A detection device, method for a magnetic levitation rotor and a magnetic levitation motor

Abstract

The present invention discloses a detection device, method and magnetic levitation motor for a magnetic levitation rotor. The device includes: a displacement acquisition unit that detects the displacement of the rotor shaft from a detachable detection surface during one rotation of the rotor shaft at a set speed, obtaining a set of displacement signals, denoted as the displacement signal group; a signal processing unit that processes the displacement signal group to obtain a set of position parameters of the rotor shaft detected from the detachable detection surface; a control unit that determines whether the detachable detection surface is qualified according to the set of position parameters; and if it is determined that the detachable detection surface is unqualified, determines that the detachable detection surface needs to be replaced, and continues to determine whether the other replaced detachable detection surfaces are qualified. This solution is beneficial to improving the levitation stability of the magnetic levitation rotor by replacing the detection surface of the magnetic levitation rotor when the material and density of the detection surface of the magnetic levitation rotor are uneven.

Description

Technical Field

[0001] The present invention belongs to the technical field of detection, and particularly relates to a detection device, method and magnetic levitation motor for a magnetic levitation rotor, and more particularly to a detection device, method and magnetic levitation motor for uneven material and density of a detection surface of a magnetic levitation rotor shaft. Background Art

[0002] Eddy current sensors are widely used in displacement detection of corresponding components in motors (such as magnetic levitation motors) due to their non-contact and simple structure. For example, when the magnetic levitation rotor in a magnetic levitation motor rotates, the object detected by the eddy current sensor is a specific annular surface of the magnetic levitation rotor, that is, the annular surface of the rotor shaft, simply referred to as the detection surface. However, in the actual production process, if the material and density of the detection surface of the magnetic levitation rotor are uneven, it will cause the detection data (i.e., displacement detection signal) of the eddy current sensor that relies on the electromagnetic induction phenomenon to detect displacement to be distorted.

[0003] As is well known, the precise control of a magnetic levitation bearing is based on the real-time detection of the suspension position of the magnetic levitation rotor by a displacement sensor (i.e., an eddy current sensor). If there is a large deviation in the displacement detection signal, the magnetic levitation rotor will surely not be able to maintain stable suspension.

[0004] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a detection device, method and magnetic levitation motor for a magnetic levitation rotor, so as to solve the problem that in a magnetic levitation motor, when using an eddy current sensor to detect the suspension position of the magnetic levitation rotor, if the material and density of the detection surface of the magnetic levitation rotor are uneven, it will cause the displacement detection signal of the eddy current sensor to be distorted, thereby affecting the suspension stability of the magnetic levitation rotor. The effect is achieved by setting the detection surface of the magnetic levitation rotor in a detachable form, and replacing the detection surface of the magnetic levitation rotor when the material and density of the detection surface of the magnetic levitation rotor are uneven, which can avoid the distortion of the displacement detection signal of the suspension position of the magnetic levitation rotor caused by the uneven material and density of the detection surface of the magnetic levitation rotor, and is beneficial to improving the suspension stability of the magnetic levitation rotor.

[0006] In a detection device for a magnetic levitation rotor provided by the present invention, the magnetic levitation rotor has a rotor shaft; the rotor shaft has a detection surface; the detection surface is a detachable detection surface; the detection device for the magnetic levitation rotor includes: a detection tooling; the detection tooling includes: a detection bearing; the rotor shaft can be sleeved in the detection bearing, and the detachable detection surface can be located in the detection bearing; the detection device for the magnetic levitation rotor further includes: a displacement acquisition unit, a signal processing unit and a control unit; wherein, the displacement acquisition unit is arranged outside the detection bearing and at a position corresponding to a set detection point on the detachable detection surface, and is configured to detect the displacement of the rotor shaft from the detachable detection surface during one rotation of the rotor shaft at a set speed, and obtain a set of displacement signals of the rotor shaft detected from the detachable detection surface, denoted as a displacement signal group; the signal processing unit is configured to process the displacement signal group to obtain a set of position parameters of the rotor shaft detected from the detachable detection surface; the control unit is configured to determine whether the detachable detection surface is qualified according to a set of position parameters of the rotor shaft detected from the detachable detection surface; and, if it is determined that the detachable detection surface is unqualified, determine that the detachable detection surface needs to be replaced, and continue to determine whether the other replaced detachable detection surfaces are qualified.

[0007] In some embodiments, on the rotor shaft, the number of the detection surfaces is two; the number of the detection bearings is the same as the number of the detection surfaces; the distance between the two detection bearings can be adjusted to adapt to the length of the rotor shaft (1).

[0008] In some embodiments, the detachable detection surface is installed on the body of the rotor shaft by means of bonding.

[0009] In some embodiments, the displacement acquisition unit includes: a pair of eddy current sensors; each of the pair of eddy current sensors is arranged outside the detection bearing and at a position corresponding to a respective set detection point on the detachable detection surface; the set detection point where one eddy current sensor in the pair of eddy current sensors is located and the set detection point where the other eddy current sensor is located are arranged at 180°.

