Rigizable insertion tool with rotating end effector

Abstract

An insertion tool is provided. The tool comprises: a flexible section comprising a plurality of rigidizable links; an end effector actuator; and an end effector coupled to the flexible section. A flexible shaft is inserted through the flexible section, where torque is transmitted from the end effector actuator to the distal end via the flexible shaft to cause rotation of the end effector. The tool may include a tool-free disconnect interface between the end effector and the flexible shaft.

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 643,163, filed May 6, 2024, entitled “Rigidizable Insertion Tool with Rotating End Effector,” U.S. Application No. 18 / 735,791, filed June 6, 2024, entitled “Rigidizable Insertion Tool with Rotating End Effector,” which are incorporated by reference herein in their entirety for all purposes. TECHNICAL FIELD

[0002] The present subject matter relates generally to insertion tools, and more particularly, to insertion tools for engine servicing. BACKGROUND

[0003] Insertion tools have a wide range of applications in various industries. In the aviation field, insertion tools can be used to inspect, service, and repair assembled engines through annular openings. These tools are designed to provide an economically efficient and time-saving solution for on-wing repair of aircraft engines, eliminating the need for engine disassembly and reducing downtime. Rigidizable insertion tools are insertion tools having a flexible section that can be selectively rigidized to facilitate inspection, service, or repair operations. BRIEF DESCRIPTION OF DRAWINGS

[0004] A complete and enabling disclosure of the present disclosure, directed to one of ordinary skill in the art, is set forth in the specification, which is to be construed in connection with the accompanying drawings, wherein:

[0005] Figure 1 is a cross-sectional schematic view of a high-bypass turbofan jet engine in accordance with some embodiments of the present disclosure.

[0006] Figure 2A is shown an insertion tool having a pneumatically driven end effector in an unrigidized state in accordance with some embodiments of the present disclosure.

[0007] Figure 2B is shown the insertion tool of Figure 2A in a rigidized state in accordance with some embodiments of the present disclosure.

[0008] Figure 3A is a cross-sectional view of two links of the insertion tool of Figure 2A in an unrigidized state in accordance with some embodiments of the present disclosure.

[0009] Figure 3B is a cross-sectional view of two links of the insertion tool of Figure 3A in a rigidized state in accordance with some embodiments of the present disclosure.

[0010] Figure 4 is a schematic view of a pneumatically driven end effector in accordance with some embodiments of the present disclosure.

[0011] Figure 5A and Figure 5B Another gas-powered drive end effector is shown in accordance with some embodiments of the present disclosure.

[0012] Figure 6 An insertion tool having a flexible shaft in accordance with some embodiments of the present disclosure.

[0013] Figure 7A and Figure 7B A tool-less disconnect interface usable in an insertion tool in accordance with some embodiments of the present disclosure. Figure 6

[0014] Figure 8 A cross-sectional view of a link of an insertion tool in accordance with some embodiments of the present disclosure. Figure 6

[0015] Figure 9A and Figure 9B Strands of a flexible shaft in accordance with some embodiments of the present disclosure.

[0016] Figure 10 Dimensions of a coiled wire in accordance with some embodiments of the present disclosure.

[0017] Figure 11 A flexible shaft having multiple strands in accordance with some embodiments of the present disclosure.

[0018] Figure 12 A cross-sectional view including several examples of strain shaft structures in accordance with some embodiments of the present disclosure.

[0019] Figure 13 An insertion tool having a segmented shaft in accordance with some embodiments of the present disclosure.

[0020] Figure 14 An end view of a joint of an insertion tool in accordance with some embodiments of the present disclosure. Figure 13

[0021] Figure 15 An axial cross-sectional view of a link having a fluid coupling in accordance with some embodiments of the present disclosure.

[0022] Figure 16 An insertion tool having a rotary end effector driven by a linear motion shaft in accordance with some embodiments of the present disclosure. DETAILED DESCRIPTION

[0023] ​​​Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the present disclosure and not as a limitation thereto. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the present disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield still a further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0024] As used herein, the terms "first," "second," "third," etc. can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0025] Unless stated otherwise, as used herein the terms "coupled," "fixed," "attached to" and the like, mean either directly coupled, fixed, or attached as applicable, or indirectly coupled, fixed or attached through one or more intermediate

[0026] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0027] Approximating language can be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about," "approximately," "substantially," and "essentially," can not to be limited to the precise value specified. In some instances, the approximating language can correspond to the precision of an instrument for measuring the value. For example, the approximating language can indicate the precision to within 1%, 2%, 4%, 10%, 15%, or 20%. These approximating language ranges can apply to individual values, to one or both ends of a range, and / or to the range of a range. In this and in other sections of the specification, ranges are used as endpoints to

[0028] There is an increasing need for efficient on-wing repair of aircraft engines to reduce the time and cost associated with engine teardown and shutdown. However, existing tools have limitations in the paths they can use to access areas of interest within the engine. To address this issue, various concepts of selectively rigidizable tools with rotating end effectors have been developed that significantly improve the state of confined space repair. The present disclosure provides various ways to transfer motion to a distal rotating end effector while still providing flexible path options for insertion into an engine or engine component. Specifically, utilizing a more robust and reliable shaft or multiple shafts with shaft couplings allows the insertion tool to have greater flexibility while maintaining the rotational power needed for operation. An insertion tool with improved flexibility. The rotating end effector can be mounted on the distal end of a rigidizable guide tube, a snake-arm robot, or other structure that can be selectively rigidized. These tools are designed to be initially flexible to facilitate insertion into the engine and then rigidized to stabilize the end effector for repair operations.

[0029] Reference will now be made to the drawings wherein like numerals refer to like components throughout.

[0030] Figure 1 is a schematic cross-sectional view of a conventional gas turbine engine 10 for an aircraft in which the repair, service, and / or inspection systems described herein can be operated. The engine 10 has a generally longitudinally extending axis or centerline 12 extending from a forward direction 14 to an aft direction 16. The engine 10 includes in downstream serial flow relationship: a fan section 18 including a fan 20; a compressor section 22 including a booster or low-pressure (LP) compressor 24 and a high-pressure (HP) compressor 26; a combustion section 28 including a combustor 30; a turbine section 32 including a HP turbine 34 and an LP turbine 36; and an exhaust section 38.

[0031] The fan section 18 includes a fan casing 40 surrounding the fan 20. The fan 20 includes a plurality of fan blades 42 disposed radially about the centerline 12.

[0032] The HP compressor 26, the combustor 30, and the HP turbine 34 form a core 44 of the engine 10 that generates combustion gases. The core 44 is surrounded by a core casing 46, which can be coupled with the fan casing 40. The casing 46 also surrounds the LP compressor 24 and the HP compressor 26.

[0033] A HP shaft or spool 48 coaxially disposed about the centerline 12 of the engine 10 drivingly connects the HP turbine 34 to the HP compressor 26. An LP shaft or spool 50 coaxially disposed about the centerline 12 of the engine 10 within the larger diameter annular HP spool 48 drivingly connects the LP turbine 36 to the LP compressor 24 and the fan 20.

[0034] The LP compressor 24 and the HP compressor 26 each include a plurality of compressor stages 52, 54 in which a set of compressor blades 56, 58 rotate relative to a corresponding set of static compressor vanes 60, 62 (also referred to as nozzles) to compress or pressurize a fluid flow passing through the stage. In a single compressor stage 52, 54, the plurality of compressor blades 56, 58 can be arranged in a ring and extend radially outward from a blade platform to a blade tip relative to the centerline 12, while the corresponding static compressor vanes 60, 62 are positioned downstream of and adjacent to the rotating blades 56, 58. Notably, Figure 1 The number of blades, vanes, and compressor stages shown in FIG. 1 is selected for illustrative purposes only, and other numbers are possible.

