Balancing device for supercritical shafts

Abstract

An apparatus for balancing a shaft in a turbomachine engine, the apparatus comprising: an annular insert configured to be positioned within the shaft at any axial position along the shaft; and a weight attached to the annular insert at any angular position within the shaft.

Description

Technical Field

[0001] This disclosure relates to a turbine engine including a turbine shaft, and to such a turbine shaft driving such a turbine engine. More specifically, this disclosure relates to a balancing device for, for example, a supercritical shaft in such a turbine engine. Background Technology

[0002] A turbofan engine, or turbomachinery engine, consists of a core engine and a power turbine that drives a bypass fan. The bypass fan generates most of the thrust of the turbofan engine. The generated thrust can be used to move a payload (e.g., an aircraft). The turbine shaft, which is coupled (directly or via a gearbox) to the power turbine and the fan, can be characterized by its first-order beam bending mode, the fundamental resonant frequency of this mode, and the critical rotational speed corresponding to the fundamental frequency. If this bending mode occurs within the engine's standard operating range, it can lead to high vibrations and an increased risk of swirling instability. Vibrations caused by the rotating shaft in turbomachinery engines still need to be addressed. Attached Figure Description

[0003] The features and advantages of this disclosure will be apparent from the following description of various exemplary embodiments, as shown in the accompanying drawings, wherein similar reference numerals generally denote the same, functionally similar, and / or structurally similar elements.

[0004] Figure 1 An example of a turbine engine according to an embodiment of the present disclosure is shown.

[0005] Figure 2 It shows along Figure 1 The schematic cross-sectional view of the turbine engine shown is taken from line 2-2.

[0006] Figure 3A A cross-sectional view taken along the centerline axis of the low-pressure shaft is shown, which is balanced by three weights attached to three (or any number) balancing devices.

[0007] Figure 3B It shows Figure 3A The weight is oriented at different angles at different axial positions along the shaft, corresponding to different displacement directions of the low-pressure shaft.

[0008] Figure 3C The image shows the view from the rear end of the low-pressure shaft forward. Figure 3A A schematic cross-sectional view of line B in one of the balancing devices.

[0009] Figure 4A shows a schematic cross-sectional view of another example of a balancing device, which is a solid disk assembly with multiple solid segments.

[0010] Figure 4B shows a schematic cross-sectional view of the balancing device of Figure 4A during insertion of the low-pressure shaft, before locking into place.

[0011] Figure 4C shows a schematic cross-sectional view of the balancing device of Figure 4A after it has been inserted and locked in place at the desired axial position along the low-pressure axis.

[0012] Figure 5A A schematic cross-sectional view of the insertion tool of some embodiments, taken along the centerline axis of the low-pressure axis, is shown.

[0013] Figure 5B A schematic cross-sectional view of another insertion tool according to some embodiments is shown, taken along the centerline axis of the low-pressure axis.

[0014] Figure 6 A schematic cross-sectional view of another example of a balancing device is shown, which is a solid disc assembly with multiple segments.

[0015] Figure 7A A schematic cross-sectional view of another example of a balancing device is shown, which is an integral disc to which a weight is attached.

[0016] Figure 7B This shows what happens after the low-pressure shaft is inserted. Figure 7A A schematic cross-sectional view of the balancing device taken along the centerline of the low-pressure shaft.

[0017] Figure 8 A schematic cross-sectional view of another example of a balancing device is shown, which is a cylindrical insert.

[0018] Figure 9 A schematic cross-sectional view of another example of a balancing device is shown, which is a double cylindrical insert.

[0019] Figure 10 A schematic cross-sectional view of another example of a balancing device is shown, which is a weighted open ring.

[0020] Figure 11 A schematic cross-sectional view of another example of a balancing device is shown, which is a hollow disk assembly with two or more hollow sections. Detailed Implementation

[0021] The features, advantages, and embodiments of this disclosure will be set forth or become apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it should be understood that the following detailed description is intended to provide further explanation and not to limit the scope of the claimed disclosure.

[0022] Various embodiments are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the art will recognize that other components and constructions can be used without departing from the spirit and scope of this disclosure.

[0023] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0024] The terms “front” (or “front portion”) and “rear portion” refer to relative positions within a gas turbine engine or vehicle, and to the normal operating posture of the gas turbine engine or vehicle. For example, for a gas turbine engine, the front portion refers to the position closer to the engine inlet, while the rear portion refers to the position closer to the engine nozzle or exhaust.

[0025] The terms "outer" and "inner" refer to the relative positions within a turbine engine compared to the engine's centerline. For example, "outer" refers to a position farther from the centerline, while "inner" refers to a position closer to the centerline.

[0026] Unless otherwise stated, the terms “connection,” “fixation,” “attachment,” etc., refer to both direct connection, fixation, or attachment, and indirect connection, fixation, or attachment through one or more intermediate components or features.

[0027] The term "propulsion system" generally refers to a thrust-generating system that generates thrust using an electric motor, a thermal engine (such as a turbine), or a combination of an electric motor and a turbine to provide thrust.

[0028] Unless the context clearly indicates otherwise, the singular forms “a,” “one,” and “the” include plural references.

[0029] As used throughout this specification and claims, approximate language is applied to modify any quantitative representation that may allow for variation without altering its underlying function. Therefore, values ​​modified by terms such as “approximately,” “approximately,” and “substantially” are not limited to specified exact values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 10%, 15%, or 20% at the endpoints of a single value, a range of values, and / or a defined range of values.

[0030] When used with compressor, turbine, shaft, or spool components, unless otherwise specified, the terms “low” and “high”, or their respective comparatives (e.g., “lower” and “higher”, if applicable), refer to relative pressure and / or relative speed within the engine. For example, “low-speed shaft” defines a component configured to operate at a rotational speed (e.g., maximum permissible rotational speed) lower than that of the engine’s “high-speed shaft.” Alternatively, unless otherwise specified, the above terms may be understood as their superlatives. For example, “low-pressure turbine” may refer to the lowest maximum pressure within the turbine section, while “high-pressure turbine” may refer to the highest maximum pressure within the turbine section. The terms “low” or “high” in these aspects may additionally or alternatively be understood relative to the minimum permissible speed and / or pressure, or relative to the minimum or maximum permissible speed and / or pressure for normal, desired, steady-state, etc., operation.

