In-pipe crawler system

Abstract

The in-pipe crawler system comprises at least one crawler propulsion unit extending along a longitudinal central axis, the at least one crawler propulsion unit having a main body and several motor pods, each motor pod comprising a pod body removably mounted on the main body and a pod arm having a proximal end pivotally connected to the pod body by a pivotal connection, the pod arm having a distal end bearing at least one propulsion wheel driven by a propulsion motor, the motor pod comprising a cylinder arranged for pivoting the pod arm in a plane containing the central longitudinal axis around the pivotal connection.

Description

[0001] IN-PIPE CRAWLER SYSTEM

[0002] The present invention concerns an in-pipe crawler system.

[0003] Nuclear facilities, such as nuclear reactors, in some countries are aging, and some of their components are beginning to surpass their original design life.

[0004] Every nuclear facility has piping and components that are experiencing degradation. As nuclear facilities age, the degradation of infrastructure becomes a growing issue which must be resolved to allow for continued operations.

[0005] NRC regulations, industry groups, and utilities are all shifting from a tradition of “fix- when-broke” to proactive repair and rehabilitation.

[0006] The focus in the industry on the rehabilitation of buried piping is presently very high and will increase as more plants get closer to life extensions.

[0007] With this huge need in the industry, there currently is no cost and time effective method for adequate buried pipe repair or preventive maintenance.

[0008] Plants therefore need a cost-effective solution for buried piping repair or preventive maintenance to allow long-term operations.

[0009] A possible technology is spraying a liner in place, on the internal surface of the pipe. However, application of the liner is not easy considering that the internal surface is not manually accessible and that the buried piping includes bends.

[0010] A previous approach was through double access of piping to be lined (access from both sides) then by wrenching manual tools through the piping to apply the liner. Small bore piping with bends were not able to be lined internally.

[0011] US2012 / 0177809 A1 discloses an in-pipe crawler with a nozzle for spraying a coating fluid inside a pipe. Said crawler must be pushed or wrenched through the pipe and has no centering capabilities around pipe bends.

[0012] This causes the current tooling to not be adequate for internal pipe lining within most power generation buried piping.

[0013] Therefore, an objective of the present disclosure is to propose an in-pipe crawler system that can travel through piping namely with bends in an easier manner, and be well- suited for internal pipe maintenance.

[0014] The objective is achieved by an in-pipe crawler system comprising at least one crawler propulsion unit extending along a longitudinal central axis, the at least one crawler propulsion unit having a main body and several motor pods, each motor pod comprising a pod body removably mounted on the main body and a pod arm having a proximal end pivotally connected to the pod body by a pivotal connection, the pod arm having a distal end bearing at least one propulsion wheel driven by a propulsion motor, the motor pod comprising a cylinder arranged for pivoting the pod arm in a plane containing the central longitudinal axis around the pivotal connection.

[0015] The in-pipe crawler system may include one of several of the following features:

[0016] - the main body of the crawler propulsion unit comprises front and rear metal end plates connected to one another with a central structure made of a light material;

[0017] - a first half of the motor pods are secured to the front end of the main body, a second half of the motor pods being secured to the rear end of the main body;

[0018] - the motor pods of the crawler propulsion unit are distributed around the longitudinal central axis, each motor pod belonging to the first half being located circumferentially between two motor pods belonging to the second half;

[0019] - the crawler propulsion unit comprises, for each motor pod, a mounting interface defining several mounting positions for the motor pod, the motor pod having a complementary mounting interface adapted to be fitted at any of the mounting positions, the mounting positions being arranged such that the motor pod is located at different distances radially from the central axis when the complementary mounting interface is fitted at different mounting positions;

[0020] - the crawler propulsion unit comprises, for each motor pod, a side spacer fixed to the mounting interface and defining additional mounting positions for the motor pod, the complementary mounting interface being adapted to be fitted at any of the additional mounting positions, the additional mounting positions being arranged such that the motor pod is fitted at the additional mounting positions than when the complementary mounting interface is fitted at the mounting positions;

[0021] - the cylinders of the motor pods are pneumatic cylinders, the in-pipe crawler system having a fixed pressured gas source and at least one flexible tube connecting the pneumatic cylinders to the pressured gas source;

[0022] - the cylinder of each motor pod is mounted on the pod body;

[0023] - the at least one propulsion wheel is removably secured to a pod shaft;

[0024] - the pod shaft passes through two support bearings mounted on the pod arm;

[0025] - the pod arm comprises two pod arm side plates facing one another, the propulsion motor comprising a motor and a gear box arranged between the two pod arm side plates and secured to the two pod arm side plates;

[0026] - the in-pipe crawler system comprises a crawler trailer unit arranged on a longitudinal front side of the at least one crawler propulsion unit and connected by a trailer flexible coupling to the at least one crawler propulsion unit, the crawler trailer unit having a trailer body extending along a trailer central axis and several trailer arms, each trailer arm having a trailer arm proximal end connected to the trailer body by a trailer link making the trailer arm displaceable with respect to the trailer body in a plane containing the trailer central axis, each trailer arm having a trailer arm distal end bearing at least one trailer wheel, the crawler trailer unit comprising a trailer actuator arranged for urging the trailer arm in said plane containing the trailer central axis away from the trailer central axis;

