Magnetic bearing rotor state detection device based on flexible detection lantern ring

Abstract

The invention discloses a magnetic bearing rotor state monitoring device based on a flexible detection lantern ring. The rotor motion state monitoring device is composed of a magnetic suspension bearing system, the flexible detection lantern ring, an emitting electrode iron core, an emitting coil, a support, frequency sweeping equipment and the like. A rotor of the magnetic suspension bearing system is sleeved with a flexible detection lantern ring, a PI flexible material is used as a base layer of the flexible detection lantern ring, a temperature sensor, an acceleration sensor and a strain sensor are arranged in the flexible detection lantern ring to collect data so as to measure data of strain, torsion, amplitude and temperature of the rotor, and the flexible detection lantern ring is charged by adopting a wireless charging technology. And finally, sensor signals are transmitted at different frequencies through an oscillating circuit and an antenna accessory circuit in the sensor matching circuit, and are transmitted to frequency sweeping equipment for frequency sweeping receiving processing. The device solves the problem that related important data of a rotor mode cannot be directly measured in real time, so that a control strategy is changed immediately when the rotor reaches a critical rotating speed, and stable operation of a magnetic bearing system is maintained.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic bearing rotor motion state detection, and in particular relates to a magnetic bearing rotor state detection device based on a flexible sleeve. Background Art

[0002] Magnetic bearings are a type of bearing technology that uses electromagnetic force to support the rotor's contactless operation. Compared with traditional mechanical bearings, magnetic bearings have the advantages of no friction, no wear, and no need for lubrication, so they can significantly reduce maintenance costs and extend equipment life. However, the stability and reliability of the magnetic suspension system directly depends on the precise detection and control of the rotor's motion state, so the rotor motion state detection technology has become one of the key issues in the research of magnetic bearings.

[0003] In the magnetic bearing system, the motion state of the rotor usually includes a variety of complex motion forms such as translation, rotation, vibration, and various disturbances. Under high-speed rotation, the rotor may experience multiple critical speed points, which correspond to the situation where the rotor's rotation frequency is close to or equal to the natural frequency of a certain mode. Near the critical speed, due to the resonance effect, the amplitude of the rotor will increase significantly, which may cause unstable operation or even damage to the system. In order to avoid the impact of resonance on the system, it is necessary to detect the rotor strain, torsion, and amplitude data in real time, so as to timely understand the rotor's modal conditions at this time to adjust the control strategy and maintain the stable operation of the system.

[0004] The existing rotor motion state detection method mainly relies on installing displacement sensors, speed sensors, etc. on the magnetic bearing stator for detection. However, since the rotor is suspended by electromagnetic force, its strain, torsion and vibration amplitude data directly related to the rotor mode can only be estimated by simulation software. There are inevitable errors with the actual operating state of the rotor, resulting in low accuracy and slow response in the acquisition of rotor motion state data, which can easily lead to system instability and needs to be improved urgently. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a magnetic bearing rotor motion state detection device based on flexible detection rings. A total of four flexible rotor rings are used on the two-level step shafts of the rotor to measure the rotor strain, torsion, amplitude and temperature data. The rings are made of PI (polyimide) flexible material, and have three built-in sensors for temperature, acceleration and strain to collect data. The rings are charged by wireless charging technology of rotating equipment, and finally different sensor signals are transmitted at different frequencies through an oscillation circuit and transmitted to a sweeping device for sweeping reception and processing, which solves the problem of being unable to directly measure important data related to the rotor mode in real time, so that the control strategy can be changed immediately when the rotor reaches the critical speed to maintain the stable operation of the magnetic bearing system.

[0006] The specific technical solutions are as follows:

[0007] A magnetic bearing rotor state monitoring device based on a flexible detection collar comprises a magnetic bearing rotor, a magnetic bearing stator and a support. The magnetic bearing stator is fixed on a bracket of the support. The inner ring of the magnetic bearing stator is circumferentially distributed with magnetic poles. The two ends of the magnetic bearing rotor respectively pass through the magnetic bearing stator and are magnetically suspended and connected to the magnetic poles.

[0008] The magnetic poles are eight-pole heteropolar magnetic bearing poles. In the structure of the heteropolar magnetic bearing, the polarities of the magnets are arranged alternately in the circumferential direction, that is, the polarities of adjacent poles are opposite. This arrangement enables the magnetic field to generate a stable supporting force to allow the rotor to suspend and rotate.

[0009] In order to achieve stable suspension, the heteropolar magnetic bearing uses electromagnets to generate a control magnetic field. By adjusting the current of the electromagnets, the system can dynamically adjust the size and direction of the magnetic force to maintain the balance and stability of the rotor.

