A measuring device for measuring axial displacement.

Abstract

This utility model discloses a measuring device for measuring axial displacement, belonging to the technical field of measuring devices. It includes a measuring surface located on a rotating component and a support system mounted on a stationary component. The support system is equipped with a displacement signal collection and processing system, which corresponds to the measuring surface. This device can reflect the internal dynamics of the rotating component in real time, verify the accuracy and stability of axial displacement measurement, and provide data support for fault early warning.

Description

Technical Field

[0001] This utility model relates to a measuring device for measuring axial displacement, belonging to the technical field of measuring devices. Background Technology

[0002] Axial displacement, as a crucial parameter describing the relative position between the axial thrust ring flange and the thrust bearing of rotating machinery, is primarily significant for eliminating friction between the rotor and stator and preventing serious malfunctions such as axial thrust bearing failure. In industrial practice, real-time monitoring is typically employed to simultaneously assess bearing wear and shaft alignment, providing data support for maintenance. Therefore, for a large rotating machine, axial displacement is one of the most important measurement parameters.

[0003] Currently, commonly used shaft axial displacement measurement equipment and conventional testing methods in the industry generally suffer from insufficient adaptability to operating conditions and limited monitoring performance. They cannot be directly applied to high-precision, high-reliability shaft monitoring scenarios in high-end rotating devices, such as reactor coolant pumps in nuclear power plants. These general-purpose monitoring devices and control systems have significant shortcomings in environmental tolerance thresholds and anti-interference capabilities, making them unable to withstand the combined impact of multiple extreme and complex operating conditions. They cannot stably adapt to harsh operating conditions such as high-intensity radiation, strong electromagnetic interference, high-amplitude vibration with a peak-to-peak value of 75μm, high-temperature environments over a wide range of 15~60℃, and extreme humidity of up to 100%. At the same time, traditional axial displacement monitoring technologies are rigid, have limited monitoring dimensions, and suffer from significant deficiencies in the real-time, continuous, and measurement accuracy of data acquisition. The monitoring data lacks fault tolerance and stability, making it difficult to achieve all-weather, high-precision, and routine dynamic control of shaft displacement parameters. This fails to meet the core technical requirements of real-time, continuous, and precise monitoring of shaft displacement in high-end industrial key rotating equipment.

[0004] Besides the shortcomings in adaptability to operating conditions, the bearing cavity of high-end precision high-speed rotating devices has extremely high internal structural precision. The axial support components and thrust structure have only a tiny assembly gap of 0.5~1.0mm, far lower than the structural gap standards of conventional industrial rotating equipment. This places stringent requirements on the measurement resolution, dynamic response rate, long-term operational stability, and accuracy of the supporting monitoring system, far exceeding industry norms. If the monitoring system's accuracy is substandard, or if there are blind spots in the monitoring coverage, it will be unable to accurately capture minute deformations and abnormal fluctuations in the axial displacement of the shaft system, and will be unable to provide timely warnings and adjustments. This can easily lead to serious equipment failures such as failure of the equipment's sealing structure, rotor jamming, and hard impacts on transmission components. Once such failures occur, they can directly cause unplanned equipment shutdowns, leakage of hazardous media, and other major operational accidents, resulting in irreversible structural damage to core equipment, generating systemic safety risks, and seriously affecting the safe, stable, and continuous operation of the entire industrial production system. Utility Model Content

[0005] The purpose of this invention is to provide a measuring device for measuring axial displacement, which can be used in complex working conditions and can accurately reflect the internal dynamics of rotating parts in real time, verify the accuracy and stability of axial displacement measurement, and provide data support for fault early warning.

[0006] The technical solution adopted in this utility model is as follows: A measuring device for measuring axial displacement includes a measuring surface located on a rotating component; and a support system disposed on a stationary component, wherein a displacement signal collection and processing system is provided on the support system, and the displacement signal collection and processing system corresponds to the measuring surface.

[0007] Alternatively, the displacement signal collection and processing system includes an eddy current displacement sensor and a signal processing unit connected together, wherein the eddy current displacement sensor contacts and senses the measurement surface.

[0008] Alternatively, the measuring surface may be magnetically conductive.

[0009] Alternatively, the measuring surface may be the end face of the rotating component; or, a plate may be provided on the end face of the rotating component by bolt fasteners, and the measuring surface may be provided by the end face of the plate; or, an electroplated layer may be provided on the end face of the rotating component, and the measuring surface may be the surface of the electroplated layer provided on the rotating component.

