Steel wire rope and a steel wire rope monitoring system thereof

Abstract

The invention relates to a steel wire rope (100) comprising: − a core steel wire (110), − a plurality of steel wires 140 wound around the core steel wire (110) in a plurality of layers, − a sensor (150) wherein the sensor comprises a tube which contains at least one optical fiber (160), satheid sensor being configured to provide measurements of at least one physical parameter of the steel wire rope. The invention also relates to a steel wire rope monitoring system and to a method of monitoring the steel wire rope.

Description

[0001] STEEL WIRE ROPE AND A STEEL WIRE ROPE MONITORING

[0002] SYSTEM THEREOF

[0003]

[0001] The present invention relates to a steel wire rope which is enabled to measure parameters such as elongation, vibration and temperatures to detect abnormal symptom, structural health and predictive analysis of failures thereby enabling the efficient operation, maintenance as well as assists in the prevention of accidents and particularly to a method of real-time monitoring of steel wire rope that enables a prognosis for the state of the steel wire rope when in operation and also ascertaining the steel wire operational life against the shock and wears during operational.

[0004]

[0002] Metal ropes comprising of steel wires are known in the art. They are used in numerous applications such as in the form of stranded or spiral ropes. Stranded ropes are used as hauling or carrying-hauling ropes in cableways installations, as hoist or balance ropes in mineshafts, as ropes for general lifting application like cranes, overhead cranes, drilling machines, winches and elevator ropes or any other load and for other purposes. Stranded ropes are composed of strands which are laid in a helical shape around an insert (core), and which are themselves formed by wires. Wires are made of steel or made coated steel such as of zinc coating or other metallic or synthetic coatings. Spiral ropes such as spiral strands, half-locked coil or full-locked coil ropes are used to carrying, tensioning ropes for cable cars, as guide ropes or hauling ropes for mine shafts, as anchoring ropes for offshore structures or as guy ropes for buildings or bridges and for other purposes.

[0005]

[0003] However, these steel wire ropes are exposed to harsh atmospheric environment for a long time subjecting them to corrosion in various adverse environments as well as adverse operating conditions. Hence, the service life of the cable ways, bridge, cranes or any equipment or structure reliant on steel wire rope are directly influenced by the service life of the Steel wire rope. Hereinafter all kind of steel ropes or steel cables or stranded ropes or spiral ropes are referred as steel wire ropes.

[0006]

[0004] The steel wire ropes from versatile uses such as cableways ropes, anchoring rope, crane ropes and others are presented herein as embodiment for better appreciation of the present invention.

[0007]

[0005] The steel wire ropes generally - if not exclusively - comprise a core around which several strands are wound. The strands are made of steel wires that are twisted together. Possibly the strands are organised in layers for example: an intermediate layer of a first type of strands is wound around the core at a first lay length and direction. On top of those intermediate strands, outer strands of a second type of strand can be twisted with a second lay length and direction. The core occupies a unique position within the steel wire rope. As it is central and surrounded by helically formed strands its length is shorter compared to the helix length of the strands. Due to tension variation in strands and / or individual wires, contact pressure between strands and / or individual wires, internal abrasion between strands and / or individual wires, corrosion of the steel individual wires or their coatings, damages such as cracks or global deformations will occur. Such damages can also be increased by outer elements such as pulleys, saddles, or others.

[0008]

[0006] Hence, the steel wire ropes deteriorate with use because of relatively heavy loads fatigue loading and harsh environmental conditions. In the case of steel wire ropes, the deterioration of the steel wire rope must be carefully determined. The wire rope wear is controlled by visual inspection performed using criterion developed conventionally or with very cumbersome equipment that are installed locally.

[0009]

[0007] Therefore, intense Research and development endeavors are put in to develop a steel wire rope for which it is easy to determine the state (the presence or absence of a flaw or the like) of a steel wire rope. Some of the examples are cited herein below for a better appreciation of the present invention.

[0010]

[0008] The wire rope breakage detection apparatus (magnetic body inspection apparatus) disclosed in Japanese Patent Laid-Open No. 2003-302379, noise due to variations in the magnetization of the steel wire rope (magnetic body) is detected. Specifically, a magnetization direction inside a magnetic body such as the steel wire rope may not be aligned in a fixed direction at the time of manufacture (after manufacture). Furthermore, the magnetization direction inside the magnetic body is also changed by application of a stress, bending, or the like when the magnetic body passes through a pulley or the like, resulting in non-uniform ity. Therefore, even in a uniform portion in which the steel wire rope is not broken, the detection coil (detector) may detect a signal based on the noise due to the variations in the magnetization direction of the steel wire rope. In such a case, there is a problem that it is not possible to easily determine the state (the presence or absence of a flaw or the like) of the magnetic body.