[0010] The heteropolar magnetic bearing can not only provide radial support force, but also control the axial position and posture of the rotor by adjusting the direction and magnitude of the magnetic force, thereby achieving support and control with multiple degrees of freedom.

[0011] The support has a vibration reduction function. Although the magnetic bearing can provide frictionless support, it is sensitive to external vibrations. External vibrations or shocks will be transmitted to the magnetic bearing and the supported rotor through the mounting structure. The vibration reduction support can effectively isolate these external vibrations, reduce the impact of vibrations on the system, and suppress resonance to ensure the stable suspension of the rotor. The support with vibration reduction function includes a rigid vibration isolation base and four spring elastic elements fixed at the bottom four corners of the vibration isolation base, which can provide flexible support, absorb external vibration energy, and reduce the transmission of vibration to the magnetic bearing system.

[0012] The vibration isolation base is the supporting structure of the vibration reduction platform, which connects the entire vibration reduction system with the magnetic bearing body and provides necessary structural support while isolating vibration.

[0013] The outer side of the magnetic bearing stator is equipped with an outer cover, which can effectively protect the internal components and prevent the intrusion of dust, moisture and other pollutants, thereby improving the reliability and service life of the magnetic bearing. In addition, the outer cover is also responsible for fastening the stator assembly to the housing of the bearing, ensuring the stability of the position of the electromagnetic coil and other internal components, thereby maintaining the appropriate gap between the stator and the rotor, and reducing the noise generated when the magnetic bearing is running.

[0014] The magnetic bearing rotor is made of high-strength stainless steel to ensure sufficient mechanical strength and rigidity when rotating at high speed. The magnetic bearing rotor is a stepped shaft structure, which includes a first-level stepped shaft, a second-level stepped shaft and a third-level stepped shaft from the middle to the end. The diameter of the first-level stepped shaft is twice the diameter of the second-level stepped shaft, and the diameter of the second-level stepped shaft is twice the diameter of the third-level stepped shaft. Shaft segments of different diameters are set to adapt to different support positions and load requirements. During the design, ensure that the transition area between each level of shaft segments has sufficient smoothness to avoid fatigue damage caused by stress concentration. The geometry of the rotor should be precise to maintain a uniform air gap with the magnetic bearing. The magnetic bearing rotor is strictly dynamically balanced to reduce vibration caused by imbalance. The dynamic balance level of the rotor reaches G2.5, making it suitable for high-speed applications and ensuring long-term stability of the rotor.

[0015] The flexible detection ring comprises a layer of insulating ring fixed on the rotor. There are four flexible detection rings in total, two of which are arranged at both ends of the primary step shaft and two are arranged on the outer ends of the secondary step shafts on both sides.

[0016] The flexible detection ring adopts PI (polyimide) organic polymer flexible material as the main base material. PI material has good flexibility and bending resistance, can withstand multiple bending and deformation without damage, and is very suitable for flexible circuit board applications that require flexibility. PI material can be made into a very thin film while maintaining high strength. These advantages allow it to be bent into a circular ring-shaped detection ring and used for a long time. PI material has excellent thermal stability and can be used for a long time at temperatures as high as 300°C or even higher, which makes it have significant advantages in the operating temperature range of 50°C-120°C of magnetic bearings. PI material has little dimensional change under different temperature and humidity conditions and has a low thermal expansion coefficient, which helps the ring maintain the stability and reliability of the circuit in a high-precision detection environment.

[0017] The circuit of the flexible detection collar includes three sensors, namely a temperature sensor, an acceleration sensor, and a strain sensor.

[0018] Furthermore, the temperature sensor can detect the temperature of the rotor at this location, and its function is to reflect the operating temperature of the rotor in different modes, serving as an auxiliary indicator for switching the control strategy when the rotor reaches a critical state, and monitoring the operating temperature of the rotor in real time.

[0019] Furthermore, the acceleration sensor can detect the amplitude acceleration of the rotor at that location, and its function is to reflect the vibration amplitude of the rotor at that location. When the vibration amplitude exceeds a certain threshold, it means that the rotor deviates from the normal working state. If it is not identified and dealt with in time, it will cause the magnetic bearing to lose control ability. And the vibration amplitude can reflect the mode of the rotor at this time, which is an important indicator for switching the control strategy when the rotor reaches a critical state.

[0020] Furthermore, the strain sensor can detect the stress and torsional force at that location on the rotor. Its function is to reflect the strain and torque at that location on the rotor. Strain and torque, as physical quantities that directly reflect the stress state and deformation of the rotor, can provide important measured data for modal characteristic analysis and serve as an important indicator for switching control strategies when the rotor reaches a critical state.