[0035] The HP turbine 34 and the LP turbine 36 each include a plurality of turbine stages 64, 66 in which a set of turbine blades 68, 70 rotate relative to a corresponding set of static turbine vanes 72, 74 (also referred to as nozzles) to extract energy from a fluid flow passing through the stage. In a single turbine stage 64, 66, the plurality of turbine blades 68, 70 can be arranged in a ring and extend radially outward from a blade platform to a blade tip relative to the centerline 12, while the corresponding static turbine vanes 72, 74 are positioned upstream of and adjacent to the rotating blades 68, 70. Notably, Figure 1 The number of blades, vanes, and turbine stages shown in FIG. 1 is selected for illustrative purposes only, and other numbers are possible.

[0036] In operation, the rotating fan 20 supplies ambient air to the LP compressor 24, which then supplies pressurized ambient air to the HP compressor 26, which further pressurizes the ambient air. The pressurized air from the HP compressor 26 is mixed with fuel in the combustor 30 and ignited, generating combustion gases. Some work is extracted from these gases by the HP turbine 34, which drives the HP compressor 26. The combustion gases are discharged into the LP turbine 36, which extracts additional work to drive the LP compressor 24, and the exhaust gases are ultimately exhausted from the engine 10 via the exhaust section 38. The driving of the LP turbine 36 drives the LP spool 50 to rotate the fan 20 and the LP compressor 24.

[0037] It will be appreciated that the engine 10 can further define a plurality of access openings that allow for inspection, servicing, and / or repair of various components within the engine 10 without disassembly or only partial disassembly of the engine 10. For example, the engine 10 can define a plurality of plug tool openings at various axial locations within the compressor section, the combustion section 28, and the turbine section 32. Additionally, the engine 10 can include one or more igniter ports within, for example, the combustion section 28 of the engine 10, which can allow for inspection, servicing, and / or repair of the combustion section 28.

[0038] It should also be appreciated that Figure 1 The exemplary engine 10 depicted is by way of example only, and in other exemplary embodiments, the engine 10 can have any other suitable configuration, including, for example, any other suitable number of shafts or spools, turbines, compressors, etc. Additionally or alternatively, in other exemplary embodiments, any other suitable turbine engine can be serviced, repaired, and / or inspected with the systems and methods described herein. For example, in other exemplary embodiments, the engine 10 can not be a turbofan engine, but can be configured as a turboshaft engine, a turboprop engine, a turbojet engine, etc., or can be an industrial gas turbine engine for power generation, fluid pumping, etc. In some embodiments, the systems and methods described herein can be used to service, repair, or inspect other aircraft or vehicle components. In some embodiments, the systems and methods described herein can be used to service and / or inspect any type of device that is susceptible to internal surface damage (such as cracks, dings, scratches, corrosion, wear, oxidation, etc.) that requires servicing and repair.

[0039] In Figures 2A-5B An embodiment of an insertion tool 100 having a pneumatically driven end effector is shown. Figure 2A An insertion tool 100 in an unrigidified state is shown in accordance with some embodiments. The insertion tool 100 includes a flexible section 106 and an end effector 108. The insertion tool 100 can include an inspection, service, and / or repair tool configured to be inserted into a confined cavity to inspect, service, or repair surfaces or components within the cavity. In some embodiments, the insertion tool 100 can be an engine inspection, service, and / or repair tool sized and shaped to be inserted through a port (e.g., an opening in the casing 46) of an engine (such as the engine 10 of FIG. 1) and secured to an exterior of the engine 10 for operation. The inspection or repair operation can include blending, grinding, drilling, milling, polishing, etc. of surfaces, devices, or components within the engine (such as the engine 10) that are susceptible to internal damage. As used herein, the end of the insertion tool 100 coupled to the end effector 108 is referred to as the distal end 110, and the opposite end is referred to as the proximal end 112. Typically, the insertion tool 100 is first inserted with the distal end 110 first, while at least a portion of the proximal end 112 can remain outside of the confined space during operation of the insertion tool 100 on the workpiece. Figure 1

[0040] The flexible section 106 includes a plurality of rigidifiable links 102 (one of which is shown in Figure 2A and Figure 2B ​The flexible section 106 includes end links 102 coupled to end links 104 of an end effector 108. In the illustrated example, the flexible section 106 is depicted as having five links 102, but can include any number of links (e.g., two, three, four, six, seven, etc.). The rigidizable links 102 can include links of a rigidizable guide tube, a snake-arm robot, or other similar device. In some embodiments, in an unrigidized state, the links 102 can be connected with connectors such as springs, hinges, one or more flexible spikes, or a shaft that drives the end effector 108. In some embodiments, the shaft couplings 114 described herein can also be used as connectors between the links when the links are rigidized and unrigidized. The rigidizable links 102 can include end features that engage with adjacent links to rigidize the flexible section 106 into a pre-defined shape when force is applied via the rigidization actuator 120. Figure 2A The insertion tool 100 is shown in an unrigidized, relaxed state, where the rigidizable links 102 are not engaged (e.g., spaced apart, touching, or touching but not tensioned). In this state, the links are able to move relative to one another in some (one, two, or three) degrees of freedom, allowing the flexible section 106 to bend during insertion of the insertion tool 100. Once the tool 100 is inserted into place, the insertion tool 100 can be rigidized from the unrigidized state shown in FIG. 1A to the rigidized state shown in FIG. 1 B to position the end effector 108 in a desired position and orientation, allowing for inspection, servicing, and / or repair of a part, such as an engine component. Figure 2A The insertion tool 100 is shown in an unrigidized, relaxed state, where the rigidizable links 102 are not engaged (e.g., spaced apart, touching, or touching but not tensioned). In this state, the links are able to move relative to one another in some (one, two, or three) degrees of freedom, allowing the flexible section 106 to bend during insertion of the insertion tool 100. Once the tool 100 is inserted into place, the insertion tool 100 can be rigidized from the unrigidized state shown in FIG. 1A to the rigidized state shown in FIG. 1 B to position the end effector 108 in a desired position and orientation, allowing for inspection, servicing, and / or repair of a part, such as an engine component. Figure 2B The insertion tool 100 is shown in an unrigidized, relaxed state, where the rigidizable links 102 are not engaged (e.g., spaced apart, touching, or touching but not tensioned). In this state, the links are able to move relative to one another in some (one, two, or three) degrees of freedom, allowing the flexible section 106 to bend during insertion of the insertion tool 100. Once the tool 100 is inserted into place, the insertion tool 100 can be rigidized from the unrigidized state shown in FIG. 1A to the rigidized state shown in FIG. 1 B to position the end effector 108 in a desired position and orientation, allowing for inspection, servicing, and / or repair of a part, such as an engine component.

[0041] The flexible section 106 can be rigidized by the rigidization actuator 120 from a relaxed or unrigidized state as shown in FIG. 1A to a rigidized state as shown in FIG. 1 B. Figure 2A The flexible section 106 can be rigidized by the rigidization actuator 120 from a relaxed or unrigidized state as shown in FIG. 1A to a rigidized state as shown in FIG. 1 B. Figure 2Btensioned or rigidized state as shown in FIGS. 1-2. In some embodiments, the rigidization actuator 120 can include a tensioning cable assembly that is inserted through the plurality of rigidizable links 102 and coupled to the end link 104, causing the links 102 to tension as the cable assembly is pulled. In some embodiments, the rigidization actuator 120 can cause rigidization of the flexible segments 106 via layer interference mechanisms, electromagnetic stiffness tuning of magneto-rheological materials, electromagnetic stiffness tuning of electro-rheological fluids, stiffness modulation with phase changes, stiffness modulation with pressurization, or other means of rigidization. When rigidized, the rigidizable links 102 can define a complex geometry that extends through a three-dimensional Cartesian coordinate system. That is, the insertion tool 100 can simultaneously extend along its length from the proximal end 112 to the distal end 110 in the X-axis, Y-axis, and Z-axis. The particular shape of the tool 100 can be configured based on the shape of the environment in which the tool 100 is used. In some embodiments, the flexible segments 106 include one or more links as described in U.S. Patent Application Publication No. US 2022 / 0221706 Al entitled “Insertion Tool,” the entirety of which is incorporated by reference herein. In some cases, the particular shape of the tool 100 can be configured to a unique predefined shape when the tool is rigidized.