[0010] Alternatively, the support system may include at least one set, each set of support systems corresponding to one set of displacement signal collection and processing systems, and each set of displacement signal collection and processing systems may include at least two axial displacement probes, all of which are uniformly distributed circumferentially.

[0011] Alternatively, when the support system and displacement signal collection and processing system include two or more sets, each set of displacement signal collection and processing system is located at a different axial position.

[0012] Alternatively, the support system may include a first support assembly located in the middle of the shaft and / or a second support assembly located at the top; the measuring surface may be located on the coupling flange end face or the shaft end face.

[0013] Alternatively, the first support assembly includes two support rods extending axially, each of which has a radially arranged first support plate at its end, and at least one axial displacement probe is provided on the inner side of each first support plate.

[0014] Alternatively, the second support assembly includes a second support plate located in the middle of the inner side of the flywheel cover, and the middle of the second support plate is provided with at least two axial displacement probes.

[0015] Alternatively, a detection bolt is provided on the end face of the rotating shaft, the end face of the detection bolt is the measuring surface, and a washer is provided between the detection bolt and the end face of the rotating shaft.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are: 1. The measuring device for measuring axial displacement provided by this utility model can correct the adverse effects of assembly accuracy or abnormal operating conditions on the measurement, which is conducive to the accurate measurement and early warning monitoring of the axial displacement of the main pump rotating shaft. At the same time, it improves the measurement accuracy, control reliability and durability for working conditions such as nuclear industry radiation, high frequency electromagnetic field and high amplitude vibration, and meets the use requirements of complex working conditions in nuclear industry environment.

[0017] 2. The measuring device for measuring axial displacement provided by this utility model meets the needs of axial displacement measurement and control in the nuclear industry environment. It can be used for remote measurement and control of rotating shafts of various key rotating equipment. It not only improves the safety and convenience of close-range measurement and control, but also enables accurate measurement and effective control of axial displacement, thus maintaining the safe operation of main equipment in the nuclear industry and the safety of monitoring personnel. Attached Figure Description

[0018] Fig. 1 This is a schematic diagram of the measuring device located in the middle of the rotating shaft.

[0019] Fig. 2 This is a schematic diagram of the measuring device located at the top of the rotating shaft.

[0020] In the diagram, the markings are: 1-rotating component, 11-measuring surface, 12-plate, 13-detection bolt, 14-shaft, 15-coupling, 2-stationary component, 21-flywheel cover, 3-support system, 31-first support assembly, 311-support rod, 312-first support plate, 32-second support assembly, 321-second support plate, and 4-eddy current displacement sensor. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings.

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. It should be noted that, except for dependent embodiments, any embodiment exists independently, and its implementation or non-implementation does not affect the integrity of the remaining embodiments, nor does the implementation or non-implementation of dependent embodiments affect the integrity of the original embodiments.

[0023] A measuring device for measuring axial displacement, such as Figs. 1-2 As shown, it includes a measuring surface 11 located on the rotating component 1; it also includes a support system 3 provided on the stationary component 2, the support system 3 being provided with a displacement signal collection and processing system, the displacement signal collection and processing system corresponding to the measuring surface 11.

[0024] In this scheme, the measuring surface 11 provides a reference for measuring axial displacement. When the rotating shaft 14 undergoes axial displacement, the measuring surface 11 follows the displacement of the rotating shaft 14. The measuring surface 11 is a plane perpendicular to the axial direction. The measuring surface 11 is fixedly connected to or integrally formed with the rotating component 1, thereby enabling the displacement of the rotating shaft 14 to be obtained. The rotating component 1 can be the rotating shaft 14, or a component mounted on the rotating shaft 14 and rotating with the rotating shaft 14. The support system 3 is used to fix the displacement signal collection and processing system, placing it close to or against the measuring surface 11. When set on the stationary component 2, it can determine the relative axial displacement between the stationary component 2 and the rotating shaft 14. The displacement signal collection and processing system can detect the distance between itself and the measuring surface 11. It is located on or near the axis of the rotating component 1, reducing the deviation of the measuring surface from the horizontal direction caused by alignment problems of the rotating shaft 14 shaft system, or reducing the deviation of the measuring surface from the horizontal direction caused by abnormal working conditions during shaft rotation. When the rotating component 1 of the main pump of the nuclear power plant experiences axial fluctuations due to operating disturbances, the distance between the measuring surface 11 and the probe changes, thereby enabling the detection of axial displacement. Specifically, the stationary component 2 can be any available component located on the outer periphery of the rotating shaft 14 in the main pump.