[0010] In some embodiments, the signal processing unit includes: a detection module and a signal conditioning module; the signal processing unit processes the displacement signal group to obtain a set of position parameters of the rotor shaft detected from the detachable detection surface, including: the detection module is configured to perform detection processing on the displacement signal group based on a set excitation signal to obtain an amplitude signal group of the displacement signal group; the signal conditioning module is configured to perform arithmetic amplification processing on the amplitude signal group to obtain a set of DC voltage signals as a set of position parameters of the rotor shaft detected from the detachable detection surface.

[0011] In some embodiments, the control unit determines whether the detachable detection surface is qualified according to a set of position parameters of the rotor shaft detected from the detachable detection surface, including: determining the maximum position parameter and the minimum position parameter in a set of position parameters of the rotor shaft detected from the detachable detection surface; determining whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to a set error range; if the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, it is determined that the detachable detection surface is unqualified.

[0012] Matched with the above device, on the other hand, the present invention provides a magnetic levitation motor, including: a magnetic levitation rotor; the magnetic levitation rotor is a rotor that has passed the inspection by the above-mentioned inspection device for the magnetic levitation rotor.

[0013] Matched with the above-mentioned inspection device for the magnetic levitation rotor, on the other hand, in a method for inspecting a magnetic levitation rotor, the magnetic levitation rotor has a rotor shaft; the rotor shaft has a detection surface; the detection surface is a detachable detection surface; a detection tooling is also provided to match the rotor shaft, and the detection tooling includes: a detection bearing; the rotor shaft can be sleeved in the detection bearing, and the detachable detection surface can be located in the detection bearing; the method for inspecting the magnetic levitation rotor includes: during the process that the rotor shaft rotates one week at a set speed, detecting the displacement of the rotor shaft from the detachable detection surface to obtain a set of displacement signals of the rotor shaft detected from the detachable detection surface, denoted as a displacement signal group; processing the displacement signal group to obtain a set of position parameters of the rotor shaft detected from the detachable detection surface; determining whether the detachable detection surface is qualified according to a set of position parameters of the rotor shaft detected from the detachable detection surface; and if it is determined that the detachable detection surface is unqualified, determining that the detachable detection surface needs to be replaced and continuing to determine whether the other replaced detachable detection surfaces are qualified.

[0014] In some embodiments, the displacement signal group is processed to obtain a set of position parameters of the rotor shaft detected from the detachable detection surface, including: based on a set excitation signal, performing demodulation processing on the displacement signal group to obtain an amplitude signal group of the displacement signal group; performing arithmetic amplification processing on the amplitude signal group to obtain a set of DC voltage signals as a set of position parameters of the rotor shaft detected from the detachable detection surface.

[0015] In some embodiments, according to a set of position parameters of the rotor shaft detected from the detachable detection surface, it is determined whether the detachable detection surface is qualified, including: determining the maximum position parameter and the minimum position parameter in a set of position parameters of the rotor shaft detected from the detachable detection surface; determining whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to a set error range; if the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, it is determined that the detachable detection surface is unqualified.

[0016] Thus, in the solution of the present invention, by determining the detection surfaces on the rotor shaft of the magnetic levitation rotor, each detection surface on the rotor shaft is set in a detachable form; and a detection bearing is arranged between each detection surface and the eddy current sensor. When the rotor shaft rotates, according to the displacement detection signal output by the eddy current sensor, it is determined whether the material and density of the corresponding detection surface are uniform, and when the material and density of a detection surface are not uniform, the detection surface is disassembled and replaced until the material and density of the replaced detection surface are uniform; thereby, by setting the detection surface of the magnetic levitation rotor in a detachable form and replacing the detection surface of the magnetic levitation rotor when the material and density of the detection surface of the magnetic levitation rotor are not uniform, it is possible to avoid the distortion of the displacement detection signal of the suspension position of the magnetic levitation rotor caused by the non-uniform material and density of the detection surface of the magnetic levitation rotor, which is beneficial to improving the suspension stability of the magnetic levitation rotor.

[0017] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0018] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the detection device for the magnetic levitation rotor of the present invention;

[0020] Figure 2 It is a schematic overall structural diagram of an embodiment of the detection device for the non-uniform material and density of the detection surface of a magnetic levitation rotor shaft of the present invention;

[0021] Figure 3 A side structure schematic diagram of a detection bearing structure of an embodiment of a detection device for uneven material and density of a detection surface of a magnetic levitation rotor shaft according to the present invention;

[0022] Figure 4 A flowchart schematic diagram of an embodiment of a detection method for uneven material and density of a detection surface of a magnetic levitation rotor shaft according to the present invention;

[0023] Figure 5 A flowchart schematic diagram of an embodiment of a detection method for a magnetic levitation rotor according to the present invention;

[0024] Figure 6 A flowchart schematic diagram of an embodiment of processing a displacement signal group in the method according to the present invention;

[0025] Figure 7 A flowchart schematic diagram of an embodiment of determining whether a detachable detection surface is qualified in the method according to the present invention.

