Sensing devices and wind power generation equipment

Abstract

This utility model relates to a sensing device for analyzing the degree of aging and degradation of liquid or paste-like materials and the impurity content in the materials, and a wind power generation device. The sensing device includes: a vibration unit, which includes a crystal oscillator that applies shear vibration to the materials under an excitation voltage; a sensing unit, which includes at least one sensor composed of interdigitated electrodes arranged on the vibration unit to detect changes in the dielectric properties of the materials under shear vibration; and a calculation unit, which is communicatively connected to the vibration unit and the sensing unit, respectively. The calculation unit receives and processes a first signal from the vibration unit and a second signal from the sensing unit, and determines the aging and degradation of the materials and the impurity content in the materials based on the first and second signals.

Description

Technical Field

[0001] This utility model relates to a sensing device and a wind power generation device for analyzing the degree of aging and degradation of liquid or paste-like materials and the content of impurities in the materials. Background Technology

[0002] Various devices are known for monitoring and analyzing the composition of liquid or paste-like analytes, especially greases and oils, such as lubricating oils or greases. Currently, the main products on the market for grease testing include elastohydrodynamic (EHL) devices, used to measure oil film formation and the frictional properties of grease-lubricated surfaces; shear viscometers for measuring grease viscosity; Karl Fischer moisture analyzers for testing the water content in greases; inductively coupled plasma mass spectrometry (IPC-MS) for testing the content of elements such as iron and copper in greases; and infrared devices for testing the turbidity and water content of greases. However, these devices are limited by their large size and are not suitable for placement in bearing systems. Therefore, they cannot perform in-situ testing of lubricating greases used in bearing system components, and thus require subsequent laboratory analysis of the collected samples. This is extremely inconvenient for applications such as wind turbines where sampling is not advisable, and it also makes it impossible to continuously monitor the object to be tested.

[0003] In recent years, some existing technologies have emerged in the market that monitor bearing temperature and vibration to provide online assessment and early warning of bearing failure. However, these technologies also have several drawbacks. On the one hand, once abnormal temperature and vibration are detected in bearing-related components, the bearing is already nearing the end of its lifespan, and remedial measures to extend its lifespan are too late. On the other hand, some existing technologies use the ratio between the dielectric constant of grease at rest and the temperature difference to determine changes in grease composition. However, this technology is not sensitive to changes in the content of elements such as copper and iron in lubricating grease, and therefore cannot provide timely and effective early warnings and assessments of these changes. The presence and content changes of these metallic elements in lubricating grease reflect the degree of wear of equipment components in the bearing system and are crucial for judging the quality of lubricating grease. Utility Model Content

[0004] Based on the above considerations, the technical problem to be solved by this utility model is how to monitor the degree of aging and degradation of liquid or paste materials and the changes in the composition of the materials in a timely and sensitive manner, especially the degree of aging and degradation of lubricating grease and the changes in its composition, so as to take remedial measures in a timely manner and effectively extend the service life of bearings.

[0005] The inventors have made a surprising discovery: the dielectric properties of materials, such as their dielectric constant, change when they flow or deform. This change in dielectric constant exhibits a linear relationship with the rheological properties they experience, such as stress, and this linear relationship has been named the stress-dielectric rule. With use, greases deteriorate due to aging and degradation of the grease itself, as well as impurities introduced through equipment wear, leading to changes in their rheological and dielectric properties. Metallic impurities, in particular, alter the dielectric constant. Based on the stress-dielectric rule, the dielectric current response signal of grease under stress load can be detected, thereby determining the correlation between the two and assessing the degree of aging and degradation, as well as changes in composition.

[0006] Among them, according to the small load approximation, the frequency shift under the first-order approximation is related to the oscillating stress σ of the resonant surface. s A linear relationship exists:

[0007]

[0008] The amplitude of the complex resonance frequency shift is:

[0009]

[0010] f r Let Γ be the resonant frequency in the current state, Γ be half the full width at half maximum (FWHM) in the current state, and f be the resonant frequency in the current state. r,ref Let Γ be the resonant frequency under the reference state, and Γ ref The value is half the full width at half maximum (FWHM) under the reference condition; f0 and Z q These are the fundamental frequency and acoustic impedance of the quartz crystal, respectively. s,ref It is the shear wave velocity under the reference state.