[0011]

[0009] Several systems can be used to perform control on ropes. Regarding tension and / or elongation, like load cells, they are generally installed on the rope extremity and give local or average data. Regarding temperatures, various sensors like thermocouples or optical pyrometers can be used, however they cannot comply with dynamic application such as passage through pulleys or saddles and they can be affected and damaged by environmental conditions and quite often they must be removed when the rope move. Regarding NDT testing main systems are based on magnetic technology, such the one disclosed in Japanese Patent Laid-Open No. 2003-302379. However, these technologies just give data about steel structure variation such like number of broken wires, section variation in the rope section that goes through the NDT device. It does not give data in real time and cannot be used when the rope passes through pulleys or saddles.

[0012]

[0010] For the foregoing reasons, there is a need for a steel wire rope and a method that overcomes or mitigates one or more of the disadvantages or defects of the prior art. Such disadvantages or defects are not necessarily included in those described above.

[0013]

[0011] The present invention has been proposed in order to solve the aforementioned problems, and an object of the present invention is to provide a steel wire rope that can be monitored in real time and with a high degree of consistency and a method thereof that is capable of easily measuring, thanks to integrated sensors, parameters such as temperature, elongation, vibrations and determining by post treatment the state of the steel wire rope, that is the presence or absence of a flaw or the like along the wire rope.

[0014]

[0012] Another object of the present invention is to solve these problems by making available a steel wire rope that can detect and inform the maintenance system of any flaws by detecting the changes in temperature, stress, strain or any other abnormal signal.

[0015]

[0013] Another object of the present invention is also to make available a method for the manufacturing of wire ropes that is compatible with conventional industrial applications while being robust towards manufacturing parameters shifts.

[0016]

[0014] Other characteristics and advantages of the invention will become apparent from the following detailed description of the invention:

[0017]

[0015] In view of the deficiencies in the prior art, an objective of the present invention is to provide a steel wire rope to increase the overall monitoring of the steel wire rope while in operation to increase the detection of flaws without increasing the costs, use, and maintenance, thereby increasing the load-carrying capability life of the steel wire rope.

[0018]

[0016] The present invention will be described in further detail with reference to the accompanying drawings. The present invention is explained in more detail below with reference to individual embodiments in figures. The figures are to be read as mutually complementary to each other insofar and similar reference in different figures have the same technical meaning. The features of the individual embodiments can also be combined with one another. Furthermore, the embodiments shown in the figures can be combined with the features outlined hereinbelow. The figures to demonstrate the structural aspect of the preferred embodiments of the present invention are mentioned hereinbelow:

[0019] - Figure 1 : represents is a cross sectional view of a first embodiment of the steel wire rope according to the present invention,

[0020] - Figure 2 : represents a cross sectional view of a second embodiment of a steel wire rope according to the present invention,

[0021] - Figure 3 : represents a cross sectional view of a third embodiment of the steel wire rope of according to the present invention, - Figure 4 : represents a cross sectional view of a fourth embodiment of the steel wire rope according to the present invention,

[0022] - Figure 5: Figure 5A, Figure 5C, Figure 5C represent a cross sectional view of the loose tube sensor, tight buffer sensor, combined sensor wherein figure 5A is for loose sensor, figure 5B is fight buffer sensor and figure 5C is a combined sensor,

[0023] - Figure 6 : represents a cross sectional view of multiple strand steel wire rope in accordance with the present invention wherein the figure 6 specifically shows the valleys present in the fourth embodiment of the present invention,

[0024] - Figure 7: represents a schematic diagram illustrating example operations with some embodiments in accordance of the present invention,

[0025] - Figure 8 : represents a flow chart of an illustrative method for a steel wire rope monitoring system according to the invention.

[0026]

[0017] The optical fibers of the present invention can, for example, be any one from Rayleigh Fibre, Bragg Fibre, Brillouin fibre or Raman Fibre, which is configured to detect any change in a physical parameter of the steel wire rope that can have a wear-inducing effect or may lead detection of a flaw in the operation of the steel wire rope and thereby the structure or the equipment in which the steel wire rope is employed. Such parameters can, for example, be the temperature, the stress, the strain, the elongation, the vibrations of the steel wire rope and to convey it to the control unit of the specific monitoring system that will be detailed below.