[0026] In combination with the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0027] 1 - Rotor shaft; 2 - Detection bearing; 3 - Detachable detection surface; 4 - Displacement sensor; 5 - Gap (i.e., the gap between the rotor shaft and the detection bearing); 6 - Uneven material area of the detection surface of the rotor shaft (assuming an uneven material area of the detection surface of the rotor shaft); 7 - Ball bearing. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Aiming at the problem that the uneven material and density of the detection surface of the magnetic levitation rotor cause the monitoring data of the eddy current sensor to be distorted, thus affecting the stability of the entire magnetic levitation system, the solution of the present invention proposes a detection device for the magnetic levitation rotor, specifically a magnetic levitation rotor with a detachable detection surface, and a detection device for uneven material and density of the detection surface, aiming to solve the problem that the uneven material and density of the detection surface of the magnetic levitation rotor cause the monitoring data of the eddy current sensor to be distorted, thus affecting the stability of the entire magnetic levitation system.

[0030] According to an embodiment of the present invention, a detection device for a magnetic levitation rotor is provided. Refer to Figure 1Schematic structural diagram of an embodiment of the device of the present invention. The magnetic levitation rotor has a rotor shaft 1. The rotor shaft 1 has a detection surface. The detection surface is a detachable detection surface 3.

[0031] The detection device of the magnetic levitation rotor includes: a detection tooling. That is, it is matched with the rotor shaft 1, and a detection tooling is also provided. The detection tooling includes: a detection bearing 2. The rotor shaft 1 can be sleeved in the detection bearing 2, and the detachable detection surface 3 can be located in the detection bearing 2. That is to say, the detection bearing 2 can be sleeved around the rotor shaft 1.

[0032] In some embodiments, on the rotor shaft 1, the number of detection surfaces is two. The number of the detection bearings 2 is the same as the number of the detection surfaces. The distance between the two detection bearings 2 can be adjusted, such as adjusted by a sliding member (such as a slide rail) to adapt to different lengths of the rotor shaft 1.

[0033] Figure 2 Schematic overall structural diagram of an embodiment of a detection device for uneven material and density of the detection surface of a magnetic levitation rotor shaft of the present invention. As Figure 2 Shown, a detection device for uneven material and density of the detection surface of a magnetic levitation rotor shaft provided by the solution of the present invention includes: a rotor shaft 1. The rotor shaft 1 has two detection surfaces. One of the two detection surfaces is the forward detection surface of the rotor shaft 1, and the other detection surface is the backward detection surface of the rotor shaft 1. Both of the two detection surfaces are detachable detection surfaces 3. Around each detection surface on the rotor shaft 1, a detection bearing 2 is sleeved. At a pair of opposite positions around the detection bearing 2, a pair of displacement sensors are provided. Each displacement sensor 4 in the pair of displacement sensors can be an eddy current sensor. The positions of the two detection bearings 2 respectively provided for the two detection surfaces, and the distance between the two detection bearings 2 can be adjusted according to the length of the rotor shaft 1 and the positions of the two detection surfaces on the rotor shaft 1, for example, can be adjusted movably by a slide rail.

[0034] Among them, when the rotor shaft 1 rotates, the displacement signals at the corresponding detection surfaces detected by each pair of displacement sensors are processed by the signal processing and quality inspection result display unit, and the processing results are displayed.

[0035] In some embodiments, the detachable detection surface 3 is installed on the body of the rotor shaft 1 by a bonding method. The body of the rotor shaft 1 refers to the remaining part of the rotor shaft 1 except the detachable detection surface 3.

[0036] In Figure 2In the example shown, each detection surface can be fixed to the rotor shaft 1 by bonding to form a detachable detection surface 3.

[0037] The detection device for the magnetic levitation rotor further includes: a displacement acquisition unit, a signal processing unit, and a control unit. The displacement acquisition unit, such as a displacement sensor 4. The signal processing unit, such as a detection circuit and a signal conditioning circuit. The control unit, such as an MCU.

[0038] Among them, the displacement acquisition unit is arranged on the periphery of the detection bearing 2 and at a position corresponding to a set detection point on the detachable detection surface 3, that is, arranged on the periphery of the detection bearing 2 and at a position corresponding to the set detection point on the detachable detection surface 3 on the rotor shaft 1, and is configured to detect the displacement of the rotor shaft 1 from the detachable detection surface 3 during one revolution of the rotor shaft 1 at a set rotational speed, and obtain a set of displacement signals of the rotor shaft 1 detected from the detachable detection surface 3, denoted as a displacement signal group.

[0039] In some embodiments, the displacement acquisition unit includes: a pair of eddy current sensors.

[0040] Each of the pair of eddy current sensors is arranged on the periphery of the detection bearing 2 and at a position corresponding to its respective set detection point on the detachable detection surface 3. The set detection point where one of the pair of eddy current sensors is located and the set detection point where the other eddy current sensor is located are arranged at 180°.

[0041] When designing the magnetic levitation rotor, the part of the rotor shaft of the magnetic levitation rotor to be detected by the displacement sensor is designed as a detachable detection surface, such as Figure 2 shown. If the detection is unqualified, only the detection surface can be replaced without remelting the entire rotor. The two detection bearings of the detection device for the uneven material and density of the detection surface of the magnetic levitation rotor shaft can freely adjust the distance to adapt to rotor shafts 1 of different lengths. A pair of displacement sensors are arranged at 180° and the positions are relatively fixed.