[0042] The plurality of links 102 can each include a central cavity 220 Figure 3A and Figure 3B such as a channel or passageway, that align when the links 102 are rigidized. For a pneumatically driven insertion tool 100, a sealing element 208 can be positioned around at least one end of the central cavity 220 and provide a fluid seal when the links are rigidized, such that a fluid path is formed to deliver fluid from the fluid source 125 to one or more of the links 102.

[0043] The insertion tool 100 also includes an end effector actuator that provides power / torque to the end effector 108. For a pneumatically driven end effector, the end effector actuator can include the fluid source 125. The end effector 108 can be rotatably coupled to the end link 104. In some embodiments, the end effector 108 includes at least one of a mixing tool, a milling tool, a drilling tool, a reaming tool, a honing tool, a cleaning tool, a polishing tool, or other applicable tool. In some embodiments, the insertion tool 100 can include a turbomachinery service tool.

[0044] Figure 3A and Figure 3B A cross-sectional view of two adjacent links 102 and 102’ of an insertion tool 100, such as the insertion tool 100 shown in FIGS. 1-2, is shown in accordance with some embodiments. In Figure 2A and Figure 2B A cross-sectional view of two adjacent links 102 and 102’ of an insertion tool 100, such as the insertion tool 100 shown in FIGS. 1-2, is shown in accordance with some embodiments. In Figure 3AIn the unrigidized state, the links 102, 102' are not tensioned and can be unrigidized tools that are inserted into engine parts or components. In the rigidized state, Figure 3B In the rigidized state, the links 102, 102' are tensioned to provide torque to the end effector 108( Figure 2A 、 Figure 2B ). Each link 102, 102' includes a seal element 208 (shown in connection with link 102 only) that provides a seal to a central cavity 220 that houses a pneumatic turbine 206 supported by a stationary guide vane 210. Each pneumatic turbine 206 includes a shaft 207 and a plurality of blades 209 configured to rotate the shaft 207 with a fluid flow through the central cavity 220. The stationary guide vane 210 is coupled to an outer shell 222 of the link and serves as a mount for the pneumatic turbine 206 via a bearing 202 around the shaft 207 of the turbine 206. A shaft coupler 114 is coupled between the shafts 207 of the pneumatic turbines 206 in adjacent links 102 and 102'. The shaft coupler 114 generally couples two or more pneumatic turbines 206 to transfer torque when the plurality of rigidizable links are rigidized, but allows relative movement of the two or more pneumatic turbines 206 when the plurality of rigidizable links are in the unrigidized state. The illustrated shaft coupler 114 includes compressible springs (e.g., coil springs) that are compressed when the links 102 are tensioned as shown in Figure 3B In the rigidized state, the springs transfer torque from the shaft 207 of an upstream turbine 206 to a downstream turbine 206. The springs can be coiled in the same direction as the rotation of the turbine so that the springs tighten as the turbine rotates. In some embodiments, the shaft coupler 114 can instead be a flexible cable, a universal coupling, a cardan coupling, a bevel gear, a magnetic coupling, a fluid coupling, a friction plate, a flexible spline shaft, or a resilient shaft.

[0045] The seal elements 208 are disposed between the rigidizable links 102 to form a fluid path along the central cavities 220 of the plurality of links. In some embodiments, the fluid path is a pneumatic sealed fluid path between a fluid source 125 Figure 2A and Figure 2B at a proximal end of the insertion tool 100 and the turbine 206 closest to the end effector 108. The seal elements 208 can include one or more of a bellows, a gasket, a spline seal, or an O-ring disposed between adjacent rigidizable links 102. In some embodiments, the fluid path can terminate before reaching the end link 104 (e.g., 2, 3, or 4 links upstream) and a flexible shaft or other type of coupling can transfer torque from the turbine embedded in the link 102 to the end link 102. Fluid can exit at the distal end, return and exit at the proximal end, or circulate in a closed fluid loop formed in the links 102.

[0046] The pneumatic turbines 206 are generally configured to convert a fluid force of fluid from the fluid path into a torque to drive rotation of the end effector 108. In some embodiments, the fluid force can include pressurized air or fluid (e.g., compressed shop air) and can drive two or more pneumatic turbines 206 via fluid pressure, fluid velocity, or a combination fluid velocity-pressure. In Figure 3A and Figure 3B In some embodiments, the pneumatic turbines 206 can include an upstream turbine and a downstream turbine having a greater diameter than the upstream turbine, or different diameters, different numbers of blades, or different blade pitch, or any combination of the foregoing, and can be axially aligned and / or centrifugal to one another.

[0047] While the pneumatic turbines 206 are shown in adjacent links 102 and 102’ in Figure 3A and Figure 3B The insertion tool 100 can include one or more pneumatic turbines 206 arranged differently along the flexible section 106. For example, the first through fourth links can be hollow, while the fifth and sixth links each house a turbine. In other words, one or more of the links can be hollow and not contain a turbine, while others of the links can contain a turbine. In other embodiments, the rigidizable links 102, when rigidized, can form two or more fluid paths, where two or more pneumatic turbines 206 forming parallel flow circuits are each driven by fluid from a different fluid path. In some embodiments, a first fluid path can flow from the proximal end 112 of the tool 100 toward the distal end 110 (i.e., a source flow), while a second fluid path can flow from the distal end 110 of the tool 100 or near thereto toward the proximal end 112 of the tool 100 (i.e., a return flow), the two fluid paths connecting at or near the distal end of the tool, thus not requiring fluid to be vented from the tool 100 except at the proximal end 112. In another embodiment, a closed fluid circuit can be formed by two or more such fluid paths, the paths containing a compressor or pump near the proximal end 112 of the tool, and turbines at the distal end of the tool or distributed along the length of the tool as previously described. In yet another embodiment, the turbines 206 can form an Archimedes screw turbine or a conical screw turbine. In some embodiments, the turbine 206 positioned closest to the end effector 108 can be coupled to the end effector 108 via a rigid or flexible shaft, resulting in rotation of the end effector 108 with rotation of the turbine 206. In some embodiments, the pneumatic turbines 206 can be housed in the end link 104 and directly coupled to a shaft of the end effector 108 Figure 2A ) In one or more of the pneumatic turbines 206 are housed in Figure 2A andFigure 2B With the plurality of rigidizable links 102 and end links 104 shown in FIG. 1, the end effector 108 can be driven by pneumatic power supplied by the fluid source 125. In embodiments where a series pneumatic turbine is housed within the plurality of links 102, having multiple stages allows for better load distribution and reduces stress on individual components, thereby extending operational life and reducing vibration in the insertion tool 100.

[0048] Utilizing a multi-stage turbine approach can help run the insertion tool 100 at higher torque at lower speeds without the need for a gearbox, which improves the efficiency of the insertion tool 100. Referring to FIG. 2, a schematic of an insertion tool 200 is shown. Figure 3A and Figure 3B The described embodiments additionally do not require lubrication, which can extend the life of the shaft couplings 114. Implementing a modular design can save time and cost, as in the event of a failed connection of the shaft 207 and the shaft coupling 114, the entire insertion tool 100 does not need to be replaced, only the failed connection. Additionally, the constant air flow through the bearings 202 and past the end effector 108 regulates the temperature of the insertion tool 100 and its components. Utilizing the shaft 207 and the shaft coupling 114 can allow the insertion tool 100 to be longer than in embodiments with a single connector connecting a plurality of rigidizable links 102, such as the flexible shaft 610 described in FIG. 1, which can be useful when inspecting, servicing, or repairing parts of the insertion tool that require a longer insertion tool, such as engine components. Furthermore, if the pneumatic turbine 206 is only in the straight section of the insertion tool 100, there is no limit to the life of the shaft coupling 114. Figure 6

[0049] In some embodiments, the end effector 108 of the insertion tool 100 can be pneumatically driven via an actuator integrated with and / or embedded in the end link 104. Upon rigidization, the central cavity 220 of the plurality of rigidizable links 102 forms a fluid path that directs fluid from the fluid source 125 to an integral actuator of the end effector 108. Examples of integral actuators include pneumatic pistons, hollow rotary end effectors, and dental air turbines.