[0025] In another specific implementation, the displacement signal collection and processing system includes an eddy current displacement sensor 4 and a signal processing unit connected together. The eddy current displacement sensor 4 contacts the measuring surface 11 and senses it.

[0026] The measuring surface 11 fluctuates due to assembly precision issues or operational disturbances. The current in the induction coil inside the displacement sensor generates eddy currents on the measuring surface 11, producing a magnetic field opposite to the displacement sensor's magnetic field through electromagnetic effects, thus increasing the coil's impedance. The operating signal is formed based on the eddy current effect between the high-frequency alternating magnetic field and the measured conductor. The eddy current displacement sensor 4 must be a radiation-resistant model. The signal processing unit includes, in sequence, the displacement sensor, an extension cable, and a preamplifier. To adapt to nuclear power plant conditions, shielded cables are used for signal transmission, providing strong resistance to external electromagnetic interference. Even in the complex electromagnetic radiation environment of a nuclear power plant, it can stably output displacement signals without signal distortion or false triggering.

[0027] In another specific implementation, the measuring surface 11 is magnetically permeable. Specifically, the sensor operates by inducing eddy currents through an alternating magnetic field, and the reverse magnetic field changes the coil impedance, with displacement corresponding to impedance changes. The magnetically permeable measuring surface 11 can reduce magnetic interference and enhance the eddy current signal strength, thereby improving sensitivity and linearity. Furthermore, the permeability variation law of magnetically permeable materials is known, allowing for pre-calibration to compensate for irradiation-induced changes in magnetic properties. In contrast, the conductivity of non-magnetically permeable materials decreases significantly with irradiation, and the change is nonlinear, making accurate compensation difficult and leading to increased measurement errors.

[0028] In another specific embodiment, the measuring surface 11 is the end face of the rotating component 1; or, a plate 12 is provided on the end face of the rotating component 1 by bolt fasteners, and the measuring surface 11 is provided by the end face of the plate 12; or, an electroplated layer is provided on the end face of the rotating component 1, and the measuring surface 11 is the surface of the electroplated layer provided on the rotating component 1. When the rotating component 1 itself has magnetic properties, the end face of the rotating component 1 itself is used as the measuring surface 11. If the rotating component 1 does not have magnetic properties, a weakly magnetic electroplated or fitted outer layer is provided on the measuring surface 11.

[0029] Furthermore, the measuring surface 11 has weak magnetic permeability. When the alternating magnetic field generated by the probe coil acts on this type of material, the interior of the material is rapidly magnetized, and a large number of magnetic field lines are constrained near the material surface to form a closed magnetic circuit. This, in turn, weakens the effective magnetic field component that passes through the material and generates eddy currents. The magnetic effect partially cancels out the eddy current effect, resulting in a significant reduction in the intensity of the induced eddy currents and a decrease in the sensitivity of the probe impedance to displacement. At the same time, the magnetization process of strongly magnetic materials is nonlinear, requiring a smaller measurement range to ensure accuracy. In this scheme, if the measuring surface 11 has strong magnetic permeability, a weakly magnetic electroplated or fitted outer layer can also be set on the measuring surface 11. Specifically, the weak magnetic permeability requires a maximum relative permeability μmax ≤ 500 and an initial permeability μi ≤ 200.

[0030] In another specific implementation, the support system 3 includes at least one set, each set of support systems 3 corresponding to one set of displacement signal collection and processing systems, and each set of displacement signal collection and processing systems includes at least two axial displacement probes, all of which are uniformly distributed circumferentially. To avoid the alignment of the main pump rotating shaft being affected by assembly accuracy or operating conditions, all axial displacement probes are uniformly distributed around the rotating shaft 360°. Even if the rotating shaft has an alignment problem, multiple axial displacement probes collect multiple axial displacement signals Si (i=1, 2, 3…n), transmit them to the programmable logic controller, extract the maximum values ​​Smax and Smin, and then input them into the in-phase summator for summation S=1 / 2*(Smax+Smin), thus obtaining the final axial displacement value. It can also determine whether the rotating shaft is tilted and measure the degree of tilt. Axial displacement probes with high rigidity and non-contact measurement characteristics are selected to adapt to high-amplitude vibration conditions, preventing probe damage or measurement drift due to mechanical collisions or frequent vibrations. The measurement stability is not significantly affected by the peak-to-peak vibration amplitude, making it suitable for the harsh and complex operating conditions in the nuclear power field.

[0031] In another specific implementation, when the support system 3 and the displacement signal collection and processing system comprise two or more sets, each set of the displacement signal collection and processing system is located at a different axial position. Each set of support system 3 is used to support one set of displacement signal collection and processing systems. By positioning the displacement signal collection and processing systems close to the measurement surface 11, errors caused by single-set measurements can be prevented.

