Intelligent bearing based on in-situ strain-temperature multi-sensing system

Abstract

The application relates to an intelligent bearing based on an in-situ strain-temperature multi-sensing system and relates to the field of industrial automation and state monitoring. The intelligent bearing comprises a bearing main body, a sensing module, a data acquisition module and an upper computer system; a strain sensing module and a temperature sensing module are integrated on a bearing outer ring in situ; a signal acquisition circuit board is innovatively designed in the form of a bearing dust cover; a steel spring plate is sleeved on the outer periphery of the signal acquisition circuit board and is embedded and installed at a corresponding position of the bearing dust cover; the in-situ integration of the multi-parameter sensor is realized under the premise of ensuring the structural integrity of the bearing and without occupying additional space, and the reliability of signal transmission is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of industrial automation and condition monitoring, and particularly relates to an intelligent bearing based on an in-situ strain-temperature multi-sensor system. BACKGROUND

[0002] Bearings are important moving parts of mechanical equipment, widely used in industrial manufacturing, aerospace and other fields, capable of supporting the movement of transmission parts and reducing friction, and are key basic elements for intelligent manufacturing and equipment upgrading. The bearing contact area is the region with the most concentrated contact stress and the most severe thermal coupling effect, and its dynamic performance evolution directly dominates the bearing life. Under extreme working conditions, this region simultaneously bears the triple effects of Hertz contact stress, friction heat shock and micro-lubrication failure, leading to a chain reaction of thermal-mechanical coupling damage of the material surface layer, and ultimately triggering various failure modes such as roller gluing and micro-pitting.

[0003] Traditional bearings lack real-time condition monitoring function, and operation and maintenance rely on periodic manual inspection, which is prone to sudden failures or excessive maintenance, leading to unplanned downtime and rising maintenance costs. Moreover, the rigid structure of traditional bearings cannot dynamically adapt to changes in load and speed, and long-term operation under non-ideal working conditions will accelerate wear. In addition, traditional bearing fault warning relies on experience-based judgment. With technological innovation, traditional mechanical bearings have gradually developed into modern intelligent bearings. Intelligent bearings can identify micron-level abnormal vibrations or temperature fluctuations in advance through built-in sensors, improving fault prediction accuracy. Currently, the combination of bearing bodies and sensors in intelligent bearings mainly includes two types: external sensor type and embedded sensor type. The external sensor type intelligent bearing places the sensor outside the outer ring or cage, which can maintain structural integrity and mechanical properties (stress and deformation characteristics remain unchanged), but requires a large space and has poor adaptability in compact layouts, limiting its application scenarios. The embedded sensor type intelligent bearing embeds the sensor inside the bearing by methods such as slotting or drilling the outer ring or inner ring. This design shortens the distance between the sensor and the signal source, effectively reducing external interference. However, slotting can damage the structural integrity of the bearing, leading to increased stress concentration and reduced bearing load capacity and fatigue life.

[0004] The film sensor of the intelligent bearing described in patent CN202422097202.4 can monitor temperature and strain synchronously, but lacks a dynamic temperature compensation mechanism, so that the piezoelectric coefficient of the strain sensor is significantly affected by temperature drift in high-temperature or severe temperature change scenarios, and the thermocouple only outputs a temperature signal independently and is not coupled with strain data in real time for correction, resulting in a temperature coupling error in the strain measurement value that cannot be ignored and affecting the fault diagnosis accuracy. To solve the problems in the prior art, the present application integrates a multilayer MEMS sensing film in situ, spatially couples the thermocouple electrode layer and the piezoelectric strain layer, realizes synchronous capture of the temperature field and the strain field, and at the same time, the host computer system constructs a temperature-strain decoupling model based on real-time data of the thermocouple, dynamically corrects the temperature drift coefficient of the piezoelectric material by using polynomial fitting or neural network, and combines the thermal expansion coefficient gradient matching design of the adhesive layer and the insulating layer to cooperatively suppress thermal stress interference and reduce temperature drift error from the physical structure and algorithm levels, which can significantly improve the strain measurement authenticity and reliability in extreme working conditions. SUMMARY

[0005] The present application provides an intelligent bearing based on an in-situ strain-temperature multi-sensing system, which can monitor the bearing state in real time and discover small faults in time. The strain sensing module body is a piezoelectric film, which is affected by temperature, so a thermocouple is added for temperature compensation to reduce the influence of temperature on the sensitivity of the strain sensor.

