Techniques for positioning accuracy between subassemblies

Abstract

A fastening system may be configured to have an interface (212, 213, 214, 222, 223, 262, 263) that supports one or more degrees of freedom between subassemblies (105, 110) during an assembly operation to facilitate component assembly (e.g., a radial degree of freedom to facilitate insertion of fasteners through holes associated with the subassemblies), and in an assembled state, the interface (212, 213, 214, 222, 223, 262, 263) supports one or more degrees of freedom between the subassemblies (105, 110) to facilitate component assembly (e.g., a radial degree of freedom to facilitate insertion of the fasteners through the holes associated with the subassemblies). The degree of freedom is convertible to one or more constraints (e.g., radial constraints between a fastener and each subassembly) that support relatively precise alignment between the subassemblies. Such a system may include a fastener (210) configured for radial constraint with one or more bushings (220, 260), and the bushings may be configured for radial degree of freedom with the subassembly during an assembly operation (e.g., when not preloaded into a mating interface by the fastener), and in an assembled state (e.g., when preloaded into a mating interface by the fastener). When preloaded into a mating interface by the fastener) is radially constrained with the subassembly.

Description

Background Art

[0001] Mechanical components can include multiple sub-components that support various techniques for assembly, disassembly, and reassembly. In some examples, the implementation of a component can benefit from relatively precise positioning between sub-components. For example, in an antenna system implementation, a first sub-component can be associated with a mounting base, and a second sub-component can be associated with an antenna component. When one or more fastening systems between the first sub-component and the second sub-component provide relatively precise positioning between the first sub-component and the second sub-component, the alignment of the antenna system, such as antenna boresight alignment or antenna position alignment (e.g., between the antenna component and the mounting base), can be relatively more precise, including such alignment provided during an assembly operation or a reassembly operation. Summary of the Invention

[0002] Methods and systems for positioning accuracy between sub-components are described. In some components, implementing a fastening system that supports relatively precise positioning or repositioning between sub-components can be associated with an overconstrained state or interference between components, which can impede or prevent assembly, disassembly, or reassembly operations. For example, the alignment tolerance between a precisely formed hole of a first sub-component and a precisely formed hole of a second sub-component may not support a precisely formed pin being freely inserted through or removed from the precisely formed hole (e.g., during an assembly or disassembly operation, because such precisely formed holes are non-concentric, misaligned, or otherwise blocked or constrained). Thus, in some examples, precisely formed pins and precisely formed holes may not be suitable for supporting some assembly, disassembly, or reassembly operations or techniques.

[0003] According to the examples disclosed herein, a fastening system can be configured to have various interfaces (e.g., physical interfaces, mating interfaces, surfaces) that support movement (e.g., one or more degrees of freedom) between subassemblies during an assembly or disassembly operation and support one or more constraints between the subassemblies in the assembled state. For example, a first subassembly can be associated with a set of one or more first coupling locations, and a second subassembly can be associated with a set of one or more second coupling locations. In the assembled state, by using a corresponding fastening system according to the examples disclosed herein, each first coupling location of the first subassembly can be coupled (e.g., connected, fastened, relatively fixed) to a corresponding second coupling location of the second subassembly (e.g., at a coupling location of the assembly associated with the corresponding first coupling location and the corresponding second coupling location). The fastening system can support one or more degrees of freedom associated with the coupling locations during an assembly operation or a disassembly operation to facilitate component assembly or disassembly (e.g., a radial degree of freedom that facilitates insertion or removal of a fastener through a hole associated with the coupling location), and in the assembled state, the one or more degrees of freedom can instead be associated with (e.g., replaced with, modified to) one or more constraints (e.g., a radial constraint between the fastener and each subassembly, where the radial constraint can refer to a translational constraint in a direction radial to an associated axis) that support relatively precise alignment or realignment between the first subassembly and the second subassembly. In some examples, the fastening system can include a fastener configured for a radial constraint (e.g., a precise fit, a sliding fit) with one or more bushings. The bushings can be configured for a radial degree of freedom with the subassemblies during an assembly operation or a disassembly operation (e.g., when not preloaded into the mating interface by the fastener) and configured for a radial constraint with the subassemblies in the assembled state (e.g., when preloaded into the mating interface by the fastener). By supporting one or more degrees of freedom during an assembly or disassembly operation and one or more constraints in the assembled state, the fastening system according to the examples disclosed herein can support improved assembly or disassembly operations while also supporting relatively precise positioning between subassemblies.

[0004] The further scope of applicability of the methods and systems described in this invention will become apparent from the following detailed description, claims and drawings. The detailed description and specific examples are given by way of illustration only, since various changes and modifications within the scope of this specification will become apparent to those skilled in the art. Brief Description of the Drawings

[0005] Figure 1 An example of a component according to the examples disclosed herein is shown that supports techniques for positioning accuracy between subassemblies.

[0006] Figure 2and Figure 3 illustrates an example of a fastening system according to an example disclosed herein, the fastening system supporting techniques for positioning accuracy between sub-assemblies.

[0007] Figure 4 illustrates an example of a component according to an example disclosed herein, the component supporting techniques for positioning accuracy between sub-assemblies.

[0008] Figure 5 illustrates a flowchart depicting a method according to an example disclosed herein, the method supporting techniques for positioning accuracy between sub-assemblies. DETAILED DESCRIPTION

[0009] Describes methods and systems for positioning accuracy between sub-assemblies. In some components, implementing a fastening system that supports relatively precise positioning or repositioning between sub-assemblies may be associated with an overconstrained state or interference between components, which may impede or prevent assembly, disassembly, or reassembly operations. For example, the alignment tolerance between a precisely formed hole of a first sub-assembly and a precisely formed hole of a second sub-assembly may not support a precisely formed pin being freely inserted through or removed from the precisely formed hole (e.g., during an assembly or disassembly operation, because such precisely formed holes are non-concentric, misaligned, or otherwise blocked or constrained). Thus, in some examples, precisely formed pins and precisely formed holes may not be suitable for supporting some assembly, disassembly, or reassembly operations or techniques.

[0010] According to examples disclosed herein, a fastening system can be configured to have various interfaces (e.g., physical interfaces, mating interfaces, surfaces) that support movement (e.g., one or more degrees of freedom) between sub-assemblies during an assembly or disassembly operation and support one or more constraints between sub-assemblies in an assembled state. For example, a first sub-assembly can be associated with a set of one or more first coupling locations, and a second sub-assembly can be associated with a set of one or more second coupling locations. In the assembled state, by using a corresponding fastening system according to examples disclosed herein, each first coupling location of the first sub-assembly can be coupled (e.g., connected, fastened, relatively fixed) to a corresponding second coupling location of the second sub-assembly (e.g., at a coupling location of the assembly associated with the corresponding first coupling location and the corresponding second coupling location). The fastening system can support one or more degrees of freedom associated with the coupling locations during an assembly operation or a disassembly operation to facilitate component assembly or disassembly (e.g., a radial degree of freedom that facilitates insertion or removal of a fastener through a hole associated with the coupling location), and in the assembled state, the one or more degrees of freedom can instead be associated with (e.g., replaced with, modified to) one or more constraints (e.g., a radial constraint between the fastener and each sub-assembly, where the radial constraint can refer to a translational constraint in a direction radial to an associated axis), and the one or more constraints support relatively precise alignment or realignment between the first sub-assembly and the second sub-assembly. In some examples, the fastening system can include a fastener configured for a radial constraint (e.g., a precise fit, a sliding fit) with one or more bushings, and the bushings can be configured for a radial degree of freedom of the sub-assembly during an assembly or disassembly operation (e.g., when not pre-loaded into the mating interface by the fastener) and a radial constraint of the sub-assembly in the assembled state (e.g., when pre-loaded into the mating interface by the fastener). By supporting one or more degrees of freedom during an assembly or disassembly operation and one or more constraints in the assembled state, the fastening system according to examples disclosed herein can support improved assembly or disassembly operations while also supporting relatively precise positioning between sub-assemblies.

[0011] Figure 1Shows an example of component 100 according to the examples disclosed herein, which supports techniques for positioning accuracy between sub-components. Component 100 includes sub-component 105 and sub-component 110, which can be coupled to each other at coupling positions 120 (e.g., coupling position 120-a, coupling position 120-b, and coupling position 120-c). Although component 100 shows an example of coupling sub-component 105 and sub-component 110 at three coupling positions 120, the described techniques for positioning accuracy between sub-component 105 and sub-component 110 can be implemented using any number of one or more coupling positions 120. Aspects of component 100 can be described with reference to the x-direction, y-direction, and z-direction according to the shown coordinate system.

