Vibration signal detection device based on magnetostriction and resonance system

Abstract

The invention relates to the technical field of motor fault detection, and particularly discloses a vibration signal detection device based on a magnetostriction and resonance system, and the device comprises a workbench connection chassis, the workbench connection chassis is provided with a fixed disc, and the interior of the fixed disc is provided with an induction assembly; the induction assembly comprises a lower neodymium-iron-boron permanent magnet arranged in the fixed disc, an induction coil is arranged above the lower neodymium-iron-boron permanent magnet, and an upper neodymium-iron-boron permanent magnet is arranged above the induction coil; the method comprises the following steps: firstly, realizing non-invasive nondestructive testing; on the premise that the original structure of the motor bearing is not damaged, efficient collection of vibration signals is achieved. Secondly, the anti-interference capability is high; on the basis of a signal conversion mechanism of a magnetostrictive inverse effect, mechanical vibration is converted into magnetic field change, traditional contact type mechanical coupling errors and electromagnetic interference are avoided, fault characteristic frequency spectrums are output in real time, a mode recognition algorithm is combined, the fault diagnosis accuracy rate reaches 95% or above, and remote monitoring and predictive maintenance are supported.

Description

Technical Field

[0001] The present invention relates to the technical field of motor fault detection, and in particular to a vibration signal detection device based on magnetostriction and resonance system. Background Art

[0002] In the field of motor operation and maintenance, bearings, as core transmission components, account for over 60% of all motor failures. Existing vibration signal detection technologies (such as contact accelerometers and piezoelectric vibration probes) generally have the following drawbacks:

[0003] 1. Requires destruction of the original structure: Traditional contact detection requires drilling holes in the bearing housing or attaching sensors, which compromises the motor's sealing, complicates installation, and easily introduces additional mass that interferes with vibration characteristics.

[0004] 2. Large signal noise interference: Contact detection is easily affected by mechanical coupling stiffness, ambient temperature and the electromagnetic interference of the motor itself. Especially under high-speed rotation conditions, the relative slip between the sensor and the measured surface will cause signal distortion;

[0005] 3. Limited detection range: Traditional single-point contact detection is difficult to cover the full circumferential vibration characteristics of the bearing, and has a high rate of missed detection of early local defects (such as pitting and microcracks).

[0006] The root cause of the above problems is that the existing technology relies on physical contact to obtain vibration signals, and cannot achieve high-precision, full-dimensional detection without destroying the motor structure. Summary of the Invention

[0007] The object of the present invention is to provide a vibration signal detection device based on magnetostriction and resonance system to solve the above-mentioned problems.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] A vibration signal detection device based on magnetostriction and resonance system includes a workbench connected to a chassis, a fixed plate is provided on the workbench connected to the chassis, and a sensing component is provided inside the fixed plate;

[0010] The workbench is connected to the chassis and is provided with a support column on one side of the fixed plate. A cantilever beam is provided at the end of the support column, and a knock rod is provided below the cantilever beam.

[0011] As a further solution of the present invention: the induction component includes a lower NdFeB permanent magnet disposed in a fixed disk, an induction coil is disposed above the lower NdFeB permanent magnet, and an upper NdFeB permanent magnet is disposed above the induction coil;

[0012] A support frame is provided in the middle of the induction coil, and two ends of the support frame are respectively located in the middle of the lower NdFeB permanent magnet and the upper NdFeB permanent magnet;

[0013] The middle part of the support frame is provided with magnetostrictive material.

[0014] As a further solution of the present invention: a chassis is provided inside the fixed plate;

[0015] The sensing component is arranged in the middle of the chassis.

[0016] As a further solution of the present invention: the chassis is arranged on the workbench connecting chassis via a plurality of fixing support bolts arranged in a circular array;

[0017] An upper cover is provided above the plurality of fixed support bolts;

[0018] The upper cover is located above the sensing component.

[0019] As a further solution of the present invention: the workbench is connected to the chassis and a chassis movable groove is opened on one side of the fixed plate, and the lower end of the support column is set in the chassis movable groove by a bolt.

[0020] As a further solution of the present invention: the end of the cantilever beam is fixedly connected to the upper end of the support column.

[0021] As a further solution of the present invention: a cantilever movable groove is provided on the cantilever beam, and the end of the knock rod is arranged in the cantilever movable groove by a bolt.

[0022] As a further solution of the present invention: the fixing plate is fixedly arranged on the workbench connection chassis by fixing bolts.

