the need for numerous operators positioned around the generator enclosure space to counteract the tilt of the cover as it swings or flips towards the generator and enclosure, and to make contact due to the lifting point being offset relative to the cover's center of gravity. In addition to eliminating the labor-intensive means currently used in the cover removal process due to this lifting point offset between the cover's center of gravity (due to its protruding section) and the limited space, operators are safer in cover removal and lifting operations performed using both cover vertical lift tools and cover axial pull tools, as they do not need to work under the suspended load. Furthermore, the control of the vertical movement and guide of the outer half of the cover outside the enclosure, with cover vertical lift tools and hoist assemblies provided to facilitate lifting, dramatically eliminates the safety risks present in current removal and lifting operations and makes those operations faster and more efficient.

[0018] According to one embodiment of the present disclosure, a system is provided for removing a cover from a generator enclosure housing a stator and a rotor. The system comprises a cover axial pull tool for pulling a section of a cover from the generator enclosure, the cover axial pull tool being configured to lift a section of the cover upward, move the section of the cover axially away from the generator enclosure to disengage it from the stator frame of the stator, and create a gap between the generator enclosure and the cover axial pull tool to park the section of the cover; a cover vertical lift tool positioned in the gap to work in cooperation with the generator enclosure and the cover axial pull tool, and configured to provide a path for the section of the cover to navigate as the cover is lifted away from the cover axial pull tool; and a hoist assembly working in cooperation with the cover axial pull tool and the cover vertical lift tool to lift a section of the cover upward from the cover axial pull tool and continue lifting the cover away from the generator enclosure without contact with the generator enclosure, while navigating the path provided by the cover vertical lift tool.

[0019] According to another embodiment, a method is provided for removing a cover from a generator enclosure housing a stator and rotor. The method involves placing a cover axial pull tool adjacent to the cover of the generator enclosure; attaching the cover axial pull tool to a section of the cover and a portion of the generator enclosure; using the cover axial pull tool to lift the section of the cover; using the cover axial pull tool to move the section of the cover axially away from the generator enclosure to disengage it from the stator frame of the stator and create a gap between the generator enclosure and the cover axial pull tool; and, after moving the section of the cover axially away from the generator enclosure, using a cover vertical lift tool to move the section of the cover into the gap formed between the generator enclosure and the cover axial pull tool. The method involves placing the cover vertical lift tool to provide a guide path for the section of the cover to navigate when lifting the cover from the cover axial pull tool, using a hoist assembly to lift the section of the cover upward from the cover axial pull tool, guiding the hoist assembly to maneuver the section of the cover along the guide path provided by the cover vertical lift tool, and continuing to use the hoist assembly to lift the section of the cover upward away from the generator enclosure without contacting the generator enclosure, while navigating the guide path provided by the cover vertical lift tool.

[0020] This technology will be better understood by referring to the attached drawings and reading the following description of non-limiting embodiments. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram illustrating one example of removing the cover from the generator enclosure using the current cover removal method. [Figure 2] This is a more detailed schematic diagram of the upper half of the cover shown in Figure 1, relating to the generator enclosure that houses the stator and rotor. [Figure 3] Schematic diagram of a cover axial pull tool used to axially move a cover from an enclosure according to an embodiment of the present disclosure. [Figure 4A] Schematic perspective view of a cover axial pull tool coupled to an enclosure and positioned around a rotor according to an embodiment of the present disclosure. [Figure 4B] Schematic cross-sectional view of a cover axial pull tool coupled to an enclosure and positioned around a rotor according to an embodiment of the present disclosure. [Figure 5] Schematic diagram of the cover axial pull tool shown in FIG. 3 carried by a hoist assembly according to an embodiment of the present disclosure. [Figure 6A] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 6B] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 6C] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 6D] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 6E] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 6F] A diagram schematically illustrating a process of using a cover axial pull tool to remove a cover from an enclosure of a generator according to an embodiment of the present disclosure. [Figure 7A]Schematic diagrams of various cover vertical lifting tools used to facilitate the vertical lifting of a cover, deployed together with a cover axial pulling tool, according to an embodiment of the present disclosure. [Figure 7B] Schematic diagrams of various cover vertical lifting tools used to facilitate the vertical lifting of a cover, deployed together with a cover axial pulling tool, according to an embodiment of the present disclosure. [Figure 7C] Schematic diagrams of various cover vertical lifting tools used to facilitate the vertical lifting of a cover, deployed together with a cover axial pulling tool, according to an embodiment of the present disclosure. [Figure 8] Schematic diagram of a trolley lift assembly, which is a component of a cover vertical lift tool used to facilitate the vertical lifting of a cover from a generator enclosure, according to an embodiment of the present disclosure. [Figure 9] Schematic diagram of a vertical guide rail assembly, which is another component of a cover vertical lift tool used together with the trolley lift assembly illustrated in FIG. 7 to facilitate the vertical lifting of a cover from a generator enclosure, according to an embodiment of the present disclosure. [Figure 10A] Schematic diagram showing the lifting operation of a cover from a generator enclosure using a cover vertical lift tool, a cover axial pulling tool, and a hoist assembly, according to an embodiment of the present disclosure. [Figure 10B] Schematic diagram showing the lifting operation of a cover from a generator enclosure using a cover vertical lift tool, a cover axial pulling tool, and a hoist assembly, according to an embodiment of the present disclosure. [Figure 10C] Schematic diagram showing the lifting operation of a cover from a generator enclosure using a cover vertical lift tool, a cover axial pulling tool, and a hoist assembly, according to an embodiment of the present disclosure. [Figure 10D]This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10E] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10F] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10G] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10H] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10I] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10J] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 10K] This figure schematically illustrates a cover lifting operation from a generator enclosure using a cover vertical lift tool, a cover axial pull tool, and a hoist assembly according to one embodiment of the present disclosure. [Figure 11]This is a schematic diagram of a hoist assembly according to one embodiment of the present disclosure, which uses two beams for load transfer between beams during the lifting operation of a cover from a generator enclosure using a cover vertical lift tool. [Figure 12] This is a schematic diagram of a hoist assembly using a cantilever beam with a counterweight that can be used during the lifting operation of a cover from a generator enclosure, according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0022] The exemplary embodiments of this disclosure are described more fully below with reference to the accompanying drawings, which show some, but not all, embodiments. In fact, the art may be embodied in many different forms and should not be construed as being limited to the embodiments described herein, but rather these embodiments are provided to satisfy the applicable legal requirements of this disclosure. Throughout, similar reference numerals may refer to similar elements.

[0023] As described above, this disclosure provides systems and methods for removing a cover from a generator enclosure. Systems and methods of various embodiments utilize cover axial pull tools and cover vertical lift tools to remove and lift sections of a cover, such as the upper half of a cover having an inner surface with a protruding section that can take the form of a bell or cone, from the enclosure. The cover axial pull tool allows the cover half to be pulled axially from the stator frame almost hands-free. Excessive rigging and repetitive movement are not required to disengage the cover from the stator frame. The cover vertical lift tool allows for a rapid and fully guided removal and lifting operation of the cover half, which works regardless of the cover's center of gravity and overhead lift point position.