[0027]

[0018] The tube in accordance with the present invention can be made from any known metallic or non-metallic materials such as Steel, Aluminium, Copper, Plastic, composite material. Further the sensor in accordance with the present invention may, for example, be chosen among loose tube sensor, tight buffer sensor, or combined sensor. The figures 5A, 5B and 5C present some embodiments using such types of sensors and showing possible positions of the optical fibers inside the tubes.

[0028]

[0019] A first embodiment provides a demonstration of the present invention in the form of a steel wire rope 100 which is a spiral strand steel wire rope and is shown in figure 1. The first preferred embodiment of the present inventive steel wire rope is used for applications such as for anchoring ropes for offshore structures, guy ropes for buildings or bridges etc. According to the first embodiment of the present invention, the steel wire rope 100 comprises a core steel wire 110, and a plurality of steel wires 140 wound around the core steel wire 110 in a plurality of layers, an optional sheathing 190 which may be made of polymer like polyethylene, polyurethane, polypropylene or PVC and at least one sensor 150, each sensor comprising a tube 170 which contains at least one optical fiber 160. The sensor 150 in accordance with the present invention can be placed in substitution of any steel wire 140, and / or in substitution of the central core steel wire 110 and / or in the valleys between the steel wires 140.

[0029]

[0020] A second embodiment provides a demonstration of the present invention in the form of steel wire rope 200 which is a half-locked coil steel wire rope and is shown in figure 2. The second embodiment of the present inventive steel wire rope 200 is used for applications such as for guidance rope in mining application etc. According to the second embodiment of the present invention the steel wire rope 200 comprises a central core steel wire 210, intermediatory wire layers 220 made of a plurality of steel wires 240, wound around the central core steel wire 210, an outer layer 230 composed of an alternance of X shaped steel wires 245 and round steel wires 240 and at least one sensor 250, each sensor comprising a tube 270 which contains at least one optical fiber 260. The sensor 250 in accordance with the present invention can be placed in substitution of any steel wire 240 of intermediary layer 220 or outer layer 230 or in central core steel wire 210 or in the valleys between the steel wires 240.

[0030]

[0021] A third preferred embodiment provides a demonstration of the present invention in the form of steel wire rope 300 which is full locked coil steel wire rope and is shown in figure 3. The third embodiment of the present inventive steel wire rope 300 is used for applications such as for carrying, tensioning ropes for cable cars. According to the third embodiment of the present invention, the steel wire rope 300 comprises a central core steel wire 310, an intermediatory layer 320 wound around the core steel wire 310, said intermediatory layer 320 comprising multiple sublayers in form of alternate presence of round steel wires 340 and / or X shaped wires 380 and / or Z shaped wires 385 or any one of them, an outer layer 330 composed of Z shaped steel wires 385 and at least one sensor 350, each sensor comprising f a tube 370 which contains at least one optical fiber 360, The sensor 350 in accordance with the present invention can be placed in substitution of any steel wires 340 of intermediary layer 320 or outer layer 330 or of central core steel wire 310 or in the valleyd between the steel wires 340, and / or X shaped wires 380 and / or Z shaped wires 385 or any one of them.

[0031]

[0022] A fourth embodiment provides a demonstration of the present invention in the form of steel wire rope 400 which is a multiple strand spiral steel wire rope and is shown in figure 4. The fourth embodiment of the present inventive steel wire rope 400 is used for applications such as for such as cranes, overhead cranes, drilling machines, winches and elevator ropes etc. According to the fourth embodiment of the present invention the steel wire rope 400 comprises a central core strand 410 that can be a synthetic element or which comprises of plurality of steel wires 442 wound around the central core steel wire 441 , a plurality of intermediatory steel wire strands 420 which also comprise a plurality of steel wires 440 wound around the central core steel wire 441 , a plurality of external steel wire strands 430, wherein each external steel wire strand 430 comprises a plurality of steel wires 442 wound around the central core steel wire 441 , those intermediatory and external steel wire strands 420 and 440 being wounded around the central steel wire strand 410 and at least one sensor 450, each sensor containing at least one optical fiber 460. The sensor 450 can be placed in substitution of any steel wires 442, of a central core steel wire 441 and / or intermediatory steel wire strands 420 and / or external steel wire strand 430 and / or in the valleys in between layers.

