A method and system for early warning suitable for large reel shafting structure

Abstract

This invention discloses an early warning method applicable to large drum shaft systems. It includes arranging high-precision measuring sensitive units on the shaft system to collect physical information about the torsional deformation and torque experienced during drum shaft rotation. This physical information is transmitted as an electrical signal to a signal conversion and transmission unit, which converts the electrical signal into a digital signal. This digital signal is then transmitted to a digital signal receiver via an induction coil. The digital signal receiver not only receives the digital signal but also engages in induced energy coupling with the induction coil. Electrical energy can be transmitted through the digital signal receiver and received by the induction coil, thereby powering the high-precision measuring sensitive units and ensuring their normal operation. The digital signal receiver transmits the digital signal to a signal processing unit, which processes it into an analog current signal and sends it to an early warning unit. The early warning unit determines whether an alarm is triggered and issues an early warning. Beneficial effects: High monitoring accuracy, wide coverage, and improved safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of drum shaft systems, and in particular to an early warning method and system applicable to large drum shaft system structures. Background Technology

[0002] The large drum shaft system consists of drums, drum shafts, reversing gearboxes, and large couplings. The drum shafts are fixedly connected to the drums and reversing gearboxes via large couplings, forming a closed shaft system. Because all drums are connected by the drum shafts to form a closed structure, this large drum shaft system can ensure synchronous rotation of the shafts as much as possible, making the movements of all drums consistent.

[0003] However, due to factors such as transmission errors in the reversing gearbox and uneven stress distribution between different drums, the movement of various components in this large drum shaft system inevitably becomes asynchronous, resulting in a slight circumferential positional difference. At this point, the torsional deformation of the drum shafts connecting each drum compensates for the slight circumferential positional difference caused by the asynchrony, preventing relative rotation between the drums and maintaining synchronous operation of the entire large drum shaft system. During this process, the inherent rigidity of the drum shaft counteracts the torsional deformation and the torque difference generated by the deformation. Therefore, it is essential to monitor the condition of the drum shafts within the system, monitoring the internal torque and torsional deformation in real time to prevent the risk of plastic deformation due to overload. This necessitates the development of an early warning system suitable for the drum shaft system structure. The current technology for monitoring the condition of large drum shaft system structures is offline testing, which has the following shortcomings: (1) Manual measurement is required during testing. Inconsistencies in personnel, equipment, and testing methods during measurement will cause systematic errors. In addition, manual testing is not accurate and has a long cycle, which affects the accuracy of test results and the normal operation of the drum shaft system structure.

[0004] (2) It cannot monitor the torque changes and structural deformation inside the drum shaft in the drum shaft system in real time, and cannot perform in-depth analysis of the test results, which is not conducive to the safe and reliable operation of the drum shaft system structure.

[0005] (3) Incomplete test coverage and low reliability. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the problems existing in the above and / or existing monitoring methods, the present invention is proposed.

[0008] Therefore, the problem to be solved by this invention is how to address the shortcomings of existing monitoring methods, such as incomplete coverage and low safety and reliability.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a warning method applicable to large drum shaft systems, comprising,

[0010] A high-precision measuring sensitive unit is arranged on the shaft system to collect physical information on the torsional deformation and torque generated when the drum shaft rotates. The physical information is transmitted to the signal conversion and transmission unit in the form of an electrical signal to convert the electrical signal into a digital signal, and then transmitted to the digital signal receiver through the induction coil.

[0011] The digital signal receiver can not only receive digital signals, but also exchange induced electrical energy with the induction coil. The electrical energy can be transmitted through the digital signal receiver and received by the induction coil, thereby powering the high-precision measurement sensitive unit and ensuring its normal operation.

[0012] The digital signal receiver transmits the received digital signal to the signal processing unit, which processes the digital signal into an analog current signal and sends it to the early warning unit.

[0013] The early warning unit determines whether to issue an early warning by comparing data.

[0014] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the high-precision measurement sensitive unit includes a stress-strain sensor and a signal amplifier.