[0024] Referring again to the figures, Figure 2 shows a more detailed schematic diagram of the upper half of the cover 10, as schematically illustrated in Figure 1, relating to the enclosure 14 of the generator 16 that houses the stator and rotor 20. As shown in Figure 2, the upper half of the cover 10 may include a semicircular section 28 having a central notch 30 to fit onto a rotor 20 mounted on a base section 32 formed by two base sections 32a and 32b separated by a notch and the rotor. Each of the semicircular section 28 of the cover 10 and the two base sections 32a and 32b may have a number of mounting holes 34 used to connect the upper half of the cover to the enclosure 14 and the lower half of the cover (not shown in Figure 2), respectively.

[0025] On the inner surface 36 of the upper half of the cover 10, which is attached to the enclosure 14 and the stator frame of the stator housed in the enclosure, there are protruding section features (not shown in Figure 2) which may have a shape corresponding to the geometric shape of the mounting surface of the stator frame on which the cover is installed. The shape typically includes a bell shape or a cone shape, but it is understood that embodiments of the present disclosure are suitable for use in any shape configured to interfere with the geometric shape of the surface of the stator frame on which the cover is installed. Figure 2 further shows that the upper half of the cover 10 may include ribs 38 on the outer surface 40 of the semicircular section 28 of the cover, extending radially from the notch 30 toward the periphery of the section 28, in order to provide structural support for axial forces generated during the operation of the generator 16.

[0026] Figure 3 shows a schematic diagram of a cover axial pull tool 42 that can be used as part of a system for removing a cover, such as the upper half portion of a cover 10 as illustrated in Figure 2, from the enclosure 14 of a generator 16, according to one embodiment of the present disclosure. In one embodiment, the cover axial pull tool 42 is configured to lift up a section of the cover (e.g., the upper half portion having a protruding feature on its inner surface), move the section of the cover axially away from the enclosure to disengage it from the stator frame of the stator housed in the enclosure 14, and park the section of the cover by creating a gap between the enclosure and the cover axial pull tool.

[0027] As shown in Figure 3, the cover axial pull tool 42 may include a cover mounting plate 44 configured to be attached to the upper half of the cover 10 and a portion of the generator enclosure 14. For clarity in describing the features of the cover axial pull tool 42, both the cover and the enclosure, as well as components housed in the enclosure such as the stator and rotor, are not shown in Figure 3. The cover axial pull tool 42 may further include a vertical lift assembly 46 coupled to the cover mounting plate, configured to lift the section of the cover vertically after the cover mounting plate 44 has been attached to the section of the cover and a portion of the generator enclosure. The cover axial pull tool 42 may also include a mechanical linear actuator assembly 48 configured to move the cover mounting plate 44 and the vertical lift assembly 46 axially relative to the generator enclosure, thereby disengaging the section of the cover from the stator frame and moving it away from the enclosure 14.

[0028] In one embodiment, as shown in Figure 3, the cover mounting plate 44 may include a semicircular upper section 50 having a plurality of fasteners 51, such as bolts, configured to fasten to mounting holes located on a semicircular section of the cover, as shown in the cover 10 in Figure 2. The opposite side of the semicircular upper section 50 (i.e., the side or face not connected to the cover) may include several lugs 53 that can be utilized by a hoist assembly to lift a cover axial pull tool 42 between the installation and removal location of the cover (i.e., the enclosure space around the enclosure and prime mover). The cover mounting plate 44 may further include a post support section 52 formed by spaced first support post structures 52a and second post support structures 52b that support the upper section 50. The cover mounting plate 44 may also include a base section 54 having a first base section 54a and a second base section 54b that correspondingly support the first support post structures 52a and second support post structures 52b thereon. In this regard, the upper section 50 is configured to be attached to the upper half of the cover and the base section 54 via a first base section 54a, and the second base section 54b is configured to be attached to the lower half of the cover having a matching flange / section.

[0029] Figures 4A and 4B show further details of the coupling of the cover axial pull tool 42 to the upper half of the cover 10, as described with respect to Figure 2, after the tool has been moved into the enclosure space between the enclosure and the prime mover and into a position for coupling with the enclosure 14 via the mechanical linear actuator assembly 48. In particular, Figure 4A shows the upper section 50 of the cover mounting plate 44 coupled to a mounting hole in the upper half of the cover 10 via a fastener 51. In one embodiment, as shown in Figures 4A and 4B, the base sections 54a and 54b of the cover mounting plate 44 can be mounted under the base sections 32a and 32b of the cover 10 via a fastener 55 which may include any of a number of fastening devices such as bolts. In this position, the vertical lift assembly 46 of the cover axial pull tool 42 can be deployed and engaged with a hydraulic cylinder and a vertically-oriented linear bearing, allowing the cover to be lifted vertically and disengaged from the stator frame.

[0030] Referring again to Figure 3, the mechanical linear actuator assembly 48 of the cover axial pull tool 42 may include a pair of spaced-apart travel plates 56 that facilitate the axial movement of the cover mounting plate 44 and the vertical lift assembly 46 relative to the generator enclosure. The mechanical linear actuator assembly 48 may further include a pair of linear bearings 58, each configured to receive one of the pair of travel plates 56 on it. The mechanical linear actuator assembly 48 may also include a pair of screw drive systems 60 that are operably coupled to the pair of linear bearings 58 and drive the axial movement of the cover mounting plate 44 and the vertical lift assembly 46 along the pair of linear bearings.

[0031] In one embodiment, each of a pair of screw drive systems 60 may include a screw rod 62 on which a male thread is formed. A screw nut 64 having a corresponding female thread can work in cooperation with the male thread of the screw rod 62, allowing the screw rod to rotate within the screw nut. Each of the screw drive systems may also include a drive wheel 66 and an accompanying timing belt for rotating the screw rod 62 within the screw nut 64. In this regard, the rotation of the drive wheel 66 results in a sliding interaction of the screw rod 62 within the screw nut 64, causing translational motion (i.e., axial movement) of the cover mounting plate 44 and the vertical lift assembly 46 positioned thereon. Although Figure 3 shows only one drive wheel 66, from the way the figure is viewed, it is understood that another drive wheel is positioned around the second post support structure 52b. In one embodiment, the drive wheel 66 may include a manually operated drive wheel, but it is understood that other drive wheel systems, such as a power-driven drive wheel, are suitable.

[0032] Figure 3 shows that a vertical lift assembly 46, which can vertically lift the upper half of the cover 10 after the cover mounting plate 44 has been attached to the cover and part of the enclosure, may include a pair of vertically oriented linear bearings 68. In addition, the vertical lift assembly 46 may include a pair of hydraulic cylinders 70 operably coupled to the pair of vertically oriented linear bearings 68. Each of the pair of hydraulic cylinders 70 is configured to receive hydraulic energy that generates a linear force and motion that advances the cylinder upward along one of the pair of vertically oriented linear bearings 68. Although not shown in Figure 3 for the sake of reading the figure, the vertical lift assembly 46 may further include a pair of limiting screws 72 configured to lock the pair of hydraulic cylinders 70 in place on the pair of vertically oriented linear bearings 68 after they have advanced upward to a predetermined position (see Figure 5, which shows another illustration of the cover axial pull tool 42).