[0006] The technical scheme of the present application is as follows:

[0007] An intelligent bearing based on an in-situ strain-temperature multi-sensing system, the intelligent bearing comprising a bearing body, a sensing module, a data acquisition module and a host computer system;

[0008] The bearing body comprises a dust cover 1000, an inner ring 2000, a retainer 3000, a roller 4000 and an outer ring 5000.

[0009] The sensing module comprises a MEMS in-situ temperature-strain sensing film 5100 integrated on a bearing outer ring end surface 5200 of the outer ring 5000; the MEMS in-situ temperature-strain sensing film 5100 comprises, from bottom to top, a transition layer 5103, a first insulating layer 5104, a thin-film thermocouple electrode layer 5105, a second insulating layer 5106, a first strain electrode layer 5107, a piezoelectric material layer 5108, a second strain electrode layer 5109, and a third insulating layer 5110; two wires extend from the thin-film thermocouple electrode layer 5105, and a thermocouple contact point 5101 at the outer ends of the two wires is arranged on an outer lip 5400 of the outer ring and connected to a temperature sensing metal probe 6004 in the data acquisition module; one wire extends from the first strain electrode layer 5107 and one wire extends from the second strain electrode layer 5109, and stress sensing contact points 5102 at the outer ends of the two wires are arranged on the outer lip 5400 of the outer ring and connected to strain sensing metal probes 6005 in the data acquisition module. The thin-film thermocouple electrode layer 5105 is an integral layer formed by splicing two half layers in the same horizontal plane, and the two half layers are respectively composed of thermocouple materials A and B with different Seebeck coefficients (common thermocouple material combinations can be selected).

[0010] Further, the material of the bearing outer ring end surface 5200 is GCr15 bearing steel, and the thermal expansion coefficient is 1.5×10 -5 to 8.0×10 -5 ℃.

[0011] Further, the transition layer 5103 is used to improve the bonding force of the first insulating layer 5104 and the bearing outer ring end surface 5200, has a thickness of 50nm-100nm, and is made of chromium, titanium or TiAlN; the thermal expansion coefficient of the material of the transition layer 5103 is between the thermal expansion coefficients of the materials of the bearing outer ring end surface 5200 and the first insulating layer 5104.

[0012] Further, the first insulating layer 5104, the second insulating layer 5106, and the third insulating layer 5110 are all used to insulate external electrical noise, are all made of aluminum oxide or polyurethane acrylate, and all have a thickness of 150nm-250nm and a thermal expansion coefficient of 5.0×10 -6 to 10.0×10 -6 ℃.

[0013] Further, the thermocouple materials A and B of the two half layers of the thin film thermocouple electrode layer 5105 are respectively: when the thermocouple material A is nickel-chromium, the thermocouple material B is nickel-silicon; when the thermocouple material A is platinum-rhodium, the thermocouple material B is platinum, and the materials and thicknesses of the wires led out by the two half layers and the thermocouple contact points 5101 at the outer ends of the wires are the same as those of the corresponding half layers. At the same time, the material of the temperature sensing metal probe 6004 needs to be the same as that of the corresponding thermocouple contact point 5101; the thickness of the thin film thermocouple electrode layer 5105 is 50-100 nm;

[0014] Further, the first and second strain electrode layers 5107 and 5109 are both used to transfer the electric charges generated by the MEMS in-situ temperature-strain sensing thin film 5100, and the thicknesses of the first and second strain electrode layers 5107 and 5109 are both 50-100 nm; the materials of the first and second strain electrode layers 5107 and 5109 are both conductor materials, preferably copper or aluminum; the materials and thicknesses of the wires led out by the first and second strain electrode layers 5107 and 5109 and the stress sensing contact points 5102 at the outer ends of the wires are the same as those of the corresponding strain electrode layers 5107 and 5109. At the same time, the material of the strain sensing metal probe 6005 needs to be the same as that of the corresponding stress sensing contact point 5102.

[0015] Further, the piezoelectric material layer 5108 is used to convert the deformation of the outer ring 5000 into an electric signal; the thickness of the piezoelectric material layer 5108 is 50-100 um; further, the piezoelectric material layer 5108 is a solid film with a thickness of 50-300 um, which is made of piezoelectric material and photosensitive resin mixed at a volume ratio of 1:4-1:1 and then solidified by blue-violet light selected area photopolymerization, wherein the piezoelectric material is barium titanate and / or zinc oxide powder, and the resin is polyurethane acrylate and / or polyester acrylate; preferably, the piezoelectric material is barium titanate, zinc oxide powder, polyurethane acrylate and polyester acrylate at a volume ratio of 1:1:1:1 to 3:3:2:2.

