Gimbal Clearance Optimization System

Abstract

To provide an apparatus for reducing clearances within a flexible joint gimbal system.SOLUTION: The apparatus comprises a washer having a centrally located hole. The washer includes a cylindrical side, where the cylindrical side is shaped to contact a side of a ring of the gimbal when the washer is located between a clevis of the gimbal and the ring. The washer further includes a spherical side, where the spherical side has a shape that enables the clevis to rotate with respect to the ring about an axis extending centrally through the hole in the washer when the washer is located between the clevis and the ring.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates generally to the manufacture and maintenance of flexible joint gimbal systems, and more specifically to reducing fatigue damage in metal corrugated bellows gimbal joints due to loose mating parts by installing spherical washers that reduce clearances in the flexible joints to within desired tolerances. [Background technology]

[0002] Flexible metal corrugated bellows gimbal joints are commonly used to connect ducting in fluid transfer systems and are beneficial in allowing relative movement between sections of ducting. However, in high strain, high vibration, or dramatic temperature shift environments, such as rocket engines, for example, excessive manufacturing clearances can result in additional unintended strain on the bellows under hoop shear loads, thereby causing significant fatigue damage and reduced life.

[0003] Existing solutions that address the cause of the damage typically require a redesign of the existing unit. For gimbals of this nature, it is standard industry practice to use ordinary spherical ball bearings. To implement this approach on an existing joint where no bearings are used to begin with, the gimbal joint would need to be destructively split, machined if thick enough, or major components replaced and reassembled, involving welding and re-cleaning. Due to the significant costs and risks associated with this procedure, it is often more feasible to replace the entire unit.

[0004] It would therefore be desirable to have a method and apparatus that takes into account at least some of the above challenges, as well as other possible challenges. For example, it would be desirable to have a method and apparatus that accomplishes the removal of these clearances without removing the joint from the assembly and without breaking the pressure barrier, resulting in full performance capability of the joint while significantly extending the fatigue resistant operational life. Additionally, it would be desirable to produce a gimbal system that includes reduced clearances within desired tolerances at the flexible joints. This reduced clearance can handle high strain environments from initial installation and provide an extended operational life. Summary of the Invention

[0005] An embodiment of the present disclosure provides a gimbal system including a ring, a first clevis connected to the ring, a second clevis connected to the ring, and a washer positioned between the first clevis and the ring.

[0006] Another embodiment of the present disclosure provides an apparatus including a washer having a centrally located hole, the washer including a cylindrical side shaped to contact a side of a ring for the gimbal when the washer is positioned between a clevis for the gimbal and a ring for the gimbal, the washer further including a spherical side shaped to allow the clevis to rotate relative to the ring about an axis extending through the center of the hole in the washer when the washer is positioned between the clevis and the ring.

[0007] Yet another embodiment of the present disclosure provides a method for mounting a washer in a gimbal, the method including identifying a distance between a clevis of the gimbal and a ring of the gimbal, and forming the washer such that the washer has a thickness such that a first gap between the washer and the ring and a second gap between the washer and the clevis cumulatively are within a desired gap tolerance.

[0008] These features and functions may be realized individually in various embodiments of the present disclosure or may be combined in yet other embodiments, further details may be found in the following description and with reference to the drawings. [Brief description of the drawings]

[0009] The novel features believed characteristic of the illustrative embodiments are set forth in the appended claims, however the illustrative embodiments and preferred modes of use, together with further objects and features thereof, will best be understood by reference to the following detailed description of illustrative embodiments of the present disclosure taken in conjunction with the accompanying drawings.

[0010] [Figure 1] 1 illustrates a gimbal system in block diagram form in accordance with an example embodiment. [Diagram 2] 1 illustrates a gimbal system in accordance with an example embodiment. [Diagram 3] 1 illustrates a gimbal system in accordance with an example embodiment. [Figure 4] 1 illustrates a cross-section of a gimbal system in accordance with an example embodiment. [Diagram 5] 1 illustrates a cross-section of a gimbal system in accordance with an example embodiment. [Figure 6] 1 illustrates a washer in accordance with an example embodiment. [Figure 7] 1 illustrates a washer in accordance with an example embodiment. [Figure 8] 1 illustrates a cross-section of a washer in accordance with an example embodiment. [Figure 9] 1 illustrates a cross-section of a washer in accordance with an example embodiment. [Figure 10] 1 illustrates a pin in accordance with an example embodiment. [Figure 11] 1 illustrates a pin in accordance with an example embodiment. [Figure 12] FIG. 13 is a flow diagram of a method for mounting a washer in a gimbal. [Figure 13] 1 shows how to install a washer in a gimbal. [Figure 14] 1 illustrates a product management system in block diagram form according to an example embodiment. [Figure 15] 1 illustrates an aircraft manufacturing and service method in accordance with an illustrative embodiment. [Figure 16] 1 illustrates an aircraft in which an illustrative embodiment may be implemented; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The illustrative embodiments recognize and take into account one or more different considerations. For example, the illustrative embodiments recognize and take into account that it is desirable to produce a flexible joint gimbal system that allows manufacturing clearances at the flexible joints to be reduced to within desired tolerances. Additionally, it is desirable for the flexible joint gimbal system to be able to withstand high strain, high vibration, or dramatic temperature shift environments typically associated with, for example, cryogenic ducting or hydraulic lines on aircraft, rockets, or satellites.