[0050] Figure 4 is an illustration of an axial piston motor 400 configured to convert pneumatic power into torque. In some embodiments, the axial piston motor 400 can be coupled at a central shaft 410 to an end effector 408 as described in FIG. 1. Figure 2A and Figure 2B ​The end effector 108 shown is driven by pneumatic power supplied from a fluid path formed by a plurality of rigidizable links 102, via an axial piston motor 400. The axial piston motor 400 includes two or more pistons 402, a swashplate 408, bearings 405, and sealing elements 404. The pistons 402 are axially arranged about a central shaft 410, and the swashplate 408 is mounted at an angle to the central shaft 410. When compressed air enters the motor and pushes the pistons 402, the pistons 402 alternately extend and retract to rotate the swashplate 408, thereby converting pneumatic pressure into rotational motion of the swashplate 408, which is transmitted to the central shaft 410 to drive the end effector 108.

[0051] Figure 5A and Figure 5B This is an illustration of a pneumatically driven end effector 108 that can be coupled to an insertion tool 100 according to some embodiments. Figure 5A This is a side view of the pneumatically driven end effector 108, and Figure 5B This is a top view of the pneumatically driven end effector 108. Pressurized air is supplied from a flow path to the hollow interior of the end effector 108 and released at an angle through multiple fluid outlets 510 of the end effector 108, causing the released air to cause a rotation 502 of the end effector 108. Although Figure 5B Four fluid outlets 510 are shown, but any number of fluid outlets 510 may be present, causing rotation 502 of the end effector 108. The end effector 108 may also include a bearing 503 at which it is connected to an end link 104, allowing the end effector 108 to rotate smoothly relative to the end link 104. In some embodiments, the end effector 108 can be rotated via a method described herein. Figures 2A-3B The fluid flow supplied by the fluid path formed by the plurality of rigid links 102 is used for driving.

[0052] Figures 6-12 An embodiment of an insertion tool 100 having a flexible shaft 610 for driving the rotation of an end effector 108 is shown. Figure 6 The insertion tool 100 shown includes a plurality of rigidizable links 102 ( Figure 6 The text refers to a flexible segment 106 formed by referencing one of these elements, and an end effector 108 connected to the distal end 110 of the flexible segment 106. In some embodiments, the flexible segment 106 and the end effector 108 may be associated with a reference. Figure 3A and Figure 3B The flexible segment 106 and end effector 108 described are the same as or similar. The flexible segment 106 may include a plurality of rigidizable links 102, each having a central cavity 220 forming a shaft guide. Figure 6In the illustrated embodiment, the flexible shaft 610 is shown as being inserted through a shaft guide formed by the plurality of rigidizable links 102 of the flexible section 106. Torque is transmitted from the end effector actuator 604 at the proximal end 112 via the flexible shaft 610 to the distal end 110. The flexible shaft 610 is coupled within the end link 104 to a shaft of the end effector 108, causing rotation 502 of the end effector 108. The flexible shaft 610 also serves as an actuator connector that connects the plurality of rigidizable links 102 in the unrigidified state.

[0053] In some embodiments, the insertion tool 100 includes a tool-less disconnect interface 720 between the end effector 108 and the flexible shaft 610 and / or between the end effector actuator 604 and the flexible shaft 610. Figure 7A , Figure 7B ) In some embodiments, the insertion tool 100 includes one or more shaft bearings 202 positioned within the central lumen 220, the links 102 of the flexible section 106, and around the flexible shaft 610. In some embodiments, the insertion tool 100 can also include a shaft tensioning assembly 605 configured to maintain a tension of the flexible shaft 610 between 1-10% of a tensile strength of the flexible shaft 610, between 1-50% of the tensile strength of the flexible shaft 610, or between 0.1-5% of the tensile strength of the flexible shaft 610. In some embodiments, the shaft tensioning assembly 605 can include a compression spring coupled to the proximal end 112 of the flexible shaft 610. In some embodiments, the shaft tensioning assembly 605 can include an active control that adjusts the shaft tension based on sensor measurements. In some embodiments, the rigidization actuator 120 is configured to actuate the plurality of rigidizable links 102 in the flexible section 106 from an unrigidified state to a rigidized state having a predefined shape. In some embodiments, the rigidization actuator 120 can perform the same or similar functions as the rigidization actuator 120 described above with reference to FIGS. 1-4. Figure 3A and Figure 3B

[0054] The end effector actuator 604 can include a motor (e.g., electric motor, pneumatically driven motor) for providing torque to the end effector 108 via the flexible shaft 610. In some embodiments, the end effector actuator 604 can be a rotary motor or a linear motor with a rotary motion conversion mechanism.

[0055] Figure 7A ​is an illustration of an insertion tool 100 with a tool-less disconnect interface 720. Tool-less disconnect interface 720 generally refers to an interface that can be manually disconnected without the use of a tool. Tool-less disconnect interface 720 can include male and female features that can be connected and disconnected without a tool. Because the life of the flexible shaft 610 is generally shorter compared to other components of the insertion tool 100, including a tool-less disconnect interface 720 allows for efficient disconnection and connection of the flexible shaft 610 during replacement. The connection and disconnection by hand is more time efficient during replacement compared to a disconnect interface that requires a tool. In Figure 7A , the tool-less disconnect interface 720 couples the flexible shaft 610 with the end effector 108 via a shaft 602 of the end effector 108, which is supported within the end link 104 via a bearing 607. In some embodiments, a second tool-less disconnect interface 720 couples a plurality of fluid outlets 510 Figure 5B ) with the end effector actuator 604. For clarity, the flexible section 106 through which the flexible shaft 610 is inserted is simplified in Figure 7A and can be the same or similar to the flexible section 106 described with reference to Figure 6 .

[0056] In Figure 7A , the flexible shaft 610 has a male feature that couples with a female feature on the end effector actuator 604 and the end effector 108. In Figure 7A depicted embodiments, the spline 707 can be a female adapter, while the adapter 706 or microchuck 708 can be a male adapter. However, the male-female interface can be reversed. In some embodiments, the tool-less disconnect interface 720 includes a swage spline or a threaded fitting. For example, the tool-less disconnect interface 720 can include the spline 707 and the microchuck 708. In Figure 7A , the flexible shaft 610 includes a spline 707 at both ends and is coupled between a microchuck 708 at the proximal end 112 and an adapter 706 at the distal end 110. The microchuck 708 is also coupled to the end effector actuator 604, and the adapter 706 is also coupled to the shaft 602 of the end effector 108. The microchuck 708 can have a low slip torque when clamped directly to the flexible shaft 610 and can slip when the operating torque is reached. When clamped to the spline 707, particularly the swage spline described above, the microchuck 708 is able to overcome the low slip torque limit described above. In some embodiments, the tool-less disconnect interface 720 can include a square spline, a hexagonal spline, or a polygonal spline on the flexible shaft 610. In some embodiments, the tool-less disconnect interface 720 can instead include a threaded fitting, where the direction of the threads of the threaded fitting is such that the threaded fitting is tightened in the direction of rotation of the flexible shaft 610.

[0057] Figure 7BAnother embodiment of a tool-less disconnect interface with a magnetic connection in a connected (720A) and disconnected (720B) state is shown. Figure 7B In this embodiment, the male feature includes a ferromagnetic spline fitting 705 on the flexible shaft 610, and the female feature includes an adapter 706 having a magnet 704. In other embodiments of the magnetic toolless disconnect interface 720, the two sides of the interface may be similar and may include a series of two or more magnets whose magnetic pole orientations alternate between alternating magnets. In some embodiments, the flexible shaft 610 may alternatively include one or more female features. In some embodiments, torque limiting features (such as a friction clutch or a magnetic clutch) may also be included in the drivetrain at a location along the length of the flexible shaft 610 or aligned with the toolless disconnect interface 720. Those skilled in the art will understand that the functionality of the toolless disconnect interface 720 and the torque limiting features can be provided by a single device (such as the previously described spline fitting and / or magnetic fitting).