[0015] The signal conversion and transmission unit includes a pulse code modulation module, an induction coil, and a digital signal receiver.

[0016] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the modulation and demodulation module can modulate and demodulate digital signals into the required 4-20mA current analog signal.

[0017] Current isolation module: can provide anti-interference protection for analog current signals.

[0018] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the early warning unit includes a PLC system and an industrial control computer.

[0019] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the PLC system includes: constructing a three-dimensional structural characterization model based on the dimensional parameters of the short drum shaft, long drum shaft, reversing gearbox shaft head, and drum shaft head; then using CAE technology, based on the three-dimensional structural model, performing simulation analysis and stress simulation to determine the structural material stress and deformation under certain stress conditions; by comparing the material stress and structural deformation under different stress conditions with the allowable limit stress and deformation values ​​of the material, the stress conditions under the allowable limit stress and deformation values ​​of the material can be deduced, i.e., the safety limit of the large drum shaft system structure; and this safety limit is directly or multiplied by a certain safety factor as the early warning limit value of the drum shaft system.

[0020] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the comparison method includes:

[0021] The obtained physical information is calculated, and the calculated torque is compared with 400kNm. If it is less than 400kNm, the output is normal. If it is greater than 400kNm, the self-test system is activated to check for calculation errors or information loss during signal transmission. If no errors occur, an early warning is issued. If errors occur, the above steps are repeated to calculate a new torque value and compare it with 400kNm. If the new value is greater than 400kNm, an early warning is issued. If the new value is less than 400kNm, the output is normal.

[0022] As a preferred embodiment of the early warning method applicable to large drum shaft systems described in this invention, the calculation of the obtained physical information includes:

[0023] When the torque generated at the measuring point is opposite to the torque generated by the axial force, the torque calculation formula is:

[0024]

[0025] Where F 测 The force at the measuring point is given by m, the module by z, the number of teeth by x, the distance from the measuring point to the point of force application by s, the distance from the measuring point to the farthest shaft end by β, and the helix angle by α. n It is the normal pressure angle;

[0026] When the torque generated at the measuring point is the same as the torque generated by the axial force, the torque calculation formula is:

[0027]

[0028] Where F 测 The force at the measuring point is given by m, the module by z, the number of teeth by x, the distance from the measuring point to the point of force application by s, the distance from the measuring point to the farthest shaft end by β, and the helix angle by α. nThis is the normal pressure angle.

[0029] In view of the problems existing in the current monitoring methods, the present invention is proposed. Therefore, the problem to be solved by the present invention is how to solve the problems of incomplete coverage and low safety and reliability of the current monitoring methods.

[0030] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a warning system suitable for large drum shaft systems, comprising,

[0031] Measurement Sensing Unit: Physical information is acquired through a stress-strain sensor, and the electrical signal is amplified through a signal amplifier;

[0032] Signal conversion and transmission unit: converts electrical signals into digital signals and transmits them to the digital signal receiver via an induction coil;

[0033] Signal processing unit: Converts digital signals into analog current signals through a modulation / demodulation module and a current isolation module;

[0034] Early warning unit: Calculates the obtained physical information and determines whether to issue an early warning.

[0035] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the method described above.

[0036] A computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the method described above.

[0037] The beneficial effects of this invention are:

[0038] 1. The early warning system for large drum shaft system structures constructed in this invention has many advantages over existing common monitoring methods such as current collector ring, transformer coupling, or radio frequency measurement during the condition monitoring stage. These advantages include no background noise, simple implementation, low manufacturing process requirements, tolerance to vibration and friction collisions, and no damage to existing drum shaft system structures.