[0023] Beneficial effects of the present invention:

[0024] This solution firstly realizes non-invasive non-destructive testing; without destroying the original structure of the motor bearing, it realizes efficient collection of vibration signals;

[0025] Secondly, it has strong anti-interference ability; the signal conversion mechanism based on the inverse magnetostrictive effect converts mechanical vibration into magnetic field changes, avoiding the mechanical coupling error and electromagnetic interference of traditional contact type;

[0026] In addition, it can be quickly deployed and intelligently analyzed, and its modular design enables quick installation in 5 minutes without the need for specialized tools. It integrates 24-bit high-precision AD acquisition and FFT algorithms, outputs fault feature spectra in real time, and, combined with pattern recognition algorithms, achieves a fault diagnosis accuracy of over 95%. It interacts with the host computer in real time through the SPI communication protocol, supporting remote monitoring and predictive maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the connection structure between the sensing component and the chassis in the present invention;

[0030] Figure 3 This is a schematic diagram of the sensor component structure in the present invention Figure 1 ;

[0031] Figure 4 This is a schematic diagram of the structure of the sensing component in the present invention Figure 2 .

[0032] In the figure: 1. Workbench connected to chassis; 10. Chassis movable slot; 2. Support column; 21. Cantilever beam; 210. Cantilever movable slot; 3. Knob; 4. Fixed plate; 41. Fixing bolt; 5. Induction component; 51. Lower NdFeB permanent magnet; 52. Upper NdFeB permanent magnet; 53. Induction coil; 54. Support frame; 55. Magnetostrictive material; 6. Upper cover; 7. Chassis; 71. Fixing support bolt. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] Example 1

[0035] See also Figure 1 As shown, the present invention is a vibration signal detection device based on magnetostriction and resonance system, comprising a workbench connecting chassis 1, a fixed plate 4 is provided on the workbench connecting chassis 1, the fixed plate 4 is fixed to the workbench connecting chassis 1 by fixing bolts 41, and a sensing component 5 is provided inside the fixed plate 4;

[0036] The induction assembly 5 includes a lower NdFeB permanent magnet 51 disposed in the fixed disk 4, an induction coil 53 is disposed above the lower NdFeB permanent magnet 51, and an upper NdFeB permanent magnet 52 is disposed above the induction coil 53;

[0037] A support frame 54 is provided in the middle of the induction coil 53, and the two ends of the support frame 54 are respectively located in the middle of the lower NdFeB permanent magnet 51 and the upper NdFeB permanent magnet 52;

[0038] A magnetostrictive material 55 is provided in the middle of the support frame 54 .

[0039] The workbench is connected to the chassis 1 and is located on one side of the fixed plate 4 with a support column 2, a cantilever beam 21 is provided at the end of the support column 2, the end of the cantilever beam 21 is fixedly connected to the upper end of the support column 2, a knock rod 3 is provided below the cantilever beam 21, the workbench is connected to the chassis 1 and is located on one side of the fixed plate 4 with a chassis movable groove 10, the lower end of the support column 2 is set in the chassis movable groove 10 by bolts, a cantilever movable groove 210 is provided on the cantilever beam 21, and the end of the knock rod 3 is set in the cantilever movable groove 210 by bolts.

[0040] A chassis 7 is provided inside the fixed disk 4, and the sensing component 5 is provided in the middle of the chassis 7; the chassis 7 is provided on the workbench connected to the chassis 1 through a number of fixed support bolts 71 arranged in a ring array, and an upper cover 6 is provided above the several fixed support bolts 71. The upper cover 6 is located above the sensing component 5. The sensing component 5, the upper cover 6 and the chassis 7 together constitute a magnetostrictive transducer.

[0041] After the installation of this device is completed, first adjust the position of the support column 2, and then appropriately adjust the position of the knocking rod 3 so that it can knock on the magnetostrictive transducer to generate an electrical signal. Then, fix the device on the workbench with bolts. When the starting motor drives the bearing to start working, the workbench will also vibrate. Then the workbench connected to the chassis 1 will drive the cantilever beam 21 to swing periodically. The cantilever beam 21 will drive the knocking rod 3 to knock on the magnetostrictive transducer periodically. The mechanical stress generated by the knocking is transmitted to the magnetostrictive material 55 through the resonance system, stimulating changes in its internal magnetic domain structure. Based on the inverse effect of magnetostriction, the magnetic permeability of the magnetostrictive material 55 changes with the action of mechanical stress, resulting in changes in the magnetic flux passing through the induction coil 53. According to Faraday's law of electromagnetic induction, a weak voltage signal is generated in the induction coil 53. The voltage signal is first amplified by a pre-amplifier circuit (such as using an operational amplifier for signal amplification) and then input into the ADC analog-to-digital converter chip.

