Turbine rotor balance weight access port

Abstract

The present invention provides a turbine rotor (110), which includes: a rotor body (112); and a balance weight slot (122), which is defined in the outer circumference (244) of the body. The balance weight slot (122) has a first axial width and a first radially outward surface (232) located at a first radial distance from the axis of the rotor. The rotor also includes a balance weight entry port (142), which is defined in a portion of the outer circumference (244) of the rotor body (112) and is aligned with the balance weight slot (122). The balance weight entry port (142) has a second axial width greater than the first axial width and a second radially outward surface (232) located at a second radial distance from the axis of the rotor body (112), the second radial distance being less than the first radial distance. A method may include machining the entry port into the rotor with a tool. The method may be applied to a new rotor or a used rotor to remove cracks caused by a previous entry port.

Description

Technical Field

[0001] The present disclosure relates generally to turbomachines, and more particularly to a turbine rotor including a balance weight entry port for introducing a balance weight into a balance weight slot of the turbine rotor and a tool for manufacturing the port, and related methods. Background Art

[0002] Certain rotating elements in industrial machines, such as turbine rotors, include balancing weights in circumferential slots coupled to the circumferential outer surface of the turbine rotor. The circumferential slots have a cross-sectional shape including a retaining member such as a tab or an ear piece, which retaining member retains one or more weights having a similar cross-sectional shape. The circumferential slots may have, for example, a dovetail or trapezoidal cross-sectional shape. The weights may slide along the slots to any circumferential position required to balance the turbine rotor and be fastened in place. In order to introduce the weights into the slots, a balancing weight entry port having an axial range greater than the slots is milled into the turbine rotor above the slots. Milling generally removes the retaining member of the slots and provides a position where the weights can be introduced circumferentially into the slots. One challenge of balancing the weight entry port is that milling the retaining member of the slots to initially form the entry port may leave a circumferential extension (peak) and sharp corners of the retaining member at the bottom of the side wall of the port. Each of these structures may lead to the initiation of damage, such as cracks in the turbine rotor. It may be very difficult to repair damage without additionally damaging the turbine rotor. Summary of the invention

[0003] A first aspect of the present disclosure provides a turbine rotor, comprising: a rotor body; a balancing weight slot defined in the outer circumference of the rotor body, the balancing weight slot having a first axial width and a first radially outward surface located at a first radial distance from the axis of the rotor body; and a balancing weight entry port defined in a portion of the outer circumference of the rotor body and aligned with the balancing weight slot, the balancing weight entry port having a second axial width greater than the first axial width and a second radially outward surface located at a second radial distance from the axis of the rotor body, the second radial distance being less than the first radial distance.

[0004] A second aspect of the present disclosure provides a tool for forming a balancing weight entry port for a balancing weight slot of a rotor body of a turbine rotor, the tool comprising: a motorized machining head; a fixture system configured to connect the motorized machining head to at least a portion of a merge joint flange of the rotor body; a head circumferential positioning system configured to position the motorized machining head relative to the balancing weight slot of the rotor body at a selected circumferential position among a plurality of circumferential positions; and a head radial positioning system configured to radially move the motorized machining head relative to the balancing weight slot on the rotor body at each of the plurality of circumferential positions to machine the rotor body, thereby modifying the balancing weight slot.

[0005] A third aspect of the present disclosure provides a method of forming a balancing weight entry port for a balancing weight slot defined in a rotor body of a turbine rotor and extending circumferentially around the rotor body, the method comprising: performing a first infeed machining process radially partially into the rotor body to modify the balancing weight slot at a first circumferential position; and performing one of: a) circumferential translation after the first infeed machining process, and b) performing a second infeed machining process radially partially into the rotor body to modify the balancing weight slot at a second circumferential position different from the first circumferential position. a balancing weight slot, wherein the opening formed by the second infeed machining process is coextensive with the opening formed by the first infeed machining process; and performing a third infeed machining process radially partially into the rotor body to modify the balancing weight slot at a third circumferential position different from the first circumferential position and the second circumferential position, wherein the opening formed by the third infeed machining process is coextensive with the openings formed by the first infeed machining process and the second infeed machining process, wherein each infeed machining process and circumferential translation removes a portion of the rotor body within or adjacent to the balancing weight slot.