[0031] As used in this article, "redline speed" refers to the maximum expected rotational speed of the shaft during normal engine operation. Redline speed can be expressed in revolutions per second (Hz), revolutions per minute (RPM), or as the linear speed of the shaft's outer diameter (in feet per second).

[0032] As used herein, "critical speed" refers to the rotational speed of a shaft that is approximately the same as the fundamental or natural frequency of its first-order bending mode (e.g., the shaft rotates at 80 Hz and its first-order modal frequency is 80 Hz). When a shaft rotates at a critical speed, it is expected to have the maximum deflection due to the excitation of the shaft's first-order bending mode, and therefore become unstable. Critical speed can be expressed in revolutions per second (Hz), revolutions per minute (RPM), or as the linear velocity of the shaft's outer diameter (in feet per second).

[0033] As used in this article, "critical frequency" is a synonym for the fundamental or natural frequency of the first-order bending mode of the shaft.

[0034] The term "subcritical speed" refers to the redline speed of an axis that is lower than the fundamental or natural frequency of its first-order bending mode (e.g., an axis rotating at a redline speed of 70 Hz, while the first-order mode frequency is approximately 80 Hz). When the rotational speed is subcritical, the axis is more stable than when rotating at the critical speed. A "subcritical axis" is an axis whose redline speed is lower than its critical speed.

[0035] The term "supercritical velocity" refers to the rotational speed of an axis that is above the fundamental or natural frequency of its first-order bending mode (e.g., an axis rotating at 80 Hz, while its first-order mode frequency is approximately 70 Hz). Supercritical axes are less stable than subcritical axes because the axis velocity can pass through the critical velocity due to its fundamental mode being below the redline velocity. A "supercritical axis" is an axis with a redline velocity above the axis's critical velocity.

[0036] One or more components of the turbine engine described below can be manufactured or formed using any suitable process, such as additive manufacturing or 3D printing. The use of such a process can allow such components to be integrally formed into a single, monolithic part, or formed into any suitable number of sub-parts. In particular, additive manufacturing processes can allow such components to be integrally formed and include a variety of features that are not possible using existing manufacturing methods. For example, the additive manufacturing methods described herein are capable of manufacturing shafts with unique features, constructions, thicknesses, materials, densities, channels, manifolds, and mounting structures that may be impossible or impractical using existing manufacturing methods. Some of these features are described herein.

[0037] This disclosure and various embodiments relate to turbine engines, also known as gas turbine engines, turboprop engines, or turbines. These turbine engines are applicable to a wide range of technologies and industries. Various embodiments can be described herein within the context of aero-engines and aircraft mechanics.

[0038] In some cases, turbine engines are constructed as direct-drive engines. In others, turbine engines can be constructed as geared engines with a gearbox. In some cases, the propeller of a turbine engine can be a fan enclosed in a fan casing and / or nacelle. This type of turbine engine can be called a "pipeline engine." In other cases, the propeller of a turbine engine can be exposed (e.g., not in a fan casing or nacelle). This type of turbine engine can be called an "open rotor engine" or a "non-pipeline engine."

[0039] Newer engine architectures are characterized by higher shaft speeds for the low-pressure turbine (LPT), the ability to have longer shafts to accommodate longer cores, and the need to operate within more limited radial space. However, these requirements lead to a lower stiffness-to-weight ratio, thereby reducing critical speeds and / or limiting the available options for increasing the critical speed of the LPT shaft. Therefore, next-generation turbine engines require different approaches to balancing the LPT shaft to allow for high-speed and even supercritical operation without resulting in unstable bending patterns during normal operation.

[0040] Some embodiments use internal balancing devices to balance the supercritical shaft, reducing excessive vibration at supercritical velocities. The balancing device can be one or more, typically disc-shaped, that can be inserted into the shaft at any desired position and / or angle. This disc may have slots, holes, or compartments for inserting counterweights, which can be solid, fluid, powder, or have a weighting component integrated with the balancing device. Each balancing device can be inserted (and removed) at the desired position and oriented at the desired angle using a specially designed insertion tool.

[0041] Figure 1 An example of a turbine engine 100 according to an embodiment of this disclosure is shown. Types of such engines include turboprop engines, turbofan engines, turbines, and turbojet engines. The turbine engine 100 is a duct-type engine covered by a protective shield 105; therefore, the only component visible in this external view is the fan assembly 110. Figure 1 The nozzles, which are not visible in the center, also protrude from the rear end of the turbine engine 100 beyond the protective cover 105.

[0042] Figure 2 It shows along Figure 1 The schematic cross-sectional view of the turbine engine 100 shown, taken by line 2-2, can be incorporated into one or more embodiments of this disclosure. In this example, the turbine engine 100 is a twin-shaft turbine comprising a high-speed system and a low-speed system, both fully covered by a protective shield 105. The low-speed system of the turbine engine 100 includes a fan assembly 110, a low-pressure compressor 210 (also referred to as a turbocharger), and a low-pressure turbine 215, all connected to a low-pressure shaft 217 (also referred to as a low-pressure spool) extending along the centerline axis 220 of the turbine engine 100 between the low-speed system components. The low-pressure shaft 217 enables the fan assembly 110, the low-pressure compressor 210, and the low-pressure turbine 215 to rotate uniformly about the centerline axis 220.

[0043] The high-speed system of the turbine engine 100 includes a high-pressure compressor 225, a combustor 230, and a high-pressure turbine 235, all of which are coupled to a high-pressure shaft 237 extending between the high-speed system components along the centerline axis 220 of the turbine engine 100. The high-pressure shaft 237 enables the high-pressure compressor 225 and the high-pressure turbine 235 to rotate uniformly about the centerline axis 220 at a different rotational speed than the low-pressure components (and, in some embodiments, at a higher rotational speed and / or in the opposite direction of rotation relative to the low-pressure system).

[0044] The components of the low-pressure and high-pressure systems are positioned such that a portion of the air drawn into the turbine engine 100 flows through the turbine engine 100 from front to back through the fan assembly 110, low-pressure compressor 210, high-pressure compressor 225, combustor 230, high-pressure turbine 235, and low-pressure turbine 215. Another portion of the air drawn into the turbine engine 100 bypasses the low-pressure and high-pressure systems and flows from front to back, as indicated by arrow 240.