[0012] In an illustrative embodiment, it is recognized and contemplated that non-destructive evaluation can be used to rework existing flexible joint gimbal systems to reduce fatigue damage from excessive movement by reducing the flexible joint clearance without dismantling the flexible joint.

[0013] Thus, the illustrative embodiments provide a flexible joint gimbal system with reduced gap clearance that can withstand the high vibrations and dramatic temperature changes common in rocket engines.

[0014] Although the exemplary embodiments for the exemplary embodiment are described with respect to a rocket engine or a satellite, the exemplary embodiments may be applied to other types of platforms, which may be, for example, mobile platforms, fixed platforms, land-based structures, water-based structures, and space-based structures.

[0015] 1, a block diagram of a gimbal system according to an example embodiment is shown. The gimbal system 100 includes a cap 102, a ring 104, a pin 106, a clevis 108, a washer 110, and a bellows 111. In the example embodiment, the clevis 108 is a U-shaped part with a hole at the end of the protrusion. The clevis 108 can allow rotation about one axis while restricting rotation about the other axis.

[0016] Gimbal systems may be found in locations where relative movement between portions of the ducting of a ducting system is beneficial, which may result from thermal deformations or from movement due to the high vibrations of the rocket engine.

[0017] The cap 102 includes a fastener 112. The fastener 112 may connect the cap 102 to the ring 104. The fastener 112 may be in the form of a bolt, threads, tabs, or any other type of fastener that secures the cap 102 to the ring 104. The cap 102 may abut against a pin 106 or a clevis 108.

[0018] The ring 104 includes channels 114 aligned concentrically with the outer periphery of the ring 104. As shown, the ring 104 and channels 114 are generally circular in shape, although any shape that defines a channel capable of surrounding the bellows 111 will suffice. The ring 104 further includes slots 116 spaced equidistantly about the outer periphery of the ring 104. The slots 116 are shown as oval in shape, but other shapes are contemplated, such as circular, rectangular, etc. The ring 104 must include at least two slots 116, and typically includes at least four slots 116. Each slot 116 passing through the ring 104 may have a first side 118 and a second side 119, and a width 120. The width 120 corresponds to the width of the ring 104. The first side 118 includes a through hole 121. The through hole 121 passes completely through the first side 118 of the slot 116. The second side 119 has a cylindrical surface 122. A longitudinal axis of the cylindrical surface 122 bisects the width 120. The cylindrical surface 122 of the second side 119 includes a blind hole 123. The blind hole 123 may or may not extend completely through the second side 119 of the slot 116. The through hole 121 and the blind hole 123 are concentrically aligned and therefore share a common central longitudinal axis.

[0019] The pin 106 is generally shown as a cylindrical shape having an outer diameter 124. The pin 106 provides an axis of rotation for the clevis 108 relative to the ring 104. The pin 106 has a width 128 corresponding to a central longitudinal axis of the cylindrical shape. The pin 106 extends through the through hole 121, the clevis 108, the washer 110, and into the blind hole 123. The outer diameter 124 fits through the through hole 121, the clevis 108, the washer 110 within a clearance tolerance 126, and into the blind hole 123. During manufacture or remachining of the gimbal system 100, the outer diameter 124 is formed such that the spacing between the pin 106, the clevis 108, the washer 110, and the blind hole 123 is within the desired clearance tolerance 126. The pin 106 may include a shoulder 130. The shoulder includes a length 132. Length 132 is less than length 128. Shoulder 130 may have an outer diameter 134. Outer diameter 134 is greater than outer diameter 124. Shoulder 130 may include a bearing surface 136. Bearing surface 136 may contact clevis 108. During manufacturing or remachining of gimbal system 100, outer diameter 134 is formed such that the spacing between shoulder 130 and through hole 121 is within a desired clearance tolerance 126. During manufacturing or remachining of gimbal system 100, length 132 is formed such that the cumulative spacing between cap 102 and pin 106 and the spacing between bearing surface 136 and clevis 108 is within a clearance tolerance 137. Clearance tolerance 137 is within 0.002 inches.

[0020] The clevis 108 includes at least two projections 138 extending from a hub 139. The hub 139 further defines a duct 144. The duct 144 supports ducting leading to the bellows 111 of the gimbal system 100. The gimbal system 100 may include one or more clevises 108. Each projection 138 of the clevis 108 is identical, and therefore only one projection 138 will be described below. The projections 138 include a hole 140. The hole 140 has a diameter 142. The diameter 142 is sized to receive the pin 106. A first surface of the projection 138 may contact the cap 102 or shoulder 130 of the pin 106. A second surface opposite the first surface contacts the washer 110. The surface contacting the washer 110 has a concave cylindrical shape.