[0006] The illustrative aspects of the present disclosure are designed to solve the problems described herein and / or other problems not discussed. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the present disclosure taken in conjunction with the accompanying drawings which depict various embodiments of the present disclosure, wherein:

[0008] Figure 1 is a schematic diagram of an exemplary gas turbine system;

[0009] Figure 2 is a side perspective view of a turbine rotor according to the prior art;

[0010] Figure 3is an enlarged perspective view of a balance weight entry port and a balance weight slot according to the prior art;

[0011] Figure 4 is a cross-sectional view of an exemplary configuration of a balance weight in a balance weight slot;

[0012] Figure 5 is a front perspective view of a tool positioned on a rotor body for forming a balance weight access port according to an embodiment of the present disclosure;

[0013] Figure 6 is a front perspective view of a tool for forming a balance weight access port according to an embodiment of the present disclosure;

[0014] Figure 7 is a rear perspective view of a tool for forming a balance weight access port according to an embodiment of the present disclosure;

[0015] Figure 8 is a top view of components of a head circumferential positioning system according to an embodiment of the present disclosure;

[0016] Fig. 9 is a cross-sectional view of a machined head for machining a balance weight access port according to an embodiment of the present disclosure;

[0017] Fig.10 is a schematic top view of a rotor body and a balance weight slot according to an embodiment of the present disclosure, wherein the machining steps are illustrated by circles representing machining heads;

[0018] Fig.11 is a schematic cross-sectional view of machining a balance weight slot to form a balance weight entry port according to an embodiment of the present disclosure; and

[0019] Fig.12 is a top view of a balance weight access port according to an embodiment of the present disclosure.

[0020] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. In the drawings, like numbers represent like elements between drawings. DETAILED DESCRIPTION

[0021] First, in order to clearly describe the subject matter of the present disclosure, it will be necessary to select certain terms when referring to and describing relevant machine components within a turbine. To the extent possible, common industry terms will be used and adopted in a manner consistent with the accepted meaning of the terms. Unless otherwise indicated, such terms should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. A person of ordinary skill in the art will understand that several different or overlapping terms may be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referenced in another context as consisting of multiple components. Alternatively, an object that may be described herein as comprising multiple components may be referred to elsewhere as a single part.

[0022] In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise stated, these terms and their definitions are as follows. As used herein, "downstream" and "upstream" are terms indicating the direction relative to the flow of a fluid, such as a working fluid through a turbine engine, or, for example, an air flow through a combustor or a coolant through one of the component systems of a turbine. The term "downstream" corresponds to the direction of the flow of the fluid, and the term "upstream" refers to the direction opposite to the flow (i.e., the direction in which the flow is emitted). In the absence of any further details, the terms "front" and "rear" refer to directions, where "front" refers to the front end or compressor end of the engine, and "rear" refers to the rear section of the turbine.

[0023] It is often necessary to describe parts that are disposed at different radial positions relative to a central axis. The term "radial" refers to movement or position perpendicular to an axis. For example, if a first component is closer to an axis than a second component, this document will describe the first component as being "radially inward" of or on the "inside" of the second component. On the other hand, if the first component resides farther from the axis than the second component, this document may describe the first component as being "radially outward" or "outside" of the second component. The term "axial" refers to movement or position parallel to an axis, such as that of a turbine rotor. Finally, the term "circumferential" refers to movement or position around an axis. It should be understood that such terms may apply relative to the central axis of the turbine.

[0024] In addition, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0025] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "one", "a kind of" and "the" are intended to also include plural forms, unless the context clearly states otherwise. It will be further understood that when used in the specification, the terms "include" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, or the parts or features described subsequently may or may not exist, and the description includes the instance in which the event occurs or the parts exist and the instance in which the event does not occur or the parts do not exist.

[0026] Where an element or layer is referred to as being "on," "engaged to," "connected to," or "coupled to," it may be directly on, engaged to, connected to, or coupled to, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to," there may be no intervening elements or layers. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0027] Figure 1 is a schematic diagram of an exemplary turbine in which a turbine rotor 110 according to an embodiment of the present disclosure may be employed. Here, the turbine includes a gas turbine (GT) system 100. The GT system 100 includes a compressor 102 and a combustor 104. The combustor 104 includes a combustion region 105 and a fuel nozzle assembly 106. The GT system 100 also includes a turbine 108 and a common turbine rotor 110. In operation, air flows through the compressor 102 and the compressed air is supplied to the combustor 104. Specifically, the compressed air is supplied to the fuel nozzle assembly 106, which is integral with the combustor 104. The assembly 106 is in fluid communication with the combustion region 105. The fuel nozzle assembly 106 is also connected to a fuel source ( Figure 1104 is fluidly connected to a turbine 108 (not shown), and guides fuel and air to a combustion region 105. The burner 104 is ignited and the fuel is burned. The burner 104 is fluidly connected to a turbine 108 so that the gas flow thermal energy is converted into mechanical rotational energy. The turbine 108 includes a multi-stage rotatable blade coupled to a turbine rotor 110, and rotatably drives the turbine rotor 110. The compressor 102 is also rotatably coupled to the turbine rotor 110. The present disclosure is not limited to any one particular GT system, and may be used in conjunction with any GT system, including, for example, any HA, F, B, LM, GT, TM, and E-class engine models of General Electric Company, Greenville, SC, South Carolina, USA, as well as engine models of other companies. In addition, the teachings of the present disclosure are not limited to turbines in the form of gas turbine systems, and may be applied to any rotating element or rotor that includes a balancing slot and requires balancing.