[0012] In some examples, component 100 can show aspects of an antenna system. For example, sub-component 105 can be an example of a mounting base or otherwise include a mounting base, which can be associated with mounting the antenna system to a fixed location (e.g., ground location, foundation, building) or a mobile location (e.g., vehicle). In some examples, sub-component 110 can be an example of an antenna component or otherwise include an antenna component, such as examples of a direct-radiation antenna component, a reflector antenna component, or a phased-array antenna component. For example, sub-component 110 can include or be coupled to a fixed antenna component (e.g., an antenna component that is fixedly aligned relative to sub-component 110), or can include or be coupled to an antenna positioning system configured to align the signal transmission direction of the antenna component relative to sub-component 110 (e.g., align the line-of-sight axis of the antenna).

[0013] In an example of the component 100, each coupling location 120 may be associated with a corresponding coupling location of the sub-component 105 and the sub-component 110, and the corresponding coupling locations form a joint (e.g., a double shear joint, a hinge joint) between the sub-component 105 and the sub-component 110. For example, the coupling location 120-a may be associated with a part (e.g., an eye part) of a first joint including the protrusion 125-a of the sub-component 105, and the coupling location 120-a may be associated with a part (e.g., a two-eye part) of a first joint including the protrusions 130-a-1 and 130-a-2 of the sub-component 110. The coupling location 120-b may be associated with a part of a second joint including the protrusion 125-b of the sub-component 105, and the coupling location 120-b may be associated with a part of a second joint including the protrusions 130-b-1 and 130-b-2 of the sub-component 110. The coupling location 120-c may be associated with a part of a third joint including the protrusion 125-c of the sub-component 105, and the coupling location 120-c may be associated with a part of a third joint including the protrusions 130-c-1 and 130-c-2 of the sub-component 110. As used herein, a protrusion may refer to a part of a sub-component that supports the coupling of the sub-component to another sub-component, etc. (e.g., at a joint) via a fastening system 150. The protrusion may include an extension from a structural member of the sub-component (e.g., as shown with respect to the protrusions 125 and 130), or may include another feature of the sub-component, such as a hole through a body part of the sub-component, which may support a coupling constructed according to a double shear joint or a single shear joint, etc.

[0014] Some joints that can be implemented at the coupling location 120 include precisely formed holes (e.g., drilled, reamed) formed in the protrusion 125 and the protrusion 130, and precisely formed pins (e.g., machined pins, ground pins, dowel pins, shoulder bolts) can be inserted through the holes. Such techniques can be associated at least with the radial constraint between the protrusion 125 and the protrusion 130 (e.g., translational constraint in the radial direction relative to the axis associated with such holes and pins). In some examples, such radial constraints can be supported based on the type of fit between such holes and pins (e.g., sliding fit, interference fit), which can be associated with various mechanical tolerance techniques. However, when such joints are implemented at multiple coupling locations 120 between the subassembly 105 and the subassembly 110, the alignment tolerance between the holes through the protrusion 125 and the holes through the protrusion 130 may not support the free insertion or removal of the precisely formed pins through the holes (e.g., during an assembly operation, because the holes through the protrusion 125 are non-concentric, misaligned, or otherwise blocked or constrained relative to one or more of the holes through the protrusion 130). Thus, in some examples, implementing precisely formed pins with precisely formed holes through the protrusion 125 and the protrusion 130 may not be suitable for supporting some assembly, disassembly, or reassembly operations or techniques of the assembly 100.

[0015] According to the examples disclosed herein, the assembly 100 can implement a corresponding fastening system 150 at each coupling location 120 (e.g., the fastening system 150-a at the coupling location 120-a, the fastening system 150-b at the coupling location 120-b, the fastening system 150-c at the coupling location 120-c) to couple the subassembly 105 and the subassembly 110. Each fastening system 150 can be configured to have various interfaces (e.g., physical interfaces, mating interfaces, surfaces) that support one or more degrees of freedom between the subassembly 105 and the subassembly 110 during an assembly or disassembly operation and support one or more constraints between the subassembly 105 and the subassembly 110 in the assembled state.

[0016] In some examples, each fastening system 150 may include a fastener, such as a shoulder bolt, configured for radial restraint (e.g., precision fit, slip fit) with one or more bushings of the fastening system 150. The bushings may be configured to support radial movement (e.g., radial degrees of freedom) with one or both of sub-assemblies 105 or 110 during an assembly or disassembly operation (e.g., when the bushings are not preloaded into a mating interface such as a mating surface associated with sub-assembly 105 or sub-assembly 110, the mating surface being configured to radially restrain the bushings via the fastener). The bushings may also be configured for radial restraint with one or both of sub-assemblies 105 or 110 in an assembled state, e.g., when the bushings are preloaded into a mating interface (e.g., mating surface) associated with sub-assembly 105 or sub-assembly 110 by the fastener (e.g., the load applied by the fastener when the fastener is tightened and thereby configured to clamp mating components together). As mentioned herein, a component or interface configured for radial restraint may be configured to be in a state associated with translational restraint (e.g., fixed, movement restricted, movement prevented) in a direction radially of one or more axes corresponding to the associated component or interface. By supporting relative movement (e.g., one or more degrees of freedom) during an assembly or disassembly operation and relative fixation (e.g., one or more restraints) in an assembled state, the fastening system 150 may support improved operations for assembling or disassembling the assembly 100 (e.g., for coupling sub-assembly 105 with sub-assembly 110), while also supporting relatively precise positioning between sub-assemblies 105 and 110.

[0017] Figure 2 and Figure 3 An example of a fastening system 150-d is shown in accordance with examples disclosed herein, the fastening system supporting techniques for positioning precision between sub-assemblies. The fastening system 150-d may be an example of one or more fastening systems 150 for implementing the assembly 100, and other examples for coupling sub-assembly 105 with sub-assembly 110 at the coupling location 120 (e.g., for coupling at a double shear joint between sub-assemblies).

[0018] Figure 2A exploded view showing examples of components that may be included in fastening system 150-d (e.g., in an unassembled state, as an example of a set of parts) is shown. The fastening system 150-d may be configured to couple a first subassembly (e.g., subassembly 105) with a second subassembly (e.g., subassembly 110), and may include at least a fastener 210, a bushing 220, and a bushing 260. In an assembled state of the first and second subassemblies, the fastener 210 may be configured to provide a clamping load that pulls the bushing 220 and the bushing 260 toward each other (e.g., when the fastener 210 is tightened), which may be associated with maintaining a preload between the bushing 220 and the bushing 260 (e.g., along axis 211, associated with the tensile load of the fastener 210, which is reacted to components such as bushing 230 or other components via the compressive load of at least the bushing 220, and is reacted to components such as bushing 250 or other components via the compressive load of the bushing 260). In some examples, such a preload may support the fastening system 150-d in establishing one or more constraints (e.g., radial constraints) between the first and second subassemblies (e.g., in the assembled state).

[0019] The fastener 210 may be associated with an axis 211 and may include interfaces 212, 213, and 214, each of which may be concentric with the axis 211. For example, the fastener 210 may be a shoulder bolt such that the interfaces 212, 213, and 214 may each correspond to respective portions of a common cylindrical surface of the fastener 210. The common cylindrical surface of the fastener 210 may be a non-threaded portion of the fastener 210 (e.g., a shoulder, a shank). In some examples, the interface 213 may be configured to support at least a radial constraint between the fastener 210 and a first subassembly relative to the axis 211 (e.g., a precisely cylindrical hole or slot of the first subassembly, or a precisely cylindrical hole or slot otherwise associated with the first subassembly, mating surfaces that inhibit movement in the radial direction). In some examples, the fastener 210 may include a threaded portion 215 (e.g., an external threaded portion), and a preload supported by the fastener 210 may be at least partially based on the mating of the threaded portion 215 with a threaded portion 265 of a bushing 260 (e.g., an internal threaded portion). The outer diameter of the threaded portion 215 may be equal to or less than the diameter of the fastener at the interfaces 212, 213, and 214. The fastener 210 may also include a head 216 that may react a tensile preload generated by the fastener 210 against the bushing 220 (e.g., counteracting the tensile preload of the fastener 210 via physical contact or a compressive load between the head 216 and the bushing 220). In various examples, the head 216 may include an internal polygonal portion (e.g., an Allen hex), an external polygonal portion (e.g., a hex head), a screw head, or some other feature that supports rotating the fastener 210 (e.g., about the axis 211) to engage the threaded portion 215 with the threaded portion 265).