[0042] The signal processing unit is arranged between the displacement acquisition unit and the control unit, and is configured to process the displacement signal group to obtain a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3.

[0043] In some embodiments, the signal processing unit includes: a detection module and a signal conditioning module.

[0044] The signal processing unit processes the displacement signal group to obtain a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3, including:

[0045] The detection module is configured to perform detection processing on the displacement signal group based on a set excitation signal to obtain an amplitude signal group of the displacement signal group.

[0046] The signal conditioning module is configured to perform operational amplification processing on the amplitude signal group to obtain a set of DC voltage signals, which are used as a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3.

[0047] Figure 3 This is a schematic side view of the detection bearing structure of an embodiment of a detection device for uneven material and density of the detection surface of a magnetic levitation rotor shaft according to the present invention. As Figure 3 shown, the displacement signals detected by a pair of displacement sensors and the excitation signal are input to the input end of the detection circuit together. The output end of the detection circuit outputs a DC voltage signal representing the position signal of the detection surface detected by the pair of displacement sensors to the MCU after passing through a two-stage operational amplifier circuit. The MCU determines whether the material and density of the detection surface are qualified based on the position signal of the detection surface and outputs the judgment result to the display screen for display. The display screen can be a touch screen. The touch screen can also be used for human-computer interaction operations.

[0048] In Figure 3 the example shown, there is a gap 5 between the rotor shaft 1 and the detection bearing 2 to facilitate the installation of the rotor shaft 1 into the detection bearing 2. The detection bearing 2 can specifically be a ball bearing 7. Assuming that there is an unevenness 6 in the material and density of the detection surface of the rotor shaft 1, the unevenness 6 can be detected by a detection device for uneven material and density of the detection surface of a magnetic levitation rotor shaft.

[0049] As Figure 2 and Figure 3 shown in the example, each detection bearing 2 can specifically be a ball bearing, and there is a pair of eddy current sensors arranged at 180 degrees and relatively fixed in position on each ball bearing. The displacement signals detected by the pair of eddy current sensors are transmitted to the main control MCU after a series of signal conditioning such as resonance, detection, and amplification through the signal processing and quality inspection result display unit. The detection process proposed by the solution of the present invention can be regarded as a process in the production process of a magnetic levitation main shaft. The structure is simple and the operation is convenient, and it consists only of a ball bearing and a touch screen. Since the magnetic levitation system involved in the solution of the present invention uses a non-contact eddy current displacement sensor and the displacement signal is crucial for its stable control, the requirements for the detection surface are relatively high.

[0050] The entire eddy current sensor relies on the law of electromagnetic induction to achieve non-contact measurement of metals within the sensor's measurement range. When a metal conductor is placed in a changing magnetic field environment, closed swirling induced currents will be generated inside the metal conductor, which are called eddy currents. Under the action of a high-frequency sinusoidal excitation signal, the change of the eddy current generated by electromagnetic induction can be converted into the change of the equivalent impedance of the LC parallel resonant circuit composed of the eddy current displacement sensor coil and a fixed capacitor (such as capacitor C). This change in equivalent impedance can be processed subsequently and converted into the analog electrical signal output of the eddy current displacement sensor, which is transmitted into the main control chip MCU after peak detection, filtering, and operational amplification.

[0051] Among them, since the geometric center positions of a pair of eddy current sensors are relatively fixed with respect to the geometric center of the ball bearing, the displacement detection signals of the pair of eddy current sensors should theoretically remain unchanged. However, in the actual process, due to factors such as the uneven material and density of the detection surface of the rotor shaft 1, the displacement signals detected by the pair of eddy current sensors fluctuate. During one rotation of the magnetic levitation rotor, the program of the MCU records the position signals (i.e., displacement signals) and finds the maximum value x max and the minimum value x min , and determines whether the value of |x max - x min | is within the set error band Δ: If so, it means the magnetic levitation rotor is qualified; if not, it means the magnetic levitation rotor is unqualified. The error band Δ represents the allowable fluctuation error of the displacement signal that does not affect the control accuracy of the magnetic levitation bearing.

[0052] The control unit is configured to determine whether the detachable detection surface 3 is qualified according to a set of position parameters of the rotor shaft 1 detected at the detachable detection surface 3. And,

[0053] In some embodiments, the control unit determines whether the detachable detection surface 3 is qualified according to a set of position parameters of the rotor shaft 1 detected at the detachable detection surface 3, including:

[0054] The control unit is specifically further configured to determine the maximum position parameter and the minimum position parameter in a set of position parameters of the rotor shaft 1 detected at the detachable detection surface 3.

[0055] The control unit is specifically further configured to determine whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to the set error range. The set error range is, for example, the error band Δ.

[0056] The control unit is specifically further configured to determine that the detachable detection surface 3 is unqualified if the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than a set error range. Of course, if the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to the set error range, it is determined that the detachable detection surface 3 is qualified.

[0057] Figure 4 The figure is a schematic flowchart of an embodiment of a detection method for uneven material and density of the detection surface of a magnetic levitation rotor shaft of the present invention. As Figure 4 shown, a detection method for uneven material and density of the detection surface of a magnetic levitation rotor shaft provided by the solution of the present invention includes:

[0058] Step 1: Install the rotor shaft 1 of the magnetic levitation rotor into the detection device, align the displacement sensor 4 with the detection surface, and start the detection.