[0011] For a parallel plate resonant surface, the shear wave displacement amplitude, u s,pp At the resonant surface:

[0012]

[0013] The quality factor Q is defined as follows:

[0014]

[0015] n is the overtone order, d 26 U is the piezoelectric strain coefficient, and U is the excitation voltage.

[0016] The corresponding shear strain is:

[0017]

[0018] Where d is the thickness of the quartz crystal; since the shear wave velocity v = du / dt = iωu, the absolute value of the shear wave velocity at the resonant surface, v s,pp It can be represented as:

[0019] v s,pp =ωu s,pp Formula 6

[0020] For a semi-infinite viscoelastic liquid covering a quartz crystal, its complex viscosity can be derived by shifting the resonant frequency and the full width at half maximum (FWHM).

[0021]

[0022] Where η liq ′,η liq ", and ρ liq These are the storage viscosity, loss viscosity, and density of the viscoelastic fluid, respectively.

[0023] The capacitance change ΔC of a dielectric constant sensor θ The stress before and after a material undergoes shear deformation can be expressed as:

[0024]

[0025] Among them 2C 0 σ represents the capacitance of the electrode in free space, ε is the dielectric constant of the material, and σ is the capacitance of the electrode in free space. yz It is the shear stress component, σ xx σ yy and σ zz It is the normal stress component, σ ll=σ xx +σ yy +σ zz Furthermore, the change in capacitance can also be expressed in terms of strain γ:

[0026]

[0027] By extracting the signal difference between at least two dielectric electrorheological sensors in different directions, the stress-dielectric coefficients λ1 and λ2, as well as the strain-dielectric coefficients α1 and α2, can be decoupled. Thus, λ1, α1, and α2 can be measured.

[0028] If the contribution of normal stress is much smaller than the contribution of shear stress, that is:

[0029]

[0030] or

[0031]

[0032] The stress-dielectric current coefficient λ1 and the strain-dielectric current coefficient α1 can be determined by the capacitance change of a single dielectric current sensor, respectively:

[0033]

[0034] and

[0035]

[0036] Among them, the shear stress or shear strain is known.

[0037] The first aspect of this utility model provides a sensing device for analyzing the degree of aging and degradation of a liquid or paste-like material and the impurity content in the material. The sensing device includes: a vibration unit comprising a crystal oscillator that applies shear vibration to the material under an excitation voltage; a sensing unit comprising at least one interdigitated electrode disposed on the vibration unit, which detects changes in the dielectric properties of the material under shear vibration by means of the interdigitated electrode; and a calculation unit communicatively connected to both the vibration unit and the sensing unit, wherein the calculation unit receives and processes a first signal from the vibration unit and a second signal from the sensing unit, and determines the degree of aging and degradation of the material and the impurity content in the material based on the first and second signals.

[0038] The crystal oscillator can generate shear vibration under the action of excitation voltage, thereby forming a vibration wave that is transmitted in the material to be analyzed.

[0039] According to a preferred embodiment, the sensing unit includes at least two radially opposed interdigitated electrodes arranged on the vibration unit, wherein each pair of interdigitated electrodes forms a sensor group.

[0040] According to a preferred embodiment, the interdigitated electrodes are arranged at uniform angular intervals.

[0041] According to a preferred embodiment, the sensing unit includes four sensor groups. In this case, the sensing unit includes a total of eight radially opposed interdigitated electrodes, which are spaced apart from each other at an angular distance of 45°.

[0042] According to a preferred embodiment, a main insulating layer is arranged between the crystal oscillator and the sensing unit to avoid signal crosstalk between the oscillator and the sensing unit.

[0043] According to a preferred embodiment, the first signal includes the rheological properties of the material to be analyzed under shear vibration, and the second signal includes the dielectric electrorheological response signal of the material to be analyzed under shear vibration. The computing unit processes the first signal and the second signal to obtain actual monitoring values, and determines the degree of aging and degradation of the material to be analyzed and the impurity content in the material to be analyzed by comparing the actual monitoring values ​​with reference values ​​stored in the computing unit.

[0044] According to a preferred embodiment, the rheological properties include the shear stress, shear strain, viscosity, and / or viscoelasticity of the material to be analyzed.

[0045] According to a preferred embodiment, the dielectric electrorheological response signal includes the change in the dielectric constant of the material being analyzed.