[0027] - the trailer link comprises a front linkage part and a rear linkage part displaceable with respect to one another along the trailer central axis by the trailer actuator, the trailer link further comprising several intermediate supports each connected to the front linkage part by a first coupling and to the rear linkage part by a second coupling, the first coupling comprising a first bar pivotally connected to the intermediate support and a first linkage bar pivotally connected to the front linkage part and pivotally connected to the first bar, the second coupling comprising a second bar pivotally connected to the intermediate support and a second linkage bar pivotally connected to the rear linkage part and pivotally connected to the second bar, one of the trailer arms being secured the first bar or to the first linkage bar, another one of the trailer arms being secured the second bar or to the second linkage bar;

[0028] - the trailer link comprises linear rails secured to the trailer body and extending along the trailer central axis, the front linkage part and the rear linkage part having slide connections to the rails;

[0029] - the trailer actuator comprises several pneumatic cylinders, distributed around the trailer central axis, and connecting the front linkage part to the rear linkage part;

[0030] - the trailer actuator urges the front linkage part and the rear linkage part toward one another;

[0031] - the trailer wheels are idle wheels;

[0032] - a tool is mounted on the crawler trailer unit and / or to the crawler propulsion unit, the tool being chosen in the following list: a video camera, a pipe surface cleaning tool, a pipe surface finishing tool, a pneumatic spray coating tool, a centrifugally propelled coating tool;

[0033] - the trailer flexible coupling comprises a flexible conduit secured at one end to the crawler propulsion unit and secured at an opposite end to the crawler trailer unit, electric conductors being received inside the flexible conduit;

[0034] - the in pipe crawler system comprises a crawler rear unit arranged on a longitudinal rear side of the crawler propulsion unit and connected by a rear flexible coupling to the crawler propulsion unit, the crawler rear unit comprising a control unit controlling the propulsion motors and the cylinders of the motor pods;

[0035] - the in pipe crawler system comprises several crawler propulsion units, a single umbilical cable, and an electrical power source located outside the pipe, all the crawler propulsion units receiving electrical power from the electrical power source through the single umbilical cable.

[0036] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0037] - The figure 1 is a view of the in-pipe crawler system, located inside a pipe;

[0038] - The figure 2 is an enlarged perspective view of the crawler propulsion unit of the in-pipe crawler system of the figure 1 , for a variant embodiment in which motor pods are fixed to side spacers;

[0039] - The figure 3 is an enlarged perspective view of the main body of the crawler propulsion unit of the figures 1 and 2;

[0040] - The figure 4 is an enlarged perspective view of one of the motor pods of the crawler propulsion unit of the figures 1 and 2;

[0041] - The figure 5 is an exploded perspective view of the motor pod of the figure 4;

[0042] - The figure 6 is an enlarged perspective view of the crawler trailer unit of the figure 1 ; and

[0043] - The figure 7 is a preferred version of the main body of the in-pipe crawler system.

[0044] The in-pipe crawler system 1 depicted on the figure 1 is particularly dedicated to the inspection and maintenance of pipes 2, especially buried pipes, of industrial facilities. It is well suited for the inspection and maintenance of pipes of a nuclear facility, such as a nuclear power reactor, but can be used as well in other type of industries such as chemical or petro-chemical industries.

[0045] The in-pipe crawler system 1 is designed for travelling inside the pipes. It is able to travel vertical down pipes and travel around bends of any type. It is able to travel around 90° bends or even higher.

[0046] The in-pipe crawler system 1 is designed for carrying out video inspection of the internal surface of the pipe, cleaning of the internal surface of the pipe using brushes or any other adapted tools, and spray coating of the internal surface of the pipe.

[0047] As shown on the figure 1 , the in-pipe crawler system 1 comprises a crawler propulsion unit 3 extending along a longitudinal central axis X.

[0048] Typically, the in-pipe crawler system 1 comprises a crawler trailer unit 5 arranged on a longitudinal front side of the crawler propulsion unit 3 and connected by a trailer flexible coupling 7 to the crawler propulsion unit 3, as shown on the figure 1.

[0049] The crawler propulsion unit 3 is shown on the figures 1 and 2.

[0050] Typically, the in-pipe crawler system 1 comprises a crawler rear unit 9 arranged on a longitudinal rear side of the crawler propulsion unit 3 and connected by a rear flexible coupling 11 to the crawler propulsion unit 3. The crawler propulsion unit 3 has a main body 13 (figure 3) and several motor pods 15 (figures 4 and 5).

[0051] The main body 13 comprises front and rear metal end plates 17, 19 connected to one another with a central structure 23 (figures 3 and 7).

[0052] The central structure 23 is advantageously made of a light material, such as aluminum (figure 7). In alternative, the central structure 23 is made of steel (not shown on the figures) or any other material such as plastic material (figure 3).

[0053] The front and rear metal end plates 17, 19 are substantially perpendicular to the longitudinal central axis X. They are removably mounted on the central structure 23.

[0054] If the central structure 23 is made of a plastic material, the main body 13 comprises front and rear metal end plates 17, 19 connected to one another by metal spars 21 (figure 3). The metal spars 21 extend longitudinally.

