Metering device for measuring rotating speed of liquid metal sliding bearing

Abstract

The utility model relates to the technical field of nondestructive testing, and discloses a metering device for measuring the rotating speed of a liquid metal sliding bearing, which comprises a driving motor, a shaft to be tested, the liquid metal sliding bearing, an acoustic emission sensor, a signal collector, a photoelectric rotating speed sensor and a monitoring computer, and is characterized in that the driving motor is in transmission fit with the shaft to be tested; a to-be-tested shaft is arranged on the liquid metal sliding bearing; the acoustic emission sensor is arranged on the outer side of the liquid metal sliding bearing; the signal collector is electrically connected with the acoustic emission sensor; the signal collector is electrically connected with the photoelectric rotating speed sensor; and the signal collector is electrically connected with the monitoring computer. The device has the effect of conveniently measuring and verifying the rotating speed of the liquid metal sliding bearing.

Description

Technical Field

[0001] This application relates to the field of nondestructive testing technology, and in particular to a measuring device for measuring the rotational speed of a liquid metal sliding bearing. Background Technology

[0002] As a critical support component in rotating machinery, the application scope of sliding bearings continues to expand with the development of industrial technology. To meet the demands of high-speed, high-reliability support in high-end equipment such as aerospace, high-speed motors, and precision machine tools, sliding bearings are evolving towards higher speeds and longer service life. However, under high-speed operating conditions, traditional oil-lubricated sliding bearings are prone to excessive temperature rise, accelerated wear, and even failure due to severe shear heat generation from the lubricant and insufficient heat dissipation capacity, which seriously restricts further performance improvements.

[0003] To overcome the aforementioned bottlenecks, novel sliding bearings using liquid metals (such as gallium-based alloys) as lubricating media have emerged in recent years. Liquid metals possess excellent thermal conductivity, low vapor pressure, and good lubrication properties, significantly improving the heat dissipation efficiency and load-bearing capacity of bearings, making them an important development direction for high-speed sliding bearing technology. However, the unique physicochemical properties of liquid metals (such as conductivity, corrosiveness, and high-temperature reactivity) also place higher demands on the monitoring and control of bearing systems. Rotational speed, as one of the key parameters reflecting the bearing's operating status, is crucial for ensuring equipment safety and optimizing operational performance.

[0004] Noise analysis is a method for measuring rotational speed. It collects vibration sound signals through acoustic emission sensors. However, when measuring rotational speed using noise analysis, it is difficult to determine the accuracy of the measurement results because it is an indirect measurement method. Before using equipment that measures rotational speed using noise analysis, the accuracy of the rotational speed measurement needs to be verified. Utility Model Content

[0005] To facilitate the measurement and verification of the rotational speed of liquid metal sliding bearings, this application provides a measuring device for measuring the rotational speed of liquid metal sliding bearings.

[0006] The metering device for measuring the rotational speed of a liquid metal sliding bearing provided in this application adopts the following technical solution:

[0007] A measuring device for measuring the rotational speed of a liquid metal sliding bearing includes a drive motor, a shaft to be measured, a liquid metal sliding bearing, an acoustic emission sensor, a signal acquisition unit, a photoelectric speed sensor, and a monitoring computer.

[0008] The drive motor and the shaft under test are connected in a transmission manner;

[0009] The shaft to be tested is mounted on the liquid metal sliding bearing;

[0010] The acoustic emission sensor is located on the outside of the liquid metal sliding bearing;

[0011] The signal acquisition device is electrically connected to the acoustic emission sensor;

[0012] The signal acquisition device is electrically connected to the photoelectric speed sensor;

[0013] The signal acquisition device is electrically connected to the monitoring computer.

[0014] Optionally, the drive motor is connected to the shaft under test via a coupling.

[0015] Optionally, the shaft to be tested is provided with reflective markings;

[0016] The photoelectric speed sensor emits infrared light onto the reflective mark on the shaft to be measured and receives the reflected infrared light.

[0017] Optionally, the drive motor is a variable frequency motor.