[0045] This portion of the air entering the flow path of the turbine engine 100 is supplied from inlet 245. For Figure 2In the illustrated embodiment, inlet 245 has an annular or axisymmetric 360-degree configuration and provides a path for incoming atmospheric air to enter the turbomachinery flow path, as described above. Such a location may be advantageous for a variety of reasons, including managing icing performance and protecting inlet 245 from various objects and materials that may be encountered during operation. However, in other embodiments, inlet 245 may be located in any other suitable location, for example, arranged in a non-axisymmetric configuration.

[0046] Combustor 230 is located between high-pressure compressor 225 and high-pressure turbine 235. Combustor 230 may include features for receiving fuel from a fuel system. Figure 2 One or more configurations of a mixture of fuel (not shown) and air from a high-pressure compressor 225. This mixture is controlled by an ignition system (…). Figure 2 (Not shown) Ignition generates hot combustion gas that flows from front to back through high-pressure turbine 235. High-pressure turbine 235 provides torque to rotate high-pressure shaft 237, thereby rotating high-pressure compressor 225. After leaving high-pressure turbine, combustion gas continues to flow from front to back through low-pressure turbine 215. Low-pressure turbine 215 provides torque to rotate low-pressure shaft 217, thereby rotating low-pressure compressor 210 and fan assembly 110.

[0047] In other words, the pre-stages of the turbine engine 100 (i.e., fan assembly 110, low-pressure compressor 210, and high-pressure compressor 225) all prepare for ignition and intake. Each pre-stage requires power to rotate. The post-stages of the turbine engine 100 (i.e., combustor 230, high-pressure turbine 235, and low-pressure turbine 215) provide the necessary power by igniting compressed air and using the resulting hot combustion gases to rotate the low-pressure shaft 217 and high-pressure shaft 237 (also referred to as spools or rotors). In this way, the post-stage uses air to physically drive the pre-stages, and the pre-stages are driven to supply air to the post-stages.

[0048] As the exhaust gas leaves the rear end of the stage, it reaches the nozzle at the rear end of the turbine engine 100. Figure 2 (Not shown in the image). When exhaust gas passes through the nozzle and combines with bypass air also driven by the fan assembly 110, an exhaust force is generated, which is the thrust produced by the turbine engine 100. This thrust propels the turbine engine 100 in a forward direction and, for example, propels an aircraft on which the turbine engine 100 may be mounted.

[0049] like Figure 2 In the illustrated embodiment, the fan assembly 110 is positioned in front of the low-pressure turbine 215 in a "puller" configuration, while the exhaust nozzle is located behind it. As shown, the fan assembly 110 is driven by the low-pressure turbine 215, and more specifically, by the low-pressure shaft 217. More specifically, Figure 2The turbine engine 100 in the illustrated embodiment includes a power gearbox ( Figure 2 (Not shown in the diagram), and the fan assembly 110 is driven by a low-pressure shaft 217 passing through a power gearbox. The power gearbox may include a set of gears for reducing the rotational speed of the low-pressure shaft 217 relative to the low-pressure turbine 215, such that the fan assembly 110 can rotate at a slower speed than the low-pressure shaft 217. Other configurations are possible and contemplated within the scope of this disclosure, such as embodiments that may be referred to as a "pusher" configuration, wherein the low-pressure turbine 215 is located in front of the fan assembly 110.

[0050] Figure 1 and 2 The turbine engine 100 depicted is merely an example. In other embodiments, the turbine engine 100 may have any other suitable configuration, including, for example, any other suitable number of shafts or spools, fan blades, turbines, compressors, etc., and the power gearbox may have any suitable configuration, including, for example, a star gear configuration, a planetary gear configuration, a single-stage, multi-stage, rotary, non-rotary, etc. The fan assembly 110 may be any suitable fixed-pitch assembly or a variable-pitch assembly. The turbine engine 100 may include components not shown in the original text. Figure 1 and Figure 2 Additional components shown, such as impeller assemblies and / or guide impellers, etc.

[0051] During operation, the low-pressure shaft 217 rotates at a speed that can be expressed in revolutions per minute (RPM) or outer diameter (OD) speed, expressed in linear velocity units (e.g., feet per second (ft / sec)). The rotational stability of the low-pressure shaft 217 relative to its operating range can be characterized by the resonant frequency of the fundamental or first-order bending mode. When the operating speed is equal to this resonant frequency, the low-pressure shaft 217 operates at its critical speed. The low-pressure shaft 217 has a mode shape for this first-order bending mode, which can generally be described as a half-sine curve, where the central shaft position experiences the maximum displacement and therefore has the maximum potential energy relative to the rest of the low-pressure shaft 217. This instability mode is a standing wave across the length of the low-pressure shaft 217. Maximum deflection occurs when the excitation source has a periodic or cyclic component close to the fundamental frequency. This instability cannot be fully mitigated using bearing dampers at the ends of the shaft or balancing platforms (lands) on the shaft surface. When designing the engine, the shaft speed at which the highest deflection or instability is expected to occur at the central shaft is equal to the critical speed.

[0052] If the critical speed of the shaft falls within the standard operating range—that is, if the critical speed is below the redline speed or the low-pressure shaft 217 is a supercritical shaft—then during normal operation, the low-pressure shaft 217 may sometimes operate at or past the critical speed, which can lead to instability. Even if the engine temporarily operates at the critical speed, there is a possibility of undetected vibration, swirling instability, and some damage.

[0053] One way to stabilize a supercritical shaft is to use a balancing device to reduce the effects of bending patterns during operation at or near the critical speed. In some embodiments, the balancing device is a ring insert configured to be positioned inside the shaft at any desired axial (i.e., horizontal) location along the shaft, with a removable weight attached to the ring insert at a specific angular location inside the shaft. The desired position of the ring insert, the angular position of the weight, and the mass of the weight are all selected to minimize observed, estimated, or simulated displacement of the supercritical shaft along its length. In practice, any number of ring inserts and / or weights can be used to balance the shaft during or after manufacturing. The axial and angular positions are also adjustable and / or removable after installation (e.g., during routine maintenance or repair).