[0055] The front and rear metal end plates 17, 19 and the metal spars 21 are made of a light metal such as aluminum. They constitute together a skeleton, ensuring the structural integrity of the main body.

[0056] The central structure 23 can be split apart into two halves allowing the umbilical to pass through the crawler without having to thread it through the center of the frame.

[0057] A first half of the motor pods 15 are secured at the front end of the main body 13, and a second half of the motor pods 15 are secured at the rear end of the main body 13. In the example shown on the figures, the crawler propulsion unit 3 comprises six motor pods 15, three of them secured to the front end of the main body, and the other three secured to the rear end of the main body.

[0058] The motor pods 15 of the crawler propulsion unit 3 are distributed around the longitudinal central axis X, each motor pod 15 belonging to the first half being located circumferentially between two motor pods 15 belonging to the second half.

[0059] Each motor pod 15 is held in place via dowel pins that provide a locating feature on the metal side plates and or extension spacer side plates 103. There is a single bolt that secures the motor pod to the extension spacers or side plates.

[0060] Each motor pod 15 comprises a pod body 25 removably mounted on the main body 13 and a pod arm 27 having a proximal end 29 pivotally connected to the pod body 25 by a pivotal connection 31 .

[0061] The pod arm 27 has a distal end 33 bearing at least one, typically two, propulsion wheels 35 driven by a propulsion motor 37. The propulsion motor 37 is typically a DC motor. The motor pod 15 further comprises a cylinder 39 arranged for pivoting the pod arm 27 in a plane containing the central longitudinal axis X, around a pivot axis C1 of the pivotal connection 31.

[0062] The pod body 25 comprises two pod body side plates 41 substantially parallel to one another and spaced from one another along the pivot axis C1. The pod body 25 further comprises a pod body base plate 43 secured to the two pod body side plates 41 . The pod body base plate 43 is arranged between distal ends 45 of the pod body plates 41.

[0063] The pod arm 27 comprises two pod arm side plates 47 facing one another.

[0064] The two pod arm side plates 47 are substantially parallel to one another and spaced from one another along the pivot axis C1.

[0065] The two pod arm side plates 47 are arranged between the two pod body side plates 41. The proximal ends 49 of the two pod arm side plates 47 are each pivotally connected to the proximal end 51 of one of the pod body side plate 41 by a connection 52, the two connections 52 together defining the pivotal connection 31.

[0066] The propulsion motor 37 comprises a motor 53 and a gear box 55 arranged between the two pod arm side plates 47 and secured to the two pod arm side plates 47.

[0067] The motor 53 is an electric motor. An output shaft (not depicted on the figures) drives a pod shaft 57 (figure 5) in rotation via the gear box 55.

[0068] The pod shaft 57 is substantially parallel to the pivot axis C1. The pod shaft 57 is substantially perpendicular to the longitudinal central axis X.

[0069] The at least one propulsion wheel 35 is removably secured to the pod shaft 57.

[0070] The pod arm 27 bears advantageously two propulsion wheels 35, arranged on opposite sides of the pod arm 27 and removably secured at opposite ends of the pod shaft 57.

[0071] Each propulsion wheel 35 comprises a plastic hub 59, and a rubber tire 61 molded on the plastic hub 59. The plastic hub 59 is advantageously 3D printed. The plastic hub 59 is secured to the pod shaft 57 by a screw 63 and a locking washer.

[0072] A metal wheel interface 65 is secured at each end of the pod shaft 57. The metal wheel interface 65 is a disk, radial driving ribs 67 being formed on the large face of the disk turned toward the propulsion wheel 35. Radial grooves 69 are formed in the plastic hub 59, the ribs 67 being accommodated in the grooves 69 such that the metal wheel interface 65 transfers the motor torque from the pod shaft 57 to the propulsion wheel 35.

[0073] The pod shaft 57 goes through two support bearings 71 mounted on the pod arm 27.

[0074] More precisely, the pod arm side plates 47, at their distal ends 72, are formed with cylindrical through holes 73 in which the support bearings 71 are accommodated.

[0075] The cylinders 39 of the motor pods 15 are pneumatic cylinders. The cylinder 39 of each motor pod is mounted on the corresponding pod body 25.

[0076] The cylinder 39 comprises a cylinder body 75 internally delimiting a cavity receiving a piston 77. The piston 77 is movable with respect to the cylinder body 75 along a displacement direction Y substantially radial with respect to the central longitudinal axis X.

[0077] The cylinder 39 is arranged for moving the pod arm 27 along the displacement direction Y both away from the central longitudinal axis X and toward the central longitudinal axis X.

[0078] For that purpose, a yoke 79 is secured to the distal end 33 of the pod arm 27. The end of the piston 77 is rotatably connected to the yoke 79.

[0079] The in-pipe crawler system 1 has a fixed pressured gas source 81 and at least one flexible pipe 83 through which the pneumatic cylinders 39 is in fluid communication with the pressured gas source 81 (figure 1). In other words, the compressed air travels through an air line to actuate the cylinders. There is a manual valve that the operator uses to actuate the cylinders.