[0028] Figure 2 A side view of a turbine rotor 110 is shown with any turbine blades / stages removed. The turbine rotor 110 may include a rotor body 112 in the form of a generally cylindrical shaft, which may have a plurality of blade stages 114 (only partially enclosed) coupled thereto. Figure 1 ) (for compressor 102 and / or turbine 108). Turbine rotor 110 may exhibit an asymmetry in its mass distribution, i.e., an imbalance. The imbalance may cause turbine rotor 110 to experience periodic forces and torques such as vertical and lateral vibrations, which may also cause the rotor to oscillate during use, similar to an unbalanced tire on a motor vehicle. To address this situation, such as Figure 3 A magnified perspective view of Figure 2 As shown, one or more balance weights 120 are coupled to circumferentially extending balance weight slots 122 ( Figure 2 The rotor is preferably provided at one or more circumferential positions (two are shown in FIG. 1 ) to balance the rotor and allow it to rotate without oscillation. Figure 4 As shown in an example of a cross-sectional view of FIG. 1 , the balance weight slot 122 and the balance weight 120 are complementarily configured to retain the balance weight in the slot. For example, the balance weight slot 122 and the balance weight 120 may have complementary cross-sectional shapes configured to retain the balance weight 120 therein. Figure 4 In one non-limiting example shown, the counterweight 120 and the counterweight slot 122 have complementary trapezoidal cross-sectional shapes. Here, the counterweight slot 122 includes opposing retaining members 124 in the form of tabs or inserts. Fasteners 125 such as set screws can be used to lock the counterweight 120 in place.

[0029] To introduce one or more balance weights 120 into the balance weight slots 122, the rotor body 112 includes one or more balance weight entry ports 126. Each balance weight entry port 126 includes an axially enlarged area of ​​the balance weight slot 122, wherein the balance weight 120 can be positioned in the slot and circumferentially slid into the slot. Figure 3 As shown in the enlarged perspective view of , the balance weight entry port 126 can be formed, for example, by machining the retaining member 124 from the slot 122, thereby forming the port 126 but leaving the peak 128. During use, the peak and / or sharp corner 130 (sharp corner - having a radius less than 0.76 mm) where the vertical sidewall 132 of the port 126 meets the radially outward surface 134 of the slot 122 can break. The crack can propagate in the rotor body 112. Therefore, the peaks and sharp corners should be avoided during initial manufacturing and may need to be removed during maintenance.

[0030] As described above, the present disclosure provides a turbine rotor comprising a rotor body and a balancing weight slot defined in the outer circumference of the body. The balancing weight slot has a first axial width and a first radially outward surface located at a first radial distance from the axis of the rotor. The rotor also includes a balancing weight entry port, which is defined in a portion of the outer circumference of the rotor body and is substantially aligned with the balancing weight slot. The balancing weight entry port has a second axial width greater than the first axial width. The balancing weight slot also has a second radially outward surface located at a second radial distance from the axis of the rotor body, the second radial distance being less than the first radial distance, which means that the entry port extends farther into the rotor body than the slot. Embodiments of the present disclosure also include methods and tools for forming an entry port into a rotor body. The tool can be used to perform a series of cross-feed machining steps to form a new balancing weight entry port. The method can be applied to a new rotor or a used rotor to remove a peak 128 ( Figure 3 ) and / or sharp corners 130( Figure 3 ), the access port may include cracks or other damage. The new balance weight access port has rounded corners to prevent new cracks.