[0046] According to a preferred embodiment, the voltage drop across the interdigitated electrodes is detected to determine the resistivity change of the material to be analyzed. Changes in the water content of the material to be analyzed result in changes in the resistivity of the material itself. Therefore, changes in the water content of the material to be analyzed can be deduced from the resistivity change. Further processing of the water content change, combined with the aforementioned first signal and / or second signal, can refine and correct the impurity content.

[0047] According to a preferred embodiment, the sensing device further includes an inductor coil to detect voltage changes across the inductor coil, thereby determining changes in the permeability of the material to be analyzed. The change in permeability of the material to be analyzed reflects the content of iron impurities in the material. Further processing of the iron content can refine and correct the impurity content by combining the aforementioned first and / or second signals. Preferably, the calculation unit pre-stores reference values ​​related to the degree of aging and degradation of the material to be analyzed and the impurity content in the material, including the voltage drop across the interdigitated electrodes, the voltage drop across the inductor coil, rheological properties, and the correlation between the dielectric current change signal and the rheological properties. The calculation unit compares these reference values ​​with the actual monitored values ​​to determine the degree of aging and degradation of the material to be analyzed and the impurity content in the material. This sensing device is particularly sensitive to changes in the content of components such as iron, copper, or water.

[0048] According to a preferred embodiment, the sensing device includes an auxiliary insulating layer covering the sensing unit. This not only insulates the sensing unit but also protects the sensor assembly from external damage.

[0049] The second aspect of this utility model provides a wind power generation device, which includes a bearing and the aforementioned sensing device, wherein the sensing device is arranged at the bearing and configured for in-situ analysis of the degree of aging and degradation of the lubricating grease in the bearing and the content of impurities in the lubricating grease.

[0050] According to a preferred embodiment, the impurity includes iron, copper, or water.

[0051] The aforementioned sensing devices have the advantages of small size, high sensitivity to aging and degradation of liquid or paste-like materials to be analyzed, and high sensitivity to the content of specific components in the materials to be analyzed. In particular, they can be particularly sensitive to in-situ detection of changes in viscosity and viscoelasticity of lubricating grease, as well as the content and changes of water, iron, copper, etc. in the lubricating grease. Thus, based on these key parameters, they can timely judge and warn of the wear degree of bearing components, especially cages and outer rings, as well as the degree of aging and degradation of lubricating grease. Attached Figure Description

[0052] The embodiments of this utility model are described below with reference to the accompanying drawings.

[0053] Figure 1 A block diagram of a sensing device according to the present invention is shown;

[0054] Figure 2 The components of the sensing device according to the present invention are schematically shown;

[0055] Figure 3 A perspective view of the crystal oscillator of the sensing device according to the present invention is schematically shown.

[0056] Figure 4 The crystal oscillator of the sensing device according to this utility model is schematically shown from two sides.

[0057] Figure 5 The sensing unit according to the present invention is shown schematically;

[0058] Figure 6 schematically shown Figure 2 The front view of the component shown;

[0059] Figures 7a to 7c The diagram illustrates the shear stress curves of different grease samples under different excitation voltages for the crystal oscillator.

[0060] Figures 8a to 8h The diagram illustrates the relationship between the dielectric electrorheological response signals and the square of the shear strain measured by sensor groups Ch1 to Ch4 for different grease samples at an excitation frequency of 1 kHz.

[0061] Figures 9a to 9c The diagram illustrates the relationship between the square root of the dielectric electrorheological response signal of different grease samples measured by one of the sensor groups Ch1 and the shear stress at an excitation frequency of 1 kHz.

[0062] Figures 10a to 10c The diagram illustrates the relationship between the dielectric electrorheological response signals of different lubricating grease samples measured by one of the sensor groups Ch1 at an excitation frequency of 1 kHz and the impurity content. Detailed Implementation

[0063] The embodiments disclosed herein are intended to exemplify the technical solutions of this utility model.

[0064] The sensing device 100 according to this invention is designed to analyze the degree of aging and degradation of liquid or paste-like materials and the content of impurities in the materials. For example, this sensing device can analyze the viscosity, viscoelasticity, and metallic impurities or water content in lubricating grease. This sensing device can be particularly deployed in the bearing system of wind power equipment for in-situ analysis of the degree of aging and degradation of lubricating grease in the bearing and the content of impurities in the lubricating grease.