[0033] Figure 5 shows a schematic diagram of a cover axial pull tool 42 illustrated in Figure 3, supported by a hoist assembly 74, which can also be used as part of a system for removing a cover from an enclosure and lifting it away from a generator. In one embodiment, the hoist assembly 74 is configured to lift the cover axial pull tool 42 into the enclosure space between the generator enclosure and the prime mover (the enclosure, generator, and prime mover are not shown in Figure 5). The hoist assembly 74 may include several components for raising and lowering a load. In general, the hoist assembly 74 may include several well-known components that can operate as part of a hoist assembly. For example, the hoist assembly 74 may include a hook, such as a lower hook 76, which can be coupled to the cover axial pull tool 42 via a sling 78, which is attached to lugs 53 located around the lower hook and the cover axial pull tool 42. As shown in Figure 5, the lug 53 can be positioned on the semicircular upper section 50, base section 54, and even the post support section 52 of the cover mounting plate 44 of the cover axial pull tool 42, although this is not explicitly shown in the figure. Figure 5 further shows that the hoist assembly 74 may include a hoist frame 80 that includes a lifting mechanism for lifting loads. A load chain 82 can connect the hoist frame 80 to a dedicated lifting point. Although not shown, the dedicated lifting point may include a beam, such as an I-beam, positioned above the enclosure space between the generator enclosure and the prime mover. In this regard, in one embodiment, the hoist assembly 74 can be used to move the cover axial pull tool 42 in and out of the enclosure space between the generator enclosure and the prime mover.

[0034] While the hoist frame 80 is broadly described as having a lower hook 76, a sling 78, the hoist frame 80, a load chain 82, and a dedicated lifting point, it is understood that the hoist assembly 74 may include additional components such as gear and pulley mechanisms, safety latches, and additional hooks, which may be part of the lifting mechanism that is part of the hoist frame. Furthermore, it is understood that the hoist assembly 74 is not limited to any particular type of assembly and may include several well-known hoist assemblies used to move loads, such as electric hoists and pneumatic hoists.

[0035] In addition, it will be understood that the use of the hoist assembly and any of the aforementioned components is illustrative and not intended to limit the various embodiments described herein. Those skilled in the art will readily recognize that other well-known lifting mechanisms / toolings used for moving and lifting large, heavy, and bulky objects with complex geometric shapes are possible options that may be useful in various embodiments.

[0036] Figures 6A to 6F schematically illustrate the process of using a cover axial pull tool 42 to remove the cover 10 from the enclosure 14 of the generator 16. In Figure 6A, the upper half of the cover 10, including the protruding inner surface 12 of the cover, is in place within the enclosure 14, engaged with the stator frame 84 of the stator, which is housed in the enclosure of the generator 16 along with other components such as the rotor. Figure 6A further shows that the cover axial pull tool 42 has been moved into place within the enclosure space of the generator 16 via the mechanical linear actuator assembly 48 of the cover axial pull tool. For example, an operator can move the travel plate 56 relative to the cover using the screw drive system 60 of the cover axial pull tool 42. The operator can then connect the cover mounting plate 44 of the cover axial pull tool 42 to the cover 10 via various fasteners 51.

[0037] In Figure 6B, the cover 10 can then be lifted vertically to a predetermined height, and the removal of the cover from the enclosure can begin. In one embodiment, a jack screw can be placed under the cover 10 and used to lift the cover vertically to a predetermined initial height. For example, in one embodiment, the jack screw can be used to initially lift the cover 10 up to 0.25 inches to facilitate the removal of the cover from the enclosure 14. It will be understood that this initial lift amount is merely an example of one possible initial height lift value and is not intended to limit the embodiments described herein. Those skilled in the art will recognize that the initial height lift depends on several factors, including, but not limited to, the geometric shapes of the cover and stator frame, as well as any gaps that may exist between them when the cover is fitted into the enclosure. In any case, the lifting of the cover with the jack screw is performed to close any gaps that may exist between the cover and the stator frame.

[0038] When the cover 10 is lifted upward, the mechanical linear actuator assembly 48 of the cover axial pull tool 42 can be used to move the cover axially away from the enclosure 14 and disengage it from the stator frame 84, as shown in Figure 6C. For example, the operator can use the screw drive system 60 to move the running plate 56 on which the cover 10 is supported axially away from the enclosure 14 and disengage it from the stator frame 84, as shown by the reference element 86 in Figure 6C.

[0039] In Figure 6D, the vertical lift assembly 46 of the cover axial pull tool 42 can be used to vertically lift the cover 10 upward by an additional height beyond the initial height provided by the jack screw. In particular, the vertical orientation linear bearing 68 and hydraulic cylinder 70 can be used to vertically lift the cover 10 to this additional vertical height. For example, in one embodiment, the vertical lift assembly 46 can be used to lift the cover a further 2 inches. Figure 6D further shows that after the cover 10 has been lifted to this additional height, a limiting screw 72 can be used to lock the cover at this height. It is understood that the limiting screw 72 can also be used as an operator reference to ensure that the vertical lift assembly 46 lifts the cover vertically to a sufficient height. Furthermore, this additional height, such as the initial height provided by the jack screw, is merely an example of a set of vertical heights and is not meant to be limiting, and those skilled in the art will recognize that the amount of vertical height required to disengage the cover depends on several factors, including, but not limited to, the geometric shape and weight of the cover, as well as the geometric shape of the stator frame.

[0040] After lifting the cover 10 to an additional vertical height, the cover axial pull tool 42 can be used to move the cover further axially away from the enclosure 14, as shown in Figure 6E. For example, the screw drive system 60 of the mechanical linear actuator assembly 48 of the cover axial pull tool 42 can move the travel plate 56 on which the cover 10 is mounted axially away from the enclosure 14. In this way, the cover axial pull tool 42 moves the cover 10 to a parking location that is away from the enclosure 14 and stator frame 84 but still in the enclosure space between the generator 16 and the prime mover, making it easier to maintain the generator and its internal components such as the stator and rotor.

[0041] Once the cover 10 is moved axially to the parking location, the cover axial pull tool 42 can be further engaged to lower the cover, as shown in Figure 6F. For example, the limiting screw 72 can be released, and the height of the cover 10 can be lowered using the vertically oriented linear bearing 68 and hydraulic cylinder 70 of the vertical lift assembly 46 of the cover axial pull tool 42. In this regard, the cover 10 can be placed on the base section 54 of the cover mounting plate of the cover axial pull tool 42 (i.e., the first base section 54a and the second base section 54b of the base section 54).

[0042] For the sake of simplicity, the actions shown in Figures 6A to 6F are described as a series of actions. It should be understood and acknowledged that the subjective innovations related to Figures 6A to 6F are not limited by the order of actions, as some actions may occur simultaneously with others in different order, and some of the shown actions may be divided and performed as two or more actions in different time instances. For example, instead of using a jack screw to facilitate the initial vertical lift of the cover, it is possible to perform this action using the vertical lift assembly 46 of the cover axial pull tool. Therefore, modifications or variations of the actions illustrated in Figures 6A to 6F are possible. Furthermore, not all exemplified actions are required to implement the methodology according to the innovation. Moreover, two or more of the disclosed exemplary methods can be combined to achieve one or more features or advantages described herein.