[0021] The washer 110 is generally disk-shaped having an outer diameter 150 and includes a central bore 154 about a central axis 158. The washer 110 includes a spherical surface 160 opposite a cylindrical surface 166. The spherical surface 160 includes a bearing surface 162. The bearing surface 162 may contact the clevis 108. The bearing surface 162 may include a coating 164. The coating 164 may be at least one of a lubricant, a dry film lubricant, a first layer of a lubricant pigment in a ceramic binder on the washer, and a second layer of graphite and phenolic resin cured on the first layer. Additionally, the coating 164 may be applied to the outer surface of the pin 106 and the cap 102. The spherical surface 160 has a shape that allows the clevis 108 to rotate relative to the ring 104 about a central axis 158 that extends through the center of the washer's central hole 154 when the washer is positioned between the clevis 108 and the ring 104.

[0022] The cylindrical surface 166 includes a bearing surface 168. The bearing surface 168 may contact the cylindrical surface 122 of the ring 104. The cylindrical surface 166 is shaped to contact the cylindrical surface 122 of the ring 104 when the washer 110 is positioned between the clevis 108 and the ring 104.

[0023] As used herein, the phrase "at least one of" used in conjunction with enumerated items means that various combinations of one or more of the enumerated items may be used and only one of each enumerated item may be required. In other words, "at least one of" means that any combination of items or some items from the enumeration may be used, but not all of the enumerated items are required. An item may be a particular object, article, or category.

[0024] For example, without limitation, "at least one of item A, item B, and item C" may include item A, item A and item B, or item B. This example may also include item A, item B, and item C, or item B and item C. Of course, any combination of these items may be present. In an example embodiment, "at least one of" may be, for example, without limitation, 2 item A, 1 item B, and 10 item C, 4 item B and 7 item C, or any other suitable combination.

[0025] The washer has a thickness 170. The thickness 170 is formed such that a first gap 176 between the washer and the ring and a second gap 178 between the washer and the clevis are cumulatively within a desired gap tolerance 174. The gap tolerance 174 is within 0.001 inches. Either the first gap or the second gap, or both, may be a zero value.

[0026] The washer 110 is made of a material having a coefficient of thermal expansion 172 within a selected range of the coefficient of thermal expansion of the ring 104 and the coefficient of thermal expansion of the clevis 108 that enables the desired spacing tolerances to be maintained between the washer and the ring and between the washer and the clevis.

[0027] The outer diameter 150 may be sized based on the width 120 of the ring 104. The outer diameter 150 may be determined so that the washer can transfer a desired compressive load 152 to a bearing surface 168 between a cylindrical side 166 of the washer and a cylindrical surface 122 of the ring.

[0028] The illustration of gimbal system 100 and the various components illustrated in FIG. 1 are not meant to imply physical or architectural limitations to the manner in which an example embodiment may be implemented. Other components in addition to or in place of the illustrated components may be used. Some components may be unnecessary. Moreover, blocks are presented to illustrate some functional components. One or more of these blocks may be combined, divided, or combined and divided into various blocks when implemented in an example embodiment.

[0029] 2 and 3, there is illustrated a gimbal system 200 according to an example embodiment. The illustrated gimbal system 200 is an example of one implementation of the gimbal system 100 of FIG.

[0030] As shown, gimbal system 200 includes multiple caps including cap 202, cap 204, cap 206, and cap 208. The caps are connected to ring 210 using fasteners 212. Ring 210 includes channel 242 and slots 214, 215, 216, and 217, each associated with a corresponding cap. Clevis 220 has a protrusion 222 that extends from hub 224 through slot 214 into ring 210. Clevis 220 has a protrusion 226 that extends from hub 224 through slot 216 into ring 210. Clevis 220 includes a duct 228. Duct 228 supports ducting to bellows 111 inside gimbal system 100.

[0031] The clevis 230 has a projection 232 that extends from the hub 234 and through a slot 215 into the ring 210. The clevis 230 has a projection 236 that extends from the hub 234 and through a slot 217 into the ring 210. The clevis 230 includes a duct 238. The duct 238 carries ducting that leads to the bellows 111 inside the gimbal system 100.

[0032] In operation, the clevis 220 can pivot about axis 244 relative to the ring 210 within the slots 214, 216. Additionally, the clevis 230 can pivot about axis 246 relative to the ring 210 within the slots 215, 217. The gimbal system 200 includes a bellows 240 positioned within the channel 242 and connected to both clevises, such that the ducting connected to the ducts 228, 238 is fluidly and flexibly interconnected within the gimbal system 200.

[0033] The overall dimensions of gimbal system 200 and the corresponding components of gimbal system 200 are determined by the intended use. More specifically, the dimensions of the ducting that requires the use of flexible bellows gimbal joints will determine the relative dimensions of gimbal system 200. As a result, the dimensions of the components can range from inches to several feet.

[0034] 4 and 5, a cross section of a gimbal system is illustrated according to an example embodiment. FIG 4 is a cross section of a protrusion in a slot of a ring including a pin, a cap, and a washer along line 4-4 of FIG 3. FIG 5 is a cross section of a protrusion in a slot of a ring including a pin, a cap, and a washer along line 5-5 of FIG 3, corresponding to a 90 degree rotation relative to the view of FIG 4. Those skilled in the art will appreciate that FIG 4 and FIG 5 represent one embodiment of a clevis to ring connection, and as shown, gimbal system 200 includes four of the same connections.