[0080] The pressured gas is typically compressed air.

[0081] The fixed pressured gas source 81 is located outside the pipe 2.

[0082] At least one flexible pipe 83 is connected to inlets of two pressured gas manifolds 85 secured to the main body of the crawler propulsion unit (figure 3). The pressured gas manifolds 85 are connected to pneumatic quick connections 87, themselves connected to pressured gas ports 89 of the cylinders 39.

[0083] In other embodiments, the cylinders are pneumatically driven or are of any other adapted type.

[0084] The crawler propulsion unit 3 comprises, for each motor pod 15, a mounting interface 91 defining several mounting positions for the motor pod 15 (figure 3).

[0085] The motor pod 15 has a complementary mounting interface 93 adapted to be fitted at any one of the mounting positions (figure 4).

[0086] The mounting positions are arranged such that the motor pod 15 is located at different distances radially from the central axis X when the complementary mounting interface 93 is fitted at different mounting positions.

[0087] In other words, a first mounting position defines a position of the motor pod 15 radially closer to the central axis 15. Said first mounting position is used for pipes 2 having a small diameter.

[0088] A second mounting position defines a position of the motor pod 15 radially slightly farther away from the central axis 15. Said second mounting position is used for pipes 2 having a slightly larger diameter. Other mounting positions define positions of the motor pod 15 radially further away from the central axis 15 than the second position. Said other mounting position are used for pipes 2 having even larger diameters.

[0089] The mounting interface 91 comprises two mounting plates 95 facing one another. The mounting plates are substantially perpendicular to the pivot axis C1 of the corresponding motor pod 15. The mounting plates 95 are spaced from one another along the pivot axis C1.

[0090] The mounting positions are defined by dowel pins 97 formed on the faces of the mounting plates 95 facing one another. On a given mounting plate 95, the dowel pins are arranged along a line substantially parallel to the displacement direction Y of the cylinder 39 of the corresponding motor pod 15, or forming a small angle with the displacement direction Y.

[0091] In other words, the complementary mounting interface 93 offers a mounting feature that mates with the dowel pins 97. This feature allows for small adjustments of 0.5in for each motor pod. These adjustments correspond to different resulting diameters based on the pipe size that is being traversed.

[0092] As shown on the figure 4, the complementary mounting interface 93 comprises several recesses 98 formed in the pod body 25.

[0093] The recesses 98 are formed in edges of the distal ends 45 of the pod body side plates 41. Each distal end 45 has two recesses 98, adapted to be fitted around two of the dowel pins 97.

[0094] The pod body 25 is removably secured to the mounting interface 91 , at any mounting position, by a bolt 99. For that purpose, one of the mounting plates 95 has several holes 100 and the pod body 25 has another hole 101 (not visible on the figure 4 but visible on the figure 5). At any given mounting position, the other hole 101 is located in front of one of the holes 100, the bolt 99 being inserted in the hole 100 and in the other hole 101.

[0095] In a variant embodiment depicted on the figure 2, the crawler propulsion unit 3 comprises, for each motor pod 15, a side spacer 102 fixed to the mounting interface 91 and defining additional mounting positions for the motor pod 15.

[0096] The complementary mounting interface 93 is adapted to be fitted at any one of the additional mounting positions.

[0097] The additional mounting positions are arranged such that the motor pod 15 is located radially farther away from the central axis X when the complementary mounting interface 93 is fitted at the additional mounting positions than when the complementary mounting interface 93 is fitted at the mounting positions.

[0098] The side spacers 102 are used in pipes 2 of large diameters. The side spacer 102, at one end, has two mounting plates 103 similar to the mounting plates 95 of the mounting interface 91 , with dowel pins (not visible on the figures) arranged in the same manner as the dowel pins 97. The complementary mounting interface 93 cooperates with the dowel pins of the mounting plates 103.

[0099] The side spacer 102, at the end opposite to the mounting plates 103, is secured to the mounting interface 91 by any adapted means.

[0100] The crawler trailer unit 5 comprises a trailer body 105 extending along a trailer central axis F and several trailer arms 107 (figure 6).

[0101] Each trailer arm 107 has a trailer arm proximal end 109 connected to the trailer body 105 by a trailer link 1 1 1 making the trailer arm 107 displaceable with respect to the trailer body 105 in a plane containing the trailer central axis F.

[0102] Each trailer arm 107 has a trailer arm distal end 113, on which is mounted at least one trailer wheel 115.

[0103] All the trailer wheels 115 are idle. They are not motorized.

[0104] The crawler trailer unit 5 further comprises a trailer actuator 117 arranged for urging the trailer arm 107 in said plane containing the trailer central axis F away from the trailer central axis F.

[0105] The trailer body 105 is preferably made of a light metal such as aluminum. In alternative, it could be made of steel or of any other material such as plastic material, for example polycarbonate. In the latter case, it could advantageously be obtained by 3D printing.

[0106] The trailer link 1 11 comprises a front linkage part 1 19 and a rear linkage part 120 displaceable with respect to one another along the trailer central axis by the trailer actuator 1 17.

[0107] The trailer link 11 1 comprises several linear rails 121 secured to the trailer body 105 and extending along the trailer central axis F.