[0016] Further, the transition layer 5103 is prepared by magnetron sputtering technology; the first insulating layer 5104, the thin film thermocouple electrode layer 5105, the second insulating layer 5106, the first strain electrode layer 5107, the second strain electrode layer 5109 and the third insulating layer 5110 are prepared by magnetron sputtering technology or evaporation technology; and the piezoelectric material layer 5108 is prepared by ink direct writing, screen printing or magnetron sputtering technology.

[0017] The data acquisition module includes a circuit board 6000 and a power supply module 6001, a power supply voltage stabilizing module 6002, a wireless communication module 6003, a temperature sensing metal probe 6004, a strain sensing metal probe 6005, an anti-aliasing low-pass filter 6007, a preamplifier 6008, a microcontroller 6009 and an A / D converter 6010 integrated on the circuit board 6000.

[0018] The size and shape of the circuit board 6000 are the same as the original dust cover 1000 of the bearing body, and the circuit board 6000 replaces the original dust cover 1000 of the bearing body to weld and electrically connect the components required for the data acquisition module.

[0019] Furthermore, a steel spring 6006 is designed on the outer periphery of the circuit board 6000 to provide tension, and the original dust cover mounting groove on the outer ring 5000 of the bearing is used. The steel spring 6006 is matched with the groove size, and the buckle mechanism is embedded and locked by hand or tool, that is, the steel spring 6006 is accurately positioned and matched with the groove to form a matching structure.

[0020] The temperature sensing metal probe 6004 and the strain sensing metal probe 6005 are welded on the circumferential periphery of the circuit board 6000, the axial direction of the temperature sensing metal probe 6004 and the strain sensing metal probe 6005 coincides with the radial direction of the circuit board 6000, and the center positions of the two correspond to the center position of the MEMS in-situ temperature-strain sensing film 5100. One end of the temperature sensing metal probe 6004 is connected to the thermocouple contact point 5101 of the sensing module, and one end of the strain sensing metal probe 6005 is connected to the stress sensing contact point 5102 of the sensing module, thereby realizing electrical connection with the MEMS in-situ temperature-strain sensing film 5100.

[0021] The preamplifier 6008 is electrically connected to the other end of the temperature sensing metal probe 6004 and the other end of the strain sensing metal probe 6005; the preamplifier 6008 is electrically connected to the anti-aliasing low-pass filter 6007; the anti-aliasing low-pass filter 6007 is electrically connected to the A / D converter 6010; the A / D converter 6010 is electrically connected to the microcontroller 6009, and the microcontroller 6009 is connected to the upper computer system through the wireless communication module 6003; the power module 6001 is connected to each module on the circuit board 6000 through the power stabilizing module 6002 to supply power to each module on the circuit board 6000.

[0022] In use, the MEMS in-situ temperature-strain sensing film 5100 generates an electrical signal according to the bearing strain and operating temperature, the preamplifier 6008 amplifies and transmits the detected electrical signal to the anti-aliasing low-pass filter 6007, which is used to filter out high-frequency electrical noise in the electrical signal, so that the electrical signal sensitivity meets the resolution requirement, while being able to improve the signal-to-noise ratio and reduce the influence of external interference, and then transmits the processed signal to the A / D converter 6010; the A / D converter 6010 is a multi-channel synchronous sampling ADC chip, which converts the electrical signal processed by the anti-aliasing low-pass filter 6007 into a digital signal and transmits it to the microcontroller 6009; after receiving the digital signal from the A / D converter 6010, the microcontroller 6009 stores and packages the data, and transmits it to the upper computer system through the wireless communication module 6003. At the same time, the microcontroller 6009 can receive control instructions from the upper computer system and issue control commands to each functional module through the information bus and information interface.

[0023] Further, the upper computer system is the decision center of the in-situ strain-temperature multi-sensing system, and its functions and cooperative relationship with other modules can be explicitly described as follows:

[0024] Real-time data interaction and transmission: the upper computer system receives digital signals (strain, temperature) from the data acquisition module through the wireless communication module 6003, and issues control instructions (such as adjusting the sampling rate, starting and stopping collection) to the microcontroller 6009 of the data acquisition module, thereby driving the anti-aliasing low-pass filter 6007 and the preamplifier 6008 in the data acquisition module to respond dynamically.

[0025] Temperature-strain dynamic compensation: based on the thermocouple contact point 5101 signal collected by the temperature sensing metal probe 6004, the built-in coupling model algorithm (such as polynomial fitting or BP neural network) is called to real-time correct the charge output deviation of the first strain electrode layer 5107 and the second strain electrode layer 5109 caused by the temperature drift of the piezoelectric material layer 5108, and ensure the strain measurement accuracy (±0.5%).