[0018] In summary, this application includes at least one of the following beneficial technical effects:

[0019] 1. By simultaneously employing both acoustic emission sensors and photoelectric speed sensors, and comparing and verifying the measurement results of the two, the error or failure that may occur with a single sensor under complex working conditions of liquid metal is effectively avoided, significantly improving the accuracy of speed measurement and the reliability of the system.

[0020] 2. The acoustic emission sensor adopts a non-contact acquisition method, which does not require direct contact with the liquid metal sliding bearing, thus avoiding interference with the bearing's operating status. It is especially suitable for harsh working conditions such as high temperature and strong corrosion, enhancing the system's adaptability and safety.

[0021] 3. The drive motor adopts a variable frequency motor, which can simulate the bearing operating state under different speed and load conditions, providing multiple sets of experimental data for the metering device. This helps to comprehensively verify the stability and accuracy of the measurement system, and provides more solid technical support for fault diagnosis and operation monitoring of liquid metal sliding bearings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0023] Figure 2 This is a working logic block diagram of an embodiment of this application.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Signal acquisition unit; 2. Drive motor; 3. Acoustic emission sensor; 4. Photoelectric speed sensor; 5. Monitoring computer; 6. Coupling; 7. Liquid metal sliding bearing. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-2 This application will be described in further detail.

[0027] This application discloses a measuring device for measuring the rotational speed of a liquid metal sliding bearing.

[0028] A measuring device for measuring the rotational speed of a liquid metal sliding bearing includes a drive motor 2, a shaft to be measured, a liquid metal sliding bearing 7, an acoustic emission sensor 3, a signal acquisition unit 1, a photoelectric speed sensor 4, and a monitoring computer 5. The drive motor 2 and the shaft to be measured are driven together. The shaft to be measured is mounted on the liquid metal sliding bearing 7. The acoustic emission sensor 3 is located on the outside of the liquid metal sliding bearing 7. The signal acquisition unit 1 is electrically connected to the acoustic emission sensor 3, the photoelectric speed sensor 4, and the monitoring computer 5.

[0029] When measuring the liquid metal sliding bearing 7, the drive motor 2 drives the shaft under test to rotate, which in turn drives the liquid metal sliding bearing 7 to rotate. During the rotation of the liquid metal sliding bearing 7, the acoustic emission sensor 3 collects the vibration sound signal of the liquid metal sliding bearing 7 during operation and sends it to the signal acquisition unit 1. The signal acquisition unit 1 converts the collected vibration sound signal into a vibration frequency signal and sends it to the monitoring computer to calculate the rotational speed. While the acoustic emission sensor 3 collects the vibration sound signal of the liquid metal sliding bearing 7, the signal acquisition unit 1 converts the rotational speed data of the shaft under test collected by the photoelectric speed sensor 4 into a jumping frequency signal and sends it to the monitoring computer to calculate the rotational speed. The monitoring computer 5 compares the rotational speed data measured by the two methods to verify the accuracy of the measurement by the acoustic emission sensor 3.

[0030] Vibration sound signals are sound wave signals generated by the propagation of vibrations of mechanical parts through a medium. Essentially, they are the coupling of vibrational energy into a sound field. The frequency of the vibration sound signal is essentially the same as the frequency of the original vibration signal because the frequency of the sound wave is determined by the vibration frequency of the source. Therefore, the frequency of the sound wave is equal to the frequency of the sound source's vibration, i.e.: f 声 =f 振 f 声 f is the frequency of the sound wave. 振 Let be the vibration frequency of the sound source; combining the fundamental relationship between vibration signal and rotational speed, the relationship between the sound vibration signal frequency and rotational speed can be expressed as: In the formula, k is the characteristic multiple, and n is the rotational speed in r / min.

[0031] Measurements are performed using an acoustic emission sensor 3, employing a non-contact method to reduce the risk of interference to the object being measured.

[0032] To facilitate the measurement of data signals of the shaft under test by the photoelectric speed sensor 4, a reflective mark is provided on the shaft under test. Multiple reflective marks can be provided axially along the axis of the shaft under test. In this embodiment of the application, only one reflective mark is provided for the purpose of measurement.