[0020] The bushing 220 may be associated with an axis 221 and may include various interfaces that support the described techniques for precise positioning between a first sub - assembly and a second sub - assembly. For example, the bushing 220 may include an interface 222 (e.g., an inner surface of the bushing 220 that is concentric with the axis 221), which is configured to couple with the interface 212 according to at least a radial constraint (e.g., relative to the axis 211, between the axis 221 and the axis 211) and is thus restricted thereby. In some examples, the interface 222 may be associated with a cylindrical bore that is configured for precise mating with the interface 212 (e.g., a sliding fit, a fit within a threshold tolerance). The mating between the interface 212 and the interface 222 may support rotational degrees of freedom (e.g., torsional degrees of freedom, rotational degrees of freedom about the axis 211 and the axis 221 or between them). The bushing 220 may also include an interface 223 (e.g., concentric with the axis 221), which is configured to support degrees of freedom during assembly or disassembly operations and to support constraints between the first sub - assembly and the second sub - assembly in the assembled state. For example, the interface 223 may be configured to couple the bushing 220 with the second sub - assembly according to at least a radial constraint (e.g., relative to the axis 221, between the axis 221 and an axis associated with or otherwise fixed relative to the second sub - assembly) when the fastener 210 maintains a pre - load (e.g., when the interface 223 is loaded to contact the bushing 230 or other components, such as by a tensile load of the fastener 210). When the pre - load is removed or otherwise the fastener 210 does not maintain a pre - load (e.g., when the interface 223 does not contact the bushing 230 or other components), the interface 223 may also support at least a radial degree of freedom between the bushing 220 and the second sub - assembly (e.g., relative to the axis 221, between the axis 221 and an axis associated with or otherwise fixed relative to the second sub - assembly).

[0021] To support radial constraint, interface 223 can include various types of surfaces, including one or more surfaces that are not perpendicular to an axis such as axis 221 or axis 211. In some examples, interface 223 can include an outer rolled surface (e.g., about axis 221) that can support a rotational degree of freedom (e.g., about axis 221) between bushing 220 and the second subassembly. In some examples, interface 223 can include a convex spherical surface of bushing 220. Interface 223 can allow angular misalignment between bushing 220 and the second subassembly, such as angular rotation about one or more axes perpendicular to axis 221 or an axis associated with a hole passing through the second subassembly. For example, the convex spherical surface of interface 223 of bushing 220 can remain in contact with a mating concave spherical surface while maintaining an associated radial constraint under a preload, the concave spherical surface being associated with the second subassembly. In various examples, such mating spherical surfaces can be associated with different solid angles from one another, which can be provided to support such angular misalignment. Supporting such angular misalignment at or between subassemblies can reduce or eliminate bending loads on fastener 210. In some other examples, interface 223 can not include an outer rolled surface, in which case interface 223 can not support a rotational degree of freedom (e.g., about axis 221 or an axis perpendicular to axis 221) between bushing 220 and the second subassembly.

[0022] The bushing 260 can be associated with an axis 261 and can also include various interfaces that support the described techniques for precise positioning between a first sub-component and a second sub-component. For example, the bushing 260 can include an interface 262 (e.g., concentric with the axis 261 and being the inner surface of the bushing 260 relative to the fastener 210), which is configured to couple with the interface 214 according to at least a radial constraint (e.g., relative to the axis 211, between the axis 261 and the axis 211). In some examples, the interface 262 can be associated with a cylindrical hole that is configured for an exact fit with the interface 214 (e.g., a sliding fit, a fit within a threshold tolerance), which can support a rotational degree of freedom (e.g., a torsional degree of freedom, a rotational degree of freedom about the axis 211 and the axis 261 or between the two). The bushing 260 can also include an interface 263 (e.g., concentric with the axis 261), which is configured to support degrees of freedom during an assembly or disassembly operation and to support constraints between the first sub-component and the second sub-component in an assembled state. For example, the interface 263 can be configured to couple the bushing 260 with the second sub-component according to at least a radial constraint (e.g., relative to the axis 261, between the axis 261 and an axis associated with or otherwise fixed relative to the second sub-component) when the fastener 210 maintains a preload, and can support at least a radial degree of freedom between the bushing 260 and the second sub-component (e.g., relative to the axis 261, between the axis 261 and an axis associated with or otherwise fixed relative to the second sub-component) when the preload is removed or otherwise the fastener 210 does not maintain a preload.

[0023] To support radial constraints, interface 263 may also include various types of surfaces, including one or more surfaces that are not perpendicular to an axis such as axis 261 or axis 211. In some examples, interface 263 may include a rolled-outward surface (e.g., around axis 261), which may support rotational freedom between bushing 260 and the second subassembly (e.g., around axis 261). In some examples, interface 263 may include a convex spherical surface of bushing 260. Interface 263 may permit angular misalignment between bushing 260 and the second subassembly, such as angular rotation about one or more axes perpendicular to axis 261 or axes associated with holes passing through the second subassembly. For example, the convex spherical surface of interface 263 of bushing 260 may remain in contact with a mating concave spherical surface while maintaining an associated radial constraint under a preload, the concave spherical surface being associated with the second subassembly. In various examples, such mating spherical surfaces may be associated with different solid angles from one another, which may be provided to support such angular misalignment. Supporting such angular misalignment at or between subassemblies may reduce or eliminate bending loads on fastener 210. In some other examples, interface 263 may not include a rolled-outward surface, in which case interface 263 may not support rotational freedom between bushing 260 and the second subassembly (e.g., around axis 261 or an axis perpendicular to axis 261).

[0024] In some examples, the fastening system 150-d may include a bearing 240 that may be associated with an axis 241. The bearing 240 may include an interface 242 (e.g., concentric with the axis 241) configured to couple with the interface 213 according to at least a radial constraint (e.g., relative to the axis 211, between the axis 211 and the axis 241). In some examples, the interface 242 may be associated with a cylindrical bore configured for a precise fit (e.g., a sliding fit, a fit within a threshold tolerance) with the interface 213, which may support rotational freedom (e.g., torsional freedom, rotational freedom about the axis 211 and the axis 241 or between them, rotational freedom between the interface 242 and the interface 213) between the bearing 240 and the fastener 210. The bearing 240 may also include an interface 243 configured to couple the bearing 240 with a first subassembly according to at least a radial constraint (e.g., relative to the axis 241 or the axis of the interface 243, between the axis 241 or the axis of the interface 243 and the axis associated with the mounting hole in the first subassembly). In some examples, the bearing 240 may be a spherical bearing or a similar bearing configured to provide spherical freedom between a first portion of the spherical bearing (e.g., including the interface 242) and a second portion of the spherical bearing (e.g., including the interface 243), which may support a degree of misalignment between the first subassembly and the hole, surface, or other features of the second subassembly. In examples of the fastening system 150-d that do not include the bearing 240, the first subassembly (e.g., the protrusion 125) may include an interface (e.g., a cylindrical bore) configured to couple with the interface 213 according to at least a radial constraint (e.g., according to a precise fit, according to a sliding fit), which may otherwise support rotational freedom (e.g., rotational freedom about the axis 211 and the axis 241 or between them).

[0025] In some examples, the fastening system 150-d may include a bushing 230 that may be associated with an axis 231. The bushing 230 may include an interface 232 that may be configured to couple (e.g., contact, mate) with the interface 223 of the bushing 220. In some examples, the interface 232 may include one or more surfaces that are not perpendicular to an axis such as axis 211 or axis 231. In some examples, the interface 232 may include a concave spherical surface of the bushing 230 that may be associated with a solid angle that is different from the solid angle associated with the convex spherical surface associated with the interface 223 (e.g., to support an angular misalignment between axis 231 and axis 221). The bushing 230 may also include an interface 233 that is configured to couple with a second subassembly (e.g., with the first protrusion 130) according to at least a radial constraint (e.g., relative to the axis 231). In some examples, the interface 233 may be configured for an exact fit, a sliding fit, or a press fit with a mating hole of the second subassembly. In some other examples, the interface 233 may be configured for a threaded connection with the second subassembly. The bushing 230 may also include an interface 234 (e.g., a flange interface) that may support the bushing 230 in reacting a preload of the fastener 210 (e.g., via the bushing 220) into the second subassembly.