[0021] Furthermore, a speed sensor and a displacement sensor are directly installed at the pole end of the stator of the magnetic bearing and fixed with polyurethane glue. The polyurethane glue has strong adhesion, certain elasticity and impact resistance, and is suitable for applications with large vibrations to ensure that the sensor fits tightly with the pole.

[0022] Furthermore, the speed sensor and displacement sensor detect the displacement deformation and speed of the rotor, and their function is to reflect the displacement and speed of the rotor at that location, which serves as an important indicator for switching the control strategy when the rotor reaches a critical state.

[0023] In order to meet the bending and ductility requirements for use in flexible rings, the temperature sensor, acceleration sensor, and strain sensor all use graphene-based sensors. The graphene sensor has excellent flexibility and can withstand 270-degree bending deformation.

[0024] The graphene strain sensor is a multi-layer structure, and its physical structure is mainly composed of a graphene film layer, a piezoelectric material layer, an electrode structure layer, a flexible substrate layer and a packaging layer.

[0025] Furthermore, the graphene film layer is a two-dimensional carbon material with a single atomic layer thickness, which has excellent mechanical properties and electrical conductivity and is used to convert externally applied mechanical strain into detectable electrical signals.

[0026] Furthermore, the piezoelectric polymer of the piezoelectric material layer is coated with polyvinylidene fluoride, which can generate electric charges when subjected to mechanical pressure. By combining with graphene, high-sensitivity strain detection can be achieved. The conductivity of graphene allows these charges to be collected and conducted, thereby outputting corresponding signals.

[0027] Furthermore, the graphene strain sensor is provided with upper and lower electrodes for transferring the charge generated by the graphene and piezoelectric material to an external circuit for signal processing. The electrode material is silver paste, a highly conductive material. The two layers of electrodes are attached to both sides of the graphene film layer to form a complete electric field path.

[0028] Furthermore, the flexible base layer of the graphene strain sensor is a flexible film material PI (polyimide).

[0029] Furthermore, in order to prevent the influence of external factors such as moisture and dust on the sensitivity of the graphene strain sensor, a silicone rubber packaging layer is added to the outside of the sensor to ensure the stability and life of the sensor.

[0030] The graphene temperature sensor is a multi-layer structure, and its physical structure is mainly composed of a graphene film layer, a thermal coupling layer, an electrode structure layer, a flexible substrate layer and a packaging layer.

[0031] The graphene temperature sensor has the same structure as the graphene strain sensor except for the thermal coupling layer, and does not have a piezoelectric material layer.

[0032] Furthermore, the thermal coupling layer of the graphene temperature sensor adopts copper plating, so that heat can be evenly and effectively conducted to the graphene film, improving the response ability of the graphene temperature sensor to external heat and ensuring that the graphene layer can accurately reflect temperature changes.

[0033] The graphene acceleration sensor is a multi-layer structure, and its physical structure is mainly composed of a graphene film layer, a diaphragm structure layer, a mass block, a flexible substrate layer, an electrode structure layer, and a packaging layer.

[0034] The graphene acceleration sensor has the same structure as the graphene strain sensor except for the diaphragm structure layer and the mass block, and does not have a piezoelectric material layer.

[0035] Furthermore, the core part of the graphene acceleration sensor includes a vibration membrane structure, which is a mechanical structure used to respond to external acceleration. Graphene is attached to the vibration membrane. When subjected to acceleration, the vibration membrane will deform, resulting in a strain change in the graphene layer, which in turn causes a change in the electrical properties of the graphene, generating an electrical signal that can reflect the acceleration.

[0036] Furthermore, the graphene acceleration sensor is designed with a tiny mass block, which is connected to the vibrating diaphragm. When acceleration acts on the sensor, inertia causes the mass block to produce relative displacement, which will cause strain in the graphene film attached to the vibrating diaphragm. The presence of the mass block makes the sensor more sensitive to acceleration changes, thereby improving the sensitivity of the sensor.

[0037] Furthermore, each flexible detection ring of the first-stage stepped shaft is provided with 8 temperature sensors, 8 acceleration sensors and 48 strain sensors, and each flexible detection ring of the second-stage stepped shaft is provided with 4 temperature sensors, 4 acceleration sensors and 24 strain sensors.

[0038] Furthermore, the sensors in the flexible detection collar are arranged symmetrically in the circumferential direction. The power of the temperature sensor is 10 milliwatts, the working voltage is 5V, and the working current is 2mA. The power of the acceleration sensor is 30 milliwatts, the working voltage is 5V, and the working current is 6mA. The power of the strain sensor is 50 milliwatts, the working voltage is 5V, and the working current is 10mA.