[0054] In some embodiments, the annular insert is a solid disk assembly, and the weight is attached to the solid disk assembly via a receiver within the solid disk assembly. The weight can be any solid object directly attached to the solid disk using a mechanism such as a keyway, clip, strip, or screw. The weight can be a solid metal (e.g., steel, aluminum, etc.), a metal composite, a fluid, or metal powder. The receiver in the solid disk is an opening, such as a slot or hole, designed to receive the weight.

[0055] Figure 3A An example of a low-pressure shaft 305 balanced by three balancing devices 310, 315, and 320 is conceptually illustrated. The balancing devices 310, 315, and 320 are also referred to herein as solid annular disk assemblies, each having an outer radius R1 that, when locked in place, is equal to the shaft's inner radius R2. For clarity, the annular width D of the balancing devices 310, 315, and 320 is also shown in exaggerated dimensions and is defined as the difference between the outer radius R1 and the inner radius R3 of the balancing devices 310, 315, and 320. R1, R2, and R3 are measured from the centerline axis 220 of the turbine engine 100 (i.e., the common axis of rotation of the low-pressure shaft 305 and the balancing devices 310, 315, and 320).

[0056] Each of the balancing devices 310, 315, and 320 is located at a different position along the axis and has corresponding weights 325, 330, and 335 attached to different angular positions within the axis. Specifically, in this example, balancing device 310 is located at axial position A, balancing device 315 at axial position B, and balancing device 320 at axial position C. These positions are... Figure 3A The middle part is indicated by a dashed line.

[0057] Figure 3B This is a conceptual diagram illustrating how weights 325, 330, and 335 are oriented at different angles corresponding to different displacement directions along the axis of the low-pressure shaft 305. Specifically, Figure 3B An end view is shown, looking forward from the rear end of the low-pressure shaft 305, with each weight 325, 330, 335 schematically depicted at its respective angular position. Weight 325 is oriented at angular position α towards the balancing device 310 ( Figure 3A On the balance device 315, the weight 330 is oriented at angular position β. Figure 3A The weight 335 is oriented at angular position γ on the balancing device 320. Figure 3A As can be seen from the figure, in this example, weights 325 and 335 are positioned at angular positions approximately opposite to the angular position of weight 330. By rotating the balancing device itself during insertion of the shaft, each weight can be oriented at its desired angular position.

[0058] Figure 3C A schematic diagram of the balancing device 315 and the weight 330, viewed from the rear end of the low-pressure shaft 305 and looking forward, is shown. The annular width D, outer radius R1, and inner radius R3 of the balancing device 315 are also shown. Figure 3C As shown in the image. Note that, for clarity, Figure 3C The low-pressure shaft 305 is omitted. The balancing device 315 has an outer portion 340 that contacts the inner surface of the low-pressure shaft 305 and an inner portion 342 to which the weight 330 is attached. The inner portion 342 and the outer portion 340 can be different parts joined together (e.g., by welding), or alternatively, they can be different parts of a single integral part. In this example, the weight 330 is attached via a groove 350 in the inner portion 342. However, alternatively, the weight 330 can also be attached to a hole 355 in the inner portion 342 using a clip or other means. In this example, the balancing device 315 has been rotated such that the weight 330 is at the angular position indicated by the solid arrow B.

[0059] In some embodiments, the solid disk assembly has a plurality of solid segments, each spanning a portion of the inner circumference of the shaft. Each solid segment has at least one receiver (e.g., slot, hole, etc.) to which a weight can be attached. The balancing device may also include an anti-rotation pin extending through a surface of the low-pressure shaft 305 and into a solid segment of the underlying solid disk assembly. The anti-rotation pin prevents the solid disk from rotating within the shaft by physically attaching the shaft to the solid segment. The solid disk assembly may also include a plurality of springs, each positioned between two solid segments, and each spring applying pressure to adjacent solid segments to engage the solid segments with each other.

[0060] Figure 4A shows an example of a balancing device 410, which is a solid disc assembly with multiple solid segments 415, 416, 417, and 418. The balancing device 410 is in a pre-inserted state outside the low-pressure shaft 305. The solid segments 415, 416, 417, and 418 have corresponding outer portions 420, 421, 422, and 423, which directly contact the inner circumference of the low-pressure shaft 305 when the balancing device 410 is installed in the low-pressure shaft 305 (Figure 4B). The solid segments 415, 416, 417, and 418 also have corresponding inner portions 425, 426, 427, and 428 to which weights can be attached. Figure 3C As in the example, each of the inner parts 425, 426, 427, 428 and their corresponding outer parts 420, 421, 422, 423 can be different components joined together (e.g., by welding), or alternatively, can be different parts of a single integral component.

[0061] In the example of Figure 4A, solid segment 417 has a weight 430 attached at the angular position indicated by arrow B. Furthermore, solid segment 418 has two receivers, a slot 435 and a hole 440, to which the additional weight can be attached. In this example, solid segments 415 and 416 have no receivers. The weight 430 is attached before the balancing device 410 is inserted into the low-pressure shaft 305. The additional weight can be attached to the balancing device 410 after insertion into, for example, the slot 435 or the hole 440.

[0062] Figure 4B illustrates the balancing device 410 during insertion of the low-pressure shaft 305, before it is locked into place. In this example, a spring assembly comprising springs 445, 450, 455, and 460 is inserted between solid sections 415, 416, 417, and 418, and is compressed during insertion of the balancing device 410 into the low-pressure shaft 305 such that the outer radius R1 of the balancing device 410 is smaller than the inner radius R2 of the low-pressure shaft 305. The compression of the springs 445, 450, 455, and 460 results in a gap 470 (width equal to R2-R1), which allows the balancing device 410 to move freely within the low-pressure shaft 305 until the balancing device 410 reaches the desired axial position along the low-pressure shaft 305.

[0063] Figure 4C shows the balancing device 410 after the low-pressure shaft 305 has been inserted and locked in place at the desired axial position along the low-pressure shaft 305. This is achieved by releasing springs 445, 450, 455, and 460 so that the outer radius R1 of the balancing device 410 is equal to the inner radius R2 of the low-pressure shaft 305. Upon release, springs 445, 450, 455, and 460 apply a force that pushes the solid segments 415, 416, 417, and 418 into place along the inner surface of the low-pressure shaft 305 and into position, and interconnects them. This force ensures that the balancing device 410 cannot move axially along the low-pressure shaft 305 away from the desired axial position after insertion.