[0031] See also Figures 5 to 12 , a method according to an embodiment of the present disclosure and a tool for performing the method will be described. Figure 5 and Figure 6 A front perspective view of a tool 140 for forming a balance weight entry port 142 for a balance weight slot 122 of a rotor body 112 of a turbine rotor 110 is shown. Figure 5 The tool 140 is shown in position on the rotor body 112, and Figure 6The tool 140 is shown separated from the rotor body 112. The tool 140 includes a motorized machining head 150. The motorized machining head 150 may include any now known or later developed rotary actuator 152 capable of rotating a machining element 154 (e.g., an electric, pneumatic, or hydraulic motor). In certain embodiments, the motorized machining head 150 is also capable of single-pass machining with a controlled and limited amount of circumferential translation, thereby reducing the number of required pass-through machining steps. The machining element 154 will be described herein. The tool 140 also includes a fixture system 156 that is configured to couple the motorized machining head 150 to at least a portion of a merge joint flange 160 of the rotor body 112. As shown, the merge joint flange 160 may include an axially coupled, radially extending merge joint flange 162, 164 of two axially coupled portions 166, 168 of the rotor body 112. However, depending on the configuration of the rotor body 112, the clamp system 156 can be coupled to one or both flanges 162, 164. For example, where the rotor body 112 is divided into sections 166, 168, the clamp system 156 can be coupled to only one of the flanges 162, 164. The clamp system 156 can include any now known or later developed system for temporarily attaching the motorized machining head 150 to the rotor body 112. In the non-limiting example shown, the clamp system 156 includes a first clamp member 170 movably coupled to a second clamp member 172, wherein one or more guide rails 174 may guide axial movement of the members. The clamp system 156 may also include an actuator 176, such as a manual crank or a motorized actuator (shown), for axially moving the clamp members 170, 172 toward or away from each other. The actuator 176 may include, for example, a motorized worm gear 177 that is threadedly coupled to the members 170, 172 and that can be rotated to change the axial position of the members. A variety of alternative actuators 176 may also be used, such as linear cylinders, etc. The actuator 176 may be operated to clamp the clamp members 170, 172 to clamp the motorized machining head 150 in place on one or both flanges 162, 164 of the merge joint flange 160 for machining the rotor body 112, and may similarly be actuated to release the motorized machining head 150 from the rotor body 112. The clamp members 170, 172 may include any structure that helps to grip the merge joint flanges 162, 164, such as a rough surface, a locking feature structure, etc.

[0032] The tool 140 may also optionally include at least one tie member 180 having a first end 182 configured to be mounted in the balance weight slot 122 and a second end 184 coupled to the clamp system 156. The first end 182 may have any shape configured to be positioned and retained in the slot 122, similar to the balance weight 120 ( Figure 4), such as a trapezoidal shape for a trapezoidal slot. For example, the first end 182 may be sized and shaped to enter the slot 122 and rotate to remain therein, or it may be sized and shaped to enter the slot 122 using a counterweight entry port 126 ( Figure 3 ). The second end 184 may include any mechanism coupled to the clamp system 156. As shown, the second end 184 may include an adjuster 186 therewith for adjusting the radial position of the first end 182 thereof; however, the adjuster 186 is not required in all cases. The adjuster 186 may include any now known or later developed mechanism to linearly change the position of the first end 182 relative to the clamp system 156 (e.g., a threaded end and fastener, clamp, etc.). One or more ties 180 may be employed.

[0033] Figure 7 A rear perspective view of certain embodiments of tool 140 is shown. Figure 7 As best shown, the tool 140 also includes a head circumferential positioning system 190 configured to position the motorized machining head 150 in one of the circumferential positions relative to the balance weight slots 122 of the rotor body 112 and to circumferentially translate the motorized machining head 150 relative to the balance weight slots 122 of the rotor body 112. The head circumferential positioning system 190 may take any form of structure capable of adjusting the circumferential position of the motorized machining head 150, such as a linear actuator, a mechanical adjustment system, etc. Figure 7 In one example shown, the positioning system 190 can include a first member 192 fixedly coupled to the motorized machining head 150 (e.g., a portion of the head) and a second member 194 fixedly coupled to the fixture system 156. As shown, the second member 194 can be part of the fixture system 156, such as the fixture member 172, or it can be a separate element coupled to the fixture system 156. Figure 8 A top view of the second member 194 is shown. The first member 192 and the second member 194 are slidably coupled. In one non-limiting example, the first member 192 may include a protrusion 196 that slidably rides in a slot 198 of the second member 194. Other arrangements are also possible, such as rails, etc.

[0034] like Figure 8As best shown, the second member 194 may include a position selection member 200A-C for each of the plurality of circumferential positions. The number of possible circumferential positions provided relative to the balance weight slot 122 of the rotor body 112 may be user-defined, depending on the circumferential extent of the desired balance weight entry port 142. However, in certain embodiments, at least three positions are possible. The first member 192 may also include a position selector 202 configured to selectively locate in a selected position selection member of the position selection members 200A-C of the second member 194 to position the motorized machining head 150 relative to the balance weight slot 122 of the rotor body 112 in a selected circumferential position of the plurality of circumferential positions. In a non-limiting example, the position selector 202 may include a pin 204 extending through the first member 192 and capable of being seated in one of the position selection members 200A-C. The position selection members 200A-C may include an opening in the second member 194 and may be spaced apart to produce the desired circumferential position of the head. As will be further described, the position selection members 200A-C may be spaced any distance required to ensure that the new access port 142 is circumferentially removed from the initial access port using the position selection members. In an alternative embodiment, the position selector 202 may be omitted, and the motorized machining head 150 may be capable of single infeed machining with a controlled and limited amount of circumferential translation determined by the length of the slot 198, thereby reducing the number of infeed machining steps required. Here, the machining element 154 may be infeed once and then translated circumferentially as the protrusion 196 of the first member 192 slidably rides in the slot 198 in the second member 194 to provide limited and controlled circumferential movement of the machining element 154 to form the access port 142.