[0039] In order to print the sensors and supporting circuits in the flexible detection collar on the flexible film, the circuits are manufactured using semiconductor technology and are designed and manufactured using the most basic circuit elements without packaging.

[0040] The supporting circuit of the temperature sensor consists of a step-down voltage-stabilizing power supply circuit, a modulation amplifier circuit, an RC oscillation circuit, a power amplifier circuit and an antenna auxiliary circuit.

[0041] Furthermore, the main function of the step-down voltage stabilizing power supply circuit of the temperature sensor is to stabilize the 12V input voltage provided by the receiving coil to an accurate 5V output, and to consume the excess input voltage in the form of heat by means of linear voltage stabilization, thereby maintaining the stability of the output voltage.

[0042] Furthermore, the step-down voltage stabilizing power supply circuit of the temperature sensor includes a differential amplifier for comparing the output voltage with a reference voltage of 5V. If the output voltage deviates from 5V, the differential amplifier controls the internal power crystal to adjust the output voltage to 5V.

[0043] Furthermore, the step-down and voltage-stabilizing power supply circuit of the temperature sensor monitors the output voltage in real time through an internal negative feedback loop. When the voltage fluctuates, the negative feedback circuit will quickly adjust the conduction state of the transistor to ensure that the output voltage always remains stable.

[0044] Furthermore, in order to protect the voltage regulator and the load, the step-down voltage-stabilizing power supply circuit of the temperature sensor also integrates an overheat protection circuit and a short-circuit protection circuit. When the current is too large or the temperature is too high, it will automatically limit the current or shut down the output.

[0045] Furthermore, after the temperature sensor is supplied with a 5V stable voltage, it collects subtle voltage changes through a circuit composed of a Schottky diode and a capacitor. The sensor signal is amplified by a 40x amplifier circuit composed of two operational amplifiers, and then a square wave with adjustable frequency is generated by an RC square wave oscillation circuit, which is then modulated by the square wave of the power amplifier circuit and the antenna auxiliary circuit before being emitted.

[0046] The supporting circuit of the acceleration sensor is composed of a step-down voltage-stabilizing power supply circuit, an amplifying and modulating circuit, an RC oscillating circuit, a power amplifying circuit and an antenna auxiliary circuit.

[0047] Furthermore, the principle of the buck-stabilized power supply circuit of the acceleration sensor is the same as above.

[0048] Furthermore, after the acceleration sensor obtains a 5V stable voltage supply and collects data, it is filtered and the sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, and then an adjustable frequency square wave is generated through an RC square wave oscillation circuit, which is modulated by the square wave of the power amplifier circuit and the antenna auxiliary circuit before being emitted.

[0049] The supporting circuit of the strain sensor is composed of a step-down voltage-stabilizing power supply circuit, an amplifying and modulating circuit, an RC oscillating circuit, a power amplifying circuit and an antenna auxiliary circuit.

[0050] Furthermore, the principle of the step-down and voltage-stabilizing power supply circuit of the strain sensor is the same as above.

[0051] Furthermore, after the strain sensor obtains a stable voltage supply of 5V, the generated subtle signal is preliminarily modulated through a bridge structure. The sensor signal is amplified by a 40x amplifier circuit composed of two operational amplifiers, and then an adjustable frequency square wave is generated through an RC square wave oscillation circuit. The square wave is modulated by the power amplifier circuit and the antenna auxiliary circuit before being emitted.

[0052] Furthermore, an emitter core is provided on the support, a transmitting coil is wound on the top of the emitter core, the transmitting coil is located directly below the flexible detection ring, the transmitting coil is connected to an external power supply, and secondary receiving coils are provided in the supporting circuits of the strain sensor, acceleration sensor and temperature sensor. The flexible detection ring is powered by a wireless charging mode of a rotating device.

[0053] Furthermore, in this wireless charging mode, the supporting circuit of each sensor in the flexible test ring is integrated with a secondary receiving coil, and the induced voltage received by the secondary receiving coil is converted into a stable voltage through the power supply circuit and supplied to the signal amplification and modulation module, signal oscillation transmission module, power amplification module, and antenna transmission module of the sensor.

[0054] Furthermore, in this wireless charging mode, the wireless charging function is realized by adopting magnetic coupling resonance. The transmitting coil and the secondary receiving coil are tuned to the same resonance frequency, and the secondary receiving coil resonates with the transmitting coil, receives the alternating magnetic field and generates an induced current.