[0065] Figure 1 A block diagram of a sensing device according to the present invention is shown. The sensing device 100 includes a vibration unit 10 and a sensing unit 20.

[0066] The vibrating unit 10 includes a crystal oscillator 12. The crystal oscillator 12 comprises a thin, sheet-like body made of quartz with a circular base area, on its top and bottom surfaces respectively deposited with... Figure 3 and Figure 4The arc-shaped metal electrode layer 122 and the circular metal electrode layer 124 shown are arranged symmetrically with respect to the center of the sheet-like main body. The material of the metal electrode layers can be gold or titanium, depending on the requirements.

[0067] The crystal oscillator 12 can be connected to a power source not specifically shown in the figure and generate shear vibrations under the excitation voltage provided by the power source, thereby forming vibration waves that are transmitted in the material to be analyzed, such as grease.

[0068] The sensing unit 20 includes at least two sensor groups arranged on the vibration unit 10, wherein each sensor group includes two interdigitated electrodes that are radially opposed to each other. For example, the sensing unit 20 may include three sensor groups, wherein each sensor group includes two interdigitated electrodes that are radially opposed to each other.

[0069] exist Figure 5 In the illustrated embodiment, the sensing unit 20 may include four sensor groups Ch1, Ch2, Ch3, and Ch4, each sensor group comprising two radially opposed interdigitated electrodes. Specifically, the first sensor group Ch1 includes two radially opposed interdigitated electrodes S1 and S5, the second sensor group Ch2 includes two radially opposed interdigitated electrodes S2 and S6, the third sensor group Ch3 includes two radially opposed interdigitated electrodes S3 and S7, and the fourth sensor group Ch4 includes two radially opposed interdigitated electrodes S4 and S8. These eight interdigitated electrodes S1 to S8 are uniformly arranged at a 45° angular spacing.

[0070] Of course, in embodiments not shown, the sensing unit 20 may also include only one interdigital electrode.

[0071] like Figure 6 As shown, the four sensor groups are laid on one side of the crystal oscillator 12 with a circular metal electrode layer, with reference to the center of the crystal oscillator 12. The auxiliary wiring SF arranged between the interdigitated electrode S5 of the first sensor group and the interdigitated electrode S4 of the fourth sensor group is arranged radially opposite to the grounding wire 1240 of the circular metal electrode layer 124.

[0072] Each sensor group can detect the dielectric properties and changes of the material being analyzed under shear vibration.

[0073] The sensing device 100 also includes a computing unit 30. The computing unit 30 is communicatively connected to both the vibration unit 10 and the sensing unit 20.

[0074] The computing unit 30 can send control signals to the crystal oscillator driving circuit associated with the vibration unit 10 and the sensor driving circuit associated with the sensing unit 20, thereby causing the crystal oscillator 12 of the vibration unit 10 to generate shear vibration at a set excitation frequency and generate a first signal, and causing the sensor group to detect the sample to be analyzed and generate a second signal.

[0075] The first signal includes information about the rheological properties of the material to be analyzed, particularly shear stress, shear strain, shear rate, viscosity, and / or viscoelasticity. The second signal includes the dielectric electrorheological response of the material to be analyzed under corresponding conditions, particularly the dielectric constant, and the voltage drop across the interdigitated electrodes, which reflects the resistivity change of the material to be analyzed. The first and second signals, after being converted into detection signals through, for example, signal conditioning, are fed back to a computing unit, which further processes the fed-back first and second signals to obtain the actual monitored values.

[0076] The actual monitored value can include the ratio of the value of the first signal to the value of the second signal. For example, the ratio of the rheological properties of the material being analyzed to its dielectric electrorheological response.

[0077] The sensing device also includes an inductor coil 60, which is arranged independently of the crystal oscillator and interdigitated electrodes. The material to be analyzed, such as lubricating grease, is filled into the cavity enclosed by the inductor coil 60. By detecting the voltage change across the inductor coil 60, the change in magnetic permeability in the material to be analyzed can be determined, and thus the change in the iron content of impurities in the material can be determined. When the iron content in the lubricating grease increases, the detection signal reflecting the voltage change detected across the inductor coil 60 increases, and vice versa.