[0064] Figure 4C also shows an example of anti-rotation pins 471 and 472, which are metal pins or screws used to prevent circumferential rotation of the balancing device 410 within the low-pressure shaft 305 after insertion. In this example, two anti-rotation pins 471 and 472 are used, but as few as one and as many as one per segment can be used. The pins can be inserted externally through holes drilled through the low-pressure shaft 305, and in this example, extend into the body of the solid segments 416 and 417.

[0065] In some embodiments, an insertion tool is used that simultaneously compresses all springs 445, 450, 455, 460 in the spring assembly during the insertion of the balancing device 410 into the low-pressure shaft 305 to facilitate movement of the solid disk assembly along the low-pressure shaft 305 to a desired axial position. The insertion tool is also configured to simultaneously release all springs 445, 450, 455, 460 when the solid disk assembly has reached the desired axial position, allowing the springs 445, 450, 455, 460 to unfold uniformly, thereby locking the solid disk assembly in place at the desired axial position. In some embodiments, the insertion tool has a pull rod for releasing the springs 445, 450, 455, 460, and a retaining rod for holding the solid disk assembly in place at the desired axial position during the release of the springs 445, 450, 455, 460 via the pull rod.

[0066] Figure 5A An insertion tool 505 of some embodiments is conceptually shown for use with a balancing device, which is a solid disc assembly with a spring assembly, such as balancing device 410. The insertion tool 505 is a cylindrical conduit having a pull rod 510, a retaining rod 515, and bearings 518, 519 to allow the pull rod 510 to move independently of the retaining rod 515.

[0067] Before using the insertion tool 505, a weight (such as weight 430) can be attached to the balancing device 410 at a desired angular position. For example, weight 430 can be attached to a slot 435 or a hole 440 (FIG. 4A). If necessary, the balancing device 410 is rotated before being attached to the insertion tool 505 to align weight 430 at the desired angular position.

[0068] Then, by directly engaging the outer portions 420, 421, 422, 423 (Figures 4A-4C) of the balancing device 410, the pull rod 510 is used to compress the springs 445, 450, 455, 460. Figure 5A (Not shown in the image) to attach the insertion tool 505 to the balancing device 410. During compression, the outer radius R1 of the balancing device 410 is smaller than the inner radius R2 of the low-pressure shaft 305. This creates a gap 470 between the inner surfaces of the balancing device 410 and the low-pressure shaft 305.

[0069] During engagement with the insertion tool 505, the retaining rod 515 also engages at least the outer portions 420, 421, 422, and 423 of the balancing device 410 (Figures 4A-4C). The retaining rod 515 and the pull rod 510 simultaneously push the balancing device 410 into place along the low-pressure shaft 305 and maintain engagement during placement.

[0070] Insertion tool 505 may have bearings, rollers, or other sliding or rolling devices. Figure 5A (not shown in the image) When the insertion tool 505 passes through the low-pressure shaft 305, these bearings, rollers or other sliding or rolling devices are adapted within the gap 470 and support the insertion tool 505 in a central position within the low-pressure shaft 305, and around the centerline axis 220.

[0071] Once the balancing device 410 has reached the desired axial position within the low-pressure shaft 305, the pull rod 510 is pulled out of the low-pressure shaft 305. During the retraction of the pull rod 510, bearings 518 and 519 allow the pull rod 510 to move freely while holding rod 515 in place and engaging the outer portions 420, 421, 422, and 423 (Figures 4A-4C) of the balancing device 410. As the pull rod 510 retracts, springs 445, 450, 455, and 460 (Figures 4B-4C) are released and the outer radius R1 of the balancing device 410 increases to equal the inner radius R2 of the low-pressure shaft 305 to lock the balancing device 410 in place. After the pull rod 510 is retracted, anti-rotation pins 471 and 472 can also be inserted. Figure 5A (Not shown in the image) A fixed balancing device 410 is used to prevent circumferential rotation.

[0072] The retaining rod 515 remains engaged and stationary during release, so that the balancing device 410 is not pulled back from the desired axial position when the pull rod 510 is retracted. After the pull rod 510 is retracted, the balancing device 410 is fully locked in place, and the retaining rod 515 can also disengage without affecting the positioning.

[0073] Figure 5B Another insertion tool 520, representing some embodiments, is conceptually shown for use with a balancing device, such as a solid disc assembly with a spring assembly, like balancing device 410. Insertion tool 520 is a cylindrical conduit having a pull rod 525, a retaining rod 530, and a spring 535 to allow the pull rod 525 to move independently of the retaining rod 530.

[0074] Before using the insertion tool 520, a weight (such as weight 430) can be attached to the balancing device 410 at a desired angular position. For example, weight 430 can be attached to a slot 435 or a hole 440 (FIG. 4A). If necessary, the balancing device 410 is rotated before being attached to the insertion tool 520 to align weight 430 at the desired angular position.

[0075] Then, by directly engaging the outer portions 420, 421, 422, 423 (Figure 4A) of the balancing device 410, the pull rod 525 is used to compress the springs 445, 450, 455, 460 (…). Figure 5B (Not shown in the image) to attach the insertion tool 520 to the balancing device 410. In some embodiments, the inner portions 425, 426, 427, 428 have profiles that match the profile of the pull rod 525. When the profiles are aligned, the inner portions 425, 426, 427, 428 are securely engaged with the pull rod 525.

[0076] During compression, the outer radius R1 of the balancing device 410 is smaller than the inner radius R2 of the low-pressure shaft 305. This creates a gap 470 between the inner surfaces of the balancing device 410 and the low-pressure shaft 305.

[0077] During engagement with the insertion tool 520, the retaining rod 530 also engages the outer portions 420, 421, 422, and 423 of the balancing device 410 (Figures 4A-4C). The retaining rod 530 and the pull rod 525 simultaneously push the balancing device 410 into place along the low-pressure shaft 305 and maintain engagement during placement.

[0078] Insertion tool 520 may have bearings, rollers, or other sliding or rolling devices. Figure 5B (not shown in the image) When the insertion tool 520 passes through the low-pressure shaft 305, these bearings, rollers or other sliding or rolling devices are adapted within the gap 470 and support the insertion tool 520 in a central position within the low-pressure shaft 305, and around the centerline axis 220.

