Highly integrated displacement / position composite sensor

Abstract

The application provides a highly integrated displacement / position composite sensor, and relates to the technical field of magnetic bearing inductance displacement and position sensor.The application is coaxially arranged with a magnetic bearing, and is used for synchronous sensing of radial displacement, axial displacement and rotor rotation angle of the magnetic bearing, and comprises a stator core, a rotor core, a partition, a stator winding, a circuit module and the like.The stator core is composed of three layers of special-shaped structure stator cores based on two different tooth structure designs of core laminations, and the stator winding adopts three completely different winding modes, so that an axial coil for axial displacement measurement, a radial coil for radial displacement measurement and a position coil for rotor position measurement are obtained, and the composite sensing function with high integration is realized in an integrated manner.The application effectively solves the technical defects of high cost and low integration in the prior art that displacement / position technology needs to rely on a combination scheme of multiple or a plurality of sensors.

Description

Technical Field

[0001] This invention relates to the field of magnetic bearing inductive displacement and position sensor technology, and in particular to a highly integrated displacement / position composite sensor. Background Technology

[0002] Magnetic levitation bearing ( Magnetic bearing Magnetic bearings (or simply magnetic bearings) levitate a rotor in mid-air using magnetic force, eliminating mechanical contact between the rotor and stator. Their working principle is based on the fact that the magnetic induction lines are perpendicular to the magnetic levitation lines, and the shaft is parallel to the magnetic levitation lines. Therefore, the rotor's weight is fixed on the running track, while the almost unloaded shaft pushes against the opposite magnetic levitation line, suspending the entire rotor on the fixed running track. Due to their numerous advantages, such as no mechanical friction, long lifespan, no oil contamination, and low noise, magnetic bearings are widely used in high-speed rotation fields such as aerospace, flywheel energy storage, and air compressors. Magnetic bearings require control of the rotor's levitation state, and their active feedback necessitates a high-sensitivity, high-resolution displacement sensor to determine the rotor's position in real time. Currently, inductive displacement sensors are widely used in displacement detection in magnetic bearing systems due to their advantages of large measurement range, high sensitivity, and high integration.

[0003] Current integrated axial and radial inductive sensors primarily combine radial and axial structures through core design. These sensors currently require two or three layers of stacked core structures, resulting in an irregular structure. Patent CN111623700A discloses a magnetic levitation bearing inductive displacement sensor. It uses multiple probe groups evenly distributed along the circumference of the magnetic levitation bearing, connecting the probes in these groups to a sine wave generation circuit and a detection circuit. However, this technical solution suffers from drawbacks, such as the magnetic field lines of the axial measurement probe being perpendicular to the rotating rotor core, which generates significant eddy current losses in the rotor core, severely impacting the axial displacement measurement bandwidth.

[0004] However, the above technical solution can only realize the axial and radial displacement measurement of the magnetic bearing rotor, but the control of the magnetic bearing, especially the control of the high-performance magnetic bearing, needs not only displacement but also adaptive current adjustment according to the rotor speed and position to reduce the vibration level of the rotor and realize a low-noise and low-vibration system. With the continuous development of magnetic bearings in the field of vibration and noise reduction, the method of active vibration reduction combined with rotor position and speed has developed rapidly, so the magnetic bearing control needs speed and position information, which generally needs external speed / position sensors or measures the rotor mechanical concave-convex structure through an eddy current sensor to realize speed measurement, which undoubtedly increases the components and complexity of the system, and is not conducive to cost and reliability. The invention patent with the publication number CN110608673 provides an integrated measurement method for rotor axial displacement, radial vibration displacement and speed, comprising the following steps: (1) laser grooving on the non-working surface of the measured rotor, the slot one circle development figure is "eight" type, the grooving is not full of the whole circumference of the measured rotor, but an interface area is reserved; (2) arranging two mutually perpendicular displacement sensors on the plane perpendicular to the axis of the measured rotor, the two displacement sensors output a series of displacement signals when passing through the non-working surface of the measured rotor; (3) the signal separation, edge detection and result calculation module are performed on the two displacement sensor output signals to the processing unit, and the axial displacement, radial vibration displacement and speed of the measured rotor are obtained at the same time. However, the above technical solution has the problems of coupling of radial displacement, axial displacement and speed information, the need for post-processing instead of directly measuring displacement information, and the technical defect of not timely measuring displacement information, because the real-time displacement information is one of the cores of feedback control.

[0005] Therefore, it is necessary to design an improved highly integrated displacement / position composite sensor to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a highly integrated displacement / position composite sensor, which, compared with the traditional inductive sensor, places the measurement displacement stator / rotor core on both sides, specifically designs the axial and radial coils, and further integrates an independent core layer in the middle, which cooperates with the design of the rotor core slot to sense the position and speed information. The manufacturing process of the composite sensor is similar to that of the traditional inductive sensor, that is, the addition of an iron core layer does not significantly increase the process complexity, greatly improving the integration and installation flexibility of the system. The highly integrated displacement / speed sensor is a new scheme that fully utilizes the inductive measurement principle and adopts multiple winding to realize reasonable magnetic circuit design, and the displacement and speed measurement core coils and circuits operate independently, which can improve the measurement information synchronously.