[0108] The front linkage part 1 19 has a front slide connection 122 to each linear rail 121. The rear linkage part 120 has a rear slide connection 123 to each linear rail 121

[0109] The front and rear slide connections 122, 123 are carriages slidingly mounted on the corresponding linear rail 121.

[0110] The front slide connection 122 travels along a front half of the corresponding linear rail 121 , and the rear slide connection 123 travels along the rear half of the corresponding linear rail 121 .

[0111] The front slide connections 122 travelling on all the rails 121 are connected to one another by the front linkage part 1 19. The rear slide connections 123 travelling on all the rails 121 are connected to one another by the rear linkage part 120. The front and rear linkage parts 119, 120 are rigid bars, extending circumferentially around the trailer central axis F.

[0112] The linear rails 121 are distributed around the trailer central axis F. Typically, the linear rails 121 are regularly spaced, circumferentially, around the trailer central axis F

[0113] In the example depicted on the figure 6, the trailer link 1 1 1 comprises five rails 121 .

[0114] The trailer link 11 1 further comprises several intermediate supports 125, each connected to the front linkage part 1 19 by a first coupling 127 and to the rear linkage part 120 by a second coupling 129.

[0115] The intermediate support 125 is a U-shaped yoke. It is arranged, along the trailer central axis F, between the front linkage part 119 and the rear linkage part 120.

[0116] The intermediate supports 125 are distributed around the trailer central axis F. Typically, the intermediate supports 125 are regularly spaced, circumferentially, around the trailer central axis F

[0117] In the example depicted on the figure 6, the trailer link 11 1 comprises five intermediate supports 125.

[0118] The first coupling 127 comprises a first bar 131 pivotally connected to the intermediate support 125 and a first linkage bar 133 pivotally connected to the front linkage part 1 19 and pivotally connected to the first bar 131 .

[0119] The second coupling 129 comprising a second bar 135 pivotally connected to the intermediate support 125 and a second linkage bar 137 pivotally connected to the rear linkage part 120 and pivotally connected to the second bar 135.

[0120] All the pivot connections are around respective pivot axis parallel to one another, the pivot axis being perpendicular to the trailer central axis F.

[0121] One of the trailer arms 107 is secured to the first bar 131 or to the first linkage bar 133, another one of the trailer arms 107 being secured to the second bar 135 or to the second linkage bar 137.

[0122] In other words, two trailer arms 107 are mounted to each intermediate support 125.

[0123] Said two trailer arms 107 extend in the same plane containing the trailer central axis F. The two trailer wheels 115 extend in the same plane, and are rotatable around respective rotation axis parallel to one another.

[0124] In the example depicted on the figures, the two trailer arms 107 are secured to the first bar 131 and to the second bar 135.

[0125] The trailer actuator 1 17 comprises several pneumatic cylinders 139, distributed around the trailer central axis F, and connecting the front linkage part 119 to the rear linkage part 120. When the in-pipe crawler system 1 is inside the pipe 2, the trailer actuator 1 17 urges the front linkage part 1 19 to the rear linkage part 120 toward one another along the trailer central axis F.

[0126] As a consequence, the angle between the first bar 131 and the first linkage bar 133 tends to reduce. The angle between the second bar 135 and the second linkage bar 137 tends to reduce as well. The trailer wheels 1 15 are resiliently urged away from the trailer central axis F, and are resiliently applied against the inner surface of the pipe 2.

[0127] Advantageously, the two trailer arms 107 connected to the same intermediate support 125 are able to pivot independently from one another. This aspect is particularly useful when the in pipe crawler circulates in a bend or through a T intersection.

[0128] The trailer arms 107 are preferably removably mounted on the trailer body 105, in order to adapt the length of the trailer arms 107 as a function of the diameter of the pipe 2.

[0129] The crawler rear unit 9 has a rear body 139 extending along a rear central axis R and several rear arms 141 (figure 1).

[0130] Each rear arm 141 has a rear proximal end fixedly connected to the rear body 139.

[0131] Each rear arm 141 has a rear distal end bearing at least one rear wheel 143.

[0132] The at least one rear wheel 143 is idle. It is not motorized.

[0133] Half of the rear arms 141 are arranged at a front end of the rear body 139. Said rear arms 141 extend radially with respect to the rear central axis R. They are angularly spaced from one another around the rear central axis R in a regular manner.

[0134] The other half of the rear arms 141 are arranged at a rear end of the rear body 139. Said rear arms 141 extend radially with respectto the rear central axis R. They are angularly spaced from one another around the rear central axis R in a regular manner.

[0135] The crawler rear unit 9 comprises a control unit 145 controlling the driving motors 37 and the cylinders 39 of the motor pods 15.

[0136] The control unit 145 comprises typically a power supply, a motor driver, a serial hardware and an ethernet switch. The serial hardware is typically a RS485 serial.

[0137] The control unit 145 is connected to a supervision unit 147, located outside the pipe 2, by a data cable 149. Data is exchanged between the control unit 145 and the supervision unit 147 through the data cable 149.

[0138] The supervision unit 147 is typically a computer.