[0079] Once the balancing device 410 has reached the desired axial position within the low-pressure shaft 305, the pull rod 525 is pulled out of the low-pressure shaft 305. During the retraction of the pull rod 525, the spring 535 allows the pull rod 525 to disengage from the inner portions 425, 426, 427, 428 (Figure 4A), while holding the rod 530 in place and engaging with the outer portions 420, 421, 422, 423 of the balancing device 410. As the pull rod 510 retracts, the springs 445, 450, 455, 460 are released and the outer radius R1 of the balancing device 410 increases to equal the inner radius R2 of the low-pressure shaft 305 to lock the balancing device 410 in place. After the pull rod 525 is retracted, anti-rotation pins 471, 472 can also be inserted. Figure 5B (Not shown in the image) A fixed balancing device 410 is used to prevent circumferential rotation.

[0080] The retaining rod 530 remains engaged and stationary during release, so that the balancing device 410 is not pulled back from the desired axial position when the pull rod 525 is retracted. After the pull rod 525 is retracted, the balancing device 410 is fully locked in place, and the retaining rod 530 can also disengage without affecting positioning.

[0081] In some embodiments, the solid disk assembly includes a plurality of magnets, each positioned between two solid segments, and each magnet applying a magnetic force to adjacent solid segments, the magnetic force connecting the solid segments to each other. Each magnet may also be positioned to prevent the solid disk from rotating within the shaft by being magnetically coupled to an inner surface of the shaft at a specific location.

[0082] Figure 6Another example of a balancing device 610 is shown, which is a solid disc assembly having multiple segments 615, 616, 617, and 618. The balancing device 610 is similar to the embodiment of the balancing device 410 discussed above with respect to Figures 4A to 4C, and similar reference numerals have been used to refer to the same or similar components. Detailed descriptions of these components will be omitted, and the following discussion focuses on the differences between these embodiments. Any various features discussed in conjunction with any embodiment discussed herein may also be applied to and used with any other embodiment.

[0083] exist Figure 6 In the example, segment 617 has a weight 630 attached at the angular position indicated by arrow B. The balancing device 610 is shown as being positioned on the low-pressure shaft 305 ( Figure 6 The exterior of the weight 630 (not shown) is in a pre-insertion state. The weight 630 is attached before the balancing device 610 is inserted into the low-pressure shaft 305.

[0084] The balancing device 610 also includes magnets 645, 650, 655, and 660 inserted between segments 615, 616, 617, and 618. These magnets 645, 650, 655, and 660 apply magnetic forces to their adjacent segments 615, 616, 617, and 618, connecting segments 615, 616, 617, and 618 to each other. In this example, magnet 645 connects segment 617 to segment 618, magnet 650 connects segment 615 to segment 617, magnet 655 connects segment 615 to segment 616, and magnet 660 connects segment 616 to segment 618. Magnets 645, 650, 655, and 660 also act as spacers to maintain the proper position of segments 615, 616, 617, and 618 relative to each other. By maintaining proper spacing, the outer radius R1 of the balancing device 610 ( Figure 6 (not shown in the image) can be equal to the inner radius R2 of the low-pressure shaft 305 ( Figure 6 (Not shown in the image) The balancing device 610 is locked in place. In some embodiments, after the balancing device 610 has been inserted into the low-pressure shaft 305 at the desired axial position, magnets 645, 650, 655, and 660 are inserted into the positions between segments 615, 616, 617, and 618.

[0085] In some embodiments, magnets 645, 650, 655, and 660 are also used to connect segments 615, 616, 617, and 618 to the inner surface of the low-pressure shaft 305. In this way, magnets 645, 650, 655, and 660 also serve as anti-rotation devices by preventing circumferential rotation of the balancing device 610 within the low-pressure shaft 305.

[0086] In some embodiments, the annular insert is a solid disk with an outer radius smaller than the inner radius of the shaft. Multiple clamps located at different angular positions are coupled to the shaft at a desired axial position. These clamps engage the solid disk and hold it in place such that the solid disk does not directly contact the shaft. In this embodiment, the solid disk is inserted into the shaft at the desired axial position by an insertion tool to which the solid disk is coupled to the clamps. The clamps also prevent the solid disk from rotating within the shaft by physically coupling the shaft to the solid disk.

[0087] Figure 7A Another example of a balancing device 710 is shown, which is an integral disk to which a weight 730 is attached. Note that, for clarity, Figure 7A The low-pressure shaft 305 is omitted. The balancing device 710 is similar to the embodiment of the balancing device 410 discussed above with respect to Figures 4A to 4C, and similar reference numerals have been used to refer to the same or similar components. Detailed descriptions of these components will be omitted, and the following discussion focuses on the differences between these embodiments. Any various features discussed in conjunction with any embodiment discussed herein may also be applied to and used with any other embodiment.

[0088] The balancing device 710 has an outer portion 740 that contacts the inner surface of the low-pressure shaft 305 and an inner portion 742 to which a weight 730 is attached. The inner portion 742 and the outer portion 740 can be different components joined together (e.g., by welding), or they can be different parts of a single integral component. In this example, the weight 730 passes through a groove in the inner portion 342 (…). Figure 7A (Not shown in the image) Attached. In this example, the balancing device 710 has been rotated so that the weight 730 is in the angular position indicated by the solid arrow B. The outer radius R1 of the integral disk is also shown.

[0089] Figure 7B A balancing device 710 inserted into a low-pressure shaft 305 is shown. The outer radius R1 of the balancing device 710 is smaller than the inner radius R2 of the low-pressure shaft 305. The low-pressure shaft 305 has a plurality of clamps 750, 751 positioned at a desired axial location, positioned around the circumference of the low-pressure shaft 305. The clamps 750, 751 engage with the outer portion 740 of the balancing device 710 to secure the balancing device 710 in place at the desired axial location. Because the outer radius R1 of the balancing device 710 is smaller than the inner radius R2 of the low-pressure shaft 305, the clamps 750, 751 ensure a clearance 765 around the entire circumference of the balancing device 710, allowing the balancing device 710 to be centered about the centerline axis 220. The clamps 750, 751 also prevent circumferential rotation of the balancing device 710 within the low-pressure shaft 305.