[0043] Another component of the system that can be used to remove the cover 10 from the enclosure 14 of the generator 16 according to one embodiment includes the use of a cover vertical lift tool 88, as further illustrated and described in relation to Figures 7A-7C, 8, and 9. In one embodiment, the cover vertical lift tool 88 is positioned in the space between the enclosure 14 and the cover axial pull tool 42 after the cover axial pull tool 42 has been moved axially away from the enclosure with the cover on it, and is configured to work in cooperation with the enclosure, the cover axial pull tool, and the hoist assembly to provide a path for the upper half of the cover to navigate when the cover is lifted from the cover axial pull tool using the hoist assembly. As shown in Figures 7A-7C, the cover vertical lift tool 88 may include a vertical guide rail assembly 90 configured to couple with the enclosure 14 and a trolley lift assembly 92 that receives the upper half of the cover 10 from the cover axial pull tool 42.

[0044] In one embodiment, the trolley lift assembly 92 may include a pair of trolley posts 94, as clearly shown in Figures 7C and 8. Each of the trolley posts 94 may have a wheel assembly 96 (e.g., steel, nylon wheels, etc.) on one side of the post. In one embodiment, the wheel assembly 96 may be positioned on the side of the trolley post 94 facing the axial end of the enclosure 14. The opposite end of the post 94 may be configured to attach to the upper half of the cover 10 via one of several fastening systems, such as a bolt and nut assembly. For example, as shown in Figure 8, one end of the trolley post 94 may be coupled to a mounting hole 34 on the periphery of the semicircular section 28 of the cover 10, and the opposing end may be coupled to the lower half of the cover near a notch 30.

[0045] In one embodiment, the vertical guide rail assembly 90 may include a pair of vertically oriented guide rails 98, as shown in Figures 7A-7C and 9. Each of the vertically oriented guide rails 98 may have a bottom section 100 and an upper section 102 that are coupled to each other via a connector 103. The bottom section 100 of the guide rail 98 is configured to be attached to a section of the enclosure 14, and the upper section 102 is configured to extend vertically upward beyond the perimeter of the enclosure 14 after the bottom section has been attached to the enclosure. As shown in Figures 7A, 7B, and 9, the bottom section 100 of the guide rail 98 may be attached to a rotor support section 110 of the enclosure 14. The rotor support section 110 of the enclosure 14 may include a bottom support portion 112 whose shape corresponds to that of the rotor 20, such that the rotor is positioned directly above it. The side platform portion 114 of the rotor support section 110 connects to the upper surface of the bottom support portion 112 and extends radially along the side of the enclosure 14. In this regard, the bottom section 100 of the guide rail 98 can be attached to these side platform portions of the rotor support section 110 via mounting holes located on one side of the side platform portion 114, using mounting bolt and nut assemblies 116.

[0046] Figures 7A, 7B, and 9 further illustrate that the upper section 102 of the guide rail 98 can also be mounted to the enclosure. In one embodiment, the upper section 102 of the guide rail 98 is mounted to a section of the enclosure above the rotor support section 110. For example, as shown in Figure 9, the upper section 102 of the guide rail 98 can be mounted to a semicircular portion 118 of the enclosure 14 surrounding the rotor. In particular, the upper section 102 of the guide rail 98 can be coupled to mounting holes arranged around the semicircular portion 118 of the enclosure 14 via a mounting bolt and nut assembly 116.

[0047] It is understood that the various sections of the guide rail 98, such as the bottom section 100 and the top section 102, are for nominal purposes only and are not intended to limit the various embodiments described. Instead of having a rail guide formed from the bottom section 100 and the top section 102, the guide rail can be formed with more or fewer guide rails. For example, the guide rail may include only intermediate section rails, or a single rail defined by segments, to distinguish different areas of the rail, as opposed to a modular arrangement of sections of rail.

[0048] The vertical guide rail assembly 90 may further include a pair of horizontally extending cross rails 104 that connect a pair of vertically oriented guide rails 98 to each other. In one embodiment, as shown in Figure 9, the horizontally extending cross rails 104 may have lifting points 120 positioned on them to facilitate moving the vertical guide rail assembly 90 in and out of the enclosure space between the enclosure 14 and the prime mover via a hoist assembly.

[0049] Figures 7A–7C and 9 show that the vertical guide rail assembly 90 may further include a pair of inclined guide rails 106 extending diagonally from the upper sections 102 of a pair of vertically oriented guide rails 98, each of which is configured to extend over the enclosure 14. This configuration of the vertical guide rail assembly 90 allows the hoist assembly 74 (not shown in Figures 7A–7C and 9) to maneuver the wheel assembly 96 on a pair of trolley posts 94 along the pair of vertically oriented guide rails 98 and the pair of inclined guide rails 106. As shown in Figure 8, lifting the trolley lift assembly 92 and the section of the cover mounted thereon over the enclosure 14 from the cover axial pull tool 42 can be facilitated by a lifting plate 108 coupled to a mounting hole on the periphery of the semicircular section 28 of the cover 10. In this regard, the cover vertical lift tool 88 can work in cooperation with the hoist assembly 74 to facilitate the lifting operation so as to prevent any contact between the upper half of the cover 10 and the enclosure 14.

[0050] In this configuration, the cover vertical lift tool 88, which may include a vertical guide rail assembly 90 and a trolley lift assembly 92, can be easily placed in the gap created by axially moving the cover axial pull tool 42, carrying the cover 10, from the enclosure 14. In this position, the vertical guide rail assembly 90 can provide sufficient clearance from the enclosure 14 for the protruding section 12 of the cover 10 so that the protruding section does not interfere with the enclosure, stator, and any other nearby structures (e.g., cables, trays, etc.). This allows the hoist assembly to lift the trolley lift assembly in a controller manner with the cover 10 supported thereon, and as a result, the hoist assembly can maneuver the trolley lift assembly along the rails, navigate the enclosure, and maneuver it to a fixed lifting point above the generator without any contact between the cover and the enclosure and the generator, avoiding any damage to these components.

[0051] Figures 10A–10K schematically illustrate the lifting operation of a cover 10 from the enclosure 12 of a generator 16 using a system 122 that includes a cover vertical lift tool 88, a cover axial pull tool 42, and a hoist assembly 74, according to one embodiment of the present disclosure. The lifting operation process begins in Figure 10A, where the cover axial pull tool 42 is used to disengage the cover 10 from the stator frame and move it axially away from the enclosure 14. If there is sufficient space to separate the disengaged cover 10 from the cover axial pull tool 42 from the enclosure 14, the cover vertical lift tool 88 can be introduced into the space and positioned on various sections of the enclosure (e.g., the rotor support section 110 of the enclosure and the semicircular section 118 of the enclosure), as shown in Figure 10B. In addition, a hoist assembly can be connected to the cover 10 according to Figures 10B, 10C, and 10D. For clarity, Figures 10A–10K show only the components of the hoist assembly, such as the fixed-position hoist beam 124 positioned above the enclosure space and the sling 78 used to attach the cover to the hoist assembly. It is understood that the hoist assembly may include other components as described above, such as the hook, hoist frame, and load chain.