[0035] See also Figure 5 and Figure 6 The tool 140 also includes a head radial positioning system 210, which is configured to radially move the mechanical machining head 150 relative to the balance weight slot 122 on the rotor body 112 (vertically as shown on the page). The radial movement can be performed at each of a plurality of circumferential positions to machine the rotor body 112 to modify the balance weight slot 122 ( Figure 3 ), and produces a balancing weight entering port 142. The head radial positioning system 210 may include any form of linear actuator 212, such as a manual crank, electric, pneumatic or hydraulic cylinder. The head radial positioning system 210 is fixed to the clamp system 156.

[0036] The machining element 154 is configured to form a balance weight entry port 142 in the rotor body 112 relative to the balance weight slot 122. The machining element 154 can be used to form the balance weight entry port 142 in the slot during the manufacture of the rotor body 112. Alternatively, the machining element 154 can be used to replace and repair a previously formed balance weight entry port 126 ( Figure 3 In the latter case, the machined element 154 is sized to be larger than the previously formed balance weight entry port 126 ( Figure 3 ) to remove additional axial portions of the rotor body 112 and remove any damage, such as cracks or other damage in the peaks 128 or corners 130. The machining element 154 may include any form of rotating machining element capable of forming the structures described herein. In non-limiting examples, the machining element 154 may include a milling head, a drill head, a grinding head, etc. Fig. 9 1 shows a cross-sectional view of an exemplary machined element 154 according to an embodiment of the present disclosure. The machined element 154 may have a circular cross-section (see, e.g., Figure 5 ), having a fillet 220 between the radial sidewall 222 and the machined surface 223. The fillet 220 is configured to form a fillet 236 ( Fig.11 ) (fillet) for balancing weight entry port 142, i.e., on radially outward surface 232 ( Fig.11 ) and its side wall 228 ( Fig.11 ). The radius may be defined by the user to remove any damage such as existing cracks, and / or to prevent any additional cracks. In certain exemplary embodiments, the fillet 220 may have a radius R in the range of 1.250 millimeters (mm) to 5.080 mm. Other ranges are possible depending on, for example, the dimensions of the rotor body 112 and the slot 122.

[0037] According to embodiments of the method of the present disclosure, a tool 140 may be used to form a balance weight access port 142 for a balance weight slot 122 defined in a rotor body 112 of a turbine rotor 110 . Fig.10 A schematic top view of the rotor body 112 and the slots 122 is shown, with the machining steps being indicated by circles representing machining elements 154 . Fig.11 1 shows a schematic cross-section of the machining of the balance weight slot 122 according to various embodiments. For reference purposes, Fig.11 The remaining circumferential face of the retaining member 124 of the slot 122 is shown. As will be appreciated, according to embodiments of the present disclosure, the machining element 154 can be used to create the balance weight entry port 142 by removing the retaining member 124 of the slot 122 and other one or more structures at any desired circumferential location (into or out of the page). Fig.11Also shown in phantom are pre-existing balance weight entry ports 226, including sidewalls 132 that meet first radially outward surfaces 134 of balance weight slots 122 at sharp corners 130. As will be described, tool 140 may be used to expand previously formed balance weight entry ports 126 to form new entry ports 142. In one non-limiting example, new entry ports 142 may be 0.050 mm to 2.540 mm in size on each side; other ranges are possible depending on the size of rotor body 112 and / or slot 122.

[0038] In operation, the tool 140 is positioned on the rotor body 112 at a desired circumferential position to clamp to one or more flanges 162, 164 (ie, for a new port or to replace an existing port 126 ( Figure 3 )) to produce the balance weight entry port 142. The head circumferential positioning system 190 is set at a first circumferential position, such as 200A, as described. The head radial positioning system 210 is used to perform multiple infeed machining operations to produce the balance weight entry port 142. Each machining operation uses a circular machining element 154. For the purpose of description, and as indicated, the embodiment of the present specification uses three circumferentially spaced positions 200A-C to perform three machining steps PM1-PM3 ( Fig.10 ) to form the entry port 142; however, more or less than three may be used. (Note that for the purpose of distinguishing from the other machining PM1, PM3, the second infeed machining PM2 is Fig.10 ). Figure 5 and 10 As shown, the tool 140 can be coupled to one or more flanges 162, 164 so that each machined element 154 is axially positioned relative to the rotor body 112 (e.g., via a fixture system 156) within a range of 0 millimeters (mm) to 0.762 mm from the center (CL) of the balance weight slot 122. It should be noted that other ranges are possible depending on the size of the rotor body 112 and / or the slot 122.