[0058] In some embodiments, Figure 7A and Figure 7B The toolless disconnect interface 720 shown can connect the flexible shaft 610 to, for example... Figure 6 The end effector actuator 604 and / or end effector 108 shown are connected. In cases where the flexible shaft 610 is a wear-prone and breakage component of the insertion tool 100, the toolless disconnect interface 720 allows for easy removal of the flexible shaft 610 for inspection, repair, and / or replacement. In some embodiments (such as...) Figure 11 In the embodiments described herein, the flexible shaft 610 may be formed from one or more strands of wire formed from multiple coiled wires. In some embodiments, the flexible shaft 610 may include strands constructed into the shaft and made of a material less susceptible to bending stress than most of the wires in the shaft. When one or more wires break, the broken flexible shaft 610 (including the broken wire segment) can be easily removed from the tool via the unbroken strands for replacement. Shaft breakage can be detected by a sensor (e.g., a torque sensor that measures a reduction in the operating torque of the tool), a fragile fiber optic element in the shaft that causes an optical open circuit upon breakage, an electrical conductor in the shaft that loses continuity in the event of shaft breakage, or any other means of measuring or inferring a flexible shaft breakage.

[0059] Figure 8 This is an axial cross-sectional view of the connecting rod 102, wherein the bearing 202 extends the length of the connecting rod 102. In some embodiments, Figure 6 The flexible section 106 in the middle can be made of Figure 8The plurality of links 102 shown in FIG. 1 are formed. The links 102 have a central cavity 220 through which a flexible shaft 610 is inserted. A bearing 202 is positioned between the link 102 and the flexible shaft 610, within the central cavity 220, to improve the life of the flexible shaft 610 by limiting the swing of the flexible shaft 610 during operation. In some embodiments, the bearing 202 comprises a stretch spring coiled around the flexible shaft 610. In some embodiments, the ratio of the inner diameter of the stretch spring to the outer diameter of the flexible shaft 610 is between 1.2 and 3.0. In some embodiments, the flexible shaft 610 comprises a plurality of layers of wire around a centerline. When the coiling direction of the stretch spring matches the coiling direction of the outermost layer of the flexible shaft 610, wear on the flexible shaft 610 can be further minimized. In some embodiments, for a coiled flexible shaft 610, the coiling direction of the spring has the same coiling direction as the outermost layer of the flexible shaft 610. In some embodiments, the shaft bearing 202 comprises a flexible hollow polytetrafluoroethylene tube or braided cable sleeve. In some embodiments, at least one inner surface of the shaft bearing 202 or an outer surface of the flexible shaft 610 is coated with one or more of a steel wire rope lubrication, a molybdenum disulfide coating, a graphite coating, a fluoropolymer, a polytetrafluoroethylene coating, or other friction-reducing coating. Generally, the insertion tool 100 has a moderate tension in the flexible shaft 610, a tight clearance between the tool 100 and the flexible shaft 610, and lubrication between the rotating shaft and any stationary interfaces, resulting in higher levels of operation in the tool 100 and shaft life.

[0060] Figure 9A is an illustration of a strand 920 of coiled wire 910 according to some embodiments. In some embodiments, the flexible shaft 610 Figure 6 ) can be formed from one or more strands 920 of coiled wire 910. Figure 9B is a cross-sectional view of the strand 920 taken along line D-D, showing a plurality of layers of coiled wire 910 within the strand 920 having a diameter 902. In Figure 9B , the strand 920 comprises four layers, with three wires, six wires, six wires, and six wires from innermost to outermost. Figure 9B is shown by way of example only, and the strand 920 can be formed from any number of wires in any number of layers. In some embodiments, the strand 920 can have a hollow core, with the coiled wire surrounding the core. For example, Figure 9BThe three innermost strands shown can be removed to form a hollow core. In some embodiments, the strands with the hollow core have a core diameter at least as wide as the diameter of the smallest strand. In some embodiments, strand 920 may include one or more straight (i.e., 0-coil angle) strands at the core radially inside the first winding layer. In some embodiments, strand 920 may have a core formed of other materials such as fibers, polymers, and / or metals. In some embodiments, the strand diameter may be between 0.01 and 0.1 inches. In some embodiments, wire 910 may be a monofilament made of one or more of stainless steel, high-performance alloys, nitinol, superelastic materials, tungsten, and / or titanium. In some embodiments, wire 910 may be interwoven with steel and self-lubricating plastic wires to form a self-lubricating shaft with reduced inter-wire friction. In some embodiments, wire 910 may be made of fibers or superelastic materials that can improve the fatigue life, flexibility, torsional capacity, and damping of the cable. In some embodiments, the flexible shaft may include a material formed by 80-90% cold working.

[0061] Figure 10 It can be coiled together with other threads to form Figure 9A The illustration shows the dimensions of the coiled wire 910 of the strand 920. The coiled wire 910 has a wire diameter (d) 902, pitch (p) 1004, helix angle (α) 1006, length 1008 (l), and coil diameter ( )1014. Pitch (p) 1004 refers to the distance between adjacent turns or coils along the helix. Pitch (p) 1004 can correspond to the number of wires in each layer of wire in strand 920. For example, in a four-strand layer, pitch (p) 1004 can be four times the wire diameter 902. Coil diameter ( 1014 refers to the average diameter of the coil. The average coil diameter is determined by dividing the sum of the outer coil diameter and the inner coil diameter by two. The helix angle (α) 1006 is the angle between the central axes 1009 of the helix and the strands. The helix angle 1006 can be determined by... To calculate.

[0062] In some embodiments, the flexible shaft includes strands 920 formed by multiple layers of lines 910 surrounding a central axis 1009 (including a first coiled layer closest to the central axis 1009). In some embodiments, the i-th coiled layer starting from the central axis 1009 includes a helix angle 1006 of α. i The spiral coil has multiple wires, where α i In α i,max and α i,max Between -10 degrees, α i,max Depend on Limited, where L iis the number of wires in the i-th layer, d i is the diameter of the wires 902 in the i-th layer, and is the average diameter of the i-th layer. In some embodiments, a max is between 10 and 80 degrees, however, in preferred embodiments, each layer of wires in the flexible shaft 610 has a helix angle equal to or close to a i,max is the helix angle of the i-th layer of wires 920. In some embodiments, the helix angle of the i-th layer of wires 920 is between 10 and 80 degrees, however, in preferred embodiments, each layer of wires in the flexible shaft 610 has a helix angle equal to or close to a

[0063] In some embodiments, the helix angle 1006 of the first layer of winds can be less than the helix angle 1006 of a second layer of winds radially outward of the first layer of winds. In some embodiments, the strand 920 can include 3 to 8 layers of winds, and the plurality of layers each include 3 to 20 wires. In preferred embodiments, the first layer of winds includes three wires, and the number of wires in a second layer of winds radially outward of the first layer of winds is between 3-8 wires. In further embodiments, the number of wires in a third to a sixth layer of winds radially outward of the second layer of winds is each between 5 to 10 wires, and the number of wires in a seventh and eighth layer radially outward of the third to sixth layer of winds is each between 6 to 12 wires.

[0064] In some embodiments, the wire diameter (d i ) 902 of the wires in a layer (i) of the plurality of layers other than the first layer of winds is determined based on where where is the diameter of the flexible shaft 902, di is the wire diameter 902 of the wires in the first layer, and Li is the number of wires in the first layer of winds. In some embodiments, the wire diameter 902 of the wires in the plurality of layers is between 0.0005 to 0.08 inches, however, the preferred wire diameter 902 can be found using the two equations above. In some embodiments, the strand 920 is formed of wires of the same diameter. In some embodiments, the wire diameter of the wires within the same layer is the same, but the wire diameter between wire layers can be different. In preferred embodiments, the wire diameter 902 of the wires in the first layer of winds is less than the wire diameter 902 of the wires in a second layer of winds radially outward of the first layer of winds.