[0078] The calculation unit 30 stores reference values ​​in advance related to the degree of aging and degradation of the material to be analyzed and the impurity content in the material. These reference values ​​reflect the relationship between the resistivity, permeability, and rheological properties and dielectric electrorheological response of the material. The calculation unit compares these reference values ​​with the actual monitored values ​​to determine the degree of aging and degradation of the material and the impurity content in the material. Preferably, the degree of aging and degradation in the material includes, but is not limited to, changes in the viscosity, viscoelasticity, and dielectric constant of the material, and the impurities in the material include, but are not limited to, water, copper, iron, etc., accumulated due to wear of bearing system components and / or moisture.

[0079] like Figure 2 As shown, in order to avoid signal crosstalk between the vibration unit 10 and the sensing unit 20, a main insulating layer 42 is also provided between the crystal oscillator 12 of the vibration unit 10 and the sensing unit 20.

[0080] The material of the main insulating layer 42 can be selected from SiO2, Al2O3, TiO2 or other inorganic insulating materials, and has a thickness of 300nm to 500nm.

[0081] In addition, to prevent damage to the sensing unit 20, an auxiliary insulating layer 44 is provided to cover the sensing unit.

[0082] The auxiliary insulating layer 44 can be made of SiO2, Al2O3, TiO2 or other inorganic insulating materials, and has a thickness of 100nm to 200nm.

[0083] The sensing device 100 also includes an interactive unit 50 that is communicatively connected to the computing unit 30. The interactive unit 50 has an input module 52 for users to input or select input parameters to the sensing device and an output module 54 for displaying monitoring results of the material to be analyzed to the user.

[0084] In this design approach, the input parameters preferably include lubricating grease type, fan type, sensor location, etc., and preferably, the monitoring results include real-time dielectric current variation signal, real-time dielectric current variation baseline, impurity content, grease condition judgment, bearing condition analysis, etc.

[0085] Fresh, i.e., uncontaminated grease, as well as grease mixed with impurities, are used as grease samples, exemplarily.

[0086] Fresh grease, and greases with different mass percentages of iron, copper, and water were applied to the sensing device 100 according to this invention. The excitation voltages used to drive the crystal oscillator for shear oscillation were set to 0.36V, 0.43V, 0.50V, and 0.57V, respectively. The overtone order used was n=1. Formula 2 was used to determine the complex resonance frequency shift of different grease samples under the four different excitation voltages, with the reference resonant frequency and full width at half maximum (FWHM) derived from the unloaded crystal oscillator. For simplicity, the resonant surface was modeled as a parallel plate structure. Since the thicknesses of the main insulating layer, auxiliary insulating layer, and metal electrode layer are negligible relative to the thickness of the crystal oscillator, their influence can also be ignored. Therefore, in Formulas 1, 3, 6, and 7, the piezoelectric strain coefficient d of the AT-cut quartz crystal was used. 26 =3.1×10 -12 m / V and the acoustic impedance Z of the quartz crystal q =8.8×10 6 kg / m 2The shear wave displacement, shear stress, and complex viscosity of various grease samples are calculated using formulas s. Furthermore, for simplicity, formulas 6 and 7 are applied as if the grease sample on the crystal oscillator were a semi-infinite body.

[0087] For dielectrostrictive measurements, the capacitance change ΔC of the sensor array, or more specifically, the interdigitated electrodes, is... θ The voltage change ΔV is recorded.

[0088]

[0089] Where V 0 It is the voltage between the electrodes before the dielectric material is deformed.

[0090] The excitation frequencies for the interdigital electrodes used to drive the dielectric constant sensors were set to 1 kHz and 10 kHz. At the 1 kHz excitation frequency, the dielectric constant response was measured at four different quartz crystal oscillation levels. At the 10 kHz excitation frequency, only the dielectric constant response at the maximum quartz crystal oscillation level was measured. Two interdigital electrodes within each sensor group, positioned 180° apart, had the same orientation. During the dielectric constant measurement, the two interdigital electrodes within each sensor group were connected to generate a stronger signal than using a single interdigital electrode. These four sensor groups are labeled Ch1, Ch2, Ch3, and Ch4, as previously described.

[0091] Figures 7a to 7c The diagram schematically illustrates the shear stress curves of different grease samples under different excitation voltages on the crystal oscillator.