[0052] As shown in Figures 10A to 10K, when the cover 10 is lifted from the cover axial pull tool 42 and directed toward the beam 124 while in the parking position on the cover axial pull tool 42, it is offset from the beam. As described above in conventional cover removal operations, this offset poses a problem because the center of gravity of the cover, due to its protruding section on this upper half of the cover portion, causes the cover to swing, oscillate, or invert toward the cover, and potentially come into contact with the enclosure. This unintended contact can damage generator components such as stator components, as well as any structures associated with the enclosure. The embodiments described above avoid this dilemma by using the cover axial pull tool 42 and the cover vertical lift tool 88 to eliminate concerns that the center of gravity of the cover may come into contact with and damage the enclosure and stator portion during removal and lifting of the cover from the generator enclosure.

[0053] As the lifting operation shown in Figures 10E, 10F, and 10G begins in earnest, the hoist assembly starts lifting the cover 10 from the cover axial pull tool 42. In this regard, the hoist assembly lifts the trolley lift assembly 92 of the vertical guide rail assembly 90, which supports the cover 10, along the guide rail of the assembly 90. By lifting the trolley and cover along the guide rail (i.e., the wheel assembly 96 moves along the rail), the system prevents the cover from coming into contact with the enclosure and generator components.

[0054] Figures 10H, 10I, and 10J show that the hoist assembly maneuvers the cover and trolley lift assembly along the guide rail of assembly 90 to the section where the rail transitions to the inclined guide rail 106. Despite the large angle of the lift of the cover and trolley lift assembly relative to the beam 124, the inclined guide rail prevents the cover from swinging or swaying at this point in the lifting motion. Furthermore, because the cover and trolley lift assembly is at the shortest distance to the beam 124 compared to its location in Figures 10A–10G, the system 122 can lift the cover and trolley lift assembly over the enclosure in a safe and controlled manner, avoiding contact and associated damage. The safe and controlled lift of the cover and trolley lift assembly continues in Figure 10J, where these components are no longer offset from the beam 124 and are instead perpendicular to the beam.

[0055] Finally, the wheel assembly 96 of the trolley lift assembly 92 is guided from the inclined guide rail 106, as shown in Figure 10K. In this regard, the hoist assembly can continue to lift the cover 10 vertically toward the beam 124 until the cover is removed from the generator plane in a location safe for the operator responsible for maintaining the generator.

[0056] Once the cover is removed and safely lifted away from the enclosure 14, the operator can perform necessary maintenance and repair work on the generator components. After the maintenance and repair work on the generator components is completed, the cover 10 can be reinstalled on the enclosure. Generally, reinstalling the cover 10 on the enclosure involves reversing the actions performed by the cover axial pull tool 42, the cover vertical lift tool 88, and the hoist assembly 74. For example, the hoist assembly 74 pulls the cover back along the guide rail toward the guide rail and finally places it on the cover axial pull tool. The guide rail and trolley can then be removed from the enclosure 14 and the cover, respectively. The cover axial pull tool can then be used to axially return the cover to its position and reattach it to the enclosure.

[0057] For the sake of simplicity, the actions shown in Figures 10A to 10K are described as a series of actions. It should be understood and acknowledged that the technological innovations relating to the subject matter in Figures 10A to 10K are not limited by the order of actions, as some actions may occur simultaneously with others in different order, and some of the shown actions may be divided and performed as two or more actions in different time instances. Therefore, modifications or variations of the actions illustrated in Figures 10A to 10K are possible. Furthermore, not all exemplified actions are required to implement the methodology according to the technological innovation. Moreover, two or more of the disclosed exemplary methods can be combined to achieve one or more features or advantages described herein.

[0058] The lifting operations described in Figures 10A to 10K represent only examples of techniques that can be used to remove a cover from a generator enclosure using a cover axial pull tool 42 and a cover vertical lift tool 88, and are not intended to be limiting so as a person skilled in the art will recognize that various modifications to the system 122, as well as modifications to the cover axial pull tool 42, the cover vertical lift tool 88, and the hoist system 74, are possible. For example, instead of using one fixed-position beam as part of the hoist assembly, one possible embodiment involves using two fixed-position beams 124 as shown in Figure 11. In this embodiment, the two fixed-position beams 124 can be used to transfer the load of the upper half of the cover 10 from one hoist beam to the other while lifting the cover upwards from the enclosure 14 via the cover vertical lift tool 88. In another embodiment illustrated in Figure 12, the fixed-position hoist beam 124 may be of a type that includes a cantilever hoist beam having a counterweight 126 to accommodate the load on the upper half of the cover 10 while the hoist assembly lifts the cover so that it moves upward away from the enclosure 14.

[0059] From the description of the embodiments presented herein, it is clear that this subject matter disclosure provides an effective solution to the complexities and challenges associated with removing a portion of a cover (e.g., the upper portion) from a generator enclosure in a confined space, particularly when the cover features a geometric shape of a protruding section that causes the cover to tilt, swing, or invert due to the offset of its center of gravity relative to a fixed lifting position above the enclosure space, which poses problems in conventional removal operations. By using the aforementioned cover axial pull tool and cover vertical lift tool together with a hoist assembly, safe and controlled removal and lifting of the cover from the enclosure becomes possible. Systems and methods utilizing these components not only provide safe operation that protects operators involved in the removal and lifting process, but these tools also require fewer operators than conventional methods for achieving the removal and lifting operation. In addition, the use of the cover axial pull tool, cover vertical lift tool, and hoist assembly is substantially hands-free, making the removal and lifting of the cover from the enclosure quicker and more labor-saving. Furthermore, the cover axial pull tool, cover vertical lift tool, and hoist assembly eliminate the risk of the cover swinging, swaying, or flipping against the enclosure, which could damage the generator and enclosure components (e.g., stator section, gaskets, etc.).

[0060] The above description relating to the illustrated embodiments of the subject matter disclosure, including those described in the abstract, is not intended to be exhaustive or to limit the disclosed embodiments to the forms disclosed herein. Certain embodiments and examples are described herein for illustrative purposes, but various modifications are possible that would be recognized by those skilled in the art as falling within the scope of such embodiments and examples. For example, parts, components, steps, and aspects from different embodiments may be combined or appropriate for use in other embodiments, even if they are not described or depicted in the drawings. Thus, since certain modifications can be made to the methods described above without departing from the spirit and scope of the improvements contained herein, all of the subject matter described above shown in the accompanying drawings should be interpreted only as examples illustrating the concept of the invention herein and not as limiting the disclosure.

[0061] In this regard, while the disclosed subject matter is described in relation to various embodiments and corresponding figures, it should be understood that, where applicable, other similar embodiments can be used to perform the same, similar, alternative, or substitute functions of the disclosed subject matter, or modifications and additions can be made to the embodiments described, without departing from the disclosed subject matter. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be interpreted broadly in accordance with the appended claims below. For example, the reference to “one embodiment” in this disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the enumerated features.