[0055] Furthermore, in this wireless charging mode, since the continuous rotation of the rotor will cause the distance and alignment status between the coils to change, the system is equipped with a frequency tracking system in the transmitting coil circuit to monitor the frequency changes of the receiving coil in real time, and change the frequency of the transmitting coil to make it the same as the frequency of the receiving coil, so as to adjust the resonant frequency of the primary and secondary coils in real time and achieve dynamic matching.

[0056] Furthermore, in this wireless charging mode, the transmitting coil and the secondary receiving coil use copper wires with smaller skin effect and higher quality factor.

[0057] Furthermore, in this wireless charging mode, the optimal coil turns formula is analyzed based on the series resonance model of the transmitting coil and the secondary receiving coil, and it is determined that the primary and secondary coils are both 12 turns. The simulation circuit model obtains that the output voltage of the secondary coil of each sensor is 12V, which is supplied to the power supply circuit for step-down filtering and rectification to obtain a 5V stable voltage supply.

[0058] Furthermore, in this wireless charging mode, the core material of the emitter uses Mn-Zn ferrite with high magnetic permeability to increase the degree of coupling and improve the transmission efficiency.

[0059] The sensor signal is transmitted through the oscillator circuit and antenna amplifier and received by the frequency scanning device.

[0060] Further, based on the formula of RC oscillator circuit frequency By changing the size of the resistor in the oscillation circuit, the frequency signal emitted by each sensor oscillation circuit is different. The sweeping frequency radar can arrange all signals by frequency to achieve the purpose of identifying different sensor signals.

[0061] Furthermore, the horizontal distance between the frequency scanning device and the flexible detection ring is 10 cm, and the smaller transmission distance ensures that the signal will not be excessively attenuated.

[0062] Furthermore, in this wireless charging mode, after the device is started, the rotor first rotates slowly to charge the sensor circuit on the detection ring. After the sensor enters the working state and the scanning device receives the signal from the sensor, the rotor starts to enter the normal rotation speed.

[0063] Furthermore, in this wireless charging mode, the vertical distance between the transmitting coil and the lowest point of the flexible detection ring is 5 cm, and the output of wireless charging will be more stable at a small distance.

[0064] Furthermore, in this wireless charging mode, the transmitting coil is powered by an external power source.

[0065] The beneficial effects of the present invention are:

[0066] 1) The present invention designs a flexible detection ring structure, and installs four flexible rings on the first and second step shafts respectively. A sufficient number of flexible sensors contained in the rings are mounted on the rotor in a magnetically suspended state to directly detect strain, torsion, amplitude, temperature and other data reflecting the motion state of the rotor in real time. The collected data is sufficient and rich in layers, so that the user can understand the motion state of the magnetically suspended rotor in a timely manner, adjust the control strategy based on the motion state of the rotor, and ensure the stable operation of the magnetic bearing rotor system.

[0067] 2) The present invention realizes the wireless charging and sensor signal transmission functions of the transmitting coil and the secondary receiving coils of each sensor in the flexible ring by designing the transmitting coil, the iron core and the support, as well as the matching circuit of the sensor and the frequency tracking system in the emitter circuit. The matching circuit of the sensor includes a step-down voltage-stabilizing power supply circuit, an amplifying modulation circuit, an RC oscillation circuit, a power amplifier circuit and an antenna auxiliary circuit to ensure that the signal collected by the sensor is stably and accurately emitted. The frequency tracking system ensures the dynamic matching of the frequency between the transmitting coil and the receiving coil, ensuring the stability and accuracy of the wireless charging path.

[0068] 3) The present invention ensures the flexibility of the sensor while also ensuring a high sensitivity of the detection signal by designing the physical structures of three graphene flexible sensors.

[0069] 4) The present invention reduces the impact of vibration on the operation of the magnetic bearing system by designing a vibration isolation system including a vibration isolation support and a spring elastic damping element. The vibration isolation support can effectively isolate external vibration, reduce the impact of vibration on the system, and suppress resonance to ensure the stable suspension of the rotor; the spring elastic damping element provides flexible support, absorbs external vibration energy, and reduces the transmission of vibration to the magnetic bearing system. The vibration isolation system improves the control stability of the control system and reduces the probability of rotor instability accidents.