[0139] The motor driver communicates directly with the computer over RS485 serial that is converted to RS232 at the motor driver. Camera feed comes directly over ethernet. Cylinders are controlled using air that is actuated by a valve. The crawler propulsion unit 3 is for example fitted with inspection cameras (not shown on the figures). The inspection cameras are connected to the control unit 145 by data cables (not shown). The data collected by the inspection cameras are transmitted to the control unit 145 by data cables, and are transmitted by the data cable 149 to the supervision unit 147.

[0140] The crawler rear unit 9 is for example fitted with temperature and humidity sensors (not shown) mounted to the exterior surface of the crawler rear unit 9 to provide information to the operator. The sensors are connected to the control unit 145 by data cables (not shown). The data collected by the sensors are transmitted over the RS485 serial to the control unit 145 by the data cables, and are transmitted by the data cable 149 to the supervision unit 147.

[0141] A tool 151 is fitted on the crawler trailer unit 5 and / or on the crawler propulsion unit 3.

[0142] The crawler rear unit 9 may be fitted with a tool as well.

[0143] The tool 151 is chosen in the following list: a video camera, a pipe surface cleaning tool, a pipe surface finishing tool, a pneumatic spray coating tool, a centrifugally propelled coating tool.

[0144] In the example shown on the figures 1 and 6, the tool 151 is a pneumatic spray coating tool. It is fitted on the crawler trailer unit 5.

[0145] The tool 151 in this case is accommodated inside the trailer body 105 and held with a hose clamp 153 or alternative mounting method.

[0146] The tool 151 comprises a spraying nozzle 155, and flexible hoses 157 / 159 feeding the spraying nozzle 151 with pressurized gas and with the two part coating in liquid form. Alternatively, the spraying nozzle 155 is fed with several liquid components of the coating, mixed inside the nozzle.

[0147] The pressurized gas flexible pipe 157 is connected to a pressurized gas source 161 located outside the pipe 2. The liquid coating or liquid coating components flexible pipe(s) 159 is connected to a pump 163 located outside the pipe 2.

[0148] The trailer link 1 11 advantageously keeps the spraying nozzle 155 centered at all times through straight pipe.

[0149] In bends the tool 151 is advantageously biased to the outside of the bend, applying less coating to the inside and more to the outside. This is desired as the inside radius is smaller and if the tool were perfectly centered the coating would not be applied as evenly.

[0150] According to another embodiment, the tool 151 is fitted on the crawler propulsion unit 3. The electric consumers on board of the crawler propulsion unit 3, the crawler trailer unit 5 and the crawler rear unit 9 are electrically connected to an electrical power source 165 by electric power feed cable 167.

[0151] The electric power source is located outside the pipe 2.

[0152] The data cables, power cables, fluid hoses, compressed air hoses / pipes are connected via electrical connections and pneumatic quick connections. Pneumatics use crimp connections and pneumatic tubing to insure a robust system.

[0153] The data cable 149, electric power feed cable 167, pressurized gas flexible pipes 83 / 157, liquid coating / coating components hose(s) 159 are gathered together and form an umbilical cable trailing behind the in-pipe crawler system.

[0154] The trailer flexible coupling 7 comprises a flexible conduit 169 secured at one end to the crawler propulsion unit 3 and secured at an opposite end to the crawler trailer unit 5.

[0155] The flexible conduit 169 is securely connected to mounts 171 / 173 fixed respectively at the front end of the crawler propulsion unit 3 and at the rear end of the crawler trailer unit 5.

[0156] Electric conductors, typically data cable and / or power feed cable, are received inside the flexible conduit 169.

[0157] The rear flexible coupling 1 1 is simply the umbilical cable as it provides sufficient rigidity.

[0158] The in-pipe crawler system of the invention has numerous advantages.

[0159] The comprehensive in-pipe crawler system integrates various components to autonomously traverse pipes of different sizes, facilitating inner pipe wall inspection, cleaning, surface finishing, and coating application. Controlled remotely via a powered umbilical, the system receives electrical power, compressed air, and signals through the umbilical cable. For spray liner application, the umbilical also houses the two part spray liner media.

[0160] The crawler propulsion unit serves as a versatile locomotive, driving a range of end effectors through the pipe.

[0161] The crawler propulsion unit propels one or several crawler trailer units through pipes using contoured wheels on modular motor pods, facilitating seamless forward or reverse movement against the inner pipe wall. The modular motor pod units, securely attached to the exoskeleton frame of the propulsion unit, offer strategic flexibility, allowing adjustability to accommodate pipes of varying diameters. The main body, featuring a central metallic structure and end plates, ensures structural integrity. Removable bulkheads facilitate the passage of the umbilical, allowing multiple crawlers in a single deployment for extended pipe exploration.

[0162] Extension spacers adapt the crawler to various pipe sizes. These spacers enable the crawler to fit into pipes ranging from 12 to 24 inches and can be further expanded to accommodate even larger pipe sizes.

[0163] The side spacers 102 are angled for larger sizes, ensuring an optimal wheelbase-to- diameter ratio. This design feature prevents the in-pipe crawler from becoming misaligned or "jack knifed" within the pipe, enhancing its stability and maneuverability during operation.