[0065] In some embodiments, the layers in the plurality of layers can have alternating directions of lay, with the outermost layer in the plurality of layers having a lay direction corresponding to the direction of rotation of the end effector 108. For example, if the rotation is clockwise, the outermost layer has a left-hand lay, while if the rotation is counterclockwise, the outermost layer has a right-hand lay. In some embodiments, the layers in the plurality of layers can have the same direction of lay, such as lang-lay, with the lay direction corresponding to the rotation of the end effector 108 as described above. Lang-lay is generally preferred due to its high flexibility and torque transmission capabilities. In some embodiments, the innermost layer in the plurality of layers is formed of a different material than the other layers, such as a super-elastic material. In preferred embodiments, the inner 20-30% of the layers in the plurality of layers are formed of a different material, preferably a super-elastic material. In some embodiments, the flexible shaft 610 can be formed of a single strand 920 as described herein. The preferred combination of parameters and ranges described for the flexible shaft 610 optimize the bending fatigue life of the flexible shaft 610 while still maintaining low bending stiffness and high torsional stiffness.

[0066] Figure 11 and Figure 12 An embodiment of a flexible shaft 610 formed of a plurality of strands 920 is shown. The multi-strand flexible shaft 610 has a core 1108 and a plurality of strands 920 wrapped around the core 1108. Figure 11 The core 1108 is shown formed of a single strand of lay wire, which can be the same or similar to the strands 920. In some embodiments, the core 1108 can include one or more wires of the same or different materials, or can be hollow. In some embodiments, each strand 920 can be the strand 920 described with reference to Figure 9A , Figure 9B and Figure 10 In some embodiments, the strands 920 can include a straight centerline 910’ or can have a hollow center. Generally, if the above-described optimized parameters and ranges do not achieve the desired life of the flexible shaft 610, a hollow shaft structure is used, in which case a hollow shaft structure with an increased number of outer layers should be used, which increases the torsional strength. In some embodiments, the strands 920 can be wrapped around the core 1108 in regular lay or lang-lay. In preferred embodiments, a steel cable with a fiber core is preferred due to better flexibility and the ability to lubricate the rope from the inside.

[0067] Figure 12Cross-sectional views of examples of commercially available multi-strand flexible shaft structures are provided in accordance with various embodiments. Example a) depicts a three-strand structure around a hollow core, each strand formed of seven wires in two layers. Example b) depicts six seven-strand wires around a core also formed of seven coiled wires. Example c) depicts six strands around a core also formed of nineteen coiled wires, each strand having nineteen wires in three layers. Example d) depicts six strands around a core also formed of 37 wires, each strand formed of 37 wires in four layers. Example e) depicts a shaft having the structure of example b) as a core, and six similarly structured ropes coiled around the core. Finally, example f) depicts a shaft having two layers of strands around a core. The first layer includes six strands, and the second radially outward layer includes twelve strands. Each strand includes nineteen wires coiled in three layers. The core similarly includes nineteen wires coiled in three layers.

[0068] Figure 12 The shaft structures in FIGS. 1-6 are provided by way of example only. In some embodiments, a flexible shaft can include any number of strands formed of any number of wires in any number of layers. For the flexible shaft 610 structures described herein, the shafts can effectively transfer torque to the end effector 108 during repair or service operations while reducing wear and breakage caused by high-speed rotational stresses.

[0069] Figure 13 is an illustration of an insertion tool 100 having a segmented shaft 1310 for driving rotation of an end effector 108. In some embodiments, the insertion tool 100 includes a flexible section 106 having a plurality of rigidizable links 102 that can be similar to the links 102 described above. The insertion tool 100 also includes an end effector 108 coupled to a distal end 110 of the flexible section 106 and a rigidization actuator 120 configured to actuate the flexible section 106 between a rigidized state and a relaxed state.

[0070] Each link 102 includes at least one segment of the segmented shaft 1310 that is rotatable within the link 102 via a bearing 202. In some embodiments, each segment of the segmented shaft 1310 includes a joint 1302, such as a universal joint between two shaft couplers 114. Each segment of the segmented shaft 1310 of each link 102 is connected to an adjacent segment of the segmented shaft 1310 and the respective link 102 via a shaft coupler 114. Within a single link 102, there can be two segments of the segmented shaft 1310 with a universal joint coupled between each segment within the single link 102. The joint 1302 can include a pair of hinges positioned close together, oriented 90° to each other, connected by a cross-axis. The joint 1302 is configured to transfer rotational motion between the shaft couplers 114 on each side of the plurality of rigidizable links 102.

[0071] In the rigidized state, the housings 222( Figure 3A ) of adjacent links 102 of the plurality of rigidizable links 102 are engaged to limit relative movement of the housings 222, and the shaft couplings 114 of the adjacent links 102 are engaged to connect the segmented shaft 1310 such that the segmented shaft 1310 can transmit torque from the end effector actuator 604 at the proximal end 112 of the flexible segment 106 to the end effector 108, causing rotation 502 of the end effector 108. In some embodiments, the segments of the segmented shaft 1310 can include bevel gears, magnetic couplings, fluid couplings, friction plates, elastic couplings such as flexible shafts, or compression springs.

[0072] Figure 14 is a further view of the shaft coupling 114 within the link 102 previously shown in Figure 13 The shaft coupling 114 can include surface features such as ridges and / or protrusions that are configured to engage with corresponding features on the shaft coupling 114 of an adjacent link when the insertion tool 100 is rigidized. When the tool 100 is not rigidized, the features of the shaft coupling 114 will not be engaged. A bearing 202 is disposed about the shaft coupling 114 to allow rotation of the shaft coupling 114 relative to the housings 222( Figure 3A ) of the plurality of rigidizable links 102. In other embodiments, the shaft coupling can include any type of mechanism previously described with respect to the toolless disconnect interface 720, such as male and female features further including a spline fitting or a threaded fitting, where the threading direction of the threaded fitting is such that the threaded fitting tightens in the direction of rotation of the flexible shaft 610.

[0073] Figure 15 A rigidizable link 102 with a fluid coupling is depicted. In Figure 15 The link 102 similarly has two shaft couplings 114 on each end that are configured to engage with shaft couplings 114 on adjacent links 102 and rotate relative to the housings 222( Figure 3A ) of the plurality of rigidizable links 102. For a link with a fluid coupling as shown in Figure 15 Each shaft coupling 114 is also coupled to a fluid coupling turbine 1502 within the central cavity 220. A seal 1305 is disposed about the shaft connecting the shaft coupling 114 and the fluid coupling turbine 1502 within the central cavity 220 to maintain a fluid seal of the central cavity 220. When one of the shaft couplings 114 is rotated by the shaft coupling 114 of an adjacent link, one of the fluid coupling turbines 1502 induces a swirl in the fluid of the central cavity 220, which drives rotation of the opposite fluid coupling turbine 1502, in turn causing rotation of the opposite shaft coupling 114. For a link with a fluid coupling as shown in Figure 15A series of links of the fluid coupling shown in FIG. 1 can transmit torque from the proximal end 112 of the insertion tool 100 to the distal end 110 to drive the end effector 108.