[0059] Step 2: Control the rotor shaft 1 to rotate one week at a set speed, such as manually and slowly rotating the rotor shaft 1 one week.

[0060] Step 3: Through the principle of electromagnetic induction, the eddy current sensor converts the change in the surface distance from the detection surface of the rotor shaft 1 into the change in the parallel impedance value of the eddy current sensor and the resonant capacitor (such as capacitor C). The detection device for uneven material and density of the detection surface of the magnetic levitation rotor shaft identifies this change by inputting a sine wave excitation signal, and after being amplified by the operational amplifier, it is transmitted to the MCU. The program of the MCU records the position signal of the rotor shaft 1 rotating one week and finds the maximum value x max and the minimum value x min . The error band Δ represents the allowable fluctuation error of the displacement signal that does not affect the control accuracy of the magnetic levitation bearing. Determine whether the value of |x max -x min | is within the error band Δ. If it is, the rotor is qualified; otherwise, it is unqualified, and it is displayed on the screen.

[0061] Step 4: If the rotor is qualified, end the detection. Otherwise, replace the detection surface, and then return to Step 1 to re-detect until it is qualified.

[0062] The control unit is further configured to determine that the detachable detection surface 3 needs to be replaced if it is determined that the detachable detection surface 3 is unqualified, and continue to determine whether the other detachable detection surfaces after replacement are qualified until the other detachable detection surfaces after replacement are qualified.

[0063] The solution of the present invention is directed to a magnetic levitation motor using an eddy current sensor, and proposes a rotor shaft with a detachable detection surface. When the material and density of the detection surface are unqualified, it can be disassembled and replaced. A detection device for the magnetic levitation rotor is also proposed. Before the magnetic levitation rotor is installed, a detection link for the material and density of the detection surface of the magnetic levitation rotor is added to identify unqualified rotor shafts, ensuring the stable suspension accuracy of the magnetic levitation rotor. In the treatment of unqualified products, a detachable detection surface is introduced, so that only the detection surface of the unqualified magnetic levitation rotor needs to be replaced, eliminating the work of remelting and remanufacturing unqualified products, and greatly reducing the manufacturing cost of qualified rotors. Thus, the problem that the monitoring data of the eddy current sensor is distorted due to the uneven material of the detection surface of the magnetic levitation rotor shaft, thereby affecting the suspension stability of the entire rotor, is solved.

[0064] Adopting the technical solution of the present invention, by determining the detection surface on the rotor shaft of the magnetic levitation rotor, each detection surface on the rotor shaft is set in a detachable form. And a detection bearing is arranged between each detection surface and the eddy current sensor. When the rotor shaft rotates, according to the displacement detection signal output by the eddy current sensor, it is determined whether the material and density of the corresponding detection surface are uniform, and when the material and density of the detection surface are uneven, the detection surface is disassembled and replaced until the material and density of the replaced detection surface are uniform. Thus, by setting the detection surface of the magnetic levitation rotor in a detachable form and replacing the detection surface of the magnetic levitation rotor when the material and density of the detection surface of the magnetic levitation rotor are uneven, it is possible to avoid the distortion of the displacement detection signal of the suspension position of the magnetic levitation rotor caused by the uneven material and density of the detection surface of the magnetic levitation rotor, which is beneficial to improving the suspension stability of the magnetic levitation rotor.

[0065] According to an embodiment of the present invention, a magnetic levitation motor corresponding to the detection device of the magnetic levitation rotor is also provided. The magnetic levitation motor may include: a magnetic levitation rotor. The magnetic levitation rotor is a rotor that has passed the detection by the above-mentioned detection device of the magnetic levitation rotor.

[0066] Since the processing and functions implemented by the magnetic levitation motor in this embodiment are basically corresponding to the embodiments, principles and examples of the device, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments, and no further elaboration will be made here.

[0067] By adopting the technical solution of the present invention, by determining the detection surface on the rotor shaft of the magnetic levitation rotor, each detection surface on the rotor shaft is set in a detachable form. A detection bearing is arranged between each detection surface and the eddy current sensor. When the rotor shaft rotates, according to the displacement detection signal output by the eddy current sensor, it is determined whether the material and density of the corresponding detection surface are uniform. When the material and density of the detection surface are not uniform, the detection surface is disassembled and replaced until the material and density of the replaced detection surface are uniform, eliminating the work of remelting and remanufacturing unqualified products and greatly reducing the manufacturing cost of qualified rotors.

[0068] According to an embodiment of the present invention, there is also provided a detection method for a magnetic levitation rotor corresponding to a magnetic levitation motor, as Figure 5 shown in the flowchart of an embodiment of the method of the present invention. The magnetic levitation rotor has a rotor shaft 1. The rotor shaft 1 has a detection surface. The detection surface is a detachable detection surface 3. Matched with the rotor shaft 1, a detection tooling is also provided. The detection tooling includes: a detection bearing 2. The rotor shaft 1 can be sleeved in the detection bearing 2, and the detachable detection surface 3 can be located in the detection bearing 2. That is to say, the detection bearing 2 can be sleeved around the rotor shaft 1.