[0090] Clamps 750, 751 can engage with the outer portion 740 of the balancing device 710 by any mechanical means, such as screws or clamps. For example, the outer portion 740 may have lips or pins at multiple locations around the circumference of the balancing device 710, extending through corresponding openings in clamps 750, 751. As an alternative example, fasteners ( Figure 7B (Not shown) can be used to fix the outer part 740 to the clamps 750, 751.

[0091] Figure 8 Another example of a balancing device 810 is shown, which is a cylindrical insert 812. The cylindrical insert 812 is placed on the low-pressure shaft 305 ( Figure 8 At the desired axial position within (not shown in the image). The cylindrical insert 812 is aligned with the centerline axis 220 (…). Figure 8 (Not shown in the image) Coaxial. One or more weights 830, 831, 832, 833, 834, 835, 836, 837 are attached to the inner surface of the cylindrical insert 812 at the desired angular location using fasteners (such as screws or magnets).

[0092] Figure 9 Another example of a balancing device 910 is shown, which is a double cylindrical insert 912. The double cylindrical insert 912 is placed on the low-pressure shaft 305 ( Figure 9 One or more spring-loaded weights 930, 931, 932, 933, 934, 935, 936, 937 are mounted to the inner cylinder 945 at a desired axial position within the cylinder (not shown in the diagram). The force applied by the springs causes the spring-loaded weights 930, 931, 932, 933, 934, 935, 936, 937 to engage with the compressible outer cylinder 950, which is located about a central axis 220 (not shown in the diagram). Figure 9 (Not shown in the image) is coaxial with the inner cylinder 945. The inner cylinder 945 and the outer cylinder 950 can be supported by an axial support member ( Figure 9 (Not shown in the diagram) Connection. The compression of the spring allows the outer cylinder 950 to be inserted into the low-pressure shaft 305 at the desired axial position. When the spring is released, the outer cylinder 950 locks in place at the desired axial position within the low-pressure shaft 305.

[0093] Figure 10 Another example of a balancing device 1010 is shown, which is a weighted open ring 1012. The weighted open ring 1012 is placed on the low-pressure shaft 305 ( Figure 10At the desired axial position within (not shown in the diagram). The weighted open ring 1012 has a first thickness extending around a large portion of the inner circumference of the low-pressure shaft 305. At both ends, the weighted open ring 1012 has a greater thickness, such that the ends of the weighted open ring 1012 act as integral weights 1030, 1031. Even with the greater thickness at the ends, the weighted open ring 1012 still has a gap 1032 between the integral weights 1030, 1031. In its uncompressed state, the outer radius R1 of the weighted open ring 1012 is equal to the inner radius R2 of the low-pressure shaft 305.

[0094] The weighted open ring 1012 is rotated before insertion, positioning the entire weight at the desired angular position. During insertion, the weighted open ring 1012 is compressed to close the gap and allow it to move to the desired axial position. In its compressed state, the outer radius R1 of the weighted open ring 1012 is smaller than the inner radius R2 of the low-pressure shaft 305.

[0095] Once in the desired axial position, the weighted open ring 1012 is then released, and the outer radius Rl expands, causing the integral weights 1030, 1031 to engage with the inner surface of the low-pressure shaft 305. The weighted open ring 1012 is thus locked in place at the desired axial position.

[0096] In some embodiments, the annular insert is a hollow disk assembly having multiple hollow segments, each segment spanning a portion of the inner circumference of a shaft. The weight is a fluid or powder filling at least one hollow segment. The hollow disk assembly can be inserted into the shaft at a desired axial position using an insertion tool that cools the hollow disk assembly during insertion to move it along the shaft to the desired axial position. At the desired axial position, the insertion tool stops cooling the hollow disk assembly to allow it to expand and lock into place.

[0097] Figure 11 Another example of a balancing device 1110 is shown, which is a hollow disk assembly having two or more hollow sections 1115, 1116, 1117, 1118, 1119, 1120, 1121, and 1122. Note that, for clarity, Figure 11 The low-pressure shaft 305 is omitted. In this example, hollow sections 1120 and 1121 are filled with weights 1130 and 1131. In this example, weights 1130 and 1131 are fluids or powders, which are conveyed into hollow sections 1120 and 1121 through ports 1140 and 1141. Ports 1140 and 1141 can be valves in the case of fluid weights, or seals in the case of powder weights.

[0098] Initially, the outer radius R1 of the balancing device 1110 is equal to that of the low-pressure shaft 305 ( Figure 11 The inner radius R2 (not shown in the diagram). In some embodiments, an insertion tool (…) is used. Figure 11 (Not shown) The balancing device 1110 is inserted, and the insertion tool cools the balancing device 1110 to cause its outer radius R1 to contract, making R1 smaller than the inner radius of the low-pressure shaft 305. Once the balancing device 1110 is in the desired axial position, the insertion tool stops cooling the balancing device 1110 or begins heating it. The balancing device 1110 then expands back to its original outer radius R1 and locks in place at the desired axial position within the low-pressure shaft 305.

[0099] In some embodiments, some or all of the hollow sections 1115, 1116, 1117, 1118, 1119, 1120, 1121, and 1122 may be filled before the balancing device 1110 is inserted into the low-pressure shaft 305. However, the hollow sections 1115, 1116, 1117, 1118, 1119, 1120, 1121, and 1122 may also be filled after insertion using an insertion tool.

[0100] Further aspects of this disclosure are provided by the subject matter of the following clauses.

[0101] An apparatus for balancing a shaft in a turbine engine, the apparatus comprising: an annular insert configured to be positioned within the shaft at a specific axial position along the shaft; and a weight attached to the annular insert at a specific angular position within the shaft.

[0102] According to the apparatus described in the preceding clause, the annular insert is a solid disk assembly, and the weight is removably connected to the solid disk assembly via a receiver in the solid disk assembly.

[0103] According to any of the preceding clauses, the weight is connected to the solid disk assembly via one of a keyway, a clamp, a metal strip, and a screw.

[0104] According to any of the preceding clauses, the receiver is one of a slot in the solid disk assembly and a hole in the solid disk assembly.

[0105] According to any of the preceding clauses, the device comprises a plurality of solid segments, each solid segment spanning a portion of the inner circumference of the shaft and having at least one receiver, wherein the weight is coupled to one of the receivers in one of the solid segments.