[0092] Figure 7a The diagram shows the shear stress σ experienced by pure grease and greases with iron mass percentages of 0.3%, 0.7%, and 1.5% when driving a crystal oscillator at excitation voltages of 0.36V, 0.43V, 0.5V, and 0.57V.

[0093] Figure 7b The diagram shows the shear stress σ experienced by pure grease, grease with a copper mass percentage of 0.5%, and grease 1.0% when the crystal oscillator is driven by excitation voltages of 0.36V, 0.43V, 0.5V, and 0.57V.

[0094] Figure 7c The diagram shows the shear stress σ experienced by greases with a mass percentage of pure grease and water of 0.3% and 1.0% when driving a crystal oscillator at excitation voltages of 0.36V, 0.43V, 0.5V, and 0.57V.

[0095] Figures 8a to 8h The diagram illustrates the relationship between the dielectric electrorheological response signals measured by sensor groups Ch1 to Ch4 and the square of shear strain for different grease samples at an excitation frequency of 1 kHz.

[0096] Figure 8a The diagram shows the voltage V as a dielectric electrorheological response signal and the square of the shear strain γ measured by sensor groups Ch1, Ch2, Ch3, and Ch4 at an excitation frequency of 1 kHz for pure lubricating grease. 2 The relationship between them.

[0097] Figures 8b to 8d The figures show the voltage V as a dielectric electrorheological response signal and the square of the shear strain γ, measured by sensor groups Ch1, Ch2, Ch3, and Ch4, at an excitation frequency of 1 kHz for greases with iron mass percentages of 0.3%, 0.7%, and 1.5%. 2 The relationship between them.

[0098] Figure 8e and Figure 8f The figures show the voltage V as a dielectric electrorheological response signal and the square of the shear strain γ measured by sensor groups Ch1, Ch2, Ch3, and Ch4 at an excitation frequency of 1 kHz for greases with copper mass percentages of 0.5% and 1.0%. 2 The relationship between them.

[0099] Figure 8g and Figure 8h The figures show the voltage V as a dielectric electrorheological response signal and the square of the shear strain γ measured by sensor groups Ch1, Ch2, Ch3, and Ch4 at an excitation frequency of 1 kHz for greases with water mass percentages of 0.3% and 1.0%. 2 The relationship between them.

[0100] Figures 9a to 9c The schematic diagram illustrates the square root V of the dielectric electrorheological response signal of different grease samples measured by the first sensor group Ch1 at an excitation frequency of 1 kHz. 1 / 2 The relationship between shear stress and shear stress.

[0101] Figure 9a The square root V of the dielectric electrorheological response signal of greases with iron mass percentages of 0.3%, 0.7%, and 1.5% is shown at an excitation frequency of 1 kHz. 1 / 2 The relationship between the shear stress σ and the shear stress σ.

[0102] Figure 9b The square root V of the dielectric electrorheological response signal of greases with copper mass percentages of 0.5% and 1.0% is shown at an excitation frequency of 1 kHz. 1 / 2 The relationship between the shear stress σ and the shear stress σ.

[0103] Figure 9c The square root V of the dielectric electrorheological response signal of greases with a water mass percentage of 0.3% and 1.0% is shown at an excitation frequency of 1 kHz. 1 / 2 The relationship between the shear stress σ and the shear stress σ.

[0104] As can be seen from the figure, the square root of the dielectric electrorheological response signal of the grease samples containing impurities such as iron, copper, or water exhibits a good linear relationship with the shear stress. Therefore, the square root of the dielectric electrorheological response signal, V... 1 / 2 The slope of the shear stress curve can be considered to be proportional to the stress-dielectric electrorheological coefficient λ.

[0105] Figure 10a The relationship between the dielectric electrorheological response signal V of lubricating grease samples with iron mass percentages of 0.3%, 0.7%, and 1.5%, measured by the first sensor group Ch1 at an excitation frequency of 1 kHz, and the iron content as an impurity is shown.

[0106] Figure 10b The dielectric electrorheological response signal V of lubricating grease samples with copper mass percentages of 0.5% and 1.0%, measured by the first sensor group Ch1 at an excitation frequency of 1 kHz, is shown to be related to the copper content as an impurity.