[0032]

[0023] Figure 6 shows some possibilities of positioning of the sensors inside the valleys present in a steel rope wire of the present invention in accordance with the fourth embodiment. One inner valley 620 and one outer valley 610 are designated to demonstrate the position where the sensor 450 can be placed in the steel wire rope 400. Each dark black round spot show in figure 6 can be termed as an inner valley 620 which can be a site where the sensor 450 can be placed in the present invention and similarly each light grey spot shown in figure 6 can be termed as an outer valley which can be a site where the sensor 450 can be placed in the present invention. Similar inner and outer valleys are also present in other embodiments of steel wire rope 100, 200, 300 where the respective sensors 150, 250, 350 of the embodiments first to third can be placed in accordance with the present invention.

[0033]

[0024] Figure 5A, 5B and 5C show three different preferred sensors of the present invention that can be placed as sensors designated in hereinabove embodiments and are mentioned as 150, 250, 350 and 450 in such respective embodiments.

[0034]

[0025] Figure 5A shows one type of sensor 150 that is a loose sensor wherein optical fibers 160 are loosely packed in the tube 170.

[0035]

[0026] Figure 5B shows one type of sensor 150 that is a tight sensor wherein the optical fibers 160 are tightly packed in a wire armoring 510 while being simultaneously held in a sheathing 520 which is held inside the tube 170.

[0036]

[0027] Figure 5C shows one type of sensor 150 that is a combined sensor including at the same time tightly packed optical fibers and loosely packed optical fibers inside the tube 170.

[0037]

[0028] According to a preferred aspect of the present invention, the wire monitoring system is described below, together with the method for monitoring the steel wire rope thereby ascertaining the real-time condition of the structure or the equipment.

[0038]

[0029] The method can, for example, be applied to any steel wire rope as described in the above embodiments as well as to any steel wire rope including at least one sensor according to the invention and selected from the following list: stranded ropes, single layer ropes, rotation resistant rope, parallel closed ropes, compacted swaged ropes, electromechanical ropes, spiral ropes, spiral strand ropes, half locked coil ropes, full locked coil ropes, ropes with coverings and / or fillings, solid polymer covered rope, solid polymer filled rope, solid polymer covered and filled rope, cushioned core rope, cushioned rope.

[0039]

[0030] Figure 7 depicts schematically a steel wire rope in an operating environment 700 such as on a crane, as a guidance rope in a mining application or any other application.

[0040]

[0031] The steel wire rope monitoring system 710 according to the invention includes a sensor data collection device 720 configured to collect measurements of at least one physical parameter of the steel wire rope 100 provided by at least one and preferably a plurality of sensors 150 deployed and embedded throughout it as described above.

[0041]

[0032] It also includes a monitoring server 740 which can optionally be remote from or close to the operating environment of the steel wire rope. The monitoring server 740 includes a database 750, which can include a memory that contains all the physical parameters profiles for the steel wire rope. Such profiles may include thermal and / or stress profile of the steel wire rope, the thermal profile including a plurality of profile elements such as temperature, each profile element including a profile internal temperature, at least one profile external temperature, and / or a profile utility run time associated with different weather conditions and the threshold value for each physical parameter which are used to determine the safe operation of the steel wire rope.

[0042]

[0033] Each sensor 150 provides data to the sensor data collection device 720 under the form of signals. The sensor data collection device 720 is in communication with the monitoring server 740, which perform various data analysis and storage functions.

[0043]

[0034] Sensors 150 deployed and embedded throughout the steel wire rope 100 are optionally in wired communication with the sensor data collection device 720.

[0044]

[0035] In all embodiments, some sensors 150 may be in wireless communication with the sensor data collection device 720, for example via an IEEE 802.11 wireless local area network. In other embodiments, sensor data may be stored locally in sensor 150 and transferred or collected from sensors 150 to the sensor data collection device 720 and / or to the monitoring server 740.

[0045]

[0036] Further, sensors 150 may optionally be locally powered by battery or direct- attached solar array in case required or may be powered via connection to a power distribution network, or may not require power or otherwise self-powered.

[0046]

[0037] During operation, output values from sensors 150 are received by the sensor data collection device 720 and transmitted to the monitoring server 740 for storage in the database 750 and for analytics and further processing by the monitoring server 740.

[0047]

[0038] In figure 7, the steel wire rope monitoring system 710 is used for measuring the stress 760, the temperature 770 and the vibration 780 profiles of the steel wire rope 100.

[0048]

[0039] Figure 8 is an illustrative method 800 of monitoring a steel wire rope in accordance with the invention. Such method 800 is performed by using a monitoring system 710 as shown in figure 7. The steel wire rope includes at least one sensor configured to provide a physical parameter of the steel wire rope.

[0049]

[0040] The method starts by an activation step 810 during which an activation signal, is sent from the monitoring server 740 to the sensor data collection device 720 to activate it for the data receival and collection, said signal being then sent to the sensors 150, to initiate the collection of the data for a defined time period.