[0070] 5) The present invention can effectively protect the internal components and prevent the intrusion of dust, moisture and other pollutants by designing the outer cover of the magnetic bearing stator, thereby improving the reliability and service life of the magnetic bearing. At the same time, the outer cover can also fasten the stator assembly in the bearing housing to ensure the stability of the position of the electromagnetic coil and other internal components, thereby maintaining an appropriate gap between the stator and the rotor and reducing the noise generated when the magnetic bearing is running. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic diagram of the detection device supporting the magnetic bearing and the flexible detection collar;

[0072] Figure 2 This is a front view of the detection device supporting the magnetic bearing and the flexible detection ring;

[0073] Figure 3It is a schematic diagram of the bottom of the detection device supporting the magnetic bearing and the flexible detection ring;

[0074] Figure 4 It is a schematic diagram of the structure of an eight-pole heteropolar magnetic bearing;

[0075] Figure 5 This is a schematic diagram of the arrangement and distribution of the ring sensors for the flexibility detection of the two-stage stepped rotor;

[0076] Figure 6 This is a schematic diagram of the auxiliary circuit of the acceleration sensor;

[0077] Figure 7 It is a schematic diagram of the auxiliary circuit of the strain sensor;

[0078] Figure 8 It is the schematic diagram of the temperature sensor auxiliary circuit;

[0079] Fig. 9 It is a partial enlarged schematic diagram of the step-down voltage-stabilizing power supply circuit;

[0080] Fig.10 It is a partial enlarged schematic diagram of the modulation amplifier circuit;

[0081] Fig.11 This is a partial enlarged schematic diagram of the RC oscillation signal transmitting circuit;

[0082] Fig.12 This is a partial enlarged schematic diagram of the power amplifier circuit and antenna auxiliary circuit.

[0083] In the figure: 1. magnetic bearing rotor; 11. first-level stepped shaft; 12. second-level stepped shaft; 13. third-level stepped shaft; 2. magnetic bearing stator; 21. magnetic pole; 3. support; 31. spring elastic element; 4. flexible detection ring; 41. strain sensor; 42. acceleration sensor; 43. temperature sensor; 5. emitter core; 6. transmitting coil; 7. outer cover; 8. core support. DETAILED DESCRIPTION

[0084] Refer to the attached Figure 1 ~Attached Fig.12 , the specific implementation steps can be described as follows:

[0085] like Figures 1 to 3 As shown, a magnetic bearing rotor state monitoring device based on a flexible detection collar comprises a magnetic bearing rotor 1, a magnetic bearing stator 2, a support 3, a flexible detection collar 4 and an emitter core 5, wherein four spring elastic elements 31 are arranged at the bottom of the support 3; the four emitter cores 5 are arranged on a core support 8, and the core support 8 is fixed to the support 3 through threaded holes; two magnetic bearing stators 2 are fixed to the bracket of the support 3; a transmitting coil 6 is wound on the emitter core 5; an outer cover 7 is added to the outer side of the magnetic bearing stator 2; as shown in FIG. Figure 4As shown, the magnetic bearing rotor 1 realizes suspended operation by controlling the magnetic poles 21 distributed circumferentially on the inner ring, and the magnetic poles 21 adopt eight-pole heteropolar magnetic bearing magnetic poles; the magnetic bearing rotor 1 is a stepped shaft structure, including a primary stepped shaft 11, a secondary stepped shaft 12 and a tertiary stepped shaft 13 from the middle to the end; wherein two flexible detection collars 4 are fixed on the primary stepped shaft 11 and the secondary stepped rotor 12 respectively; the diameter of the primary stepped shaft 11 is twice the diameter of the secondary stepped shaft 12, and the diameter of the secondary stepped shaft 12 is twice the diameter of the tertiary stepped shaft 13; each flexible detection collar 4 on the primary stepped shaft 11 is integrated with 64 sensors, including 8 temperature sensors, 8 acceleration sensors, and 48 strain sensors; each flexible detection collar 4 on the secondary stepped shaft 12 is integrated with 32 sensors, including 4 temperature sensors, 4 acceleration sensors, and 24 strain sensors; the sensor arrangement distribution diagram of the flexible detection collar 4 on the secondary stepped shaft 12 is as shown in the attached figure Figure 5 As shown, circumferential symmetry is achieved, and the arrangement and distribution of sensors of the flexible detection ring 4 on the primary stepped shaft 11 are similar; the schematic diagram of the auxiliary circuit of the acceleration sensor, the schematic diagram of the auxiliary circuit of the strain sensor, and the schematic diagram of the auxiliary circuit of the temperature sensor included in the flexible detection ring 4 are shown in the attached Figure 6 , Attachment Figure 7 , Attachment Figure 8 As shown in the figure, the supporting circuits corresponding to these three sensors are the same, including the buck-stabilized power supply circuit, modulation amplifier circuit, RC oscillation signal transmission circuit, power amplifier circuit and antenna auxiliary circuit as shown in the attached figure. Fig. 9 , Attachment Fig.10 , Attachment Fig.11 , Attachment Fig.12 As shown in the figure, ports with the same number indicate that the circuits here are connected to each other; the sensor supporting circuits on the flexible detection ring 4 are all printed directly on the PI flexible material using semiconductor technology, and are protected by an insulating layer and a heat insulation layer; the flexible detection ring 4 is fixed to the magnetic bearing rotor 1 by a polyurethane glue with strong viscosity, certain elasticity and impact resistance.