[0026] Multi-parameter data storage and analysis: multi-dimensional data such as strain spectrum and temperature field distribution are stored synchronously at a sampling rate of 40ksps, combined with the physical properties of the bearing outer ring end face 5200 (such as the fatigue curve of GCr15 steel), a bearing characteristic parameter database is established, which provides a training set and real-time comparison benchmark for deep learning fault diagnosis.

[0027] Visualize and Intelligent Early Warning: Real-time display of strain nephogram, temperature gradient and roller 4000 motion trajectory of outer ring 5000 through human-computer interface, when monitoring value exceeds preset threshold (such as sudden increase of outer ring raceway 5300 strain or temperature overrun), trigger multi-level early warning (from sound and light alarm to emergency stop instruction), and push alarm information to operation and maintenance terminal through wireless communication module 6003.

[0028] System Parameter Dynamic Regulation: According to the running state of the bearing, remotely adjust the sampling rate of the data acquisition module (control the working mode of A / D converter 6010) or the sensitivity of the sensor (adjust the gain of preamplifier 6008), optimize the system power consumption and signal SNR.

[0029] The beneficial effects of the application: In view of the problems existing in the prior art, the application proposes an intelligent bearing based on in-situ strain-temperature multi-sensor system, which integrates strain sensing module and temperature sensing module in the bearing outer ring, innovatively designs the signal acquisition circuit board in the form of bearing dust cover, and embeds the steel spring sheet in the corresponding position of the bearing dust cover. On the premise of ensuring the integrity of the bearing structure and without additional space occupation, the in-situ integration of multi-parameter sensors is realized, and the reliability of signal transmission is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is the overall view of the intelligent bearing;

[0031] Figure 2 It is the schematic view of the sensing module structure of the intelligent bearing;

[0032] Figure 3 It is the schematic view of the sensing structure position of the intelligent bearing;

[0033] Figure 4 It is the schematic view of the data acquisition module of the intelligent bearing;

[0034] Figure 5 It is the in-situ stress temperature signal correction logic diagram;

[0035] In the diagram: 1000 Dust cover; 2000 Inner ring; 3000 Cage; 4000 Roller; 5000 Outer ring; 6000 Circuit board; 5100 MEMS in-situ temperature-strain sensing film; 5200 Bearing outer ring end face; 5300 Outer ring raceway; 5400 Outer ring outer lip; 5101 Thermocouple contact point; 5102 Stress sensing contact point; 5103 Transition layer; 5104 First insulating layer; 5105 Thin-film thermocouple electrode layer; 5106 Second... Insulating layer; 5107 First strain electrode layer; 5108 Piezoelectric material layer; 5109 Second strain electrode layer; 5110 Third insulating layer; 6001 Power module; 6002 Power voltage regulator module; 6003 Wireless communication module; 6004 Temperature sensing metal probe; 6005 Strain sensing metal probe; 6006 Steel spring; 6007 Anti-aliasing low-pass filter; 6008 Preamplifier; 6009 Microcontroller; 6010 A / D converter. Detailed Implementation

[0036] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] like Figures 1 to 5 As shown, step one involves fabricating a MEMS in-situ temperature-strain sensing thin film 5100.

[0038] (1) A transition layer 5103 is prepared on the bearing outer ring end face 5200 of the bearing body using magnetron sputtering technology. The transition layer 5103 is made of chromium and has a thickness of approximately 80 nm. The coefficient of thermal expansion of the transition layer 5103 is between that of the bearing body and the first insulating layer 5104, and can improve the bonding force of the first insulating layer 5104. In this embodiment, the bearing body is selected as GCr15 bearing steel, which has a coefficient of thermal expansion of 1.5 × 10⁻⁶. -5 Up to 8.0×10 -5 Between / ℃; to prevent thermal stress mismatch from causing the MEMS in-situ temperature-strain sensing film 5100 to peel off, while the material of the transition layer 5103 has good adhesion to the material of the bearing body and the material of the first insulating layer 5104 respectively; the transition layer 5103 can improve the adhesion of the first insulating layer 5104 and improve the thermocouple pressure resistance and wear resistance of the MEMS in-situ temperature-strain sensing film 5100.

[0039] (2) A first insulating layer 5104 is prepared on the surface of the transition layer 5103. The material is alumina and the magnetron sputtering technology is selected. The thickness is 200 nm.