[0069] The detection method of the magnetic levitation rotor includes: step S110 to step S140.

[0070] In step S110, through the displacement acquisition unit, during the process that the rotor shaft 1 rotates one week at a set speed, the displacement of the rotor shaft 1 is detected from the detachable detection surface 3, and a set of displacement signals of the rotor shaft 1 detected from the detachable detection surface 3 is obtained, denoted as the displacement signal group. The displacement acquisition unit is arranged outside the detection bearing 2 and at a position corresponding to the set detection point on the detachable detection surface 3, that is, arranged outside the detection bearing 2 and at a position corresponding to the set detection point on the detachable detection surface 3 of the rotor shaft 1. The displacement acquisition unit is, for example, a displacement sensor 4.

[0071] In step S120, the displacement signal group is processed to obtain a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3.

[0072] In some embodiments, the specific process of processing the displacement signal group in step S120 to obtain a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3 is as follows in the following exemplary description.

[0073] The following combines Figure 6Schematic diagram of a process flow of an embodiment for processing a displacement signal group in the method of the present invention, further illustrating the specific process of processing the displacement signal group in step S120, including: step S210 and step S220.

[0074] Step S210: Based on a set excitation signal, perform demodulation processing on the displacement signal group to obtain an amplitude signal group of the displacement signal group.

[0075] Step S220: Perform operational amplification processing on the amplitude signal group to obtain a set of DC voltage signals, which are used as a set of position parameters of the rotor shaft 1 detected at the detachable detection surface 3.

[0076] Figure 3 Side structure schematic diagram of a detection bearing structure of an embodiment of a detection device for uneven material and density of a detection surface of a magnetic levitation rotor shaft of the present invention. As Figure 3 shown, displacement signals detected by a pair of displacement sensors and the excitation signal are input together to the input end of a demodulation circuit. The output end of the demodulation circuit outputs a DC voltage signal representing the position signal of the detection surface detected by the pair of displacement sensors to the MCU after passing through a two-stage operational amplifier circuit. The MCU determines whether the material and density of the detection surface are qualified based on the position signal of the detection surface, and outputs the determination result to a display screen for display. The display screen can be a touch screen. The touch screen can also be used for human-computer interaction operations.

[0077] In Figure 3 the example shown, there is a gap 5 between the rotor shaft 1 and the detection bearing 2 to facilitate the installation of the rotor shaft 1 into the detection bearing 2. The detection bearing 2 can specifically be a ball bearing 7. Assume that there is an unevenness 6 in the material and density of the detection surface of the rotor shaft 1, and the unevenness 6 can be detected by the detection device for uneven material and density of the detection surface of the magnetic levitation rotor shaft.

[0078] As Figure 2 and Figure 3 shown in the example, each detection bearing 2 can specifically be a ball bearing, and there is a pair of eddy current sensors arranged at 180 degrees and relatively fixed in position on each ball bearing. The displacement signals detected by the pair of eddy current sensors are transmitted to the main control MCU after a series of signal conditioning such as resonance, demodulation, and amplification through a signal processing and quality inspection result display unit. The detection process proposed by the solution of the present invention can be regarded as an operation in the production process of a magnetic levitation spindle, with a simple structure and convenient operation, consisting only of a ball bearing and a touch screen. Since the magnetic levitation system involved in the solution of the present invention uses non-contact eddy current displacement sensors and displacement signals are crucial for its stable control, the requirements for the detection surface are relatively high.

[0079] The entire eddy current sensor relies on the law of electromagnetic induction to achieve non-contact measurement of metals within the measurement range of the sensor. When a metal conductor is placed in a changing magnetic field environment, closed vortex-shaped induced currents will be generated inside the metal conductor, which are called eddy currents. Under the action of a high-frequency sinusoidal excitation signal, the change of the eddy current generated by electromagnetic induction can be converted into the change of the equivalent impedance of the LC parallel resonance circuit composed of the coil of the eddy current displacement sensor and a fixed capacitor (such as capacitor C). This change in equivalent impedance can be processed subsequently and converted into the analog electrical signal output of the eddy current displacement sensor, which is transmitted into the main control chip MCU after peak detection, filtering, and operational amplification.

[0080] Among them, since the geometric center positions of a pair of eddy current sensors and the ball bearing are relatively fixed, the displacement detection signals of the pair of eddy current sensors should theoretically remain unchanged. However, in the actual process, due to factors such as uneven material and density of the detection surface of the rotor shaft 1, the displacement signals detected by the pair of eddy current sensors fluctuate. During one rotation of the magnetic levitation rotor, the program of the MCU records the position signals (i.e., displacement signals) and finds the maximum value x max and the minimum value x min , and determines whether the value of |x max -x min | is within the set error band Δ: if so, it means that the magnetic levitation rotor is qualified; if not, it means that the magnetic levitation rotor is unqualified. The error band Δ represents the fluctuation error of the displacement signal that can be accepted without affecting the control accuracy of the magnetic levitation bearing.