[0039] 2. This invention has high testing accuracy, with strain sensor resolution up to 0.2με and overall measurement accuracy of 1.25%FS. It also has no time lag. Combined with the early warning limit obtained by accurate simulation calculation, it can monitor the health status of the drum shaft system in real time and issue early warnings in possible dangerous working conditions, ensuring safe use and guiding the operation of the overall mechanical system based on the drum shaft system. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0041] Figure 1 This is a flowchart of an early warning method applicable to large drum shaft systems in Example 1;

[0042] Figure 2 This is a system structure diagram of an early warning method applicable to large drum shaft systems in Example 1. Detailed Implementation

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0045] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0046] Example 1

[0047] Reference Figure 1 and Figure 2 This is the first embodiment of the present invention, which provides an early warning method suitable for large drum shaft systems. The method includes first measuring the inherent torque within the drum shaft system, and then monitoring the state of the drum shaft system online.

[0048] Because large-scale drum shaft systems have a large volume (diameter reaching hundreds of millimeters and lengths reaching several meters), their mechanical rigidity is good, and their self-deformation under operating conditions is relatively small (≤100με micro-strain), requiring high accuracy in torque measurement. Furthermore, since the drum shaft rotates during operation, data transmission for measurement must be wireless. Therefore, torque measurement of drum shaft systems requires small strain, high accuracy, and high stability, with stringent requirements for temperature and time drift.

[0049] To address the aforementioned requirements for measuring the inherent torque of the drum shaft system, an online monitoring system for the condition of the drum shaft system has been invented.

[0050] Each drum shaft is equipped with a monitoring point and a stress-strain sensor. When torque exists inside the drum shaft, the torque causes the drum shaft to undergo minute torsional deformation. The sensor captures the minute torque strain of the drum shaft and outputs a differential micro-voltage signal corresponding to the minute strain.

[0051] The differential micro-voltage signal is input to the signal amplification and PCM (Pulse Code Modulation) module for amplification and analog-to-digital conversion to obtain a digital signal containing the measured torque information. A set of induction coils is fixed around the circumference of the drum shaft, and the digital signal is transmitted wirelessly through these induction coils.

[0052] A wireless pickup sensor is fixedly installed near the induction coil on the drum shaft to receive the digital signal containing torque measurement emitted by the induction coil. At the same time, induced electrical energy is coupled and exchanged between the wireless pickup sensor and the induction coil. That is, electrical energy can be transmitted through the wireless pickup sensor and received by the induction coil, thereby powering the stress-strain sensor and ensuring its normal operation.

[0053] A modem module is connected after the wireless pickup sensor to modulate the digital signal received by the sensor into the required 4-20mA analog current signal. This conversion to an analog current signal is chosen because current signals are less affected by interference, making them suitable for long-distance transmission and fitting the large spatial structure of large drum shaft systems. The current signal output from the modem module is transmitted via cable to a current isolation module, which provides anti-interference protection. It is then output to a PLC early warning acquisition system. The PLC system performs analog-to-digital conversion on the received current signal, and the resulting digital data is processed using algorithms to obtain the final torque data.

[0054] The overall drum shaft system online monitoring system has a detection accuracy of up to 1.25%FS, a resolution of 0.2με, a sampling frequency of 1kHz, and a measurement range of -100με to 100με.

[0055] Once the inherent torque in the drum shaft system is accurately measured, the foundation for constructing an early warning system suitable for large drum shaft systems is obtained. To construct such an early warning system, the early warning limits for the drum shaft system need to be confirmed.

[0056] Example 2

[0057] The second embodiment of the present invention differs from the first embodiment in that it further includes, to verify and illustrate the technical effects employed in this method, demonstrating the process of determining the warning limit, including:

[0058] In a large drum shaft system, the main components are the short drum shaft, the long drum shaft, the reversing gearbox shaft end, and the drum shaft end. The primary warning points are also these four structural elements. Using Solidworks Simulation software, stress-deformation simulation analyses were performed on each component. The simulation conditions were that one end of the shaft was fixed, and different torques were applied to the other end. Since the standard model couplings used in the large drum shaft system have a safe torque capacity of 400 kNm for their laminated flexible couplings, a torque value of 400 kNm was selected for simulating each shaft section and shaft end to verify whether the entire drum shaft system can operate safely under this torque. If so, this 400 kNm can be determined as the warning limit.