[0062] In the attached claims, the terms “including” and “in which” are used as plain English synonyms for “comprising” and “wherein,” respectively. Furthermore, in the following claims, terms such as “first,” “second,” “third,” “upper,” “lower,” “bottom,” and “top” are used merely as markers and are not intended to impose numerical or positional requirements on those objects. The terms “substantially,” “generally,” and “about” indicate conditions within manufacturing and assembly tolerances that are achievable without strain for an ideal desired condition suitable for achieving the functional purpose of a component or assembly. Furthermore, the following limitations in the claims are not written in means-plus-function form, nor are they intended to be interpreted as such, unless such limitations explicitly use the phrase “means for” in combination with a description of function lacking further structure.

[0063] The foregoing includes examples of systems and methods illustrating the disclosed subject matter. Of course, it is impossible to describe here all combinations of components or methodologies. Those skilled in the art will recognize that many further combinations and substitutions of the claimed subject matter are possible. Furthermore, to the extent that terms such as “includes,” “has,” and “possesses” are used in the detailed description, claims, appendices, and drawings, such terms are intended to be as comprehensive as “comprising,” as the term “comprising” is interpreted when used as a transitional term in the claims. That is, unless explicitly stated otherwise, embodiments that “comprising,” “include,” or “having” an element or a plurality of elements having a particular nature may further include such elements that do not have that nature. Furthermore, the articles “a” and “an” used herein and in the accompanying drawings should generally be interpreted as meaning “one or more,” unless otherwise specifically stated and it is clear from the context that they refer to a singular form.

[0064] This specification uses examples to disclose several embodiments of the Disclosure, including in best form, and to enable a person skilled in the art to practice the embodiments of the Disclosure, including the fabrication and use of any device or system, and the implementation of any incorporated method. The patentable scope of the Disclosure is defined by the claims and may include other examples that a person skilled in the art may conceive. Such other examples are intended to be within the claims if they have structural elements that do not differ from the language of the claims, or if they include equivalent structural elements that do not substantially differ from the language of the claims.

[0065] Further aspects of this disclosure are provided by the subject matter of the following clauses.

[0066] A system for removing a cover from a generator enclosure housing a stator and rotor, comprising a cover axial pull tool for pulling a section of the cover from the generator enclosure, the cover axial pull tool being configured to lift the section of the cover upward, move the section of the cover axially away from the generator enclosure to disengage it from the stator frame of the stator, and create a gap between the generator enclosure and the cover axial pull tool to park the section of the cover, and the generator enclosure and the cover axial pull tool A system comprising: a cover vertical lift tool positioned at the interval to work in cooperation with the cover axial pull tool and configured to provide a path for the section of the cover to navigate when the cover is lifted from the cover axial pull tool; and a hoist assembly that works in cooperation with the cover axial pull tool and the cover vertical lift tool to lift the section of the cover upward from the cover axial pull tool and continue to lift the cover upward away from the generator enclosure without contacting the generator enclosure, while navigating the path provided by the cover vertical lift tool.

[0067] The system according to the preceding clause, wherein the cover axial pull tool comprises a cover mounting plate configured to be attached to the section of the cover and a portion of the generator enclosure; a vertical lift assembly coupled to the cover mounting plate, configured to lift the section of the cover vertically after the cover mounting plate has been attached to the section of the cover and the portion of the generator enclosure; and a mechanical linear actuator assembly configured to move the cover mounting plate and the vertical lift assembly axially relative to the generator enclosure, wherein the mechanical linear actuator assembly is configured to disengage the section of the cover from the stator frame and move the cover axially away from the generator enclosure.

[0068] The system according to any one of the preceding clauses, wherein the cover mounting plate comprises an upper section, a post support section formed by spaced first support post structures and second post support structures supporting the upper section, and a base section having a first base section and a second base section correspondingly supporting the first support post structures and the second support post structures thereon, wherein the upper section is configured to be attached to the section of the cover, and the base section is configured to be attached to a part of the generator enclosure.

[0069] The system according to any one of the preceding clauses, wherein the mechanical linear actuator assembly comprises a pair of spaced-apart traveling plates that facilitate the axial movement of the cover mounting plate and the vertical lift assembly relative to the generator enclosure; a pair of linear bearings, each configured to receive one of the pair of traveling plates on which it rests; and a pair of screw drive systems operably coupled to the pair of linear bearings and driving the axial movement of the cover mounting plate and the vertical lift assembly along the pair of linear bearings.

[0070] The system according to any one of the preceding clauses, wherein each of the pair of screw drive systems comprises a screw rod having a male thread formed thereon, a screw nut having a corresponding female thread to work in cooperation with the male thread of the screw rod, and a drive wheel for rotating the screw rod within the screw nut, the rotation of which results in a sliding interaction of the screw rod within the screw nut, causing translational motion of the cover mounting plate and the vertical lift assembly.

[0071] The system according to any one of the preceding clauses, wherein the vertical lift assembly comprises a pair of vertically oriented linear bearings and a pair of hydraulic cylinders operably coupled to the pair of vertically oriented linear bearings, each of the pair of hydraulic cylinders being configured to receive hydraulic energy that generates a linear force and motion that advances the cylinder upward along one of the pair of vertically oriented linear bearings.

[0072] The system according to any one of the preceding clauses, wherein the vertical lift assembly further comprises a pair of limiting screws configured to lock the pair of hydraulic cylinders into a fixed position in the pair of vertically oriented linear bearings after it has advanced upward to a predetermined position.

[0073] The system according to any one of the preceding clauses, wherein the cover vertical lift tool comprises a vertical guide rail assembly configured to be coupled to the generator enclosure and a trolley lift assembly that receives the section of the cover from the cover axial pull tool, and the hoist assembly is configured to lift the section of the cover on the trolley lift assembly upward along the vertical guide rail assembly, preventing any contact between the section of the cover and the generator enclosure.

[0074] The trolley lift assembly comprises a pair of trolley posts, each of which has a wheel assembly on one side of the post, and the other side of the post is configured to be attached to the section of the cover, as described in any one of the preceding clauses.

[0075] The vertical guide rail assembly comprises a pair of vertically oriented guide rails, each of which has a bottom section and an upper section, the bottom section being configured to be attached to a section of the generator enclosure, the upper section being configured to extend vertically upward beyond the perimeter of the generator enclosure after the bottom section has been attached to the generator enclosure, a pair of horizontally extending cross rails connecting the pair of vertically oriented guide rails to each other, and a pair of inclined guide rails extending diagonally from the upper sections of the pair of vertically oriented guide rails, each of which has a pair of inclined guide rails extending over the generator enclosure, the system according to any one of the preceding clauses, wherein the hoist assembly is configured to steer the wheel assembly on the pair of trolley posts along the pair of vertically oriented guide rails and the pair of inclined guide rails, during which the hoist assembly lifts the trolley lift assembly and the section of the cover placed thereon upward from the cover axial pull tool onto the generator enclosure.

[0076] The system according to any one of the preceding clauses, wherein the hoist assembly includes at least one fixed-position hoist beam positioned above the generator enclosure, the at least one fixed-position hoist beam being configured to support lifting the section of the cover above the generator enclosure along the cover axial pull tool to the cover vertical lift tool.

[0077] The system according to any one of the preceding clauses, wherein the at least one fixed-position hoist beam comprises two fixed-position hoist beams that transfer the load of the section of the cover from one hoist beam to the other hoist beam while lifting the cover away from the generator enclosure.