[0026] In some examples, the bushing 230 may include an opening 235 for receiving the bushing 220. The diameter or cross-sectional area of the opening 235 may be greater than the corresponding diameter or cross-sectional area of the bushing 220 (e.g., the portion 224 of the bushing 220), which may support a radial degree of freedom between the bushing 220 and the bushing 230 (e.g., when the fastener 210 does not hold a preload, when the interface 223 is not in contact with the interface 232, between axis 221 and axis 231). Additionally, the bushing 230 may include an opening 236 through which the fastener 210 may be inserted. The diameter or cross-sectional area of the opening 236 may be greater than the corresponding diameter or cross-sectional area of the fastener 210, which may support a radial degree of freedom between the fastener 210 and the bushing 230 (e.g., between axis 211 and axis 231). In examples of the fastening system 150-d that do not include the bushing 230, the interface 232 may be replaced by a corresponding interface of the second subassembly, such as a precisely formed surface of the second subassembly (e.g., a surface of the first protrusion 130, a concave spherical surface), with which the interface 223 of the bushing 220 may couple (e.g., contact, mate) to provide a radial constraint between the bushing 220 and the second subassembly (e.g., when preloaded by the fastener 210).

[0027] Additionally or alternatively, in some examples, the fastening system 150-d can include a bushing 250 that can be associated with an axis 251. The bushing 250 can include an interface 252 that can be configured to couple with an interface 263 of a bushing 260. In some examples, the interface 252 can include one or more surfaces that are not perpendicular to an axis such as axis 211 or axis 251. In some examples, the interface 252 can include a concave spherical surface of the bushing 250 that can be associated with a solid angle that is different from the solid angle associated with a convex spherical surface associated with the interface 263 (e.g., to support an angular misalignment between axis 251 and axis 261). The bushing 250 can also include an interface 253 that is configured to couple with a second subassembly (e.g., with a second protrusion 130) according to at least a radial constraint (e.g., relative to axis 251). In some examples, the interface 253 can be configured for an exact fit, a sliding fit, or a press fit with a mating hole of the second subassembly. In some other examples, the interface 253 can be configured for a threaded connection with the second subassembly. The bushing 250 can also include an interface 254 (e.g., a flange interface) that can support the bushing 250 in reacting a preload of the fastener 210 (e.g., via the bushing 260) into the second subassembly.

[0028] In some examples, the bushing 250 can include an opening 255 for receiving the bushing 260. The diameter or cross-sectional area of the opening 255 can be greater than a corresponding diameter or cross-sectional area of the bushing 260 (e.g., a portion 264 of the bushing 260), which can support a radial freedom between the bushing 260 and the bushing 250 (e.g., when the fastener 210 is not holding a preload, when the interface 263 is not in contact with the interface 252, between axis 261 and axis 251). Additionally, the bushing 250 can include the opening 255 through which the fastener 210 can be inserted. The diameter or cross-sectional area of the opening 255 can be greater than a corresponding diameter or cross-sectional area of the fastener 210, which can support a radial freedom between the fastener 210 and the bushing 250 (e.g., between axis 211 and axis 251). In examples of the fastening system 150-d that do not include the bushing 250, the interface 252 can be replaced by a corresponding interface of the second subassembly, such as a precisely formed surface of the second subassembly (e.g., a surface of the second protrusion 130, a concave spherical surface), with which the interface 263 of the bushing 260 can couple (e.g., contact, mate) to provide a radial constraint between the bushing 260 and the second subassembly (e.g., when preloaded by the fastener 210).

[0029] In some examples of the fastening system 150-d that includes the bushing 250, the bushing 260 may include an interface 266, and the bushing 250 may include an interface 257, which (e.g., combinatorially) may be configured to limit the rotation of the bushing 260 (e.g., about the axis 261, at least partially based on the physical contact between the interface 256 and the interface 266). For example, the interface 266 may be associated with a hexagonal or other polygonal perimeter or cross-section, and the interface 257 may be associated with a split or otherwise corresponding opening configured to receive the interface 266 or otherwise couple with the interface (e.g., according to a loose or imprecise fit). Such contact interfaces may inhibit the rotation of the bushing 260 within the bushing 250 due to, for example, rotating (e.g., tightening, loosening) the fastener 210.

[0030] Additionally or alternatively, some examples of the fastening system 150-d that includes the bushing 250 may further include a retainer 270 (e.g., a retaining clip, a snap ring), which may be configured to couple with the bushing 250 (e.g., within the opening 255 or in a slot or groove along the opening). The retainer 270 may be configured to limit the displacement of the bushing 260 relative to the bushing 250 along the axis 261 (e.g., in a direction opposite to the interface 263 to capture the bushing 260 within the bushing 250).

[0031] Fastening system 150-d shows an example of components configured to support degrees of freedom (e.g., radial degrees of freedom) between components to facilitate assembly operations or disassembly operations (e.g., of sub-assembly 105 and sub-assembly 110). For example, in the case of including bearing 240, bearing 240 can be coupled to the first sub-assembly, which can involve sliding, pressing, threading, or otherwise mating bearing 240 with a hole or other feature (e.g., a hole or other feature of protrusion 125) of the first sub-assembly, which can establish a radial constraint between the first sub-assembly and interface 243. In some cases, interface 243 can establish a fixed relationship between bearing 240 and the first sub-assembly. Bearing 240 can support one or more rotational degrees of freedom between interface 243 and interface 242, which can support various misalignments between the first sub-assembly and the second sub-assembly, but interface 242 can be radially constrained relative to interface 243. For example, axis 241 can be offset or distorted relative to the axis associated with interface 243, but axis 241 can coincide with such an axis at a point (e.g., as a point constraint, supporting at least a radial constraint between axis 241 and the first sub-assembly, a coupling relationship between interface 242 and interface 243 that allows relative rotation and inhibits relative translation). In some examples, the rotational degrees of freedom provided by bearing 240 can facilitate the insertion of fastener 210 through the various components of fastening system 150-d, or can reduce the loads (e.g., bending loads of fastener 210) on fastening system 150-d in the assembled state, among other advantages. In some other examples, the installation of bearing 240 onto the first sub-assembly can be omitted, such as for example where the interface corresponding to interface 242 (e.g., a cylindrical hole, precision hole, precision groove) is formed as part of the first sub-assembly.

[0032] For cases including the bushing 230, the bushing 230 can be coupled to the second subassembly, which can involve sliding, pressing, threading, or otherwise mating the bushing 230 with a hole or other feature of the second subassembly (e.g., a hole or other feature of the first protrusion 130), which can establish at least a radial constraint (if not a fixed relationship) between the second subassembly and the interface 232. In some other examples, mounting the bushing 230 to the second subassembly can be omitted, such as where the interface corresponding to the interface 232 (e.g., a concave spherical surface) is formed as part of the second subassembly (e.g., formed as the forming surface of the first protrusion 130). Additionally, for cases including the bushing 250, the bushing 250 can be coupled to the second subassembly, which can involve sliding, pressing, threading, or otherwise mating the bushing 250 with a hole or other feature of the second subassembly (e.g., a hole or other feature of the second protrusion 130), which can establish at least a radial constraint (if not a fixed relationship) between the second subassembly and the interface 252. In some other examples, mounting the bushing 250 to the second subassembly can be omitted, such as where the interface corresponding to the interface 252 (e.g., a concave spherical surface) is formed as part of the second subassembly (e.g., formed as the surface of the second protrusion 130).

[0033] To assemble the fastening system 150-d at the joint between a first sub-component (e.g., at the joint location of the first sub-component associated with the protrusion 125) and a second sub-component (e.g., at the joint location of the second sub-component associated with the two protrusions 130), the bushing 260 can be inserted into the bushing 250 (e.g., where applicable), which can include inserting the bushing 260 into the opening 255 of the bushing 250. Since the opening 255 has a larger diameter or cross-section than the bushing 260 (e.g., when the interface 263 is not pre-loaded to the interface 252 or otherwise in contact with this interface), the bushing 260 can have a radial degree of freedom relative to the bushing 250 (e.g., at least a radial degree of freedom between the axis 261 and the axis 251). In some examples, such a radial degree of freedom can be supported without the bushing 260, such as when the surface of the second sub-component includes an interface that mates with the interface 263 (e.g., with or without an opening or other portion corresponding to the opening 255). After the bushing 260 is inserted into the bushing 250, the retainer 270 can be installed in the groove of the bushing 250, which can hold the bushing 260 in the bushing 250 (e.g., along the axis 251 or along the axis 261). In some examples, the bushing 260 and the retainer 270 can be assembled together with the bushing 250 before the bushing 250 is coupled to the second sub-component. Similarly, the bushing 220 can be inserted into the bushing 230 (e.g., where applicable), which can include inserting the bushing 220 into the opening 235 of the bushing 230. Since the opening 235 has a larger diameter or cross-section than the bushing 220 (e.g., when the interface 223 is not pre-loaded to the interface 232 or otherwise in contact with this interface), the bushing 220 can have a radial degree of freedom relative to the bushing 230 (e.g., at least a radial degree of freedom between the axis 221 and the axis 231). In some examples, such a radial degree of freedom can be supported without the bushing 230, such as when the surface of the second sub-component includes an interface that mates with the interface 223 (e.g., with or without an opening or other portion corresponding to the opening 235).