[0086] Each sensor supporting circuit on the flexible detection collar 4 includes a small secondary receiving coil; the emitter coil 6 connected to the external power supply is wound on the emitter core 5, and wireless charging is realized by magnetic resonance. The resonant frequency of the transmitting coil and the secondary receiving coil is adjusted in real time through the frequency tracking system to ensure the stable operation of the magnetic resonance; the secondary receiving coil provides the 12V output voltage to the step-down regulated power supply circuit (such as Fig. 9 ) processing, after voltage reduction, filtering, rectification and voltage stabilization, it outputs a 5V voltage, which is supplied to the three sensor auxiliary circuits ( Figure 6 , Figure 7 , Figure 8 ) output sensor signal, modulation amplifier circuit (such as Fig.10As shown) amplifying signal, RC oscillating signal transmitting circuit (as shown Fig.11 As shown) to generate a square wave with adjustable frequency, a power amplifier circuit and an antenna auxiliary circuit (such as Fig.12 As shown in the figure, the sensor sends a signal; finally, the sensor sends the detection signal to the frequency sweeping device for processing; by changing the RC oscillation signal transmission circuit (as shown in the figure, Fig.11 The resistance value of the resistor in the sensor is set to realize the transmission of square waves of different frequencies, distinguish the individual signals of each sensor, and the scanning device receives the signals and hands them over to the host computer program for analysis and processing, so as to complete the real-time collection of the strain, torsion, amplitude and temperature data of the magnetic bearing rotor 1, so as to analyze the motion mode of the rotor at this time to adjust the control strategy in time and maintain the stable operation of the magnetic bearing system.

[0087] Specifically, after the temperature sensor 43 is supplied with a 5V stable voltage, it collects subtle voltage changes through a circuit composed of a Schottky diode and a capacitor. The sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, and then passes through an RC square wave oscillation circuit to generate a square wave with an adjustable frequency, which is then modulated by a power amplifier circuit (square wave with Vmax≈VCC) and an antenna auxiliary circuit before being emitted.

[0088] After the acceleration sensor 42 obtains a 5V stable voltage supply and collects data, it is filtered and processed. The sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, and then an adjustable frequency square wave is generated through an RC square wave oscillation circuit. The square wave is modulated by a power amplifier circuit (square wave of Vmax≈VCC) and an antenna auxiliary circuit and then emitted.

[0089] After the strain sensor 41 obtains a stable voltage supply of 5V, the generated subtle signal is preliminarily modulated through a bridge structure. The sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, and then passes through an RC square wave oscillation circuit to generate a square wave with adjustable frequency. The square wave is modulated by a power amplifier circuit (square wave of Vmax≈VCC) and an antenna auxiliary circuit before being emitted.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A magnetic bearing rotor condition monitoring device based on a flexible detection collar, characterized in that: The invention comprises a magnetic bearing rotor (1), a magnetic bearing stator (2) and a support (3), wherein the magnetic bearing stator (2) is fixed on a bracket of the support (3), the inner ring of the magnetic bearing stator (2) is provided with magnetic poles (21) distributed in an annular direction, the two ends of the magnetic bearing rotor (1) respectively pass through the magnetic bearing stator (2) and are connected to the magnetic poles (21) in a magnetic suspension manner, the magnetic bearing rotor (1) is provided with a flexible detection collar (4), the flexible detection collar (4) is provided with a strain sensor (41), an acceleration sensor (42) and a temperature sensor (43) for directly measuring state signals of strain, torsion, amplitude and temperature of the magnetic bearing rotor (1), and the support (3) is provided with an emitter core. (5), a transmitting coil (6) is wound around the top of the emitter core (5), the transmitting coil (6) is located directly below the flexible detection collar (4), the transmitting coil (6) is connected to an external power supply, and the supporting circuits of the strain sensor (41), the acceleration sensor (42) and the temperature sensor (43) are all provided with secondary receiving coils, which are wirelessly charged with the transmitting coil (6) by means of magnetic coupling resonance during the rotation process. The supporting circuit sends the detected signal to the frequency scanning device through a step-down voltage stabilization circuit, a modulation amplifier circuit, an RC oscillation circuit, a power amplifier circuit and an antenna auxiliary circuit to obtain real-time status data, so as to adjust and realize the stable operation of the magnetic bearing rotor (1).

2. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 1, characterized in that: The base material of the flexible detection ring (4) is PI organic polymer flexible material, and the strain sensor (41), the acceleration sensor (42) and the temperature sensor (43) are all graphene sensors. The strain sensor (41) is a multi-layer structure, including a graphene film layer, a piezoelectric material layer, an electrode structure layer, a flexible base layer and a packaging layer; the temperature sensor (43) is a multi-layer structure, including a graphene film layer, a thermal coupling layer, an electrode structure layer, a flexible base layer and a packaging layer; the acceleration sensor (42) is a multi-layer structure, including a graphene film layer, a diaphragm structure layer, a mass block layer, a flexible base layer, an electrode structure layer and a packaging layer.

3. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 1, characterized in that: A spring elastic element (31) is provided at the bottom of the support (3); the magnetic properties of adjacent magnetic poles (21) are opposite; and an outer cover (7) is installed on the outer side of the magnetic bearing stator (2).

4. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 1, characterized in that: The magnetic bearing rotor (1) is a stepped shaft structure, comprising a primary stepped shaft (11), a secondary stepped shaft (12) and a tertiary stepped shaft (13) from the middle to the end, the diameter of the primary stepped shaft (11) is twice the diameter of the secondary stepped shaft (12), the diameter of the secondary stepped shaft (12) is twice the diameter of the tertiary stepped shaft (13), and a flexible detection collar (4) is sleeved on both ends of the primary stepped shaft (11) and the outer ends of the secondary stepped shafts (12) on both sides.

5. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 4, characterized in that: Each flexible detection collar (4) of the primary stepped shaft (11) is provided with 8 temperature sensors (43), 8 acceleration sensors (42) and 48 strain sensors (41), and each flexible detection collar (4) of the secondary stepped shaft (12) is provided with 4 temperature sensors (43), 4 acceleration sensors (42) and 24 strain sensors (41).

6. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 2, characterized in that: The piezoelectric material layer adopts piezoelectric polymer material, the piezoelectric polymer adopts polyvinylidene fluoride coating, the electrode structure layer includes two layers of electrodes, the electrode material adopts high conductive material silver paste, the flexible substrate layer adopts flexible thin film material PI, the packaging layer adopts silicone rubber material, the thermal coupling layer adopts copper plating material, and the diaphragm structure layer is a vibrating membrane structure.

7. The magnetic bearing rotor state monitoring device based on a flexible detection collar according to claim 1, characterized in that: The step-down voltage regulator circuit is used to accurately regulate the 12V input voltage provided by the secondary receiving coil to a 5V output, and a differential amplifier for comparing the output voltage with a 5V reference voltage is provided inside the step-up voltage regulator circuit; after the temperature sensor (43) obtains the 5V stable voltage supply, the voltage change is collected through a circuit composed of a Schottky diode and a capacitor, and the sensor signal is amplified by a 40-fold amplification circuit composed of two operational amplifiers, and then a square wave with adjustable frequency is generated through an RC oscillation circuit, which is modulated by the square wave of the power amplifier circuit and the antenna auxiliary circuit before being emitted.

8. The magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 7, characterized in that: After the acceleration sensor (42) is supplied with a 5V stable voltage, data is collected and filtered. After the sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, a square wave with adjustable frequency is generated by an RC square wave oscillation circuit, and then the square wave is modulated by the power amplifier circuit and the antenna auxiliary circuit before being emitted.

9. A magnetic bearing rotor state monitoring device based on a flexible detection collar as claimed in claim 8, characterized in that: After the strain sensor (41) is supplied with a 5V stable voltage, the generated signal is preliminarily modulated through a bridge structure. The sensor signal is amplified by a 40-fold amplifier circuit composed of two operational amplifiers, and then a square wave with adjustable frequency is generated through an RC square wave oscillation circuit. The square wave is modulated by the power amplifier circuit and the antenna auxiliary circuit before being emitted.

10. The magnetic bearing rotor state monitoring device based on a flexible detection collar according to claim 1, characterized in that: The transmitting coil (6) and the secondary receiving coil both use copper wires, and both have 12 turns of coils. The transmitting pole core (5) uses Mn-Zn ferrite with high magnetic permeability. The vertical distance between the transmitting coil (6) and the lowest point of the flexible detection collar (4) is 5 cm. The detection signal of the sensor is transmitted and handed over to the frequency sweeping device for processing. By changing the resistance value of the resistor in the RC oscillation circuit, the transmission of square waves of different frequencies is realized, and the individual signal of each sensor is distinguished. After receiving the signal, the frequency sweeping device hands it over to the host computer program for analysis and processing, and completes the real-time collection of the strain, torsion, amplitude and temperature data of the magnetic bearing rotor.

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