[0078] The system according to any one of the preceding clauses, wherein the at least one fixed-position hoist beam comprises a cantilever hoist beam having a counterweight for dealing with the load on the section of the cover while lifting the cover away from the generator enclosure.

[0079] A method for removing a cover from a generator enclosure housing a stator and rotor, comprising: placing a cover axial pull tool on the generator enclosure adjacent to the cover; attaching the cover axial pull tool to a section of the cover and a portion of the generator enclosure; using the cover axial pull tool to lift the section of the cover; using the cover axial pull tool to move the section of the cover axially away from the generator enclosure to disengage it from the stator frame of the stator and create a gap between the generator enclosure and the cover axial pull tool; and after moving the section of the cover axially away from the generator enclosure, between the generator enclosure and the cover axial pull tool A method comprising: placing a cover vertical lift tool in the gap formed therein, wherein the cover vertical lift tool provides a guide path for the section of the cover to navigate when lifting the cover from the cover axial pull tool; using a hoist assembly to lift the section of the cover upward from the cover axial pull tool; guiding the hoist assembly to maneuver the section of the cover along the guide path provided by the cover vertical lift tool; and continuing to use the hoist assembly to lift the section of the cover upward away from the generator enclosure without contact with the generator enclosure, while navigating the guide path provided by the cover vertical lift tool.

[0080] The method according to the preceding clause, wherein the cover axial pull tool comprises a cover mounting plate configured to be attached to the section of the cover and a portion of the generator enclosure, a vertical lift assembly coupled to the cover mounting plate configured to lift the section of the cover vertically after the cover mounting plate has been attached to the section of the cover and the portion of the generator enclosure, and a mechanical linear actuator assembly configured to move the cover mounting plate and the vertical lift assembly axially relative to the generator enclosure, the mechanical linear actuator assembly configured to disengage the section of the cover from the stator frame and move the cover axially away from the generator enclosure, the cover vertical lift tool comprises a vertical guide rail assembly configured to be coupled to the generator enclosure, and a trolley lift assembly to receive the section of the cover from the cover axial pull tool, the hoist assembly configured to lift the section of the cover on the trolley lift assembly upward along the vertical guide rail assembly and prevent any contact between the section of the cover and the generator enclosure. [Explanation of symbols]

[0081] 10 Cover / End Shield 12. Protruding inner surface of cover 10 14 Enclosures 16 Generators 18 Hoist Assembly 20 rotors 22 beams 24 Engine 26 Sling or tagline 27 Operators 28 Semicircular section of cover 10 30 Cover 10 cutouts 32 Base section formed by base sections 32a and 32b 34 mounting holes 36 Inner surface of cover 10 to be attached to enclosure 14 38 Structural Ribs 40 Cover 10 outer surface 42 Cover Axial Pull Tool 44 Cover mounting plate 46 Vertical Lift Assembly 48 Mechanical Linear Actuator Assembly 50 Semicircular upper section of cover mounting plate 44 51 Fasteners (bolts) on the semicircular upper section 50 of the cover mounting plate 44 52 Post support section of cover mounting plate 44 formed by the first support post structure 52a and the second post support structure 52b 53 rug 54 Base section of cover mounting plate formed by the first base section 54a and the second base section 54b 55 Fasteners 56 Pair of travel plates of mechanical linear actuator assembly 48 58 Pair of linear bearings of mechanical linear actuator assembly 48 60 Mechanical Linear Actuator Assembly 48 Screw Drive System 62 Screw drive system 60 screw rods 64 Screw drive system 60 screw nuts 66 Drive Wheels 68 Vertical Lift Assembly 46 Vertical Orientation Linear Bearing 70 Vertical lift assembly with 46 hydraulic cylinders 72 Vertical lift assembly 46 limiting screw 72 74 Hoist Assembly 76 Lower hook of hoist assembly 78 Sling 80 Hoist Frame 82 Load Chain 84 Stator Frame 86. Disengaging the cover from the stator frame. 88 Cover Vertical Lift Tool 90 Vertical Guide Rail Assembly 92 Vertical Guide Rail Assembly 90 Trolley Lift Assembly 94 Pair of trolley posts 96 Wheel assembly on trolley post 94 98 Vertical Guide Rail Assembly 90 Pair of Vertically Oriented Guide Rails 100 Guide rail 98 bottom section 102 Upper section of guide rail 98 103 Connector connecting the bottom section 100 and the upper section 102 of the guide rail 98. 104 Horizontally extending cross rails 106 Pair of inclined guide rails 106 108 Lifting plate coupled to mounting holes on the periphery of the semicircular section 28 of cover 10 110 Rotor support section of enclosure 14 112 Bottom support portion of rotor support section 110 114 Side platform portion of rotor support section 110 116 Mounting bolt and nut assembly 118 Semicircular portion of enclosure 14 surrounding the rotor 120 Lifting point on horizontally extending cross rail 104 122 System 124 Fixed position hoist beam 126 counterweights

Claims

1. A system for removing a cover (10) from a generator enclosure (14) that houses a stator and rotor (20), A cover axial pull tool (42) for pulling a section (28) of the cover (10) from the generator enclosure (14), wherein the cover axial pull tool (42) is configured to lift the section (28) of the cover (10) upward, move the section (28) of the cover (10) axially away from the generator enclosure (14) to disengage it from the stator frame (84) of the stator, and create a gap between the generator enclosure (14) and the cover axial pull tool (42) to park the section (28) of the cover (10), A cover vertical lift tool (88) is mounted at the interval to work in cooperation with the generator enclosure (14) and the cover axial pull tool (42), and is configured to provide a path for the section (28) of the cover (10) to navigate when the cover (10) is lifted from the cover axial pull tool (42), A hoist assembly (74) operates in cooperation with the cover axial pull tool (42) and the cover vertical lift tool (88) to lift the section (28) of the cover (10) upward from the cover axial pull tool (42), and continues to lift the cover (10) upward away from the generator enclosure (14) without contacting the generator enclosure (14) while navigating the path provided by the cover vertical lift tool (88). A system that includes these features.