[0039] like Fig.10 As shown, the head radial positioning system 210 is used to perform a first infeed machining PM1 radially and partially into the rotor body 112 to modify the balance weight slot 122 at the first circumferential position 200A. Figure 7) The head circumferential positioning system 190 is set at a second circumferential position, for example, 200B. The head radial positioning system 210 is used to perform a second infeed machining PM2 radially and partially into the rotor body 112 at the second circumferential position 200B, again modifying the balancing weight slot 122. As described above, the second circumferential position 200B is different from the first circumferential position 200A. The opening 230 formed by the second infeed machining PM2 is coextensive with the opening 232 formed by the first infeed machining PM1. Next, the head circumferential positioning system 190 is set at a third circumferential position, for example, 200C, by the position selector 202. Figure 7 ). The head radial positioning system 210 is used to perform a third infeed machining PM2 radially and partially into the rotor body 112 at a third circumferential position 200C, again modifying the balancing weight slot 122. As described above, the third circumferential position 200C is different from the first circumferential position 200A and the second circumferential position 200B. The opening 234 formed by the third infeed machining PM2 is coextensive with the openings 230, 232 formed by the first infeed machining PM1 and the second infeed machining PM2. Each machining (i.e., each circumferential position 200A-C) can be spaced apart from the center circumference of the adjacent machining by any desired and / or required distance to jointly form an entry port 142 having a desired circumferential range, for example, to completely remove the circumferential range of the initial entry port. As shown, each infeed machining PM1-PM3 removes a portion of the rotor body 112 in or near the balancing weight slot 122, for example, a portion of the sidewall 229 of the retaining member 124 and the slot and / or the previous slot 126. As noted, in other embodiments, the motorized machine processing head 150 can perform a single infeed machining with a controlled and limited amount of circumferential translation, thereby reducing the number of required infeed machining steps. In this case, a single infeed machining can be completed by the circumferential translation of the machining element 154 to form an enlarged circumferential entry port 142. Here, the position selector 202 can be omitted, as described. In any case, once completed, any lacing 180 can be loosened and removed, and the clamp system 156 can be loosened so that the tool 140 can be removed from the flanges 162, 164.

[0040] In the case of repairing a pre-existing balance weight access port 126 ( Figure 3 and 11 ), the method may include installing the tool 140 using the clamp system 156 to at least a portion of the merge joint flange 160, namely, including the previously existing (first) balance weight entry port 126 ( Figure 3 and 11) of one or both flanges 162, 164 of an already used rotor body 112. Advantageously, the tool 140 can be used anywhere within the field of use, even if the turbine rotor 110 is to be installed in a power plant with the casing removed. The method may include performing one or more infeed machining processes, e.g., first infeed machining processes, second infeed machining processes, and third infeed machining processes PM1-PM3, to modify the rotor body 112, thereby forming a new (second) balancing weight entry port 142 for a balancing weight slot 122 in the same circumferential position as a previously existing balancing weight entry port 126. Here, the previously existing balancing weight entry port 126 has a first axial width W1 ( Fig.11 ), and the new balance weight entry port 142 has a second axial width W2 greater than the first axial width W1. That is, the machined element 154 is wider than the first axial width W1. The second axial width W2 can be defined by the new sidewall 228 of the new entry port 142.