[0035] As shown in Figures 4 and 5, the projection 226 of the clevis 220 extends through the slot 216 in the ring 210. The pin 404 extends through a through hole 430 in the ring 210, a through hole 432 in the projection 226, a central hole 434 in the washer 410, and into a blind hole 416 in the ring 210. The pin 404 has an outer diameter 418. A shoulder 406 of the pin 404 has an outer diameter 419. The cap 208 is connected to the ring 210 with a fastener 212. A bearing surface 408 of the shoulder 406 connects to the projection 226. The projection 226 contacts a spherical surface 412 of the washer 410. A cylindrical surface 414 of the washer 410 contacts a cylindrical surface 422 of the ring 210. The pin 404 provides an axis of rotation 440 for the projection 226 relative to the ring 210. The spherical surface 412 is shaped to allow the clevis projection 226 to rotate relative to the ring about an axis extending through the central bore 434. The spherical surface may include a coating (e.g., a lubricant) to promote smoother rotation. The washer 410 has a thickness 424 such that the gap between the washer 410 and the ring 210 and the gap between the washer 410 and the projection 226 are cumulatively within a desired clearance tolerance.

[0036] 6-9, a washer is shown in accordance with an exemplary embodiment. As shown, washer 600 is an example of one implementation of washer 110 of FIG. 1 and washer 410 of FIGS. 4 and 5.

[0037] As shown, washer 600 includes a spherical surface 602 and a cylindrical surface 604. The washer has an outer diameter 606 and a central bore 608. The central bore has a diameter 610. When in contact with a clevis, the spherical surface 602 is the bearing surface for the washer 600. When in contact with a ring, the cylindrical surface 604 is the bearing surface for the washer 600. The central bore 608 is sized to receive pin 106 in FIG. 1 and pin 404 in FIGS. 4 and 5. During manufacturing or remachining of the illustrated gimbal system, the pin is sized such that the spacing between the pin and central bore 608 is within a desired clearance tolerance.

[0038] 10 and 11, a pin according to an example embodiment is shown. As shown, pin 1000 is an example of one implementation of pin 106 of FIG. 1 and pin 404 of FIG. 4 and FIG.

[0039] As shown, the pin 1000 is generally shown as a cylindrical shape having an outer diameter 1002. The pin 1000 has a length 1004. The outer diameter 1002 fits within the ring, clevis, and washer within a desired clearance tolerance. During manufacturing or reworking of the gimbal system 100, the outer diameter 1002 is formed such that the spacing between the pin 1000, the clevis, the washer, and the ring is within a desired clearance tolerance. The pin 1000 may include a shoulder 1006. The shoulder 1006 may have an outer diameter 1008. The outer diameter 1008 is larger than the outer diameter 1002. The shoulder 1008 may include a bearing surface 1010. The bearing surface 1010 may contact the clevis. During manufacturing or reworking of the gimbal system 100, the outer diameter 1008 is formed such that the spacing between the shoulder 1000 and the through hole in the ring is within a desired clearance tolerance. During manufacturing or rework of the gimbal system 100, the length 1004 is made such that the cumulative spacing between the cap and the pin 1000 and the spacing between the bearing surface 1010 and the clevis is within a clearance tolerance that is within 0.002 inches.

[0040] The components of gimbal system 100 in Figures 2-11 are illustrated to illustrate various physical embodiments of gimbal system 100 shown in block form in Figure 1. These illustrations are not intended to limit the manner in which other illustrative embodiments may be implemented.

[0041] 12, a flow diagram of a process 1200 for mounting a washer in a gimbal system according to an example embodiment is shown. The illustrated process may be implemented in the gimbal system 100 of FIG.

[0042] Process 1200 begins by determining the distance between the gimbal clevis and the gimbal ring (operation 1202). If the distance between the gimbal clevis and the ring is too large, there may be excessive relative motion between the two components in an unintended direction of motion. This excessive motion in an unintended direction may cause fatigue in the component and shorten the life cycle of the component and the entire gimbal system.

[0043] In operation 1204, the washer is formed to have a thickness such that a first gap between the washer and the ring and a second gap between the washer and the clevis cumulatively are within a desired gap tolerance. Forming the washer may include machining a blank to a desired shape, pouring material into a mold, finish machining, laser cutting the blank, etc. The first gap or the second gap, or both, may have a value of zero. Forming the washer may include forming a cylindrical side on the washer. The cylindrical side is shaped to contact a side of the ring when the washer is positioned between the clevis and the ring. Forming the washer may further include forming a spherical side on the washer. The spherical side has a shape that allows the clevis to rotate relative to the ring about an axis extending through a center of the washer when the washer is positioned between the clevis and the ring.

[0044] In operation 1206, at least one of the clevis or the ring is machined so that a pin inserted through the ring, clevis, and washer meets a desired gap tolerance range between the pin and the clevis, between the pin and the ring, and between the pin and the washer.

[0045] In operation 1208, a coating is applied to the spherical side of the washer. The coating is selected from at least one of a lubricant, a dry film lubricant, a first layer of a lubricant pigment in a ceramic binder on the washer, and a second layer of graphite and phenolic resin cured on the first layer.