[0074] Figure 16 is an illustration of an insertion tool 100 having a linear motion shaft 1605 and a motion conversion mechanism 1702 for driving rotational motion of an end effector 108. The insertion tool 100 includes a flexible section 106 comprising a plurality of rigidizable links 102 and a tensioned actuator 1610 configured to actuate the flexible section 106 between a tensioned state and a relaxed state. The insertion tool 100 also includes an end effector 108 coupled to a distal end 110 of the flexible section 106 and a linear motion shaft 1605 inserted through the plurality of rigidizable links 102. An end effector actuator 604 can be configured to cause reciprocating linear movement of the linear motion shaft 1605, and the motion conversion mechanism 1702 is configured to convert the linear movement of the linear motion shaft 1605 to rotational motion to drive rotation 502 of the end effector 108. The rigidizable links 102 also include bearings 202 fitted around the linear motion shaft 1605 to reduce friction during linear movement. In some embodiments, the motion conversion mechanism 1702 is a linear-to-rotational motion conversion mechanism, such as a helical cam mechanism. In some embodiments, the linear motion shaft 1605 can be a steel wire rope or a solid wire having high axial and buckling strength. The steel wire rope can have layers wound in opposite directions, and the innermost layer can be solid. In some embodiments, the linear motion shaft 1605 can be the same or similar to one or more embodiments of the flexible shaft 610 described herein with reference to FIGS. 1-4. Figures 6-12

[0075] Various embodiments of insertion tools 100 having a rotating end effector 108 are provided herein. The insertion tools 100 described herein allow for maintenance and repair operations within confined spaces, such as the interior of a turbine engine. Flexible shafts used to transmit rotational motion to the end effector 108 are prone to breaking due to stresses from the rotational motion and friction. When the flexible shaft breaks at high rotational speeds, the tool and even the device being repaired can be damaged. In some embodiments of the insertion tools 100 described herein, specific structures of the flexible shaft 610 are provided to reduce the likelihood of breakage. In other embodiments, the flexible shaft is replaced with other motion transmission mechanisms, such as segmented shafts, pneumatic turbines, and / or linear motion shafts, to eliminate the risks associated with flexible cable shaft breakage.

[0076] Further aspects of the present disclosure are provided by the subject matter of the following clauses:

[0077] ​An insertion tool comprising: a flexible section; a rigidizing actuator configured to actuate the flexible section between a rigidized state and a relaxed state, wherein in the rigidized state a fluid path is formed within the flexible section; an end effector coupled to the flexible section; and an end effector actuator comprising at least one pneumatic turbine configured to convert a fluid force of fluid from the fluid path into a torque to drive rotation of the end effector.

[0078] The insertion tool of any preceding clause, wherein the flexible section comprises a plurality of rigidizable links.

[0079] The insertion tool of any preceding clause, wherein the end effector actuator is housed within one or more of the plurality of rigidizable links.

[0080] The insertion tool of any preceding clause, wherein the end effector actuator comprises two or more pneumatic turbines each housed within a different rigidizable link of the plurality of rigidizable links.

[0081] The insertion tool of any preceding clause, wherein the two or more pneumatic turbines form a serial flow circuit along the fluid path.

[0082] The insertion tool of any preceding clause, wherein the two or more pneumatic turbines comprise an upstream turbine and a downstream turbine having different diameters, numbers of blades, and / or blade pitch.

[0083] The insertion tool of any preceding clause, wherein the plurality of rigidizable links, when rigidized, form two or more fluid paths, and the two or more pneumatic turbines form a parallel flow circuit each driven via fluid from a different path.

[0084] The insertion tool of any preceding clause, wherein the plurality of rigidizable links, when rigidized, form two or more fluid paths, wherein the two or more fluid paths form a parallel flow path, a source and return flow path, or a closed loop flow path.

[0085] The insertion tool of any preceding clause, wherein the two or more pneumatic turbines comprise at least two turbines that are axially aligned or centrifugal to each other.

[0086] The insertion tool of any preceding clause, wherein the two or more pneumatic turbines form an Archimedes screw turbine or a conical screw turbine.

[0087] The insertion tool according to any preceding clause, wherein the two or more gas turbines are connected via a shaft coupling, the two or more gas turbines are coupled when the plurality of rigidizable links are in the rigidized state, and the shaft coupling allows relative movement of the two or more gas turbines when the plurality of rigidizable links are in the relaxed state.

[0088] The insertion tool according to any preceding clause, wherein the shaft coupling comprises at least one of a flexible cable, a universal coupling, a cardan coupling, a bevel gear, a magnetic coupling, a fluid coupling, a friction plate, a resilient shaft, or a compression spring.

[0089] The insertion tool according to any preceding clause, wherein each of the plurality of rigidizable links houses a fluid tube, and the fluid path is formed by connecting the fluid tubes within each of the plurality of rigidizable links.

[0090] The insertion tool according to any preceding clause, wherein one or more of the plurality of rigidizable links comprises a sealing element for forming the fluid path with an adjacent rigidizable link, wherein the fluid path is a pneumatically sealed fluid path between a proximal end of the insertion tool and the end effector actuator.

[0091] The insertion tool according to any preceding clause, wherein a link of the plurality of rigidizable links comprises a shaft guide configured to position a gas turbine of the at least one gas turbine housed within the link, and wherein the shaft guide comprises an opening through which a shaft of the gas turbine is inserted.

[0092] The insertion tool according to any preceding clause, wherein the shaft guide further comprises a bearing surrounding the opening, the bearing configured to reduce friction between the shaft and the shaft guide.

[0093] The insertion tool according to any preceding clause, wherein the plurality of rigidizable links comprises an end link, the end link housing a drive shaft and a bearing to support the end effector.

[0094] The insertion tool according to any preceding clause, wherein the fluid force comprises a fluid pressure, a fluid velocity, or a compound fluid velocity-pressure.

[0095] The insertion tool according to any preceding clause, wherein the end effector actuator is substantially housed within an end link that supports the end effector.

[0096] The insertion tool of any preceding clause, wherein the end effector comprises at least one of a mixing tool, a milling tool, a drilling tool, a reaming tool, a honing tool, or a polishing tool.

[0097] The insertion tool of any preceding clause, wherein the insertion tool comprises a turbomachinery service tool.

[0098] An insertion tool comprising: a flexible section comprising a plurality of rigidizable links; an end effector actuator; an end effector coupled to a distal end of the flexible section; a flexible shaft inserted through the flexible section, wherein torque is transmitted from the end effector actuator to the distal end via the flexible shaft to cause rotation of the end effector; and a toolless disconnect interface between the end effector and the flexible shaft.

[0099] The insertion tool of any preceding clause, wherein the flexible shaft comprises a strand formed from a plurality of layers of wire about a central axis of the strand, the plurality of layers comprising a first coiled layer closest to the central axis.

[0100] The insertion tool of any preceding clause, wherein the flexible shaft comprises 3 to 8 coiled layers.

[0101] The insertion tool of any preceding clause, wherein the plurality of layers each comprise 3 to 20 wires or 3 to 12 wires.

[0102] The insertion tool of any preceding clause, wherein the first coiled layer comprises three wires.

[0103] The insertion tool of any preceding clause, wherein the number of wires in a second to fourth coiled layer radially outward of the first coiled layer is between 3 to 8 wires.

[0104] The insertion tool of any preceding clause, wherein the number of wires in a fifth to sixth coiled layer radially outward of the second to fourth coiled layer is each between 5 to 10 wires.

[0105] The insertion tool of any preceding clause, wherein the number of wires in a seventh and eighth layer radially outward of the fifth to sixth coiled layer is each between 6 to 12 wires.

[0106] The insertion tool of any preceding clause, wherein a wire diameter (d i ) of a wire in layer (i) of the plurality of layers other than the first coiled layer is determined based on wherein wherein is an average diameter of the flexible shaft, di is the wire diameter of the wire in the first layer, and Li is a number of wires in the first coiled layer.

[0107] The insertion tool of any preceding clause, wherein a wire diameter of the wire in the plurality of layers is between 0.0005 inches and 0.08 inches.

[0108] The insertion tool of any preceding clause, wherein an i-th coiled layer from the central axis comprises a plurality of wires forming a helical coil with a helix angle of a i where a i is between a i,max and a i,max -10 degrees, a i,max is defined by where L i is a number of wires in the i-th coiled layer, d i is a diameter of the wire in the i-th coiled layer, and is an average diameter of the i-th coiled layer.

[0109] The insertion tool of any preceding clause, wherein a max is between 10 and 80 degrees.

[0110] The insertion tool of any preceding clause, wherein the flexible shaft comprises a hollow core radially inside the first coiled layer.