[0059] The short drum shaft is 2848mm long and made of Q345B steel with the following material properties: yield strength 345MPa, tensile strength 470MPa, and shear strength calculated at 60% of the yield strength, which is 207MPa. Under an applied torque of 400kN·m, simulation analysis shows that the maximum shear stress on the shaft is 25.71MPa, and the maximum total displacement of the entire shaft is 0.5451mm.

[0060] The long drum shaft is 4848mm long and made of Q345B steel with the following material properties: yield strength 345MPa, tensile strength 470MPa, and shear strength calculated as 60% of the yield strength, which is 207MPa. Under an applied torque of 400kN·m, simulation analysis shows that the maximum shear stress on the shaft is 53.87MPa, and the maximum total displacement of the entire shaft is 2.070mm.

[0061] The shaft head material for the reversing gearbox is 34CrNi3Mo, with the following material properties: yield strength 685 MPa, tensile strength 805 MPa, and shear strength calculated at 60% of the yield strength, which is 411 MPa. Under an applied torque of 400 kN·m, simulation analysis shows that the maximum shear stress on the shaft is 260.2 MPa, and the maximum total displacement of the entire shaft head is 0.9489 mm.

[0062] The material selected for the drum shaft head is 34CrNi3Mo, with the following material properties: yield strength 685 MPa, tensile strength 805 MPa, and shear strength calculated as 60% of the yield strength, which is 411 MPa. Under an applied torque of 400 kN·m, simulation analysis shows that the maximum shear stress on the shaft is 394.5 MPa, and the maximum total displacement of the entire shaft head is 0.3076 mm.

[0063] Based on the simulation results above, the following conclusions can be drawn:

[0064] (1) When the applied torque is 400 kN·m, the maximum shear stress on the short drum shaft (2848 mm in length) is 25.71 MPa, and the maximum shear stress on the long drum shaft (4848 mm in length) is 53.87 MPa. Both the short and long synchronous shafts are made of Q345B steel, which has a shear strength of 207 MPa. According to the simulation results, when both are subjected to a torque of 400 kN·m, their static strength fully meets the requirements for use.

[0065] (2) When the applied torque is 400 kN·m, the maximum shear stress on the reversing gearbox shaft head is 260.2 MPa, and the maximum shear stress on the drum shaft head is 394.5 MPa. Both the reversing gearbox shaft head and the drum shaft head are made of 34CrNi3Mo material, which has a shear strength of 411 MPa. According to the simulation results, when both are subjected to a torque of 400 kN·m, their static strength fully meets the usage requirements.

[0066] (3) When a torque of 400 kN·m is applied, stress concentration will occur at the notch of the drum shaft due to its structure. At this time, the stress is 394.5 MPa, which is close to the shear strength limit of 411 MPa.

[0067] Therefore, based on the simulation results and conclusions, and considering the rated parameter that the standard model coupling used in the large drum shaft system can withstand a safe torque of 400kNm, the warning limit of the drum shaft system is set at 400kNm to fully ensure the safety and stability of the entire drum shaft system during operation. This value can be substituted into the warning system constructed in this patent.

[0068] Example 3

[0069] One embodiment of the present invention differs from the previous two embodiments in that: if the function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0070] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0071] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0072] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0073] Example 4

[0074] The fourth embodiment of the present invention differs from the previous three embodiments in that: a warning method and system applicable to large drum shaft systems includes, in order to verify and explain the technical effect of the method, a comparative test is conducted between the traditional technical solution and the present invention, and the test results are compared by means of scientific demonstration to verify the real effect of the method.

[0075] The following table compares the method for monitoring the condition of large drum shaft systems using manual measurement data with the method of this invention:

[0076] Table 1 Comparison between manual measurement methods and the method of the present invention

[0077]

[0078]

[0079] As can be seen from the comparison in the table above, the method of the present invention reduces measurement error and improves measurement accuracy by adopting a systematic measurement approach. Furthermore, the system monitors the deformation and stress of the shaft in real time, shortening the time from the occurrence of a problem to the start of an early warning, and improving the safety of the operation.