[0040] (3) The thin film thermocouple electrode layer 5105 is prepared on the surface of the first insulating layer 5104 by using the magnetron sputtering technology, the thermoelectric material A and the thermoelectric material B of the two half layers of the thin film thermocouple electrode layer 5105 are respectively: nickel-chromium and nickel-silicon; two wires are extended from the thin film thermocouple electrode layer 5105, the thermocouple contact point 5101 at the outer end of the two wires has a radius of about 80 um; the materials and the thicknesses of the wires and the thermocouple contact point 5101 extended by the two half layers are the same as those of the corresponding half layers; the thickness of the thin film thermocouple electrode layer 5105 is 80 nm;

[0041] (4) The second insulating layer 5106 is prepared on the surface of the thin film thermocouple electrode layer 5105 by using the same material and preparation process as the first insulating layer 5104, and the thickness is 200 nm;

[0042] (5) The first strain electrode layer 5107 is prepared on the surface of the second insulating layer 5106 by using the copper conductor material, and a wire is extended from the first strain electrode layer 5107 by using the magnetron sputtering technology; the materials and the thicknesses of the wire and the stress sensing contact point 5102 at the outer end of the wire are the same as those of the first strain electrode layer 5107; the thickness is 80 um.

[0043] (6) The piezoelectric material layer 5108 is prepared on the surface of the first strain electrode layer 5107; the piezoelectric material layer 5108 is selected from barium titanate, zinc oxide powder, polyurethane acrylate and polyester acrylate with a volume ratio of 1:1:1:1, which has high piezoelectric performance and high dielectric constant; the polyurethane acrylate and the polyester acrylate produce chain polymerization reaction after being irradiated by light of a certain wave band, the resin molecules gradually crosslink to form a three-dimensional network structure, and finally solidify into a film together with the barium titanate and the zinc oxide powder. The piezoelectric film has a positive piezoelectric effect, that is, when the material is deformed under stress, opposite charges will be generated on its two surfaces, which will convert mechanical energy into electrical energy and directly obtain an electrical signal, simplifying subsequent signal processing. The piezoelectric film is prepared by using the magnetron sputtering technology; the thickness is 80 um.

[0044] (7) The second strain electrode layer 5109 is prepared on the surface of the piezoelectric material layer 5108 by using the same material and preparation process as the first strain electrode layer 5107; the thickness is 80 um.

[0045] (8) The third insulating layer 5110 is prepared on the surface of the second strain electrode layer 5109 by using the same material and preparation process as the first insulating layer 5104, and the thickness is 200 nm;

[0046] Step two, install the data acquisition module at the corresponding position. The specific settings of the data acquisition module are as follows:

[0047] The circuit board 6000 is annular in shape, has the same size as the dust cover, and has a thickness of 2 mm, which is the thickness of a commonly used circuit board. The circuit board 6000 is used for welding and electrically connecting the components required for the data acquisition module, and is sleeved with a steel spring 6006 on the outer periphery to provide tension force and is installed at the corresponding position of the dust cover 1000, so as to prevent the circuit board 6000 from being subjected to radial stress, causing the components to be detached or fail. Further, three specific grooves for matching the steel spring 6006 are arranged on the side of the outer lip 5400 close to the outer ring raceway 5300. When installed, the buckle mechanism needs to be manually or by a tool to be embedded in the locking position, that is, the steel spring 6006 is accurately positioned with the groove to form a matching structure.

[0048] The temperature sensing metal probe 6004 and the strain sensing metal probe 6005 are welded on the annular outer periphery of the circuit board 6000. The axial direction of the temperature sensing metal probe 6004 and the strain sensing metal probe 6005 coincides with the radial direction of the circuit board 6000, and the center positions of the two correspond to the center position of the MEMS in-situ temperature-strain sensing film 5100. One end of the temperature sensing metal probe 6004 is connected to the thermocouple contact point 5101 of the sensing module, and one end of the strain sensing metal probe 6005 is connected to the stress sensing contact point 5102 of the sensing module, thereby realizing electrical connection with the MEMS in-situ temperature-strain sensing film 5100.