[0042] The ADC chip samples the analog voltage signal at a set sampling rate and converts it into a digital signal, which is then transmitted to the STM32 microprocessor in real time via the SPI interface. After receiving the digital signal from the ADC chip, the STM32 microprocessor first filters it to remove noise and interference components and improve signal quality.

[0043] Then, by running the FFT algorithm, the time domain signal is converted into a frequency domain signal, and the characteristic frequency components and their amplitude, phase and other parameters are extracted. The processed signal characteristic data is packaged according to a pre-defined communication protocol and transmitted to the host computer via the serial port.

[0044] After receiving the signal signature data from the STM32 microprocessor, the host computer imports it into the fault diagnosis software. The software uses a built-in fault diagnosis model to analyze and compare the signal signatures, for example, comparing the current signal signature with pre-stored normal bearing signal signatures and signal signatures under various fault modes. By calculating similarity or using a pattern recognition algorithm, the software determines whether the motor bearing is faulty and the type of fault (such as inner race fault, outer race fault, rolling element fault, etc.). The software then displays the diagnostic results in real time on the user interface and issues a fault warning signal when necessary.

[0045] Example 2

[0046] Based on the above embodiment 1, this embodiment provides a method for using a vibration signal detection device based on a magnetostrictive and resonance system, specifically: further comprising: an STM32 microprocessor, an ADC analog-to-digital conversion voltage acquisition chip;

[0047] Mechanical deformation of the magnetostrictive material 55 triggers changes in the surrounding magnetic field. Magnetostrictive material 55 is made of an iron-gallium alloy (Terfenol-D). When subjected to mechanical stress, its internal magnetic domain structure changes, resulting in a change in the material's magnetic permeability. A static bias magnetic field is created by two upper and lower neodymium iron boron permanent magnets (N45 model, remanence Br = 1.3T), allowing the magnetostrictive material 55 to operate in the linear region of the magnetization curve, significantly enhancing stress-magnetic field conversion efficiency. The upper and lower permanent magnets are arranged with opposite polarity (NS), forming a closed magnetic circuit through the magnetostrictive material 55. Magnetostrictive material 55 (20 mm × 10 mm) is cylindrical, 10 mm in diameter and 20 mm in height. It is secured with a non-magnetic stainless steel clamp, with a preload of approximately 5 MPa applied at both ends (precise preload is achieved using a combination of M3 hexagon socket head cap screws and spring washers). This preload optimizes the magnetomechanical coupling coefficient (k33 > 0.7), making the material more sensitive to weak vibrations. When the magnetostrictive material 55 changes its magnetic permeability due to beating, the induction coil 53 (enameled wire Φ0.15mm, 2000 turns) surrounding it cuts the magnetic lines of force. According to Faraday's law of electromagnetic induction, Generate induced electromotive force.

[0048] Based on the principle of mechanical resonance, the resonance system parameters are designed by calculating the characteristic frequency of the bearing fault. The theoretical resonance frequency formula is: Wherein L is the length of the cantilever beam 21 ; E is the elastic modulus; ρ is the material density; I is the moment of inertia of the area; and A is the cross-sectional area.

[0049] When the knock rod 3 strikes the magnetostrictive transducer, the induction coil 53 generates an induced electromotive force. An analog-to-digital conversion chip is used to collect voltage data at a sampling rate of 30 kSPS, sufficient for detecting motor bearing faults. An STM32 microprocessor receives and processes the voltage return data from the analog-to-digital conversion chip, transmitting the processed data to the host computer. A Fourier transform is then performed, converting the time domain data into the frequency domain to extract characteristic signals, thereby determining the health of the motor bearings.

[0050] In this solution, non-invasive non-destructive testing is first implemented; without destroying the original structure of the motor bearing, efficient collection of vibration signals is achieved;

[0051] Secondly, it has strong anti-interference ability; the signal conversion mechanism based on the inverse magnetostrictive effect converts mechanical vibration into magnetic field changes, avoiding the mechanical coupling error and electromagnetic interference of traditional contact type;

[0052] In addition, it can be quickly deployed and intelligently analyzed, and its modular design enables quick installation in 5 minutes without the need for specialized tools. It integrates 24-bit high-precision AD acquisition and FFT algorithms, outputs fault feature spectra in real time, and, combined with pattern recognition algorithms, achieves a fault diagnosis accuracy of over 95%. It interacts with the host computer in real time through the SPI communication protocol, supporting remote monitoring and predictive maintenance.