[0034] The fastener 210 can be inserted through the bushing 220 (e.g., after or before inserting the bushing 220 into the bushing 230), through the bushing 230 (e.g., where applicable), through the bearing 240 (e.g., where applicable), through the bushing 250 (e.g., where applicable), and through the bushing 260. In some examples, the fastener 210 can be radially constrained relative to the bushing 220 (e.g., due to radial constraints associated with the interfaces 212 and 222, such as a slip fit or other precise fit), radially constrained relative to the first sub-assembly (e.g., where applicable, due to radial constraints associated with the interfaces 213 and 242, such as a slip fit or other precise fit, radially constrained relative to the bearing 240), and radially constrained relative to the bushing 260 (e.g., due to radial constraints associated with the interfaces 214 and 262, such as a slip fit or other precise fit). However, the fastener 210, the bushing 220, and the bushing 260 may not yet be constrained (e.g., radially constrained) relative to the second sub-assembly. For example, the combination of radial constraints of the fastener 210, the bushing 220, the first sub-assembly (e.g., the bearing 240), and the bushing 260 can have degrees of freedom (e.g., radial degrees of freedom relative to the second sub-assembly) supported by the following combinations: an opening 235 greater than the bushing 220 (e.g., greater than the portion 224) (e.g., where applicable), an opening 236 greater than the fastener 210 (e.g., greater than the interface 212 of the fastener 210 or other diameter or dimension) (e.g., where applicable), an opening 255 greater than the fastener 210 (e.g., greater than the interface 214 of the fastener 210 or other diameter or dimension) (e.g., where applicable), and an opening 255 greater than the bushing 260 (e.g., greater than the portion 264) (e.g., where applicable). According to these and other examples, compared to other techniques that do not support such degrees of freedom (e.g., where aspects of the first sub-assembly and the second sub-assembly may be overconstrained or non-concentric), such degrees of freedom can facilitate the insertion of the fastener 210.

[0035] The connection between the first sub-component and the second sub-component can be continued by engaging the threaded portion 215 of the fastener 210 with the threaded portion 265 of the bushing 260, and this engagement can be achieved by translating the fastener 210 into the bushing 260 (e.g., along axis 211) and rotating the fastener 210 (e.g., about axis 211). The rotation of the bushing 260 about the axis 261 can be inhibited by the contact between the interface 266 of the bushing 260 and the interface 257 of the bushing 250. Engaging the threaded portions can establish a tensile preload in the fastener 210, and this tensile preload can be reacted as a compressive preload among or between other components of the fastening system 150-d and the sub-components. For example, a compressive preload can be established between the head 216 of the fastener 210 and the bushing 220 and between the bushing 220 and the bushing 230, which can couple the interfaces 223 and 232 (e.g., mating, contacting). Since this connection of the surfaces is not perpendicular to the axis 211 (e.g., other axes along a similar direction), a radial constraint can be established between the bushing 220 and the bushing 230 (e.g., between the axis 221 and the axis 231). Similarly, a compressive preload can be established at the bushing 260 (e.g., based on the mating of the threaded portion 215 of the fastener 210 with the threaded portion 265 of the bushing 260) and between the bushing 260 and the bushing 250, which can couple the interfaces 263 and 252 (e.g., mating, contacting). Since this connection of the surfaces is not perpendicular to the axis 211 (e.g., other axes along a similar direction), a radial constraint can be established between the bushing 260 and the bushing 250 (e.g., between the axis 261 and the axis 251). Thus, based on the preloading force provided by the fastener 210 (e.g., corresponding to the assembled state of the fastening system 150-d), a radial constraint can be established between the first sub-component and the second sub-component (e.g., at the connection location of corresponding components such as component 100) based on the set of radial constraints established between the first sub-component and the fastening system 150-d, between the second sub-component and the fastening system 150-d, and between the components of the fastening system 150-d itself.

[0036] Figure 3 An example of the fastening system 150-d in an assembled state is shown. In the assembled state of the fastening system 150-d (e.g., corresponding to at least a partially assembled state of the first and second sub-components), the fastener 210 can be configured to hold the bushing 220 (in Figure 3The preload between the (e.g., hidden inside the bushing 250 in the view of) bushing 250 and the bushing 260 (e.g., along the axis 211, associated with the tensile load of the fastener 210 that is reacted by the compressive loads of at least the bushing 220 and the bushing 260). This preload can support the fastening system 150-d to establish one or more constraints (e.g., at least radial constraints) between the first subassembly and the second subassembly (e.g., in the assembled state).

[0037] The preload of the fastener 210 can be reacted by various components of the fastening system 150-d, one or both of the coupled subassemblies, or various combinations thereof. In some examples, at least a portion of the preload can be reacted via the bushing 220 and the bushing 230, and the bushing 230 can apply the transferred preload on the first protrusion 130 of the second subassembly (e.g., via the interface 234, via the flange interface). Similarly, at least a portion of the preload can be reacted via the bushing 260 and the bushing 250, and the bushing 250 can apply the transferred preload on the second protrusion 130 of the second subassembly (e.g., via the interface 254, via the flange interface). In such examples, the transferred preload can be applied as a bending load on each protrusion 130 at least in part, and this bending load can be reacted between the protrusions 130 via the physical connection of the second subassembly between the protrusions 130. In some examples, such a bending load can be associated with the bending deformation of the protrusions 130, and the associated deformation of the protrusions 130 (e.g., associated with the angular misalignment between the bushing 230 and the bushing 250) can be adjusted by the spherical interface of the fastening system 150-d (e.g., by mating the spherical surfaces of the interface 223 and the interface 232, by mating the spherical surfaces of the interface 263 and the interface 252). In some examples, such adjustment can reduce the bending load applied on the fastener 210 due to the generated preload. In some examples (e.g., in the case where the preload of the fastener 210 is fully reacted via the protrusions 130), the fastening system 150-d can be associated with the axial degree of freedom (e.g., the translational degree of freedom along the axis 241) between the first subassembly and the second subassembly (e.g., associated with the separation between the bearing 240 and one or both of the bushing 230 or the first protrusion 130, associated with the separation between the bearing 240 and one or both of the bushing 250 or the second protrusion 130).

[0038] Additionally or alternatively, in some examples, at least a portion of the preload may be reacted via bearing 240. For example, bushing 230, bushing 250, or both may contact an inner portion of bearing 240 (e.g., an inner race, a portion of bearing 240 associated with interface 242), and such an inner portion of bearing 240 may transfer at least a portion of the preload as a compressive load in a direction along axis 241. In some such examples, bearing 240 may be associated with providing axial restraint (e.g., translational restraint along axis 241) between the first subassembly and the second subassembly. Some such examples may include omitting interface 234, interface 254, or both, such that the preload of fastener 210 may be reacted entirely via bearing 240.

[0039] Thus, according to these and other embodiments of the examples disclosed herein, fastening system 150 may be configured to have various interfaces (e.g., physical interfaces, mating interfaces, surfaces). Fastening system 150 may support one or more degrees of freedom between subassemblies during assembly or disassembly operations and support one or more constraints between subassemblies in the assembled state. By supporting one or more degrees of freedom during assembly or disassembly operations and supporting one or more constraints in the assembled state, fastening system 150 according to the examples disclosed herein may support improved assembly or disassembly operations while also supporting relatively precise positioning between subassemblies. For example, fastening system 150 may be configured to have an interface that provides one or more radial degrees of freedom during assembly or disassembly operations, such that it facilitates the insertion or removal of fastener 210 despite any misalignment or overconstraint between subassemblies, and the interface provides one or more radial constraints in the assembled state, such that it supports relatively precise positioning between subassemblies in the assembled state.