[0081] At step S130, according to a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3, it is determined whether the detachable detection surface 3 is qualified. And,

[0082] In some embodiments, the specific process of determining whether the detachable detection surface 3 is qualified according to a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3 in step S130 is as follows in the following exemplary description.

[0083] The following combines Figure 7 a schematic flowchart of an embodiment of determining whether the detachable detection surface 3 is qualified in the method of the present invention shown, and further illustrates the specific process of determining whether the detachable detection surface 3 is qualified in step S130, including: step S310 to step S330.

[0084] Step S310, determine the maximum position parameter and the minimum position parameter in a set of position parameters of the rotor shaft 1 detected from the detachable detection surface 3.

[0085] Step S320: Determine whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to a set error range. The set error range is, for example, the error band Δ.

[0086] Step S330: If the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, determine that the detachable detection surface 3 is unqualified. Of course, if the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to the set error range, determine that the detachable detection surface 3 is qualified.

[0087] Figure 4 It is a schematic flowchart of an embodiment of a detection method for uneven material and density of the detection surface of a magnetic levitation rotor shaft of the present invention. As Figure 4 shown, a detection method for uneven material and density of the detection surface of a magnetic levitation rotor shaft provided by the solution of the present invention includes:

[0088] Step 1: Install the rotor shaft 1 of the magnetic levitation rotor into the detection device, align the displacement sensor 4 with the detection surface, and start the detection.

[0089] Step 2: Control the rotor shaft 1 to rotate one week at a set speed, such as manually and slowly rotating the rotor shaft 1 one week.

[0090] Step 3: The eddy current sensor converts the change in the surface distance from the detection surface of the rotor shaft 1 into a change in the parallel impedance value of the eddy current sensor and the resonant capacitor (such as capacitor C) through the principle of electromagnetic induction. The detection device for uneven material and density of the detection surface of the magnetic levitation rotor shaft identifies this change by inputting a sine wave excitation signal, amplifies it through an operational amplifier, and transmits it to the MCU. The program of the MCU records the position signal of the rotor shaft 1 rotating one week and finds the maximum value x max and the minimum value x min . The error band Δ represents the allowable displacement signal fluctuation error without affecting the control accuracy of the magnetic levitation bearing. Judge whether the value of |x max -x min | is within the error band Δ. If it is, the rotor is qualified; otherwise, it is unqualified, and it is displayed on the screen.

[0091] Step 4: If the rotor is qualified, end the detection. Otherwise, replace the detection surface, and then return to Step 1 to re-detect until it is qualified.

[0092] At step S140, if it is determined that the detachable detection surface 3 is unqualified, it is determined that the detachable detection surface 3 needs to be replaced, and continue to determine whether the other replaced detachable detection surfaces are qualified until the other replaced detachable detection surfaces are qualified.

[0093] The solution of the present invention is directed to a magnetic levitation motor using an eddy current sensor, and proposes a rotor shaft with a detachable detection surface. When the material and density of the detection surface are unqualified, it can be disassembled and replaced. A detection device for a magnetic levitation rotor is also proposed. Before installing the magnetic levitation rotor, a detection link for the material and density of the detection surface of the magnetic levitation rotor is added to screen out unqualified rotor shafts, ensuring the stable suspension accuracy of the magnetic levitation rotor. In the treatment of unqualified products, a detachable detection surface is introduced, so that only the detection surface of the unqualified magnetic levitation rotor needs to be replaced, saving the work of remelting and remanufacturing unqualified products, and greatly reducing the manufacturing cost of qualified rotors. Thus, the problem that the monitoring data of the eddy current sensor is distorted due to the uneven material of the detection surface of the magnetic levitation rotor shaft, thereby affecting the stable suspension of the entire rotor, is solved.

[0094] Since the processing and functions implemented by the method of this embodiment are basically corresponding to the embodiments, principles and examples of the foregoing magnetic levitation motor, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments and will not be repeated here.

[0095] By adopting the technical solution of this embodiment, by determining the detection surface on the rotor shaft of the magnetic levitation rotor, each detection surface on the rotor shaft is set in a detachable form; and a detection bearing is provided between each detection surface and the eddy current sensor. When the rotor shaft rotates, according to the displacement detection signal output by the eddy current sensor, it is determined whether the material and density of the corresponding detection surface are uniform, and when the material and density of the detection surface are uneven, the detection surface is disassembled and replaced until the material and density of the replaced detection surface are uniform, ensuring the stable suspension accuracy of the magnetic levitation rotor.

[0096] In summary, it is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0097] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A detection device for a magnetic levitation rotor, characterized in that, The magnetic levitation rotor has a rotor shaft (1); the rotor shaft (1) has a detection surface; The detection surface is a detachable detection surface (3); The detection device of the magnetic levitation rotor includes: a detection tooling; the detection tooling includes: a detection bearing (2); the rotor shaft (1) can be sleeved in the detection bearing (2), and the detachable detection surface (3) can be located in the detection bearing (2); The detection device of the magnetic levitation rotor further includes: a displacement acquisition unit, a signal processing unit and a control unit; Wherein, The displacement acquisition unit is arranged outside the detection bearing (2) and at a position corresponding to a set detection point on the detachable detection surface (3), and is configured to detect the displacement of the rotor shaft (1) from the detachable detection surface (3) during one rotation of the rotor shaft (1) at a set speed, and obtain a set of displacement signals of the rotor shaft (1) detected from the detachable detection surface (3), denoted as a displacement signal group; The signal processing unit is configured to process the displacement signal group to obtain a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3); The control unit is configured to determine whether the detachable detection surface (3) is qualified according to a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3); and, If it is determined that the detachable detection surface (3) is unqualified, it is determined that the detachable detection surface (3) needs to be replaced, and it continues to determine whether the other replaced detachable detection surfaces are qualified. When the material and density of the detection surface are uneven, the detection surface is disassembled and replaced until the material and density of the replaced detection surface are uniform.