[0080] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A warning method applicable to large drum shaft systems, characterized in that: include, A high-precision measuring sensitive unit is arranged on the shaft system to collect physical information on the torsional deformation and torque generated when the drum shaft rotates. The physical information is transmitted to the signal conversion and transmission unit in the form of an electrical signal to convert the electrical signal into a digital signal, and then transmitted to the digital signal receiver through the induction coil. The digital signal receiver can not only receive digital signals, but also exchange induced electrical energy with the induction coil. The electrical energy can be transmitted through the digital signal receiver and received by the induction coil, thereby powering the high-precision measurement sensitive unit and ensuring its normal operation. The digital signal receiver transmits the received digital signal to the signal processing unit, which processes the digital signal into an analog current signal and sends it to the early warning unit. The early warning unit determines whether to issue an early warning by comparing data. The early warning unit includes a PLC system and an industrial control computer; The PLC system includes a three-dimensional model constructed based on the dimensional parameters of the short drum shaft, long drum shaft, reversing gearbox shaft head, and drum shaft head to form a structural characterization model. Then, CAE technology is used to perform simulation analysis and stress simulation based on the three-dimensional structural model to determine the stress and deformation of the structural materials under certain stress conditions. By comparing the material stress and structural deformation under different stress conditions with the allowable limit stress and deformation values ​​of the material, the stress conditions under the allowable limit stress and deformation values ​​of the material can be obtained, i.e., the safety limit of the large drum shaft system structure. This safety limit is then used directly or multiplied by a certain safety factor as the early warning limit value of the drum shaft system. The comparison method includes calculating the obtained physical information, comparing the calculated torque with 400kNm, and if it is less than 400kNm, outputting normally; if it is greater than 400kNm, activating the self-test system to detect whether there is a calculation error or information loss during signal transmission. If no error occurs, a warning is issued; if an error occurs, the above steps are repeated to calculate a new torque value and compare it with 400kNm. If the value is greater than 400kNm, a warning is issued; if it is less than 400kNm, outputting normally. The calculation of the obtained physical information includes... When the torque generated at the measuring point is opposite to the torque generated by the axial force, the torque calculation formula is: in Let m be the force at the measuring point, z be the module, z be the number of teeth, x be the distance from the measuring point to the point of force application, and s be the distance from the measuring point to the farthest shaft end. For the pitch circle helix angle, It is the normal pressure angle; When the torque generated at the measuring point is the same as the torque generated by the axial force, the torque calculation formula is: in Let m be the force at the measuring point, z be the module, z be the number of teeth, x be the distance from the measuring point to the point of force application, and s be the distance from the measuring point to the farthest shaft end. For the pitch circle helix angle, This is the normal pressure angle.

2. The early warning method applicable to large drum shaft systems as described in claim 1, characterized in that: The high-precision measurement sensing unit includes a stress-strain sensor and a signal amplifier; The signal conversion and transmission unit includes a pulse code modulation module, an induction coil, and a digital signal receiver.

3. A warning method applicable to large drum shaft systems as described in claim 1 or 2, characterized in that: The signal processing unit includes, Modulation / demodulation module: can modulate and demodulate digital signals into the required 4~20mA current analog signal; Current isolation module: can provide anti-interference protection for analog current signals.

4. A warning system suitable for large drum shaft systems, employing a warning method for large drum shaft systems as described in any one of claims 1 to 3, characterized in that, include, Measurement Sensing Unit: Physical information is acquired through a stress-strain sensor, and the electrical signal is amplified through a signal amplifier; Signal conversion and transmission unit: converts electrical signals into digital signals and transmits them to the digital signal receiver via an induction coil; Signal processing unit: Converts digital signals into analog current signals through a modulation / demodulation module and a current isolation module; Early warning unit: Calculates the obtained physical information and determines whether to issue an early warning.

5. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

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