[0053] The monitoring device can extract fault features without any modification to the original structure of the bearing. It is made of a material with a high magnetostrictive coefficient and is arranged at a suitable position around the motor bearing, maintaining a non-contact state with the bearing, and serves as a core component for converting mechanical knocking force into an electrical signal. A flexible movable knocking rod 3 is used, which is made of a lightweight and high-strength material and has a hammer head at one end. It can be flexibly moved within a certain range and is used to apply a controllable knocking force to the magnetostrictive transducer. A resonance system is used, including a resonance base and an elastic support structure. The magnetostrictive transducer is fixed on the resonance base and connected to the workbench through the elastic support structure, so that the entire system can resonate with the vibration generated when the motor is running, thereby enhancing the transmission and response of the knocking signal. A signal processing module is used, which is composed of a preamplifier, a filter, an A / D converter, etc., to amplify, filter and digitize the weak electrical signal output by the magnetostrictive transducer.

[0054] Furthermore, the knocking rod 3 is located above the magnetostrictive transducer, allowing for flexible movement and positioning via a guide structure to ensure accurate striking of the magnetostrictive transducer. The magnetostrictive transducer is securely mounted on a resonant base, which is connected to the workbench via an elastic support structure to form a stable resonant system. The signal processing module is connected to the magnetostrictive transducer via a shielded cable to transmit and process electrical signals. When the motor is running, the vibration of the bearing drives the workbench to generate micro-vibrations. The resonant system resonates with the vibration of the workbench, enhancing the vibration effect. The cantilever beam drives the knocking rod 3 up and down, striking the magnetostrictive transducer. Based on the inverse magnetostrictive effect, the mechanical stress generated by the striking is converted into an electrical signal through the induction coil 53. The electrical signal is transmitted via a shielded cable to the signal processing module. After amplification, filtering, and digitization, it is output to the data unit for processing. By analyzing the electrical signal characteristics, it is determined whether the motor bearing is faulty and what type of fault it is. Therefore, the system can efficiently obtain accurate vibration signals that represent the operating status of the bearing without damaging the bearing structure.

[0055] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A vibration signal detection device based on magnetostriction and resonance system, characterized in that: It comprises a workbench connecting chassis (1), a fixing plate (4) is provided on the workbench connecting chassis (1), and a sensing component (5) is provided inside the fixing plate (4); The workbench is connected to the chassis (1) and is provided with a support column (2) on one side of the fixed plate (4); a cantilever beam (21) is provided at the end of the support column (2); and a knock rod (3) is provided below the cantilever beam (21).

2. The vibration signal detection device based on magnetostriction and resonance system according to claim 1, characterized in that: The induction component (5) comprises a lower NdFeB permanent magnet (51) disposed in a fixed disk (4), an induction coil (53) is disposed above the lower NdFeB permanent magnet (51), and an upper NdFeB permanent magnet (52) is disposed above the induction coil (53); A support frame (54) is provided in the middle of the induction coil (53), and two ends of the support frame (54) are respectively located in the middle of the lower NdFeB permanent magnet (51) and the upper NdFeB permanent magnet (52); A magnetostrictive material (55) is provided in the middle of the support frame (54).

3. The vibration signal detection device based on magnetostriction and resonance system according to claim 1, characterized in that: A chassis (7) is provided inside the fixed plate (4); The sensing component (5) is arranged in the middle of the chassis (7).

4. The vibration signal detection device based on magnetostriction and resonance system according to claim 3, characterized in that: The chassis (7) is arranged on the workbench connection chassis (1) via a plurality of fixing support bolts (71) arranged in a ring array; An upper cover (6) is provided above the plurality of fixed support bolts (71); The upper cover (6) is located above the sensing component (5).

5. The vibration signal detection device based on magnetostriction and resonance system according to claim 1, characterized in that: The workbench is connected to the chassis (1) and is provided with a chassis movable groove (10) on one side of the fixed plate (4). The lower end of the support column (2) is arranged in the chassis movable groove (10) by means of bolts.

6. The vibration signal detection device based on magnetostriction and resonance system according to claim 1, characterized in that: The end of the cantilever beam (21) is fixedly connected to the upper end of the support column (2).

7. The vibration signal detection device based on magnetostriction and resonance system according to claim 6, characterized in that: A cantilever movable groove (210) is provided on the cantilever beam (21), and the end of the knock rod (3) is arranged in the cantilever movable groove (210) via a bolt.

8. The vibration signal detection device based on magnetostriction and resonance system according to claim 1, characterized in that: The fixed plate (4) is fixedly arranged on the workbench connecting chassis (1) via fixing bolts (41).

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