[0049] The preamplifier 6008 is electrically connected to the other end of the temperature sensing metal probe 6004 and the other end of the strain sensing metal probe 6005. The preamplifier 6008 is electrically connected to the anti-aliasing low-pass filter 6007. The anti-aliasing low-pass filter 6007 is electrically connected to the A / D converter 6010. The A / D converter 6010 is electrically connected to the microcontroller 6009. The microcontroller 6009 (using an MCU chip) is connected to the upper computer system through a wireless communication module 6003 (such as Wi-Fi or Bluetooth). The power module 6001 is connected to each module on the circuit board 6000 through the power stabilizing module 6002 to supply power to each module on the circuit board 6000. The power module 6001 is a wireless charging coil that receives electromagnetic waves emitted by an external wireless charging transmitting coil and converts them into stable electric energy. The power stabilizing module 6002 can use an LDO or DC-DC method to realize long-term power supply for the sensor system and meet the requirements of compactness and light weight.

[0050] In use, the MEMS in-situ temperature-strain sensing film 5100 generates an electrical signal according to the bearing strain and operating temperature, the preamplifier 6008 amplifies the detected electrical signal and transmits it to the anti-aliasing low-pass filter 6007, which is used to filter out high-frequency electrical noise in the electrical signal, so that the electrical signal sensitivity meets the resolution requirement, while being able to improve the signal-to-noise ratio and reduce the influence of external interference, and then transmits the processed signal to the A / D converter 6010; the A / D converter 6010 is a multi-channel synchronous sampling ADC chip, which converts the electrical signal processed by the anti-aliasing low-pass filter 6007 into a digital signal and transmits it to the microcontroller 6009; after receiving the digital signal from the A / D converter 6010, the microcontroller 6009 stores and packages the data, and transmits it to the upper computer system through the wireless communication module 6003. At the same time, the microcontroller 6009 can receive control instructions from the upper computer system and issue control commands to each functional module through the information bus and information interface.

[0051] Step three, insulating packaging of the circuit board

[0052] In order to protect the data acquisition module (including the circuit board 6000, the microcontroller 6009 and other key components) from environmental erosion and mechanical stress interference, a fourth insulating packaging process is added: a Parylene coating with a thickness of 8um is uniformly coated on the surface of the circuit board by vacuum vapor deposition method; during the deposition process, the antenna area of the wireless communication module 6003 is protected by a mask. The coating has high density (porosity <0.1%), flexibility (elongation at break >200%) and dielectric strength (>5kV / mm), which can block the intrusion of water vapor and oil stains, absorb high-frequency vibration, and strengthen high-voltage insulation. At the same time, the reliability is verified by insulation resistance (>10^12Ω), salt spray (48h without corrosion) and high temperature and humidity (85℃ / 85%RH, 500h) tests after packaging, and finally the protection level is improved to IP67, ensuring the long-term stable operation of the intelligent bearing in extreme working conditions such as high temperature, high humidity and strong vibration.

[0053] For the upper computer system of the intelligent bearing, its functions and cooperative relationship with other modules can be described as follows:

[0054] Real-time data interaction and transmission: the upper computer system receives digital signals (strain, temperature) from the data acquisition module through the wireless communication module 6003, and issues control instructions (such as adjusting the sampling rate, starting and stopping collection) to the microcontroller 6009 of the data acquisition module, which in turn drives the anti-aliasing low-pass filter 6007 and the preamplifier 6008 in the data acquisition module to respond dynamically.

[0055] Temperature-strain dynamic compensation: Based on the thermocouple contact point 5101 signal collected by the temperature sensing metal probe 6004, the built-in coupling model algorithm (such as polynomial fitting or BP neural network) is called to correct the charge output deviation of the first strain electrode layer 5107 and the second strain electrode layer 5109 caused by the temperature drift of the piezoelectric material layer 5108 in real time, ensuring the strain measurement accuracy (±0.5%).

[0056] Multi-parameter data storage and analysis: Synchronously store multi-dimensional data such as strain spectrum and temperature field distribution at a sampling rate of 40ksps, combine with the physical characteristics of the bearing outer ring end face 5200 (such as the fatigue curve of GCr15 steel), establish a bearing characteristic parameter database, and provide a training set and real-time comparison benchmark for deep learning fault diagnosis.

[0057] Visualization and intelligent early warning: Real-time display of strain nephogram, temperature gradient and roller 4000 motion trajectory of outer ring 5000 through human-computer interface, when the monitoring value exceeds the preset threshold (such as sudden increase of outer ring raceway 5300 strain or temperature overrun), trigger multi-level early warning (from sound and light alarm to emergency shutdown instruction), and push alarm information to operation and maintenance terminal through wireless communication module 6003.

[0058] System parameter dynamic regulation: According to the running state of the bearing, remotely adjust the sampling rate of the data acquisition module (control the working mode of A / D converter 6010) or the sensitivity of the sensor (adjust the gain of preamplifier 6008), optimize the system power consumption and signal SNR.