[0046] In operation 1210, the cap is secured to the ring such that the cap sits on the pin, the pin sits on the clevis, and the clevis sits on the washer while maintaining the desired spacing tolerances between the washer and the ring and between the washer and the clevis. Process 1200 can be performed when a washer is being installed on a newly manufactured gimbal, or process 1200 can be performed when installation of the washer is a rework of an existing gimbal.

[0047] The operations described above are not limited to the order in which they are presented. Some operations may be performed before the operations described above, and some operations may occur simultaneously. The order in which the operations are presented does not imply an order in which the operations should be performed.

[0048] 13 illustrates a method 1300 of mounting a washer in a gimbal system according to an example embodiment. At 1302, an existing cap 1304 and pin 1306 are removed from a ring 1308 and clevis 1310. At 1312, a tool alignment pin 1314 is inserted into and secured to the ring 1308 and clevis 1310. At 1318, a through hole 1320 is machined into the ring 1308, a hole 1322 into the clevis, and a blind hole 1324 into the ring to the desired dimensions to reduce clearance. At 1330, a tool retaining pin 1316 is inserted and 1302, 1312, and 1318 are repeated at each location around the ring 1308. At 1332, machining of all of the through holes 1320, holes 1322, and blind holes 1324 to the desired tolerances is completed. At 1334, washers 1336, replacement pins 1338, and replacement caps 1340 are installed at each location around the ring 1308. At any point during the method, only one cap and pin combination is disassembled from the gimbal system at a time to protect the integrity of the bellows of the gimbal system.

[0049] 14, a block diagram of a product management system is shown in accordance with an illustrative embodiment. Product management system 1400 is a physical hardware system. In this illustrative embodiment, product management system 1400 includes at least one of a manufacturing system 1402 or a maintenance system 1404.

[0050] The manufacturing system 1402 is configured to manufacture products, such as the gimbal system 100 of Figure 1. As shown, the manufacturing system 1402 includes a manufacturing facility 1406. The manufacturing facility 1406 includes at least one of a processing facility 1408 or an assembly facility 1410.

[0051] The processing equipment 1408 is equipment used to fabricate components for parts used to form the gimbal system 100 of FIG. 1. For example, the processing equipment 1408 may include machines and tools. These machines and tools may be at least one of a drill, a hydraulic press, a combustion chamber, a mold, a composite tape laying machine, a vacuum system, a lathe, or other suitable type of equipment. The processing equipment 1408 may be used to fabricate at least one of a metal part, a composite part, a semiconductor, a circuit, a fastener, a rib, a skin panel, a spar, an antenna, or other suitable type of part.

[0052] The assembly facility 1410 is a facility used to assemble parts that form the gimbal system 100 of FIG. 1. Specifically, the assembly facility 1410 is used to assemble the components and parts that form the gimbal system 100 of FIG. 1. The assembly facility 1410 may further include machines and tools. Such machines and tools may be at least one of a robotic arm, a crawler, a fastener installation system, a rail-based drilling system, or a robot. The assembly facility 1410 may be used to assemble parts such as seats, horizontal stabilizers, wings, engines, engine housings, landing gear systems, and other parts for the gimbal system 100 of FIG. 1.

[0053] In this illustrative example, maintenance system 1404 may include maintenance facility 1412. Maintenance facility 1412 may include any equipment necessary to perform maintenance on gimbal system 100 of FIG. 1. Maintenance facility 1412 may include tools to perform various operations on components of gimbal system 100 of FIG. 1. Such operations may include at least one of disassembling the components, refurbishing the components, inspecting the components, reworking the components, manufacturing replacement parts, or other operations to perform maintenance on aircraft gimbal system 100 of FIG. 1. Such operations may be routine maintenance, inspection, renewal, refurbishment, or other types of maintenance operations.

[0054] In this illustrative example, maintenance facility 1412 may include ultrasound inspection equipment, x-ray imaging systems, vision systems, drills, crawlers, and other suitable equipment. In some cases, maintenance facility 1412 may include fabrication equipment 1408, assembly equipment 1410, or both, for producing and assembling parts needed for maintenance.

[0055] The product management system 1400 further includes a control system 1414. The control system 1414 is a hardware system and may further include software or other types of components. The control system 1414 is configured to control operations of at least one of the manufacturing system 1402 or the maintenance system 1404. In particular, the control system 1414 may control operations of at least one of the processing facility 1408, the assembly facility 1410, or the maintenance facility 1412.

[0056] The hardware in the control system 1414 may be implemented using hardware that may include computers, circuits, networks, and other types of equipment. The control may take the form of direct control of the manufacturing equipment 1406. For example, robots, computer controlled machines, and other equipment may be controlled by the control system 1414. In other illustrative examples, the control system 1414 may manage operations performed by personnel 1416 in performing manufacturing or maintenance of the gimbal system 100. For example, the control system 1414 may assign tasks, provide instructions, display models, or perform other operations to manage operations performed by personnel 1416.

[0057] In various illustrative examples, operations personnel 1416 may operate or interact with at least one of the manufacturing facility 1406, the maintenance facility 1412, or the control system 1414. This interaction may occur to manufacture the gimbal system 100 of FIG.