[0164] The motor pod, consisting of a modular unit attached to the exoskeleton frame, incorporates a motor, a worm gearbox, and a pneumatic cylinder. This modular design allows for easy replacement of damaged motor pods and adaptation to different pipe sizes. The pneumatic cylinders apply outward force on the pipe wall, allowing the crawler propulsion unit to adjust its diameter during navigation through bends and changes in pipe diameter. Some of the motor pods incorporate encoders 175 (figure 2) providing live feedback on the crawler speed for closed loop control.

[0165] The motor pod features convenient, easily replaceable propulsion wheels. The custom-molded propulsion wheels, equipped with plastic hubs, are securely fastened to the motor pod using a single bolt and a Nord lock washer. A locating feature is integrated into the metal wheel interface, connected to a keyed shaft. This design includes two additional bearings in the shaft and side motor mounts, providing robust support for the high load exerted by the wheels against the pipe wall.

[0166] The crawler trailer unit functions as a passive vehicle to position the tool embarked on board of the crawler trailer unit. This is particularly advantageous when the tool is a spraycoating tool, positioned optimally for spraying in straight pipes or around bends. The spraycoating tool's offset is adjustable, improving the tool ability to apply an even coat.

[0167] The crawler trailer unit has a trailer mechanical link connecting all sets of wheels, keeping the crawler trailer unit centered while accommodating changes in pipe size and bends. Pneumatically controlled, the trailer link ensures compliance with varying pipe configurations, allowing the crawler trailer unit to navigate over bumps and through T sections efficiently.

[0168] The trailer flexible coupling between the crawler propulsion unit and crawler trailer unit is a piece of flexible electrical conduit that allows for freedom of motion between the two units while still providing a secure link.

[0169] The in-pipe crawler system thus has unique features:

[0170] - crawler trailer unit centering abilities and design. - heavy duty design focused on serving power generation piping systems

[0171] - versatile in-pipe crawler platform design, allowing for flexibility and adaptability of tooling deployments within piping.

[0172] The in-pipe crawler system is focused on being able to spray long runs of pipe.

[0173] According to an embodiment, the in-pipe crawler system comprises several crawler propulsion units, and a single umbilical cable. All the crawler propulsion units receive electrical power from the electrical power source through the single umbilical cable. Typically, the crawler propulsion units receive compressed air, data and possibly liquid coating / coating components via the single umbilical cable.

[0174] One or several crawler trailer units can be associated to the crawler propulsion units.

[0175] One or several crawler rear units can be associated to the crawler propulsion units.

[0176] The multiple crawler propulsion units deployed along a single pipe run will help pull the umbilical through the pipe.

[0177] The crawler is designed to be modular and adaptable with universal motor pods and side spacers with various lengths. The in-pipe crawler system is also designed to allow for navigation around pipes with bends.

[0178] The crawler trailer unit has a unique trailer linkage design that is engineered to keep a spray coating tool in the optimal location for spraying liner around bends as well as straight sections. It also allows for the spray coating tool to be adjusted in and out to adjust how close the tool rides to the outside edge of a bend.