[0041] Whether it is a new rotor body 112 or an already used rotor body 112, the infeed machining also extends into the balance weight slot 122 beyond its first radially outward surface 134, thereby forming a new radially outward surface 232. Fig.11 As shown, the balance weight slot 122 has a position located at an axis A (also see Figure 1 ) a first radially outward surface 134 at a first radial distance RD1, and an inlet port 142 having a second radially outward surface 238, the second radially outward surface being located at a second radial distance RD2 from the axis A of the rotor body 112 that is less than the first radial distance RD1. For repair purposes, the deeper radially outward surface 232 ensures that damage, such as cracks, are completely removed. The difference between the first radial distance RD1 from the axis A of the rotor body 112 and the second radial distance RD2 from the axis A of the rotor body 112 can be in the range of 0.254 millimeters (mm) to 2.286 mm; however, the range can vary depending on, for example, the extent of damage to be removed in the pre-existing inlet port 126. It should be noted that the balance weight slot 122 includes a sidewall 229 (formed by the retaining member 124) extending from the slot (first) radially outward surface 134, which may be at a non-perpendicular angle α, and the new balance weight entry port 142 has a sidewall 228 extending from the new (second) radially outward surface 232 at a perpendicular angle β. However, the machining element 154 forms a fillet 236 that joins the new radially outward surface 232 and the sidewall 228 of the new balance weight entry port 142. That is, the machining removes the sharp corner 130 and sidewall 132 of the previously existing balance weight entry port 126, as well as any existing peak 128 ( Figure 3), these peaks may include cracks or other damage. The axial dimension of the sidewall 228 is increased by the machined element 154. Each sidewall 228 may be increased in the axial direction by up to 25.4 millimeters (mm), but other ranges are possible depending on the size of the rotor body 112 and the slot 122. Thus, the balance weight entry port 142 provides a means for introducing the balance weight 120 ( Figure 4 ) space, but provides a fillet 236 that is used to reduce cracks in the rotor body 112 during subsequent use. The fillet 236 may have a radius in the range of 1.250 millimeters (mm) to 5.080 mm, for example.

[0042] See also Figures 10 to 12 , a turbine rotor 240 according to an embodiment of the present disclosure may include a rotor body 112, and a balance weight slot 122 defined in an outer circumference 244 of the rotor body 112. Fig.11 As shown, the balance weight slot 122 has an axial width W3 and a first radially outward surface 134 located at a first radial distance RD1 from the axis A of the rotor body 112. The rotor body 112 may include a first merge joint flange 162 and a second merge joint flange 164 (axially coupled to the first merge joint flange 162 at a rotor flange interface 250). Fig.10 ). The balance weight slot 122 may be axially adjacent to the rotor flange interface 250; however, other locations are possible.

[0043] The turbine rotor 240 also includes a balance weight entry port 142 defined in a portion of an outer circumference 244 of the rotor body 112 and aligned with the balance weight slot 122. The balance weight entry port 142 has an axial width W2 greater than the axial width W3 of the slot 122, thereby allowing the balance weight 120 ( Figure 4 ) is introduced into the slot at the entry port. The balance weight entry port 142 also includes a radially outward surface 232 ( Fig.11 ), which is less than the radial distance RD1 of the radially outward surface 134 of the slot 122. The difference between the radial distance RD1 of the slot from the axis A of the rotor body 112 and the radial distance RD2 of the inlet port 142 from the axis A of the rotor body 112 may be in the range of 0.254 millimeters (mm) to 2.286 mm.

[0044] like Fig.12 As shown in the top view of FIG. 1 , the balance weight entry port 142 includes an interface 252 between the radially outward surface 134 of the slot 122 and the radially outward surface 232 of the port 142. Due to the fillet 220 ( Fig. 9 ), the interface 252 is rounded, i.e., has the same radius as the fillet 236. The balance weight slot 122 has a first cross-sectional shape, such as a trapezoid, and the balance weight entry port 142 has a cross-sectional shape different from the first cross-sectional shape of the slot, such as a rectangle with rounded corners 236. The balance weight slot 122 includes a sidewall 229 ( Fig.11 ). In contrast, the balance weight entry port 142 has a sidewall 228 extending from a radially outward surface 232 of the port at a perpendicular angle β. As described above, the entry port 142 includes a fillet 236 that joins the second radially outward surface 232 of the balance weight entry port and the sidewall 228. The fillet 236 may have a radius in the range of 1.250 millimeters (mm) to 5.080 mm; however, other ranges are possible depending on the size of the rotor body 112 and / or the slot 122.

[0045] Embodiments of the present disclosure provide a turbine rotor with an inlet port having rounded corners to prevent damage such as cracking. The inlet port also extends further into the rotor body to reduce damage. Methods and tools according to embodiments of the present disclosure allow for the formation of an inlet port in a new or used rotor body. In the case of application to a used rotor body, forming a new inlet port can eliminate damage to the rotor body. The tool and method can be advantageously used in a manufacturing location or in the art.

[0046] The foregoing describes and illustrates the associated processes according to several embodiments of the present disclosure. It should also be noted that in some alternative implementations, the actions mentioned in the drawings or text may not occur in the order shown, or, for example, may actually be performed substantially simultaneously or in reverse order, depending on the actions involved. Moreover, one of ordinary skill in the art will recognize that additional steps, such as machining or finishing steps, may be added.