[0033] The photoelectric speed sensor 4 emits infrared light onto a reflective mark on the shaft under test and receives the reflected infrared light. When the infrared light is reflected back to the photoelectric speed sensor 4 via the reflective mark on the shaft under test, the data transmitted by the photoelectric speed sensor 4 to the signal acquisition unit 1 will change once, thus obtaining the changing frequency.

[0034] If N reflective markers are installed, the output of the photoelectric sensor will change N times during one revolution of the measured shaft. The rotational speed is calculated by dividing the frequency of these changes by the number of reflective markers, resulting in the following formula: f is the switching frequency, and n is the rotational speed, in r / min.

[0035] By using a photoelectric speed sensor 4 to measure the speed accuracy of the acoustic emission sensor 3, the problems of insufficient accuracy, low reliability, and poor adaptability of a single sensor in the complex environment of liquid metal are solved. This not only improves the accuracy of speed measurement but also provides more comprehensive technical support for the safe operation and fault diagnosis of the liquid metal sliding bearing 7.

[0036] The drive motor 2 can be a fixed-frequency motor or a variable-frequency motor. In this embodiment, the drive motor 2 is a variable-frequency motor to simulate the working state of the liquid metal sliding bearing 7 under different working conditions, providing technical support for multiple sets of data for the metering device and verifying the accuracy and stability of the metering device.

[0037] The drive motor 2 rotates with the shaft under test through the coupling 6. The coupling 6 rotates together with the shaft during the transmission of motion and torque. At the same time, it acts as a safety device to prevent the drive motor 2 from bearing excessive load, thus providing overload protection.

[0038] The implementation principle of the metering device for measuring the rotational speed of a liquid metal sliding bearing according to an embodiment of this application is as follows: First, the shaft to be measured is driven to rotate by the drive motor 2. The shaft rotates in the liquid metal sliding bearing 7, generating mechanical vibration and exciting sound wave signals. The acoustic emission sensor 3 collects the vibration sound signals generated during the operation of the bearing and transmits them to the signal acquisition unit 1. The signal acquisition unit 1 converts the sound signals into vibration frequency signals and transmits them to the monitoring computer 5. The computer calculates the rotational speed value based on the relationship between the sound signal frequency and the rotational speed. At the same time, the photoelectric speed sensor 4 generates a jumping frequency signal by detecting the infrared signal reflected by the reflective marks on the shaft to be measured. The signal acquisition unit 1 transmits this signal to the monitoring computer 5. The computer calculates the rotational speed value based on the jumping frequency and the number of reflective marks. Finally, the monitoring computer 5 compares and analyzes the rotational speed data obtained by the two measurement methods to verify the accuracy and reliability of the measurement results of the acoustic emission sensor 3.

[0039] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A measuring device for measuring the rotational speed of a liquid metal sliding bearing, characterized in that: It includes a drive motor, the shaft under test, a liquid metal sliding bearing, an acoustic emission sensor, a signal acquisition unit, a photoelectric speed sensor, and a monitoring computer, among which... The drive motor and the shaft under test are connected in a transmission manner; The shaft to be tested is mounted on the liquid metal sliding bearing; The acoustic emission sensor is located on the outside of the liquid metal sliding bearing; The signal acquisition device is electrically connected to the acoustic emission sensor; The signal acquisition device is electrically connected to the photoelectric speed sensor; The signal acquisition device is electrically connected to the monitoring computer.

2. The measuring device for measuring the rotational speed of a liquid metal sliding bearing according to claim 1, characterized in that: The drive motor is connected to the shaft under test via a coupling.

3. The metering device for measuring the rotational speed of a liquid metal sliding bearing according to claim 1, characterized in that: The shaft to be tested is equipped with reflective markings; The photoelectric speed sensor emits infrared light onto the reflective mark on the shaft to be measured and receives the reflected infrared light.

4. The metering device for measuring the rotational speed of a liquid metal sliding bearing according to claim 1, characterized in that: The drive motor is a variable frequency motor.

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