Claims

CLAIMS1.- In-pipe crawler system comprising at least one crawler propulsion unit (3) extending along a longitudinal central axis, the at least one crawler propulsion unit (3) having a main body (13) and several motor pods (15), each motor pod (15) comprising a pod body (25) removably mounted on the main body (13) and a pod arm (27) having a proximal end (29) pivotally connected to the pod body (25) by a pivotal connection (31), the pod arm (27) having a distal end (33) bearing at least one propulsion wheel (35) driven by a propulsion motor (37), the motor pod (15) comprising a cylinder (39) arranged for pivoting the pod arm (27) in a plane containing the central longitudinal axis around the pivotal connection (31).2.- In-pipe crawler system according to the claim 1 , wherein the main body (13) of the crawler propulsion unit (3) comprises front and rear metal end plates (17, 19) connected to one another with a central structure (23) made of a light material.3.- In-pipe crawler system according to the claim 2, wherein a first half of the motor pods (15) are secured to the front end of the main body (13), a second half of the motor pods (15) being secured to the rear end of the main body (13).4.- In-pipe crawler system according to the claim 3, wherein the motor pods (15) of the crawler propulsion unit (3) are distributed around the longitudinal central axis, each motor pod (15) belonging to the first half being located circumferentially between two motor pods (15) belonging to the second half.5.- In-pipe crawler system according to anyone of the claims 1 or 4, wherein the crawler propulsion unit (3) comprises, for each motor pod (15), a mounting interface (91) defining several mounting positions for the motor pod (15), the motor pod (15) having a complementary mounting interface (93) adapted to be fitted at any of the mounting positions, the mounting positions being arranged such that the motor pod (15) is located at different distances radially from the central axis when the complementary mounting interface (93) is fitted at different mounting positions.6.- In-pipe crawler system according to the claim 5, wherein the crawler propulsion unit (3) comprises, for each motor pod, a side spacer (102) fixed to the mounting interface (91) and defining additional mounting positions for the motor pod (15), the complementary mounting interface (93) being adapted to be fitted at any of the additional mounting positions, the additional mounting positions being arranged such that the motor pod (15) is located radially farther away from the central axis when the complementary mounting interface(93) is fitted at the additional mounting positions than when the complementary mounting interface (93) is fitted at the mounting positions.7.- In-pipe crawler system according to anyone of the claims 1 to 6, wherein the cylinders (39) of the motor pods are pneumatic cylinders, the in-pipe crawler system (1) having a fixed pressured gas source (81) and at least one flexible tube (83) connecting the pneumatic cylinders (39) to the pressured gas source (81).8.- In-pipe crawler system according to anyone of the claims 1 to 7, wherein the cylinder (39) of each motor pod (15) is mounted on the pod body (25).9.- In-pipe crawler system according to anyone of the claims 1 to 8, wherein the at least one propulsion wheel (35) is removably secured to a pod shaft (57).10 - In-pipe crawler system according to the claim 9, wherein the pod shaft (57) passes through two support bearings (71) mounted on the pod arm (27).11.- In-pipe crawler system according to the claim 9 or 10, wherein the pod arm (27) comprises two pod arm side plates (47) facing one another, the propulsion motor (37) comprising a motor (53) and a gear box (55) arranged between the two pod arm side plates (47) and secured to the two pod arm side plates (47).12.- In-pipe crawler system according to anyone of the claims 1 to 11 , wherein the in-pipe crawler system (1) comprises a crawler trailer unit (5) arranged on a longitudinal front side of the at least one crawler propulsion unit (3) and connected by a trailer flexible coupling (7) to the at least one crawler propulsion unit (3), the crawler trailer unit (5) having a trailer body (105) extending along a trailer central axis and several trailer arms (107), each trailer arm (107) having a trailer arm proximal end (109) connected to the trailer body (105) by a trailer link (111) making the trailer arm (107) displaceable with respect to the trailer body (105) in a plane containing the trailer central axis, each trailer arm (107) having a trailer arm distal end (113) bearing at least one trailer wheel (115), the crawler trailer unit (5) comprising a trailer actuator (117) arranged for urging the trailer arm (107) in said plane containing the trailer central axis away from the trailer central axis.13.- In-pipe crawler system according to anyone of the claims 1 to 12, wherein the trailer link (111) comprises a front linkage part (119) and a rear linkage part (120) displaceable with respect to one another along the trailer central axis by the trailer actuator (117), the trailer link (111) further comprising several intermediate supports (125) each connected to the front linkage part (119) by a first coupling (127) and to the rear linkage part (120) by a second coupling (120), the first coupling (127) comprising a first bar (131) pivotally connected to the intermediate support (125) and a first linkage bar (133) pivotally connected to the front linkage part (119) and pivotally connected to the first bar (131), the second coupling (120) comprising a second bar (135) pivotally connected to the intermediate support (125) and a second linkage bar (137) pivotally connected to the rear linkage part (120) and pivotally connected to the second bar (135), one of the trailerarms (107) being secured the first bar (131) or to the first linkage bar (133), another one of the trailer arms (107) being secured the second bar (135) or to the second linkage bar (137).14.- In-pipe crawler system according to the claim 13, wherein the trailer link (111) comprises linear rails (121) secured to the trailer body (105) and extending along the trailer central axis, the front linkage part (119) and the rear linkage part (120) having slide connections to the rails.15 - In-pipe crawler system according to the claim 13 or 14, wherein the trailer actuator (117) comprises several pneumatic cylinders (139), distributed around the trailer central axis, and connecting the front linkage part (119) to the rear linkage part (120).16.- In-pipe crawler system according to anyone of the claims 13 to 14 , wherein the trailer actuator (117) urges the front linkage part (119) and the rear linkage part (120) toward one another.17.- In-pipe crawler system according to anyone of the claims 1 to 16, wherein the trailer wheels (115) are idle wheels.18.- In-pipe crawler system according to anyone of the claims 1 to 17, wherein a tool (151) is mounted on the crawler trailer unit (5) and / or to the crawler propulsion unit (3), the tool (151) being chosen in the following list: a video camera, a pipe surface cleaning tool, a pipe surface finishing tool, a pneumatic spray coating tool, a centrifugally propelled coating tool.19.- In-pipe crawler system according to anyone of the claims 1 to 18, wherein the trailer flexible coupling (7) comprises a flexible conduit (169) secured at one end to the crawler propulsion unit (3) and secured at an opposite end to the crawler trailer unit (5), electric conductors being received inside the flexible conduit (169).20.- In-pipe crawler system according to anyone of the claims 1 to 19, wherein the in pipe crawler system (1) comprises a crawler rear unit (9) arranged on a longitudinal rear side of the crawler propulsion unit (3) and connected by a rear flexible coupling (11) to the crawler propulsion unit (3), the crawler rear unit (9) comprising a control unit (145) controlling the propulsion motors (37) and the cylinders (39) of the motor pods (15).21.- In-pipe crawler system according to anyone of the claims 1 to 20, wherein the in pipe crawler system (1) comprises several crawler propulsion units (3), a single umbilical cable, and an electrical power source (165) located outside the pipe (2), all the crawler propulsion units (3) receiving electrical power from the electrical power source (165) through the single umbilical cable.

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