[0047] As used throughout the specification and claims, approximate language may be used to modify any quantitative representation that may be permitted to vary without resulting in a change in the basic function to which it is associated. Therefore, values ​​modified by one or more terms (such as "about," "approximately," and "substantially") are not limited to the precise values ​​specified. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations may be combined and / or interchangeable; unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. "Approximately" applied to a particular value of a range applies to both end values ​​and may indicate + / -10% of the value unless otherwise dependent on the precision of the instrument measuring the value.

[0048] The corresponding structures, materials, actions and equivalents of all means or steps plus function elements in the following claims are intended to include any structure, material or action for performing functions in conjunction with other claimed elements specifically claimed. A description of the present disclosure has been given for the purpose of illustration and description, but it is not intended to be exhaustive or to limit the present disclosure to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and essence of the present disclosure. Embodiments have been selected and described in order to best explain the principles and practical applications of the present disclosure, and to enable other persons of ordinary skill in the art to understand the various embodiments of the present disclosure with various modifications suitable for the intended specific use.

Claims

1. A turbine rotor (110), comprising: A rotor body (112); a balance weight slot (122) defined in an outer circumference (244) of the rotor body (112), the balance weight slot (122) having a first axial width and a first radially outward surface (134) located at a first radial distance from an axis of the rotor body (112), wherein the first radially outward surface extends a full length of the first axial width; and A balance weight entry port (142) defined in a portion of the outer circumference (244) of the rotor body (112) and aligned with the balance weight slot (122), the balance weight entry port (142) having a second axial width greater than the first axial width, and a second radially outward surface (238) located at a second radial distance from the axis of the rotor body (112), wherein the second radially outward surface extends a full length of the second axial width, and wherein the second radial distance is less than the first radial distance.

2. The turbine rotor (110) of claim 1, wherein the rotor body (112) includes a first merge joint flange (160) and a second merge joint flange (160), the second merge joint flange being axially coupled to the first merge joint flange (160) at a rotor flange interface (250), wherein the balance weight slot (122) is axially adjacent to the rotor flange interface (250).

3. The turbine rotor (110) of claim 1, wherein the balance weight entry port (142) includes an interface (252) between the first radially outward surface (134) and the second radially outward surface (238), and the interface (252) is rounded.

4. The turbine rotor (110) of claim 1, wherein the balance weight slot (122) has a first cross-sectional shape and the balance weight entry port (142) has a second cross-sectional shape different from the first cross-sectional shape.

5. The turbine rotor (110) of claim 1, wherein the balance weight slot (122) includes a sidewall (132) extending from the first radially outward surface (134) at a non-perpendicular angle, and the balance weight entry port (142) has a sidewall (132) extending from the second radially outward surface (238) at a perpendicular angle and further includes a fillet (236) connecting the second radially outward surface (230) and the sidewall (132) of the balance weight entry port (142).

6. The turbine rotor (110) of claim 5, wherein the fillet (236) has a radius in the range of 1.250 mm to 5.080 mm.

7. The turbine rotor (110) of claim 1, wherein a difference between the first radial distance from the axis of the rotor body (112) and the second radial distance from the axis of the rotor body (112) is in the range of 0.254 mm to 2.286 mm.

8. A tool (140) for forming a balance weight entry port (142) for a balance weight slot (122) of a rotor body (112) of a turbine rotor (110) according to any one of claims 1 to 7, the tool (140) comprising: A mechanical processing head (150); a clamping system (156) configured to couple the motorized machining head (150) to at least a portion of a merge joint flange (160) of the rotor body (112); a head circumferential positioning (200A-C) system configured to position the motorized machining head (150) relative to the balance weight slot (122) of the rotor body (112) in a selected circumferential position of a plurality of circumferential positions (200A-C); and A head radial positioning system (190) is configured to radially move the motorized machining head (150) relative to the balance weight slot (122) on the rotor body (112) at each of the plurality of circumferential positions (200A-C) to machine the rotor body (112) to modify the balance weight slot (122).

9. The tool (140) of claim 8, wherein the plurality of circumferential locations (200A-C) of the balance weight slot (122) relative to the rotor body (112) comprises at least three locations.

10. The tool (140) of claim 8, wherein the head circumferential positioning (200A-C) system comprises: a first member (192) fixedly coupled to the motorized machining head (150); and a second member (194) fixedly connected to the clamp system (156), wherein the second member (194) includes a position selection member (200A-C) for each of the plurality of circumferential positions (200A-C) and is slidably coupled to the first member (192), and wherein the first member (192) includes a position selector (202) configured to position the first member (192) relative to the second member (194) in a selected one of the position selection members (200A-C) of the second member (194) to position the motorized machining head (150) relative to the balance weight slot (122) of the rotor body (112) in a selected one of the plurality of circumferential positions (200A-C).

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