[0058] Of course, the product management system 1400 may be configured to manage other products besides the gimbal system 100 of Figure 1. Although the product management system 1400 is described in connection with manufacturing in the aerospace industry, the product management system 1400 may be configured to manage products in other industries. For example, the product management system 1400 may be configured to manufacture products in the automotive industry, as well as any other suitable industry.

[0059] An example embodiment of the disclosure may be described with reference to aircraft manufacturing and service method 1500 shown in Figure 15 and aircraft 1600 shown in Figure 16. Turning initially to Figure 15, an aircraft manufacturing and service method is illustrated in accordance with an example embodiment. During pre-production, aircraft manufacturing and service method 1500 may include specification and design 1502 of aircraft 1600 in Figure 16, and material sourcing 1504.

[0060] During production, component and subassembly manufacturing 1506 and system integration 1508 of the aircraft 1600 of Figure 16 takes place. The aircraft 1600 may then undergo certification and delivery 1510 and be placed into service 1512. While in customer service 1512, the aircraft 1600 is scheduled for routine maintenance and service 1514, which may include modification, reconfiguration, refurbishment, and other maintenance or service.

[0061] Each process of aircraft manufacturing and service method 1500 may be performed or carried out by a system integrator, a third party, an entity, or some combination thereof. In these examples, an entity may be a customer. For purposes of this specification, a system integrator may include, but is not limited to, any number of aircraft manufacturers and subcontractors of major systems, a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers, an operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0062] 16, a diagram of an aircraft is shown in which illustrative embodiments may be implemented. In this example, the aircraft 1600 may include an airframe 1602 having a number of systems 1604 and an interior 1606. The example systems 1604 include one or more of a propulsion system 1608, an electrical system 1610, a hydraulic system 1612, and an environmental system 1614. Any number of other systems may be included. Although an aerospace example is shown, the various illustrative embodiments may be applicable to other industries, such as the automotive industry. Apparatus and methods embodied herein may be employed during at least one of the stages of the aircraft manufacturing and service method 1500 of FIG. 15.

[0063] In an example embodiment, the components or subassemblies produced in component and subassembly manufacturing 1506 in FIG. 15 may be fabricated or manufactured in a similar manner as the components or subassemblies produced during service 1512 of aircraft 1600 in FIG. 15. As yet another example, one or more apparatus embodiments, method embodiments, or combinations thereof may be utilized during the production stages of component and subassembly manufacturing 1506 and system integration 1508 in FIG. 15. One or more apparatus embodiments, method embodiments, or combinations thereof may be utilized during service 1512 of aircraft 1600 in FIG. 15, during maintenance and service 1514, or both. For example, a gimbal system may be used during maintenance and service 1514 to reduce clearances within the gimbal system in aircraft 1600.

[0064] Thus, the exemplary embodiments provide a flexible joint gimbal system that can reduce manufacturing clearances at the flexible joints to within desired tolerances. Additionally, the exemplary embodiments provide a gimbal system that reduces clearances inside the system without destructive disassembly. Additionally, the exemplary embodiments provide a flexible joint gimbal system that can withstand high strain, high vibration, or dramatic temperature change environments typically associated with cryogenic ducting or hydraulic lines in aircraft, rockets, or satellites, for example. The exemplary embodiments provide a process for reworking existing flexible joint gimbal systems to reduce fatigue damage from excessive movement by reducing the clearances at the flexible joints without dismantling the flexible joints by using non-destructive evaluation. The description of the various exemplary embodiments has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the embodiments in the disclosed form. The various exemplary embodiments describe components that perform tasks or operations. In the exemplary embodiments, the components may be configured to perform the described tasks or operations. For example, the component may have a configuration or design for the structure that gives the component the capability to perform the tasks or operations that the component is described as performing in the example embodiment.

[0065] Numerous modifications and variations will be apparent to those skilled in the art. Additionally, various exemplary embodiments may provide different features as compared to other preferred embodiments. The selected embodiment or embodiments have been chosen and described in order to best explain the principles and practical applications of the embodiments and to facilitate understanding by others skilled in the art of the disclosure of the various embodiments and various modifications suitable for the particular application contemplated.

[0066] As used herein, a first component is "connected to" a second component means that the first component can be directly or indirectly connected to the second component. That is, there may be additional components between the first and second components. If there are one or more additional components between the two components, the first component is considered to be indirectly connected to the second component. If the first component is directly connected to the second component, there are no additional components between the two components.

[0067] Clause 1 A gimbal system comprising a ring, a first clevis connected to the ring, a second clevis connected to the ring, and a washer positioned between the first clevis and the ring.

[0068] Clause 2 2. The gimbal system of claim 1, comprising a pin extending through a centrally located hole in the ring, the first clevis, and the washer, a cap attached to the ring and in contact with the pin, and a shoulder on the pin providing a bearing surface with the first clevis.

[0069] Clause 3 The washer has a centrally located hole, a cylindrical side shaped to contact the side of the ring, and a spherical side shaped to allow the clevis to rotate relative to the ring about an axis extending through the center of the hole. 3. The gimbal system of claim 1 or 2, further comprising:

[0070] Clause 4 4. The gimbal system of any one of clauses 1 to 3, wherein the washer has an outer diameter based on a width of the ring.