[0106] The device according to any of the preceding clauses further includes an anti-rotation pin that extends through the surface of the shaft and into one of the solid segments of the solid disk assembly, the anti-rotation pin preventing the solid disk assembly from rotating within the shaft by physically connecting the shaft to each solid segment.

[0107] According to any of the preceding clauses, the device further includes a plurality of springs, each spring positioned between two solid segments, and each spring applying pressure on adjacent solid segments, the pressure connecting the solid segments to each other.

[0108] According to any of the preceding clauses, the solid disk assembly is inserted into the shaft at the specific axial position by an insertion tool, the insertion tool (a) compressing the plurality of springs during insertion to move the solid disk assembly along the shaft to the specific axial position, and (b) releasing the plurality of springs when the solid disk assembly reaches the specific axial position to allow the plurality of springs to unfold and thereby lock the solid disk assembly in place at the specific axial position.

[0109] According to any of the preceding clauses, the insertion tool includes a pull rod for releasing the plurality of springs and a retaining rod for holding the solid disc assembly in the particular axial position during the release of the plurality of springs via the pull rod.

[0110] According to any of the preceding clauses, the solid disk assembly further includes a plurality of magnets, each magnet being positioned between two of the solid segments, and each magnet applying a magnetic force to adjacent solid segments, the magnetic force connecting the solid segments to each other.

[0111] According to any of the preceding clauses, each magnet is further positioned to prevent the solid disk assembly from rotating within the shaft by being magnetically coupled to the inner surface of the shaft at the particular axial position.

[0112] According to any of the preceding clauses, the annular insert is a hollow disk assembly comprising a plurality of hollow segments, each hollow segment spanning a portion of the inner circumference of the shaft.

[0113] According to any of the preceding clauses, the weight is one of a fluid and a powder filling at least one of the hollow sections.

[0114] According to any of the preceding clauses, the hollow disk assembly is inserted into the shaft at the specific axial position by an insertion tool, the insertion tool (a) shrinking the hollow disk assembly by cooling during insertion to move the hollow disk assembly along the shaft to the specific axial position, and (b) stopping cooling the hollow disk assembly at the specific axial position along the shaft to allow the hollow disk assembly to expand and lock in place at the specific axial position.

[0115] According to any of the preceding clauses, the annular insert is an integral disk with an outer radius smaller than the inner radius of the shaft, wherein the device further includes a plurality of clamps connected to the shaft at a specific axial position, the plurality of clamps being at different angular positions at the specific axial position, the plurality of clamps supporting the integral disk within the shaft at the specific axial position such that the integral disk does not directly contact the shaft.

[0116] According to any of the preceding clauses, the integral disk is inserted into the shaft at a specific axial position by means of an insertion tool that is coupled to the integral disk to the plurality of clamps, and wherein the plurality of clamps prevent the integral disk from rotating within the shaft by means of ...

[0117] According to any of the preceding clauses, the annular insert comprises an outer cylindrical insert, and the weight is attached to the inner surface of the outer cylindrical insert at the specific angular position by one of a screw and a magnet.

[0118] According to any of the preceding clauses, the annular insert includes an inner cylindrical insert, the weight is spring-connected to the inner cylindrical insert, and the compression of the spring allows the outer cylindrical insert to be inserted into the shaft at the specified axial position.

[0119] According to any of the preceding clauses, the annular insert includes a clamp having a first thickness extending about a portion of the inner circumference of the axis, wherein the weight includes a first end and a second end of the clamp, the first end and the second end of the clamp each having a second thickness greater than the first thickness, and the clamp has an uncompressed state defining a gap between the first end and the second end of the clamp.

[0120] According to any of the preceding clauses, the clamp is inserted into the shaft by compressing the clamp, such that the gap between the first end and the second end of the clamp is at least partially closed, thereby reducing the outer radius of the clamp; the outer radius of the clamp is restored by releasing the clamp to lock the clamp in place within the shaft at the specified axial position; and the clamp is rotated during insertion to position both the first end and the second end of the clamp at the specified angular position.

[0121] While the foregoing description is directed to preferred embodiments, it should be noted that other variations and modifications will be apparent to those skilled in the art and can be made without departing from the spirit or scope of this disclosure. Furthermore, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A device for balancing shafts in a turbine engine, characterized in that, The device includes: A solid disc assembly comprising a plurality of solid segments and a plurality of springs, each solid segment spanning a portion of the inner circumference of the shaft and having at least one receiver, the solid disc assembly being configured to be positioned within the shaft at a specific axial location along the shaft, each spring being positioned between adjacent solid segments and each spring applying pressure to adjacent solid segments, the pressure connecting the solid segments to each other; and A weight, at a specific angular position within the shaft, is removably attached to one of the plurality of solid segments of the solid disk assembly via a receiver in one of the solid segments. The solid disk assembly is inserted into the shaft at the specific axial position using an insertion tool, the insertion tool (a) simultaneously compressing the plurality of springs during insertion to move the solid disk assembly along the shaft to the specific axial position, and (b) simultaneously releasing the plurality of springs when the solid disk assembly reaches the specific axial position to allow the plurality of springs to unfold and thereby lock the solid disk assembly in place at the specific axial position. The insertion tool includes a pull rod and a retaining rod, the pull rod being used to release the plurality of springs, and the retaining rod being used to hold the solid disc assembly in the specific axial position during the release of the plurality of springs via the pull rod.

2. The apparatus according to claim 1, characterized in that, in, The weight is connected to the solid disk assembly via a keyway, a clip, a metal strip, or a screw.

3. The apparatus according to claim 1, characterized in that, in, The receiver is one of the slots and holes in the solid disk assembly.

4. The apparatus according to claim 1, characterized in that, The device further includes an anti-rotation pin that extends through the surface of the shaft and into one of the solid segments of the solid disk assembly, the anti-rotation pin preventing the solid disk assembly from rotating within the shaft by physically connecting the shaft to each solid segment.

5. The apparatus according to claim 1, characterized in that, in, The solid disk assembly further includes a plurality of magnets, each magnet positioned between two of the solid segments, and each magnet applies a magnetic force to adjacent solid segments, the magnetic force connecting the solid segments to each other.

6. The apparatus according to claim 5, characterized in that, in, Each magnet is further positioned to prevent the solid disk assembly from rotating within the shaft by being magnetically coupled to the inner surface of the shaft at the specific axial position.

Images