[0059] The intelligent bearing of the application has strain and temperature multi-parameter monitoring function, and does not damage the bearing main structure, does not increase the size of the bearing main body, can directly reflect the load distribution of the bearing main body, effectively realizes the monitoring of the sudden rise of the bearing temperature, and will help to reduce the safety risk caused by the failure of the bearing.

Claims

1. An intelligent bearing based on an in-situ strain-temperature multi-sensing system, characterized by, The intelligent bearing comprises a bearing body, a sensing module, a data acquisition module and an upper computer system; The bearing body comprises a dust cover (1000), an inner ring (2000), a retainer (3000), a roller (4000) and an outer ring (5000); The sensing module comprises a MEMS in-situ temperature-strain sensing film (5100) integrated on a bearing outer ring end face (5200) of the outer ring (5000); the MEMS in-situ temperature-strain sensing film (5100) comprises, from bottom to top, a transition layer (5103), a first insulating layer (5104), a film thermocouple electrode layer (5105), a second insulating layer (5106), a first strain electrode layer (5107), a piezoelectric material layer (5108), a second strain electrode layer (5109) and a third insulating layer (5110); two wires extend from the film thermocouple electrode layer (5105), and thermocouple contact points (5101) at outer ends of the two wires are arranged on an outer lip (5400) of the outer ring and connected to a temperature sensing metal probe (6004) in the data acquisition module; one wire extends from the first strain electrode layer (5107) and one wire extends from the second strain electrode layer (5109), respectively, and stress sensing contact points (5102) at outer ends of the two wires are arranged on the outer lip (5400) of the outer ring and connected to a strain sensing metal probe (6005) in the data acquisition module; the film thermocouple electrode layer (5105) is an integral layer formed by splicing two half layers in the same horizontal plane, and the two half layers are respectively composed of a thermoelectric material A and a thermoelectric material B having different Seebeck coefficients; The data acquisition module comprises a circuit board (6000) and a power supply module (6001), a power supply voltage stabilizing module (6002), a wireless communication module (6003), a temperature sensing metal probe (6004), a strain sensing metal probe (6005), an anti-aliasing low-pass filter (6007), a preamplifier (6008), a microcontroller (6009) and an A / D converter (6010) integrated on the circuit board (6000); The size and shape of the circuit board (6000) are the same as those of the original dust cover (1000) of the bearing body, and the circuit board (6000) replaces the original dust cover (1000) of the bearing body and is used for welding and electrically connecting components required by the data acquisition module. The temperature sensing metal probe (6004) and the strain sensing metal probe (6005) are welded on the circumferential outer periphery of the circuit board (6000), the axial directions of the temperature sensing metal probe (6004) and the strain sensing metal probe (6005) coincide with the radial direction of the circuit board (6000), the center positions of the two correspond to the center position of the MEMS in-situ temperature-strain sensing film (5100), one end of the temperature sensing metal probe (6004) is connected to the thermocouple contact point (5101) of the sensing module, and one end of the strain sensing metal probe (6005) is connected to the stress sensing contact point (5102) of the sensing module, thereby realizing electrical connection with the MEMS in-situ temperature-strain sensing film (5100). The preamplifier (6008) is electrically connected to the other end of the temperature sensing metal probe (6004) and the other end of the strain sensing metal probe (6005); the preamplifier (6008) is electrically connected to the anti-aliasing low-pass filter (6007); the anti-aliasing low-pass filter (6007) is electrically connected to the A / D converter (6010); the A / D converter (6010) is electrically connected to the microcontroller (6009), and the microcontroller (6009) is connected to the upper computer system through the wireless communication module (6003); the power module (6001) is connected to each module on the circuit board (6000) through the power stabilizing module (6002) to supply power to each module on the circuit board (6000).

2. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, characterized in that, The bearing outer ring end face (5200) is made of GCr15 bearing steel, and the thermal expansion coefficient is 1.5x10 -5 -8.0x10 -5 ℃.

3. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The transition layer (5103) is used to improve the bonding force of the first insulating layer (5104) and the bearing outer ring end face (5200), has a thickness of 50nm-100nm, and is made of chromium, titanium or TiAlN; the thermal expansion coefficient of the material of the transition layer (5103) is between the thermal expansion coefficients of the materials of the bearing outer ring end face (5200) and the first insulating layer (5104).

4. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The first insulating layer (5104), the second insulating layer (5106) and the third insulating layer (5110) are all used for isolating external electric noise, and are all made of aluminum oxide or polyurethane acrylate, and have a thickness of 150nm-250nm and a thermal expansion coefficient of 5.0x10 -6 -10.0x10 -6 ℃.

5. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The thermoelectric material A and the thermoelectric material B of the two half layers of the thin film thermocouple electrode layer (5105) are respectively: when the thermoelectric material A is nickel-chromium, the thermoelectric material B is nickel-silicon; when the thermoelectric material A is platinum-rhodium, the thermoelectric material B is platinum, the materials and thicknesses of the wires led out by the two half layers, the thermocouple contact points (5101) at the outer ends of the wires, and the corresponding half layers are the same; at the same time, the material of the temperature sensing metal probe (6004) is required to be the same as that of the corresponding thermocouple contact point (5101); the thickness of the thin film thermocouple electrode layer (5105) is 50nm-100nm.

6. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The first strain electrode layer (5107) and the second strain electrode layer (5109) are both used for transmitting the electric charge generated by the MEMS in-situ temperature-strain sensing film (5100), and the thicknesses of the two are both 50nm-100nm; the materials of the two are both conductor materials, and the materials are copper or aluminum; the materials and thicknesses of the first strain electrode layer (5107), the second strain electrode layer (5109), the wires led out by the two, and the stress sensing contact points (5102) at the outer ends of the wires are all the same; meanwhile, the material of the strain sensing metal probe (6005) needs to be the same as that of the corresponding stress sensing contact point (5102).

7. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The piezoelectric material layer (5108) is used for converting the deformation of the outer ring (5000) into an electric signal, and the thickness of the piezoelectric material layer (5108) is 50um-100um; further, the piezoelectric material layer (5108) is a solid film with a thickness of 50um-300um, which is made by mixing piezoelectric material and photosensitive resin in a volume ratio of 1:4-1:1 and then performing blue-violet light selected area photopolymerization, wherein the piezoelectric material is barium titanate and / or zinc oxide powder, and the resin is polyurethane acrylate and / or polyester acrylate.

8. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The transition layer (5103) is prepared by using a magnetron sputtering technology; the first insulating layer (5104), the thin film thermocouple electrode layer (5105), the second insulating layer (5106), the first strain electrode layer (5107), the second strain electrode layer (5109), and the third insulating layer (5110) are prepared by using a magnetron sputtering technology or an evaporation technology; and the piezoelectric material layer (5108) is prepared by using an ink direct writing, screen printing or magnetron sputtering technology.

9. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 8, characterized in that, Steel springs (6006) are designed on the outer periphery of the circuit board (6000) to provide tension, and the original dust cover mounting groove on the outer ring (5000) of the bearing is used, the steel springs (6006) are matched with the groove in size, and the buckle mechanism is embedded into the locking position by hand or tool, that is, the steel springs (6006) are accurately positioned with the groove to form a matching structure.

10. The smart bearing based on in-situ strain-temperature multi-sensing system according to claim 1, wherein, The host computer system is the decision center of the in-situ strain-temperature multi-sensing system, and the functions and cooperative relationships with other modules are as follows: Real-time data interaction and transmission: the host computer system receives digital signals from the data acquisition module through the wireless communication module (6003), and sends control instructions to the microcontroller (6009) of the data acquisition module, so as to drive the anti-aliasing low-pass filter (6007) and the preamplifier (6008) in the data acquisition module to respond dynamically; Temperature-strain dynamic compensation: based on the thermocouple contact point (5101) signal collected by the temperature sensing metal probe (6004), the built-in coupling model algorithm is called to correct the output deviation of the first strain electrode layer (5107) and the second strain electrode layer (5109) caused by the temperature drift of the piezoelectric material layer (5108) in real time, so as to ensure the strain measurement accuracy; Multi-parameter data storage and analysis: multi-dimensional data of strain spectrum and temperature field distribution are stored synchronously at a sampling rate of 40ksps, and a bearing characteristic parameter database is established in combination with the physical characteristics of the bearing outer ring end face (5200), so as to provide a training set and a real-time comparison benchmark for deep learning fault diagnosis; Visualization and intelligent early warning: real-time display of strain cloud map, temperature gradient and roller (4000) motion trajectory of outer ring (5000) through human-computer interface, triggering multi-level early warning when monitoring value exceeds preset threshold, and pushing alarm information to operation and maintenance terminal through wireless communication module (6003); System parameter dynamic regulation: remote adjustment of sampling rate or sensor sensitivity of data acquisition module according to bearing running state, optimizing system power consumption and signal signal-to-noise ratio.

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