[0071] Clause 5 4. The gimbal system of claim 3, wherein the centrally located hole in the washer has a diameter based on an outer diameter of the ring, the first clevis, and a pin that extends through the centrally located hole in the washer.

[0072] Clause 6 6. The gimbal system of any one of clauses 1 to 5, wherein the washer has a thickness such that a gap between the washer and the ring and a gap between the washer and the clevis are cumulatively within a desired gap tolerance.

[0073] Clause 7 7. The gimbal system of any one of clauses 1 to 6, wherein the washer is made of a material having a thermal expansion coefficient within a selected range of the thermal expansion coefficient of the ring and the thermal expansion coefficient of the clevis that enables a desired spacing tolerance to be maintained between the washer and the ring and between the washer and the clevis.

[0074] Clause 8 The gimbal system of any one of clauses 1 to 7, further comprising a plurality of washers having a centrally located hole, a cylindrical side shaped to contact a corresponding side of the ring, and a spherical side shaped to allow the first clevis and second clevis to rotate relative to the ring about an axis extending through the center of the corresponding hole in the washer.

[0075] Clause 9 1. An apparatus comprising: a washer having a centrally located hole; a cylindrical side on the washer shaped to contact a side of a ring for a gimbal when the washer is positioned between a clevis for a gimbal and a ring for the gimbal; and a spherical side on the washer shaped to allow the clevis to rotate relative to the ring about an axis extending through the center of the hole in the washer when the washer is positioned between the clevis and the ring.

[0076] Clause 10 10. The device of clause 9, further comprising a coating located on the bulbous side.

[0077] Clause 11 11. The apparatus of claim 10, wherein the coating is selected from at least one of a lubricant, a dry film lubricant, a first layer of a lubricating pigment in a ceramic binder on the washer, and a second layer of graphite and phenolic resin cured on the first layer.

[0078] Clause 12 12. The apparatus of any one of clauses 9 to 11, wherein the washer has a diameter selected to transmit a desired compressive load to a bearing surface between the cylindrical side of the washer and a surface of the ring.

[0079] Clause 13 13. The apparatus of any one of clauses 9 to 12, wherein the washer has a thickness such that both a gap between the washer and the ring and a gap between the washer and the clevis are cumulatively within a desired gap tolerance.

[0080] Clause 14 14. The apparatus of any one of clauses 9 to 13, wherein the washer is made of a material having a coefficient of thermal expansion within a selected range of the coefficient of thermal expansion of the ring and the coefficient of thermal expansion of the clevis that enables a desired spacing tolerance to be maintained between the washer and the ring and between the washer and the clevis.

[0081] Clause 15 15. The apparatus of any one of clauses 9 to 14, wherein the clevis in the gimbal connects to ducting for one of a fluid transfer system, a liquid transfer system, a gas transfer system, a cryogenic system, a hydraulic system, and a fuel system.

[0082] Clause 16 16. The apparatus of any one of clauses 9 to 15, wherein a cylindrical side on the washer forms a first bearing surface for the ring and the spherical side forms a second bearing surface for the clevis.

[0083] Clause 17 1. A method for mounting a washer in a gimbal, the method comprising: identifying a distance between a clevis of the gimbal and a ring of the gimbal; and forming the washer to have a thickness such that a first gap between the washer and the ring and a second gap between the washer and the clevis cumulatively are within a desired gap tolerance.

[0084] Clause 18 18. The method of claim 17, wherein forming the washer includes forming a cylindrical side on the washer, the cylindrical side being shaped to contact a side of the ring when the washer is positioned between the clevis and the ring.

[0085] Clause 19 19. The method of claim 17 or 18, wherein forming the washer includes forming a spherical side on the washer, the spherical side having a shape that allows the clevis to rotate relative to the ring about an axis extending through a center of the washer when the washer is positioned between the clevis and the ring.

[0086] Clause 20 20. The method of any one of clauses 17 to 19, further comprising machining at least one of the clevis or the ring such that a pin inserted through the ring, clevis, and washer meets a desired gap tolerance range between the pin and the clevis, between the pin and the ring, and between the pin and the washer.

[0087] Clause 21 19. The method of claim 18, further comprising applying a coating to the spherical side portion, the coating being selected from at least one of a lubricant, a dry film lubricant, a first layer of a lubricating pigment in a ceramic binder on the washer, and a second layer of graphite and phenolic resin cured on the first layer.

[0088] Clause 22 20. The method of claim 19, further comprising securing the cap to the ring such that the cap sits on the pin, the pin sits on the clevis, and the clevis sits on the washer while maintaining a desired spacing tolerance between the washer and the ring and between the washer and the clevis.

[0089] Clause 23 23. The method according to any one of clauses 17 to 22, wherein the installation of the washer is performed on a new gimbal.

[0090] Clause 24 24. The method of any one of clauses 17 to 23, wherein the installation of the washer is a re-working of an existing gimbal.