[0040] Figure 4 An example of component 100-a according to the examples disclosed herein is shown, which supports techniques for positioning accuracy between subassemblies. Component 100-a includes subassembly 105-a and subassembly 110-a, which may be examples of subassemblies 105 and 110 described herein (e.g., refer to Figure 1 ). Subassembly 105-a and subassembly 110-a may be coupled to each other at coupling locations 120 (e.g., coupling location 120-e, coupling location 120-f, and coupling location 120-g). Figure 4 Aspects of which may show the assembled state of component 100-a, which may be associated with the assembled states of a set of fastening systems 150-d (e.g., fastening system 150-d-1 at coupling location 120-e, fastening system 150-d-2 at coupling location 120-f, fastening system 150-d-3 at coupling location 120-g). InFigure 4 In the example of, the assembly 100-a is shown according to a cross-sectional view through the fastening systems 150-d-1 and 150-d-2, providing a view of the interface of the fastening systems 150-d-1 and 150-d-2 coupled in the assembled state.

[0041] The assembly of the sub-assembly 105-a and the sub-assembly 110-a can be supported according to various step-by-step assembly operations of the fastening system 150-d, which can be supported by one or more degrees of freedom during the various assembly operations. For example, the sub-assembly 105-a and the sub-assembly 110-a can be positioned to support the orientation of installing the fastening systems 150-d-1 and 150-d-2, which may or may not correspond to the orientation aligned with the coupling position of the sub-assembly 105-a and the sub-assembly 110-a associated with the coupling position 120-g (e.g., the positioning that may or may not support the installation of the fastening system 150-d-3). For the coupling positions 120-e and 120-f (e.g., for the fastening systems 150-d-1 and 150-d-2 respectively), the corresponding fasteners (e.g., Figure 3 fastener 210) (e.g., supported by various radial degrees of freedom as described herein) can be inserted and then fastened into the corresponding bushings (e.g., Figure 3 bushing 260), which can establish various constraints as described herein. For example, fastening the fastener 210 for the fastening system 150-d-1 can support establishing a radial constraint between the protrusion 125-e and one or both of the protrusions 130-e-1 and 130-e-2, and fastening the fastener 210 for the fastening system 150-d-2 can support establishing a radial constraint between the protrusion 125-f and one or both of the protrusions 130-f-1 and 130-f-2.

[0042] The installation of the fastening systems 150-d-1 and 150-d-2 can establish various constraints and degrees of freedom between the sub-assembly 105-a and the sub-assembly 110-a. For example, the radial constraints associated with the fastening systems 150-d-1 and 150-d-2 can establish a radial constraint between the sub-assembly 105-a and the sub-assembly 110-a relative to the axis 410. The axis 410 can be along the respective axis 211 of each of the fastening systems 150-d-1 and 150-d-2 (e.g., referring to Figure 2aligned with the axis 211), or aligned within a tolerance along such an axis 211. In some examples, the installation of fastening systems 150-d-1 and 150-d-2 can be associated with the translational degrees of freedom (e.g., axial degrees of freedom, i.e., degrees of freedom in the direction along axis 410) between sub-assemblies 105-a and 110-a, including the following cases: there is a gap between protrusion 125-e and protrusions 130-e-1 and 130-e-2, and there is a gap between protrusion 125-f and protrusions 130-f-1 and 130-f-2 (e.g., in the direction along axis 410) and other gaps. In some other examples, the installation of fastening systems 150-d-1 and 150-d-2 can be associated with the translational constraints (e.g., axial constraints, i.e., constraints in the direction along axis 410) between sub-assemblies 105-a and 110-a, including the following cases: protrusion 125-e is loaded to contact one or both of protrusions 130-e-1 and 130-e-2, or protrusion 125-f is loaded to contact one or both of protrusions 130-f-1 and 130-f-2, or one or more bushings (e.g., referring to Figure 3 one or more bushings 230 or 250) are loaded to contact a bearing (e.g., referring to Figure 3 bearing 240) and other loaded contacts.

[0043] In some examples, the installation of fastening systems 150-d-1 and 150-d-2 can be associated with the rotational degrees of freedom between sub-assemblies 105-a and 110-a, such as the rotational degrees of freedom about axis 410. Such rotational degrees of freedom can be supported by various rotational degrees of freedom of fastening systems 150-d-1 and 150-d-2 (e.g., supported by various rotations of components or interfaces about the respective axis 211). In some examples, such rotational degrees of freedom can support aspects of the assembly or disassembly of assembly 100-a. For example, after installing fastening systems 150-d-1 and 150-d-2, sub-assembly 110-a can rotate relative to sub-assembly 105-a about axis 410 to position protrusions 130-g-1 and 130-g-2 relative to protrusion 125-g, thus supporting the installation of fastening system 150-d-3 at the coupling position 120-g. For example, at such a position, for fastening system 150-d-3, the corresponding fastener 210 can be inserted (e.g., supported by various radial degrees of freedom as described herein), and then fastened into the corresponding bushing 260, which can further establish various constraints as described herein (e.g., referring to Figure 3 fastener 210 and bushing 260).

[0044] Combined with the radial constraints provided by fastening system 150-d-1, fastening system 150-d-2, and fastening system 150-d-3, subassembly 105-a and subassembly 110-a can be coupled with at least planar constraints such that rotation about any axis between subassembly 105-a and subassembly 110-a can be inhibited (e.g., prevented), and translation between subassembly 105-a and subassembly 110-a in any direction perpendicular to axis 410 can be inhibited. In various examples, assembly 100-a may further include translational constraint in the direction of axis 410 between subassembly 105-a and subassembly 110-a, or assembly 100-a may include limited translational freedom in the direction of axis 410 between subassembly 105-a and subassembly 110-a. In some examples, such as implementations in an antenna system or other systems associated with angular pointing, this translational freedom in the direction of axis 410 may have a limited or negligible impact on positioning tolerances (e.g., pointing tolerance, pointing accuracy), and can be part of an appropriate trade-off between assembly accuracy and ease of assembly or disassembly (e.g., where the limited freedom in the direction of axis 410 can facilitate aspects of assembly or disassembly).

[0045] The features of the fastening system 150-d can also support aspects of partial or complete disassembly of the component 100-a, which can include disassembling or removing one or more of the fastening system 150-d. For example, the fastening system 150-d-3 can be removed, which can support the rotation of the sub-component 110-a relative to the sub-component 105-a (e.g., about the axis 410), which can support various maintenance operations associated with the sub-component 110-a. For example, such rotation of the sub-component 110-a can support maintenance operations on the antenna assembly or other components associated with the sub-component 110-a. The removal of the fastening system 150-d-3 can include the removal of the associated fastener 210. When the preload of the associated fastener 210 is removed, the radial degrees of freedom supported by the fastening system 150-d-3 can facilitate the removal of the fastener 210. For example, by loosening the associated fastener 210, the bushing 220 of the fastening system 150-d-3 can have radial degrees of freedom relative to the sub-component 110-a (e.g., due to the gap between the interface 223 and the sub-component 110-a or the gap between the interface 232 of the bushing 230 coupled to the sub-component 110-a), or the bushing 260 of the fastening system 150-d-3 can have radial degrees of freedom relative to the sub-component 110-a (e.g., due to the gap between the interface 263 and the sub-component 110-a or the gap between the interface 252 of the bushing 250 coupled to the sub-component 110-a), or both. Such radial degrees of freedom can support the radial degrees of freedom between the associated fastener 210 of the fastening system 150-d-3 and the sub-component 110-a. Thus, even if there is a radial constraint between the associated fastener 210 of the fastening system 150-d-3 and the sub-component 105-a (e.g., via the bearing 240), the associated fastener 210 can be freely removed because these components are not overconstrained at the coupling position 120-g (e.g., due to the misalignment between the axis associated with the coupling position of the sub-component 105-a and the axis associated with the coupling position of the sub-component 110-a). Therefore, compared to the removal of a precisely formed pin from a precisely formed hole, the associated fastener 210 can be more easily removed, where the overconstraint condition between the sub-component 105-a and the sub-component 110-a may be associated with a significant constraint that hinders or prevents the removal of such a precisely formed pin). After such maintenance operations, the sub-component 110-a can be rotated (e.g., about the axis 410) back to the proper position so that the fastening system 150-d-3 can be reinstalled. Due to the precise radial constraints associated with the fastening system 150-d, when reinstalling the fastening system 150-d-3, the sub-component 110-a can return to the same position as before the fastening system 150-d-3 was disassembled (e.g., within the tolerances between the components of the component 100-a).The radial degrees of freedom associated with the fastening system 150-d-3, prior to preloading of the associated fastener 210, may again facilitate such reinstallation, which can support the free insertion of the associated fastener 210 through the corresponding components.