2. The aforementioned cover axial pull tool (42) is, A cover mounting plate (44) is configured to be attached to the section (28) of the cover (10) and a part of the generator enclosure (14), A vertical lift assembly (46) coupled to the cover mounting plate (44), wherein the vertical lift assembly (46) is configured to vertically lift the section (28) of the cover (10) after the cover mounting plate (44) has been attached to the section (28) of the cover (10) and the part of the generator enclosure (14), A mechanical linear actuator assembly (48) configured to move the cover mounting plate (44) and the vertical lift assembly (46) axially relative to the generator enclosure (14), wherein the mechanical linear actuator assembly (48) is configured to disengage the section (28) of the cover (10) from the stator frame (84) and move the cover (10) axially from the generator enclosure (14) The system according to claim 1, comprising:

3. The cover mounting plate (44) is Upper section (50) and A post support section (52) is formed by a first support post structure (52a) and a second post support structure (52b) spaced apart, and supports the upper section (50), A base section (54) having a first base section (54a) and a second base section (54b) that correspondingly support the first support post structure (52a) and the second support post structure (52b), wherein the upper section (50) is configured to be attached to the section (28) of the cover (10), and the base section (54) is configured to be attached to a part of the generator enclosure (14) and The system according to claim 2, comprising:

4. The mechanical linear actuator assembly (48) is A pair of spaced-apart traveling plates (56) that facilitate the axial movement of the cover mounting plate (44) and the vertical lift assembly (46) relative to the generator enclosure (14), A pair of linear bearings (58) each configured to support one of the pair of running plates (56) on top of it, A pair of screw drive systems (60) are operably coupled to the pair of linear bearings (58) and drive the axial movement of the cover mounting plate (44) and the vertical lift assembly (46) along the pair of linear bearings (58). The system according to claim 2, comprising:

5. Each of the pair of screw drive systems (60) is A screw rod (62) with a male thread formed on it, A screw nut (64) having a corresponding female thread that works in cooperation with the male thread of the screw rod (62), A drive wheel (66) that rotates the screw rod (62) within the screw nut (64), wherein the rotation of the drive wheel (66) causes a sliding interaction of the screw rod (62) within the screw nut (64), causing translational motion of the cover mounting plate (44) and the vertical lift assembly (46). The system according to claim 4, comprising:

6. The vertical lift assembly (46) is A pair of vertically oriented linear bearings (68) and A pair of hydraulic cylinders (70) operably coupled to the pair of vertically oriented linear bearings (68), wherein each of the pair of hydraulic cylinders (70) is configured to receive hydraulic energy that generates a linear force and motion that advances the cylinder (70) upward along one of the pair of vertically oriented linear bearings (68) The system according to claim 2, comprising:

7. The system according to claim 6, wherein the vertical lift assembly (46) further comprises a pair of limiting screws (72) configured to lock the pair of hydraulic cylinders (70) in place on the pair of vertically oriented linear bearings (68) after they have advanced upward to a predetermined position.

8. The cover vertical lift tool (88) is, A vertical guide rail assembly (90) configured to be coupled to the generator enclosure (14), A trolley lift assembly (92) that receives the section (28) of the cover (10) from the cover axial pull tool (42) and Equipped with, The hoist assembly (74) is configured to lift the section (28) of the cover (10) on the trolley lift assembly (92) upward along the vertical guide rail assembly (90) and to prevent any contact between the section (28) of the cover (10) and the generator enclosure (14). The system according to claim 1.

9. The system according to claim 8, wherein the trolley lift assembly (92) comprises a pair of trolley posts (94), each of the trolley posts (94) having a wheel assembly (96) on one side of the post (94), and the opposite side of the post (94) is configured to be attached to the section (28) of the cover (10).

10. The vertical guide rail assembly (90) is A pair of vertically oriented guide rails (98), each of which has a bottom section (100) and an upper section (102), wherein the bottom section (100) is configured to be attached to a section of the generator enclosure (14), and the upper section (102) is configured to extend vertically upward beyond the perimeter of the generator enclosure (14) after the bottom section (100) has been attached to the generator enclosure (14), A pair of horizontally extending cross rails (104) connect the pair of vertically oriented guide rails (98) to each other, A pair of inclined guide rails (106) extending diagonally from the upper section (102) of the pair of vertically oriented guide rails (98), each of the inclined guide rails (106) is a pair of inclined guide rails (106) extending over the generator enclosure (14) Equipped with, The hoist assembly (74) is configured to steer the wheel assembly (96) on the pair of trolley posts (94) along the pair of vertically oriented guide rails (98) and the pair of inclined guide rails (106), during which the hoist assembly (74) lifts the trolley lift assembly (92) and the section (28) of the cover (10) placed thereon from the cover axial pull tool (42) onto the generator enclosure (14). The system according to claim 9.

11. The system according to claim 1, wherein the hoist assembly (74) includes at least one fixed-position hoist beam (124) located above the generator enclosure (14), the at least one fixed-position hoist beam (124) being configured to support lifting the section (28) of the cover (10) above the generator enclosure (14) along the cover axial pull tool (42) to the cover vertical lift tool (88).

12. The system according to claim 11, wherein the at least one fixed-position hoist beam (124) comprises two fixed-position hoist beams (124) that transfer the load of the section (28) of the cover (10) from one hoist beam (124) to the other hoist beam (124) while lifting the cover (10) away from the generator enclosure (14).

13. The system according to claim 11, wherein the at least one fixed-position hoist beam (124) comprises a cantilever hoist beam having a counterweight (126) for dealing with the load on the section (28) of the cover (10) while lifting the cover (10) away from the generator enclosure (14).

14. A method for removing a cover (10) from a generator enclosure (14) housing a stator and rotor (20), A cover axial pull tool (42) is placed on the generator enclosure (14) at a position adjacent to the cover (10), The cover axial pull tool (42) is attached to a section (28) of the cover (10) and a part of the generator enclosure (14), Using the cover axial pull tool (42), lift the section (28) of the cover (10), Using the cover axial pull tool (42), the section (28) of the cover (10) is moved axially from the generator enclosure (14) to disengage it from the stator frame (84) of the stator, and a gap is formed between the generator enclosure (14) and the cover axial pull tool (42), After moving the section (28) of the cover (10) axially away from the generator enclosure (14), the cover vertical lift tool (88) is placed in the gap formed between the generator enclosure (14) and the cover axial pull tool (42), wherein the cover vertical lift tool (88) provides a guide path for the section (28) of the cover (10) to navigate when the cover (10) is lifted away from the cover axial pull tool (42). Using the hoist assembly (74), the section (28) of the cover (10) is lifted upward from the cover axial pull tool (42), To guide the hoist assembly (74) to maneuver the section (28) of the cover (10) along the guide path provided by the cover vertical lift tool (88), Continuing to use the hoist assembly (74) to lift the section (28) of the cover (10) away from the generator enclosure (14) without contacting the generator enclosure (14), while navigating the guide path provided by the cover vertical lift tool (88) and Methods that include...

15. The aforementioned cover axial pull tool (42) is, A cover mounting plate (44) is configured to be attached to the section (28) of the cover (10) and a part of the generator enclosure (14), A vertical lift assembly (46) coupled to the cover mounting plate (44), wherein the vertical lift assembly (46) is configured to vertically lift the section (28) of the cover (10) after the cover mounting plate (44) has been attached to the section (28) of the cover (10) and the part of the generator enclosure (14), A mechanical linear actuator assembly (48) configured to move the cover mounting plate (44) and the vertical lift assembly (46) axially relative to the generator enclosure (14), wherein the mechanical linear actuator assembly (48) is configured to disengage the section (28) of the cover (10) from the stator frame (84) and move the cover (10) axially from the generator enclosure (14) The cover vertical lift tool (88) is equipped with, A vertical guide rail assembly (90) configured to be coupled to the generator enclosure (14), A trolley lift assembly (92) that receives the section (28) of the cover (10) from the cover axial pull tool (42) and Equipped with, The hoist assembly (74) is configured to lift the section (28) of the cover (10) on the trolley lift assembly (92) upward along the vertical guide rail assembly (90) and to prevent any contact between the section (28) of the cover (10) and the generator enclosure (14). The method according to claim 14.

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