Claims

1. Ring (104), a first clevis (220) connected to said ring (104); a second clevis (230) connected to said ring (104); a washer (110) positioned between the first clevis (220) and the ring (104); a pin (106) extending through a centrally located hole (154) in the ring (104), the first clevis (220), and the washer (110); a cap (102) attached to said ring (104) and in contact with said pin (106); a shoulder (130) of said pin (106) providing a bearing surface (136) with said first clevis (220); A gimbal system that is equipped with

2. The washer is a cylindrical side (166) shaped to contact the side (122) of said ring (104); and a spherical side (160) shaped to allow the clevis (220) to rotate relative to the ring (104) about an axis (158) that extends through the center of the centrally located hole (154); The gimbal system of claim 1 , further comprising:

3. The gimbal system of claim 1 or 2, wherein the washer (110) has an outer diameter (150) based on a width (120) of the ring.

4. 3. The gimbal system of claim 2, wherein the centrally located hole (154) in the washer has a diameter (156) based on an outer diameter (124) of the ring (104), the first clevis (220), and a pin that extends through the centrally located hole (154) in the washer.

5. 5. The gimbal system of claim 1, wherein the washer has a thickness such that a gap between the washer and the ring and a gap between the washer and the clevis are cumulatively within a desired gap tolerance.

6. A plurality of washers (110) having a centrally located hole (154), a cylindrical side (166) shaped to contact a corresponding side of said ring (104), and a spherical side (160) shaped to allow said first clevis (220) and second clevis (230) to rotate relative to said ring about an axis (158) extending through the center of the corresponding hole in the washer. The gimbal system of claim 1 , further comprising:

7. a washer (110) having a centrally located hole (154); a cylindrical side (166) on said washer (110) shaped to contact a side (122) of said ring for said gimbal (100) when said washer (110) is positioned between a clevis (108) for said gimbal (100) and a ring (104) for said gimbal (100); a spherical side (160) on said washer (110) having a shape that allows said clevis (108) to rotate relative to said ring (104) about an axis extending through the center of said hole in said washer (158) when said washer (110) is positioned between said clevis (108) and said ring (104); a pin (106) extending through a centrally located hole (154) in said ring (104), said clevis (108), and said washer (110); a cap (102) attached to said ring (104) and in contact with said pin (106); A shoulder (130) of said pin (106) providing a bearing surface (136) with said clevis (108). An apparatus comprising:

8. A coating (164) located on said bulbous side portion (160). The apparatus of claim 7 further comprising:

9. 9. The apparatus of claim 8, wherein the coating (164) is selected from at least one of a lubricant, a dry film lubricant, a first layer of a lubricant pigment in a ceramic binder on the washer (110), and a second layer of graphite and phenolic resin cured on the first layer.

10. 10. The apparatus of any one of claims 7 to 9, wherein the washer (110) has a diameter (150) selected to transmit a desired compressive load (152) to a bearing surface (168) between the cylindrical side (166) of the washer (110) and a surface (122) of the ring (104).

11. 11. The apparatus of any one of claims 7 to 10, wherein the washer (110) has a thickness (170) such that both a gap (176) between the washer and the ring and a gap (178) between the washer and the clevis are cumulatively within a desired gap tolerance (174).

12. 12. The apparatus of claim 7, wherein the clevis in the gimbal connects to ducting for one of a fluid transfer system, a liquid transfer system, a gas transfer system, a cryogenic system, a hydraulic system, and a fuel system.

13. 13. The apparatus of any one of claims 7 to 12, wherein the cylindrical side (166) on the washer forms a first bearing surface (168) for the ring and the spherical side (160) forms a second bearing surface (162) for the clevis.

14. 1. A method for mounting a washer in a gimbal, comprising: Determining a distance between the gimbal clevis and the gimbal ring (1202); forming the washer (1204) such that the washer has a thickness such that a first gap between the washer and the ring and a second gap between the washer and the clevis are cumulatively within a desired gap tolerance; Inserting the pin through the ring, the clevis, and the washer, and securing the cap to the ring such that the cap sits on the pin, the pin sits on the clevis, and the clevis sits on the washer, while maintaining a desired spacing tolerance between the washer and the ring and between the washer and the clevis (1210). The method includes:

15. forming the washer, 15. The method of claim 14, including forming a cylindrical side on the washer (1204), the cylindrical side being shaped to contact a side of the ring when the washer is positioned between the clevis and the ring.

16. forming the washer, 16. The method of claim 14 or 15, comprising forming (1204) a spherical side on the washer, the spherical side having a shape that allows the clevis to rotate relative to the ring about an axis extending through a center of the washer when the washer is positioned between the clevis and the ring.

17. A method according to any one of claims 14 to 16, comprising machining (1206) at least one of the clevis or the ring so that the pin meets a desired gap tolerance range between the pin and the clevis, between the pin and the ring, and between the pin and the washer.

18. 17. The method of claim 16, further comprising: applying a coating to the spherical side portion, the coating being selected from at least one of a lubricant, a dry film lubricant, a first layer of a lubricant pigment in a ceramic binder on the washer, and a second layer of graphite and phenolic resin cured on the first layer (1208).

19. 19. The method according to any one of claims 14 to 18, wherein the installation of the washer is performed on a new gimbal (1200).

20. 19. The method of any one of claims 14 to 18, wherein the attachment of the washer is a reworking of an existing gimbal (1200).

Images