[0050]

[0041] Second step is a data collection step 820 during which the data collection device 720 receives the data sent by the sensors 150 and relay them to the monitoring server 740.

[0051]

[0042] Third step is a conversion step 830 during which the monitoring server 740 conduct an analysis of the collected and relayed signals from the data collection device 720. In this analysis step 830, the monitoring server 740 transforms the sensor signals into each physical parameter which is monitored.

[0052]

[0043] Then, an ordering step 840 takes place during which each physical parameters value is arranged in an ascending order to identify its minimum and maximum value during the time period.

[0044] Then, an analysis step 850 takes place during which a comparison between such minimum and maximum values and reference parameter values stored in the database 750 and that can, for example, be associated with different operational conditions such as during rain, storm or harsh environment. If the parameter values analyzed during the step 850 are within the authorized limits of predetermined threshold values for the given parameter, then the parameter values can simply be recorded in the database 750 for the future monitoring.

[0053]

[0045] On the contrary, a warning step 860 is launched if the parameter values are outside the authorized limits of predetermined threshold value of the respective physical parameter of the database 750. The monitoring system 710 can be warned about the parameter value that is outside the predetermined threshold values and the position from which it is measured on the steel wire rope. Thereafter the monitoring system 710 can raise an alarm and alert an operator about the wear-inducing effect or the flaw in the operation of the steel wire rope.

Claims

CLAIMS1 . A steel wire rope (100, 200, 300, 400) comprising:- a core steel wire (110, 210, 310, 410),- a plurality of steel wires (140, 240, 340, 440) wound around the core steel wire (110, 210, 310, 410) in a plurality of layers,- at least one sensor (150, 250, 350, 450) comprising a tube (170, 270, 370, 470) which contains at least one optical fiber (160, 260, 360, 460), said sensor being configured to provide measurements of at least one physical parameter of said steel wire rope.

2. A steel wire rope (100, 200, 300, 400) according to claim 1 , wherein a sensor (150, 250, 350, 450) may comprise any one or more sensors from loose tube sensor, tight buffer sensor, combined sensor.

3. A steel wire rope (100, 200, 300, 400) according to claims 1 or 2, wherein a sensor (150, 250, 350, 450) may be placed instead of any steel wire (140, 240, 340, 440), and / or in central core steel wire (110, 210, 310, 410) and / or in the valleys between the steel wires (140, 240, 340, 440).

4. A steel wire rope (100, 200, 300, 400) according to claim 1 , wherein the tube (170, 270, 370, 470) of sensor (150, 250, 350, 450) is made from any metallic or non-metallic materials.

5. A steel wire rope (100, 200, 300, 400) according to claim 1 , wherein the optical fiber (160, 260, 360, 460) can be any one from Rayleigh Fibre, Bragg Fibre, Brillouin fibre or Raman Fibre.

6. A steel wire rope (100, 200, 300, 400) according to claim 3, wherein said valleys between the steel wires (140, 240, 340, 440) can be either an inner valley (610) or an outer valley (620).

7. A steel wire rope monitoring system (710) comprising:- a sensor data collection device (720) configured to collect measurements of at least one physical parameter of a steel wire rope according to any of claims 1 to 6,- a monitoring server (740) wherein the monitoring server (740) includes a database (750).

8. The steel wire rope monitoring system (710) according to claim 7, wherein the sensors (150, 250, 350, 450) are in wireless communication with sensor data collection device (720).

9. A method of monitoring a steel wire rope (100, 200, 300, 400) according to anyone of claims 1 to 6, using a steel wire rope monitoring system (710) according to claims 7 or 8, and comprising the following successive steps:- an activation step (810) during which an activation signal is sent from the monitoring server (740) to the sensor data collection device (720) to activate it for the data receival and collection, said signal being then sent to the sensors (150), to initiate the collection of data for a defined time period,- a data collection step (820) during which the data collection device (720) receives the data sent by the sensors (150) and relay them to the monitoring server (740),- a conversion step (830) during which the monitoring server (740) conducts an analysis of the collected and relayed signals from the data collection device (720) and transforms the sensor signals into physical parameters values,- an ordering step (840), during which each physical parameter value is arranged in an ascending order to identify its minimum and maximal value during said time period,- an analysis step (850) during which a comparison between such minimum and maximum values and reference parameter values stored in the database (750),- a warning step (860) being launched if said minimum and / or maximum values are outside authorized limits of predetermined threshold values of the respective physical parameter stored in the database (750).

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