[0032] In another specific embodiment, the support system 3 includes a first support assembly 31 located in the middle of the shaft 14 and / or a second support assembly 32 located at the top; the measuring surface 11 is located on the flange end face of the coupling 15 or the end face of the shaft 14. The first support assembly 31 is mounted on the key pressure-bearing components of the main pump to detect axial displacement of the end face of the coupling 15 in the middle of the shaft 14, thus determining the relative axial positional relationship between the axial thrust ring flange and the thrust bearing. The measuring system of the second support assembly 32 is mounted on the flywheel cover to detect axial displacement of the top of the shaft 14. The top plane has a smaller radius around the axis and is far from the high-temperature environment inside the shaft, therefore it is less affected by assembly precision and abnormal operating conditions, resulting in better measurement accuracy.

[0033] In another specific embodiment, the first support assembly 31 includes two support rods 311 mounted on the stationary component 2 and extending axially. Each support rod 311 has a radially arranged first support plate 312 at its end. At least one axial displacement probe is disposed on the inner side of each first support plate 312. The support rods 311 bring the axial displacement probe closer to the measuring surface 11 axially, while the first support plates 312 bring the axial displacement probe closer to the inner side axially. This reduces the radius of the measuring point on the measuring surface around the axis of rotation, reducing the deviation of the measuring surface from the horizontal direction due to alignment issues in the shaft system 14, or reducing the deviation of the measuring surface from the horizontal direction due to abnormal operating conditions encountered during shaft rotation.

[0034] In another specific embodiment, the second support assembly 32 includes a second support plate 321 located in the middle of the inner side of the flywheel cover 21, and at least two axial displacement probes are provided in the middle of the second support plate 321. Compared with the previous embodiment, this solution does not need to avoid the rotating shaft 14. Therefore, by setting the second support plate 321, the axial displacement probes can be directly set near the axis.

[0035] In another specific embodiment, a detection bolt 13 is provided on the end face of the rotating shaft 14, the end face of the detection bolt 13 being the measuring surface 11, and a washer is provided between the detection bolt 13 and the end face of the rotating shaft 14. Considering that a lifting screw hole is provided at the end of the pump shaft 14, in order to improve the detection sensitivity of axial displacement, a detection bolt 13 is provided on the screw hole at the center of the end of the main pump shaft 14, and an additional detection plane is provided through the end face of the detection bolt 13.

[0036] In another specific implementation, the surface roughness of the measuring surface 11 is Ra0.4-1.6 μm. During eddy current testing, the rough surface texture is equivalent to multiple defects causing eddy current truncation, generating a bottom wave interference signal. Furthermore, the rough surface affects the impedance of the coil. The range specified in this solution can increase the intensity of the eddy currents on the measuring surface 11, thereby improving the measurement accuracy. Moreover, since the indicating instrument has a certain filtering or averaging effect, it can partially offset the error caused by roughness. Therefore, the surface roughness requirement is slightly relaxed, facilitating practical control.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are: (1) The displacement signal collection and processing system of this utility model can simultaneously realize real-time measurement and monitoring of axial displacement at multiple locations. This utility model can collect information on multiple axial displacement changes at the middle and end of the rotating part 1 through a measurement system component consisting of multiple eddy current displacement sensors 4, extension cables, and signal processing units, and convert it into voltage signals through the measurement system. At the same time, to avoid misalignment of the rotating part 1 during assembly, multiple sets of axial displacement probes are set around the axis of the rotating part 1 at the same location in the middle or top of the rotating part 1. A programmable logic controller and a co-directional adder are set at the rear end of each preamplifier to process the data from the two sets of measurement systems, thereby eliminating the error caused by the tilt of the measuring surface 11. Therefore, the axial displacement measurement principle of this utility model is simple, and the manufacturing and assembly of each part of the measurement and control system are simple and convenient, without special requirements. It can be modified and copied according to different sizes and has wide applicability.

[0038] (2) The automated axial displacement measuring device provided by this utility model can remotely complete data acquisition, reducing the difficulty of manual measurement. For measuring equipment in nuclear power plants, remote measurement can also significantly reduce the risk of personnel exposure to radiation. Through the accumulation of multiple displacement data, the wear trend of equipment can be analyzed to achieve predictive maintenance. For example, in reactor coolant pumps, small changes in axial displacement may indicate bearing wear or defects. Finding the cause and replacing the bearing can avoid product quality problems.