[0107] Figure 10c The relationship between the dielectric electrorheological response signal V of lubricating grease samples with water mass percentages of 0.3% and 1.0%, measured by the first sensor group Ch1 at an excitation frequency of 1 kHz, and the water content as an impurity is shown.

[0108] The aforementioned measurement data and processing results can be stored as reference values ​​in the computing unit. The sensing device according to this invention is arranged at the bearing of a wind power generator to continuously or as needed at set time intervals to generate actual monitoring values. By comparing the reference values ​​with the actual detected values, for example through interpolation or by reading charts, the condition of the lubricating grease and the content of impurities can be determined in a timely manner.

[0109] The aforementioned measurement data and processing results can also be used as input features for various machine learning models. Output features include the state of the grease and the content of impurities such as iron, copper, and water. Using machine learning models, algorithms can be used to determine and predict the current and future state of the grease in use, i.e., its degree of aging and degradation, the impurity content in the grease, as well as the wear of bearing components and the moisture ingress into the bearing system. This allows for advance planning of grease replacement, bearing maintenance or replacement, or maintenance or replacement of related components within the bearing system.

Claims

1. A sensing device for analyzing liquid or paste-like materials, characterized in that, The sensing device includes: Vibration unit (10), the vibration unit (10) includes a crystal oscillator (12), the crystal oscillator (12) applies shear vibration to the material to be analyzed under an excitation voltage; A sensing unit (20) comprising at least one interdigitated electrode (S1-S8) disposed on the vibration unit (10), wherein the interdigitated electrode (S1-S8) is used to detect changes in the dielectric properties of the material to be analyzed under the shear vibration; and The calculation unit (30) is communicatively connected to the vibration unit (10) and the sensing unit (20), respectively. The calculation unit (30) receives and processes a first signal from the vibration unit (10) and a second signal from the sensing unit (20), and determines the degree of aging and degradation of the material to be analyzed and the impurity content in the material to be analyzed based on the first signal and the second signal.

2. The sensing device according to claim 1, characterized in that, The sensing unit (20) includes at least two radially opposed interdigital electrodes (S1-S8) arranged on the vibration unit (10), wherein each pair of interdigital electrodes forms a sensor group (Ch1-Ch4).

3. The sensing device according to claim 2, characterized in that, The interdigitated electrodes (S1-S8) are arranged at uniform angular intervals.

4. The sensing device according to claim 2, characterized in that, The sensing unit (20) includes four sensor groups.

5. The sensing device according to claim 1, characterized in that, A main insulating layer (42) is arranged between the crystal oscillator (12) and the sensing unit (20) to avoid signal crosstalk between the vibration unit (10) and the sensing unit (20).

6. The sensing device according to claim 1, characterized in that, The first signal includes the rheological properties of the material to be analyzed under shear vibration, and the second signal includes the dielectric electrorheological response signal of the material to be analyzed under shear vibration. The calculation unit (30) processes the first signal and the second signal to obtain the actual monitoring value, and determines the degree of aging and degradation of the material to be analyzed and the content of impurities in the material to be analyzed by comparing the actual monitoring value with the reference value stored in the calculation unit (30).

7. The sensing device according to claim 6, characterized in that, The rheological properties include the shear stress, shear strain, viscosity, and / or viscoelasticity of the material being analyzed.

8. The sensing device according to claim 6, characterized in that, The dielectric electrorheological response signal includes the change in the dielectric constant of the material being analyzed.

9. The sensing device according to claim 1, characterized in that, The voltage drop across the interdigitated electrodes (S1-S8) is detected to determine the resistivity change of the material to be analyzed.

10. The sensing device according to claim 1, characterized in that, The sensing device also includes an inductor coil (60) to detect the voltage change across the inductor coil (60) in order to determine the change in magnetic permeability of the material to be analyzed.

11. The sensing device according to claim 1, characterized in that, The sensing device includes an auxiliary insulating layer (44) covering the sensing unit.

12. A wind power generation device, characterized in that, The wind power generation equipment includes a bearing and a sensing device according to any one of claims 1 to 11, wherein the sensing device is arranged at the bearing and configured for in-situ analysis of the degree of aging and degradation of the grease in the bearing system and the content of impurities in the grease.

13. The wind power generation equipment according to claim 12, characterized in that, The impurities include iron, copper, or water.

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