[0111] The insertion tool of any preceding clause, wherein the flexible shaft comprises one or more straight wires radially inside the first coiled layer.

[0112] The insertion tool of any preceding clause, wherein the plurality of layers comprises a plurality of monofilament wires.

[0113] The insertion tool of any preceding clause, wherein layers in the plurality of layers have alternating coiled directions.

[0114] The insertion tool of any preceding clause, wherein an outermost layer in the plurality of layers has a lay direction corresponding to a direction of rotation of the end effector, wherein the outermost layer has a left-hand lay if the rotation is clockwise, and wherein the outermost layer has a right-hand lay if the rotation is counterclockwise.

[0115] The insertion tool of any preceding clause, wherein an innermost layer in the plurality of layers is formed of a different material than other layers.

[0116] The insertion tool of any preceding clause, wherein 20-30% of layers in the plurality of layers are formed of a different material than other layers.

[0117] The insertion tool of any preceding clause, wherein the inner 20-30% of the layer is formed of a superelastic material.

[0118] The insertion tool of any preceding clause, wherein the flexible shaft comprises a plurality of strands coiled around a core.

[0119] The insertion tool of any preceding clause, wherein the core comprises a single strand of coiled wire.

[0120] The insertion tool of any preceding clause, wherein each of the plurality of strands has regular lay or regular lay.

[0121] The insertion tool of any preceding clause, wherein the flexible shaft has a diameter between 0.01 inches and 0.1 inches.

[0122] The insertion tool of any preceding clause, wherein the flexible shaft comprises wire made of one or more of stainless steel, high performance alloy, nitinol, superelastic material, tungsten, or titanium.

[0123] The insertion tool of any preceding clause, wherein the flexible shaft comprises a material formed by 80-90% cold working.

[0124] The insertion tool of any preceding clause, further comprising a shaft bearing positioned within the flexible section and around the flexible shaft.

[0125] The insertion tool of any preceding clause, wherein the shaft bearing comprises a stretch spring around the flexible shaft.

[0126] The insertion tool of any preceding clause, wherein a ratio of an inner diameter of the stretch spring to an outer diameter of the flexible shaft is between 1.2 and 3.0.

[0127] The insertion tool of any preceding clause, wherein a coiling direction of the stretch spring has a same coiling direction as an outermost layer of the flexible shaft.

[0128] The insertion tool of any preceding clause, wherein at least one of an inner surface of the shaft bearing or an outer surface of the flexible shaft is coated with one or more of a wire rope lubrication, a molybdenum disulfide coating, a graphite coating, or a polytetrafluoroethylene coating.

[0129] The insertion tool of any preceding clause, wherein the shaft bearing comprises a flexible hollow polytetrafluoroethylene tube or a braided cable sleeve.

[0130] The insertion tool of any preceding clause, further comprising a shaft tensioning assembly configured to maintain tension of the flexible shaft between 1-10% of a tensile strength of the flexible shaft.

[0131] The insertion tool of any preceding clause, wherein the tool-less disconnect interface comprises a ferromagnetic spline fitting on the flexible shaft and a magnetic female adapter coupled to the end effector.

[0132] The insertion tool of any preceding clause, wherein the tool-less disconnect interface comprises a swage spline fitting on the flexible shaft and a micro-chuck coupled to the end effector actuator.

[0133] The insertion tool of any preceding clause, wherein the tool-less disconnect interface comprises a square spline, a hexagonal spline, or a polygonal spline on the flexible shaft.

[0134] The insertion tool of any preceding clause, wherein the tool-less disconnect interface comprises a threaded fitting, wherein a thread direction of the threaded fitting is such that the threaded fitting is tightened in a rotational direction of the flexible shaft.

[0135] The insertion tool of any preceding clause, further comprising a tensioning assembly configured to actuate the plurality of rigidizable links in the flexible section from a relaxed state to a rigidized state having a predefined shape.

[0136] The insertion tool of any preceding clause, wherein the tensioning assembly comprises one or more wires inserted through wire guides in the plurality of rigidizable links.

[0137] An insertion tool comprising: a flexible section comprising a plurality of rigidizable links, wherein each link in the plurality of rigidizable links comprises a housing and one or more shaft couplings configured to rotate within the housing; an end effector coupled to a distal end of the flexible section; and a rigidization actuator configured to actuate the flexible section between a tensioned state and a relaxed state; wherein in the tensioned state, housings of adjacent links in the plurality of rigidizable links are engaged to limit relative movement of the housings and shaft couplings of adjacent links are engaged to transmit force from an end effector actuator at a proximal end of the flexible section to the end effector, thereby causing rotation of the end effector.

[0138] The insertion tool of any preceding clause, wherein one or more links in the plurality of rigidizable links comprise two shaft couplings connected via a universal joint.

[0139] The insertion tool of any preceding clause, wherein one or more links of the plurality of rigidizable links comprises two shaft couplings connected via a fluidic coupling.

[0140] The insertion tool of any preceding clause, wherein the shaft couplings of adjacent links comprise a male feature and a female feature configured to engage when the plurality of rigidizable links are tensioned.

[0141] An insertion tool comprising: a flexible section comprising a plurality of rigidizable links; a rigidization actuator configured to actuate the flexible section between a tensioned state and a relaxed state; an end effector coupled to a distal end of the flexible section; an effector connector inserted through the plurality of rigidizable links; an end effector actuator configured to cause linear movement of the effector connector; and a linear-to-rotational motion conversion mechanism configured to transfer force from the linear movement of the effector connector to drive rotation of the end effector.

[0142] The insertion tool of any preceding clause, wherein the linear movement comprises an oscillating linear motion.

[0143] The insertion tool of any preceding clause, wherein the linear-to-rotational motion conversion mechanism comprises a helical cam mechanism.

Claims

1. An insertion tool characterized by, comprising: a flexible section comprising a plurality of rigidizable links; an end effector actuator; an end effector coupled to a distal end of the flexible section; a flexible shaft extending through the flexible section, wherein torque is transmitted from the end effector actuator to the distal end via the flexible shaft to cause rotation of the end effector; and a toolless disconnect interface between the end effector and the flexible shaft. wherein:

2. The insertion tool of claim 1, wherein, the flexible shaft comprises a strand formed from a plurality of layers of wire about a central axis of the strand, the plurality of layers comprising a first layer of wind closest to the central axis. wherein:

3. The insertion tool of claim 2, wherein, wherein: The wire diameter (d i ) of the wires in layer (i) of the plurality of layers other than the first coiled layer is determined based on wherein wherein is the average diameter of the flexible shaft, d1 is the wire diameter of the wires in the first coiled layer, and L1 is the number of wires in the first coiled layer.

4. The insertion tool of claim 2, wherein, wherein: The i-th winding layer, starting from the central axis, comprises a plurality of wires forming a helical coil with a helix angle a i , wherein a i is between a i,max and a i,max -10 degrees, a i,max is defined by , wherein L i is the number of wires in the i-th winding layer, d i is the diameter of the wires in the i-th winding layer, and is the average diameter of the i-th winding layer.

5. The insertion tool of claim 2, wherein, the flexible shaft comprises a hollow core radially inside the first layer of wind. wherein:

6. The insertion tool of claim 2, wherein, layers of the plurality of layers have alternating directions of wind. wherein:

7. The insertion tool of claim 2, wherein, an outermost layer of the plurality of layers has a lay direction corresponding to a direction of rotation of the end effector, wherein the outermost layer has a left-hand lay if the rotation is clockwise, and wherein the outermost layer has a right-hand lay if the rotation is counterclockwise. wherein:

8. The insertion tool of claim 2, wherein, an innermost layer of the plurality of layers is formed from a different material than other layers. wherein:

9. The insertion tool of claim 2, wherein, the flexible shaft comprises a plurality of strands wound about a core. wherein:

10. The insertion tool of claim 1, wherein, a diameter of the flexible shaft is between 0.01 inches and 0.1 inches. ​

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