[0039] (3) The device of this utility model is compactly installed and integrates two functional modules: precise measurement and comparative analysis of the eddy current displacement sensor 4. It has high operational reliability, high measurement accuracy, precise axial displacement control, and good impact resistance. After the assembly of each part of the device of this utility model, the overall size is compact and concentrated in a small space. Since the measurement and control system of this utility model incorporates multiple features such as vibration resistance, radiation resistance, and explosion protection in its structural design and material selection, the long-term reliability of the system is greatly improved. In addition, the measurement and control system uses a high-precision eddy current displacement sensor 4 and a signal processing unit to perform axial signal conversion, which ensures measurement accuracy and control accuracy.

[0040] (4) This utility model has a convenient manufacturing, installation, debugging, disassembly and maintenance process. The eddy current displacement sensors 4 are independent of each other and do not interfere with each other. Each component can be installed, wired, calibrated and replaced independently. It has obvious convenience in the installation, disassembly, maintenance and debugging process. This is because the number of components is small, the shape of each part is regular, the material source is wide, the dimensional accuracy requirement is low, and it is easy to process and manufacture. Among them, the measuring system in the middle of the rotating part 1 is installed on the key component of the main pump to detect the axial displacement of the flange end face of the coupling 15 in the middle of the rotating part 1. The measuring system at the top of the rotating part 1 is installed on the second support plate 321 in the middle of the inner side of the flywheel cover 21 to detect the axial displacement of the top of the rotating part 1. The components of the measuring system and its support system 3 are connected by welding and a few threads, which not only has good rigidity and ensures the reliability of measurement and control under high frequency vibration conditions, but also facilitates disassembly and replacement of parts. Moreover, the axial displacement measurement and control system and the nuclear power plant system are connected by quick connectors, which facilitates quick isolation for maintenance.

[0041] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. The present utility model extends to any new features or combinations disclosed in this specification, and any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model. It is obvious to those skilled in the art that the present utility model is not limited to the details of the above exemplary embodiments, and that detailed technical features not disclosed in this embodiment, such as specific structures, are all prior art and can be obtained by those skilled in the art from the prior art; the connection method can be a fixed connection, a detachable connection, or an integral part; it can be a fixed connection, a movable connection, or a hinged connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific manner of the above terms in the embodiments of the present utility model according to the specific circumstances, and the present disclosure does not specifically limit this aspect.

Claims

1. A measuring device for measuring axial displacement, characterized in that: It includes a measuring surface located on a rotating component; it also includes a support system provided on a stationary component, wherein a displacement signal collection and processing system is provided on the support system, and the displacement signal collection and processing system corresponds to the measuring surface.

2. The measuring device as described in claim 1, characterized in that: The displacement signal collection and processing system includes an eddy current displacement sensor and a signal processing unit connected together. The eddy current displacement sensor contacts the measurement surface and senses it.

3. The measuring device as described in claim 1, characterized in that: The measuring surface is magnetically conductive.

4. The measuring device as described in claim 1, characterized in that: The measuring surface is the end face of the rotating component; or, a plate is provided on the end face of the rotating component by bolt fasteners, and the measuring surface is provided by the end face of the plate; or, an electroplated layer is provided on the end face of the rotating component, and the measuring surface is the surface of the electroplated layer provided on the rotating component.

5. The measuring device as described in claim 1, characterized in that: The support system includes at least one set, each set of support systems corresponds to one set of displacement signal collection and processing systems, and each set of displacement signal collection and processing systems includes at least two axial displacement probes, all of which are evenly distributed circumferentially.

6. The measuring device as described in claim 5, characterized in that: When the support system and displacement signal collection and processing system include two or more sets, each set of displacement signal collection and processing system is located at a different axial position.

7. The measuring device as described in claim 6, characterized in that: The support system includes a first support component located in the middle of the shaft and / or a second support component located at the top; the measuring surface is located on the coupling flange end face or the shaft end face.

8. The measuring device as described in claim 7, characterized in that: The first support assembly includes two support rods extending axially, each of which has a radially arranged first support plate at its end, and at least one axial displacement probe is provided on the inner side of each first support plate.

9. The measuring device as described in claim 7, characterized in that: The second support assembly includes a second support plate located in the middle of the inner side of the flywheel cover, and at least two axial displacement probes are provided in the middle of the second support plate.

10. The measuring device as described in claim 7, characterized in that: A detection bolt is provided on the end face of the rotating shaft, the end face of the detection bolt is the measuring surface, and a washer is provided between the detection bolt and the end face of the rotating shaft.

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