[0046] Thus, in these and other embodiments according to the examples disclosed herein, the fastening system 150 may be configured to have various interfaces (e.g., physical interfaces, mating interfaces, surfaces). The fastening system 150 may support one or more degrees of freedom between subassemblies during assembly or disassembly operations and support one or more constraints between subassemblies in the assembled state. By supporting one or more degrees of freedom during assembly or disassembly operations and supporting one or more constraints in the assembled state, the fastening system 150 according to the examples disclosed herein may support improved assembly or disassembly operations while also supporting relatively precise positioning between subassemblies. For example, the fastening system 150 may be configured to have an interface that provides one or more radial degrees of freedom during assembly or disassembly operations, such that it facilitates the insertion or removal of the fastener 210 despite any misalignment or overconstraint between subassemblies, and the interface provides one or more radial constraints in the assembled state, such that it supports relatively precise positioning between subassemblies in the assembled state.

[0047] Figure 5 A flowchart illustrating a method 500 according to the examples disclosed herein is shown, which method supports techniques for positioning accuracy between subassemblies.

[0048] At 505, the method 500 may include inserting a first fastener (e.g., the first fastener 210, a fastener of the first fastening system 150) through a first opening of a first bushing (e.g., an opening of the first bushing 220, an opening associated with the first interface 232), a second opening associated with a first subassembly (e.g., a first opening associated with the subassembly 105, an opening of the first protrusion 125, an opening of the first bearing 240 associated with the interface 242), and a third opening of a second bushing (e.g., an opening of the first bushing 260, an opening associated with the first interface 262). In some examples, inserting the first fastener may be at least partially based on (e.g., supported by, facilitated by) a radial degree of freedom between the first bushing (e.g., the first bushing 220) and the second subassembly (e.g., the subassembly 110), or a radial degree of freedom between the second bushing (e.g., the first bushing 260) and the second subassembly, or a combination thereof. The operation of 505 may be performed according to the examples disclosed herein.

[0049] At 510, the method can include preloading a first surface of a first bushing (e.g., interface 223) at least in part based on a second surface associated with a second sub-component (e.g., a first surface of sub-component 110, a surface of first protrusion 130, interface 232), and preloading a third surface of a second bushing (e.g., interface 263) with a fourth surface associated with the second sub-component (e.g., a second surface of sub-component 110, a surface of second protrusion 130, interface 252) (e.g., using a first fastener), while constraining a first sub-component and a second sub-component in a direction radially of an axis of the first fastener (e.g., first axis 211). In some examples, preloading the first surface with the second surface can be associated with a radial constraint between the first bushing and the second sub-component (e.g., can be applied, can be defined). Additionally or alternatively, in some examples, preloading the third surface with the fourth surface can be associated with a radial constraint between the second bushing and the second sub-component (e.g., can be applied, can be defined). The operation of 510 can be performed in accordance with examples as disclosed herein.

[0050] At 515, the method can include inserting a second fastener (e.g., second fastener 210, fastener 210 of second fastening system 150) through a fourth opening of a third bushing (e.g., an opening of second bushing 220, an opening associated with second interface 232), a fifth opening associated with the first sub-component (e.g., a second opening associated with sub-component 105, an opening of second protrusion 125, an opening of second bearing 240 associated with interface 242), and a sixth opening of a fourth bushing (e.g., an opening of second bushing 260, an opening associated with second interface 262). In some examples, inserting the second fastener can be at least in part based on (e.g., supported by, facilitated by) a radial degree of freedom between the third bushing (e.g., second bushing 220) and the second sub-component, or a radial degree of freedom between the fourth bushing (e.g., second bushing 260) and the second sub-component, or a combination thereof. The operation of 515 can be performed in accordance with examples as disclosed herein.

[0051] At 520, the method can include at least partially preloading a fifth surface of a third bushing (e.g., interface 223) with a sixth surface associated with a second subassembly (e.g., a third surface of subassembly 110, a surface of third protrusion 130, interface 232), and preloading a seventh surface of a fourth bushing (e.g., interface 263) with an eighth surface associated with the second subassembly (e.g., a fourth surface of subassembly 110, a surface of fourth protrusion 130, interface 252) (e.g., using a second fastener), while constraining a first subassembly and a second subassembly in a direction radial to an axis of the second fastener (e.g., second axis 211). In some examples, preloading the fifth surface with the sixth surface can be associated with a radial constraint (e.g., can be applied, can be defined) between the third bushing (e.g., second bushing 220) and the second subassembly. Additionally or alternatively, in some examples, preloading the seventh surface with the eighth surface can be associated with a radial constraint (e.g., can be applied, can be defined) between the fourth bushing (e.g., second bushing 260) and the second subassembly. The operation of 520 can be performed according to examples as disclosed herein.

[0052] In some examples of method 500, the first surface, the second surface, the third surface, and the fourth surface can not be perpendicular to an axis of the first fastener, and the first surface, the second surface, the third surface, and the fourth surface can not be perpendicular to an axis of the first fastener.

[0053] Additionally or alternatively, some examples of method 500 can further include rotating the second subassembly relative to the first subassembly at least partially based on a rotational degree of freedom about an axis of the first fastener (e.g., about axis 410) between the first subassembly and the second subassembly, after preloading the first surface with the second surface and preloading the third surface with the fourth surface.

[0054] It should be noted that the described method includes possible embodiments, and the operations and steps can be rearranged or otherwise modified, and other embodiments are possible. Additionally, portions from two or more of the described methods can be combined.

[0055] A system for coupling a first subassembly and a second subassembly is described. An overview of aspects of the system as described herein is provided below:

[0056] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that are implementable or within the scope of the claims. The term “exemplary” as used herein means “serving as an example, instance, or illustration” and does not mean “preferred over” or “better than” other examples. To provide an understanding of the described technology, the detailed description includes specific details. However, the technology may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0057] As used herein, including in the claims, the term “or” as used in a list of items (e.g., a list of items prefaced with a phrase such as “at least one of...” or “one or more of...”) means an inclusive list, such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase “based on” should not be construed as referring to a closed set of conditions. For example, an exemplary step described as “based on condition A” may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” should be interpreted in the same manner as the phrase “at least partially based on”.

[0058] In the figures, similar components or features may have the same reference label. Additionally, various components of the same type may be distinguished by following the reference label with a dash and a second label that differentiates among the similar components. If only the first reference label is used in the specification, the description applies to any one of the similar components having the same first reference label regardless of the second reference label.

[0059] The present description is provided to enable a person skilled in the art to make or use the present disclosure. Those skilled in the art will readily appreciate various modifications to the present disclosure, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but rather is accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for coupling a first sub - assembly and a second sub - assembly, the system comprising: A fastener (210) configured to maintain a pre - load between a first bushing (220) and a second bushing (260) along an axis (211) of the fastener. The fastener includes a first interface (213) concentric with the axis of the fastener, a second interface (212) concentric with the axis of the fastener, and a third interface (214) concentric with the axis of the fastener. Wherein the first interface is configured to provide at least a radial constraint between the fastener and the first sub - assembly with respect to the axis of the fastener; The first bushing includes: A fourth interface (222) configured to couple with the second interface according to at least a radial constraint with respect to the axis of the fastener; and A fifth interface (223) configured to: When maintaining the pre - load, couple the first bushing and the second sub - assembly according to at least a radial constraint with respect to an axis of the first bushing; and When removing the pre - load, provide at least a radial degree of freedom between the first bushing and the second sub - assembly with respect to the axis of the first bushing; and The second bushing includes: A sixth interface (262) configured to couple with the third interface according to at least a radial constraint with respect to the axis of the fastener; and A seventh interface (263) configured to: When maintaining the pre - load, couple the second bushing and the second sub - assembly according to at least a radial constraint with respect to an axis of the second bushing; and When removing the pre - load, provide at least a radial degree of freedom with respect to the axis of the second bushing.

2. The system according to claim 1, further comprising: A bearing (240) including: An eighth interface (242) configured to couple with the first interface according to at least a radial constraint with respect to the axis of the fastener; and A ninth interface (243) configured to couple the bearing and the first sub - assembly according to at least a radial constraint with respect to an axis of the bearing.