2. The detection device for the magnetic levitation rotor according to claim 1, characterized in that, On the rotor shaft (1), the number of the detection surfaces is two; the number of the detection bearings (2) is the same as the number of the detection surfaces; the distance between the two detection bearings (2) can be adjusted to adapt to the length of the rotor shaft (1).

3. The detection device for the magnetic levitation rotor according to claim 1, wherein, The detachable detection surface (3) is installed on the body of the rotor shaft (1) by a bonding method.

4. The detecting device for the magnetic levitation rotor according to claim 1, wherein The displacement acquisition unit includes: a pair of eddy current sensors; Each of the pair of eddy current sensors is arranged outside the detection bearing (2) and at a position corresponding to its respective set detection point on the detachable detection surface (3); the set detection point where one eddy current sensor in the pair of eddy current sensors is located and the set detection point where the other eddy current sensor is located are arranged at 180°.

5. The detecting device for a magnetic levitation rotor according to any one of claims 1 to 4, characterized in that, The signal processing unit includes: a demodulation module and a signal conditioning module; The signal processing unit processes the displacement signal group to obtain a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3), including: The demodulation module is configured to perform demodulation processing on the displacement signal group based on a set excitation signal to obtain an amplitude signal group of the displacement signal group; The signal conditioning module is configured to perform operational amplification processing on the amplitude signal group to obtain a group of DC voltage signals, which are used as a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3).

6. The detection device for a magnetic levitation rotor according to any one of claims 1 to 4, characterized in that, The control unit determines whether the detachable detection surface (3) is qualified according to a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3), including: Determining the maximum position parameter and the minimum position parameter in a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3); Determining whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to a set error range; If the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, it is determined that the detachable detection surface (3) is unqualified.

7. The detecting device for the magnetic levitation rotor according to claim 5, characterized in that The control unit determines whether the detachable detection surface (3) is qualified according to a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3), including: Determining the maximum position parameter and the minimum position parameter in a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3); Determining whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to a set error range; If the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, it is determined that the detachable detection surface (3) is unqualified.

8. A magnetic levitation motor, characterized in that, Including: Magnetic levitation rotor; The magnetic levitation rotor is a rotor that has been detected and qualified by the detection device of the magnetic levitation rotor according to any one of claims 1 to 7.

9. A detection method for a magnetic levitation rotor, characterized in that, The magnetic levitation rotor has a rotor shaft (1); the rotor shaft (1) has a detection surface; the detection surface is a detachable detection surface (3); a detection tooling is also provided to match the rotor shaft (1), and the detection tooling includes: a detection bearing (2); the rotor shaft (1) can be sleeved in the detection bearing (2), and the detachable detection surface (3) can be located in the detection bearing (2); The detection method of the magnetic levitation rotor includes: During the process that the rotor shaft (1) rotates one week at a set speed, the displacement of the rotor shaft (1) is detected at the detachable detection surface (3) to obtain a group of displacement signals of the rotor shaft (1) detected at the detachable detection surface (3), denoted as the displacement signal group; Processing the displacement signal group to obtain a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3); Determining whether the detachable detection surface (3) is qualified according to a group of position parameters of the rotor shaft (1) detected at the detachable detection surface (3); and, If it is determined that the detachable detection surface (3) is unqualified, it is determined that the detachable detection surface (3) needs to be replaced, and it continues to determine whether the other detachable detection surfaces after replacement are qualified. When the material and density of the detection surface are uneven, the detection surface is disassembled and replaced until the material and density of the detection surface after replacement are uniform.

10. The detection method of the magnetic levitation rotor according to claim 9, characterized in that, Process the displacement signal group to obtain a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3), including: Based on the set excitation signal, perform demodulation processing on the displacement signal group to obtain the amplitude signal group of the displacement signal group; Perform arithmetic amplification processing on the amplitude signal group to obtain a set of DC voltage signals as a set of position parameters of the rotor shaft (1) detected at the detachable detection surface (3).

11. The detection method of the magnetic levitation rotor according to claim 9 or 10, characterized in that, Determine whether the detachable detection surface (3) is qualified according to a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3), including: Determine the maximum position parameter and the minimum position parameter in a set of position parameters of the rotor shaft (1) detected from the detachable detection surface (3); Determine whether the absolute value of the difference between the maximum position parameter and the minimum position parameter is less than or equal to the set error range; If the absolute value of the difference between the maximum position parameter and the minimum position parameter is greater than the set error range, it is determined that the detachable detection surface (3) is unqualified.

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