3. The system according to claim 2, wherein: The bearing includes a spherical bearing configured to provide a spherical degree of freedom between a first part of the spherical bearing and a second part of the spherical bearing. The first part includes the eighth interface and the second part includes the ninth interface.

4. The system according to any one of claims 1 to 3, wherein the first interface, the second interface and the third interface each correspond to a respective part of a common cylindrical surface of the fastener.

5. The system according to any one of claims 1 to 3, wherein: The fastener includes an external thread portion (215); and The second bushing includes an internal thread portion (265), wherein the pre - load is at least partially based on the mating of the external thread portion and the internal thread portion.

6. The system according to any one of claims 1 to 3, further comprising: A third bushing (230) including: A tenth interface (232) configured to be coupled with the fifth interface; and An eleventh interface (233) configured to be coupled with the second subassembly according to at least a radial constraint relative to the axis (231) of the third bushing; and A fourth bushing (250) including: A twelfth interface (252) configured to be coupled with the seventh interface; and A thirteenth interface (253) configured to be coupled with the second subassembly according to at least a radial constraint relative to the axis (251) of the fourth bushing.

7. The system according to claim 6, further comprising: A retainer (270) configured to be coupled with the fourth bushing and restrict displacement of the second bushing relative to the fourth bushing along the axis of the second bushing in a direction opposite to the seventh interface.

8. The system according to any one of claims 6 or 7, wherein: The third bushing includes a first opening (235) for receiving the first bushing, wherein the cross-sectional area of the first opening is larger than the cross-sectional area of the first bushing; and The fourth bushing includes a second opening (255) for receiving the second bushing, wherein the cross-sectional area of the second opening is larger than the cross-sectional area of the first bushing.

9. The system according to any one of claims 6 to 8, wherein: The second bushing includes a fourteenth interface (266); and The fourth bushing includes a fifteenth interface (257) configured to restrict rotation of the second bushing about the axis of the second bushing at least partially based on contact with the fourteenth interface.

10. The system according to any one of claims 6 to 9, wherein: The fifth interface includes a first convex spherical surface; The seventh interface includes a second convex spherical surface; The tenth interface includes a first concave spherical surface; and The twelfth interface includes a second concave spherical surface.

11. The system according to claim 10, wherein: The first convex spherical surface is associated with a first solid angle; The second convex spherical surface is associated with a second solid angle; The first concave spherical surface is associated with a third solid angle different from the first solid angle; and The second concave spherical surface is associated with a fourth solid angle different from the second solid angle.

12. An apparatus, which comprises: A first subassembly (105) associated with a first coupling position and a second coupling position; A second subassembly (110) associated with a third coupling position and a fourth coupling position; A first fastener (210) associated with a first axis (211), the first fastener configured to be coupled with the first coupling position according to a first radial constraint; A first bushing (220) having a first opening configured to be coupled with the first fastener according to a second radial constraint; A second bushing (260) having a second opening configured to be coupled with the first fastener according to a third radial constraint; A second fastener (210) associated with a second axis (211), the second fastener configured to be coupled with the second coupling position according to a fourth radial constraint; A third bushing (220) having a third opening configured to couple with the second fastener in accordance with a fifth radial constraint; and a fourth bushing (260) having a fourth opening configured to couple with the second fastener in accordance with a sixth radial constraint, wherein: the first bushing and the second bushing are configured to couple with the third coupling location in accordance with a seventh radial constraint at least partially based on a preload of the first fastener between the first bushing and the second bushing; and the third bushing and the fourth bushing are configured to couple with the fourth coupling location in accordance with an eighth radial constraint at least partially based on a preload of the second fastener between the third bushing and the fourth bushing.

13. The apparatus of claim 12, wherein: the configuration for coupling in accordance with the fifth radial constraint is at least partially based on a surface of the first bushing that is not perpendicular to the first axis and a surface of the second bushing that is not perpendicular to the first axis; and the configuration for coupling in accordance with the sixth radial constraint is at least partially based on a surface of the third bushing that is not perpendicular to the second axis and a surface of the fourth bushing that is not perpendicular to the second axis.

14. The apparatus of any one of claims 12 or 13, wherein: the configuration for coupling in accordance with the fifth radial constraint is at least partially based on a first surface of the second subassembly that is not perpendicular to the first axis and a second surface of the second subassembly that is not perpendicular to the first axis; and the configuration for coupling in accordance with the sixth radial constraint is at least partially based on a third surface of the second subassembly that is not perpendicular to the second axis and a fourth surface of the second subassembly that is not perpendicular to the second axis.

15. The apparatus of any one of claims 12 to 14, further comprising: a fifth bushing (230) that couples with the second subassembly at the third coupling location in accordance with a seventh radial constraint; a sixth bushing (250) that couples with the second subassembly at the third coupling location in accordance with an eighth radial constraint; a seventh bushing (230) that couples with the second subassembly at the fourth coupling location in accordance with a ninth radial constraint; and an eighth bushing (250) that couples with the second subassembly at the fourth coupling location in accordance with a tenth radial constraint, wherein: the configuration for coupling in accordance with the fifth radial constraint is at least partially based on a surface of the fifth bushing that is not perpendicular to the first axis and a surface of the sixth bushing that is not perpendicular to the first axis; and the configuration for coupling in accordance with the sixth radial constraint is at least partially based on a surface of the seventh bushing that is not perpendicular to the second axis and a surface of the eighth bushing that is not perpendicular to the second axis.

16. The apparatus of any one of claims 12 to 15, further comprising: A first spherical bearing (240) configured for spherical freedom of movement between a first part and a second part, wherein the first part includes a fifth opening configured to couple with the first fastener in accordance with an eleventh radial constraint, and wherein the second part is configured to couple with the first subassembly at the first coupling location in accordance with a twelfth radial constraint; and A second spherical bearing (240) configured for spherical freedom of movement between a third part and a fourth part, wherein the third part includes a sixth opening configured to couple with the second fastener in accordance with a thirteenth radial constraint, and wherein the fourth part is configured to couple with the first subassembly at the second coupling location in accordance with a fourteenth radial constraint.

17. The apparatus according to any one of claims 12 to 16, wherein: One of the first subassembly or the second subassembly includes a mounting base; and The other of the first subassembly or the second subassembly includes an antenna assembly.

18. A method, which comprises: Inserting a first fastener (210) through a first opening of the first bushing (220), a second opening associated with the first subassembly (105), and a third opening of the second bushing (260) at least in part based on the radial freedom between the first bushing and the second subassembly (110) and the radial freedom between the second bushing and the second subassembly; Constraining the first subassembly and the second subassembly in a direction radial to the axis (211) of the first fastener at least in part based on preloading a first surface of the first bushing with a second surface associated with the second subassembly and preloading a third surface of the second bushing with a fourth surface associated with the second subassembly using the first fastener, wherein preloading the first surface with the second surface is associated with the radial constraint between the first bushing and the second subassembly, and wherein preloading the third surface with the fourth surface is associated with the radial constraint between the second bushing and the second subassembly; Inserting a second fastener (210) through a fourth opening of the third bushing (220), a fifth opening associated with the first subassembly, and a sixth opening of the fourth bushing (260) at least in part based on the radial freedom between the third bushing and the second subassembly and the radial freedom between the fourth bushing and the second subassembly; and Constraining the first sub - assembly and the second sub - assembly in a direction radial to the axis (211) of the second fastener, at least in part, based on pre - loading the fifth surface of the third bushing with a sixth surface associated with the second sub - assembly using the second fastener and pre - loading the seventh surface of the fourth bushing with an eighth surface associated with the second sub - assembly, wherein pre - loading the fifth surface with the sixth surface is associated with a radial constraint between the third bushing and the second sub - assembly, and wherein pre - loading the seventh surface with the eighth surface is associated with a radial constraint between the fourth bushing and the second sub - assembly.

19. The method according to claim 18, wherein: the first surface, the second surface, the third surface, and the fourth surface are not perpendicular to the axis of the first fastener; and the first surface, the second surface, the third surface, and the fourth surface are not perpendicular to the axis of the first fastener.

20. The method according to any one of claims 18 or 19, wherein, after pre - loading the first surface with the second surface and pre - loading the third surface with the fourth surface, rotating the second sub - assembly relative to the first sub - assembly, at least in part, based on a rotational degree of freedom about the axis of the first fastener between the first sub - assembly and the second sub - assembly.

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