[0007] In a first aspect, to achieve the above object, the application provides a highly integrated displacement / position composite sensor coaxially arranged with a magnetic bearing for synchronous sensing of radial displacement, axial displacement and rotor rotation angle of the magnetic bearing; the highly integrated displacement / position composite sensor is highly integrated and arranged, and comprises:

[0008] The stator core is a sandwich structure formed by sequentially arranging and stacking three layers of stator core laminations, and comprises a first stator core and a third stator core which are arranged with identical tooth portions, and a second stator core arranged in the middle; the tooth portion of the second stator core is arranged differently from the tooth portion of the first stator core or the third stator core;

[0009] The rotor core is three layers of rotor core laminations arranged in cooperation with the three layers of stator core laminations; the second rotor core arranged in the middle is provided with a non-uniform tooth slot structure cooperating with the tooth portion of the second stator core; the first rotor core and the third rotor core arranged on both sides are circular ring structures;

[0010] The partition plate is arranged between the adjacent two layers of laminations of the three layers of stator core laminations and the three layers of rotor core laminations;

[0011] The stator winding comprises an axial coil for axial displacement measurement, radial coils for radial X and Y direction displacement measurement, and a position coil for rotor position measurement.

[0012] As a further improvement of the application, the position coil is wound around the tooth portion of the second stator core arranged in the middle and arranged in a circumferential direction, and after winding, the position coils adjacent in the circumferential direction are connected in series to form an independent position coil group.

[0013] As a further improvement of the application, the axial coils are wound around the tooth portions of the first stator core and the third stator core arranged on both sides and arranged in a circumferential direction, and after winding, the axial coils adjacent in the circumferential direction are connected in series to form a group, respectively forming an upper axial coil group and a lower axial coil group.

[0014] As a further improvement of the application, the radial coils are wound around the tooth portions of the first stator core and the third stator core arranged on both sides as a whole and arranged in an axial direction, and after winding, the radial coils of each group form a first radial coil group and a second radial coil group.

[0015] As a further improvement of the application, the partition plate is made of a non-magnetic metal material.

[0016] As a further improvement of the application, the partition plate is a metal structural member.

[0017] As a further improvement of the application, the partition plate is a metal with thermal conductivity close to that of the core.

[0018] As a further improvement of the present application, the highly integrated displacement / position composite sensor is applicable to a low frequency range, and the low frequency size is set to tens (20 kHz) to 200 kHz, too low will reduce the measurement bandwidth of the sensor, too high will cause a larger eddy current effect, greatly reducing the measurement sensitivity.

[0019] As a further improvement of the present application, the highly integrated displacement / position composite sensor further comprises a circuit module, the circuit module comprising a displacement measurement module and a position / rotation speed measurement module;

[0020] The displacement measurement module is electrically connected with the axial coil and the radial coil respectively, to form an axial sensing circuit and a radial sensing circuit; the position / rotation speed measurement module is electrically connected with the position coil, to form a position measurement circuit.

[0021] As a further improvement of the present application, the magnetic field lines formed after the independent position coil groups are energized are set to be distributed radially along the core, and repel each other in the circumferential direction.

[0022] The several pairs of independent position coil groups form position / rotation speed sensing channels, which interact with the surface of the second rotor core of the rotor, to detect the rotation angle of the rotor of the magnetic bearing.

[0023] As a further improvement of the present application, the non-uniform tooth slot structure of the second rotor core comprises a starting part (i.e. a toothless part with the widest width, providing a reference position) and a coding part (i.e. composed of a plurality of equal-width tooth slots, used to provide counting and position calculation for coding).

[0024] As a further improvement of the present application, the magnetic field lines formed after the axial coil groups of the upper layer and the lower layer are energized are set to be in the same direction, and opposite to the circumferentially adjacent coil groups.

[0025] The several pairs of axial coil groups of the upper layer and the lower layer form axial sensing channels, which interact with the surface of the magnetic bearing, to detect the axial relative displacement of the magnetic bearing.

[0026] As a further improvement of the present application, the magnetic field lines formed after the first radial coil groups arranged circumferentially adjacent are energized are opposite to the magnetic field lines formed by the adjacent coil groups.

[0027] The magnetic field lines formed after the second radial coil groups arranged circumferentially adjacent are energized are opposite to the magnetic field lines formed by the adjacent coil groups.

[0028] A plurality of pairs of the first radial coil groups and the second radial coil groups form X-direction radial sensing channels and Y-direction radial sensing channels, respectively; the radial sensing channels interact with the surface of the magnetic bearing to detect the radial relative displacement of the magnetic bearing.

[0029] As a further improvement of the present application, the X-direction radial sensing channels, the axial sensing channels, the position / speed sensing channels, the Y-direction radial sensing channels are arranged in sequence in the circumferential direction and are independently arranged.

[0030] As a further improvement of the present application, the X-direction radial sensing channels, the position / speed sensing channels, the axial sensing channels, the Y-direction radial sensing channels are arranged in sequence in the circumferential direction and are independently arranged.

[0031] In the second aspect, the present application further provides a magnetic bearing system comprising the highly integrated displacement / position composite sensor.

[0032] In the third aspect, the present application further provides an electric machine system comprising the highly integrated displacement / position composite sensor or the magnetic bearing system.

[0033] The present application has the following beneficial effects:

[0034] 1. The highly integrated displacement / position composite sensor provided by the present application has the first stator core and the third stator core arranged on both sides and having the same tooth structure, the second stator core arranged in the middle and having a different tooth structure, and the rotor core structure matched with the stator core, so that the basic configuration of the composite sensor only needs two core laminations to form a three-layer special-shaped structure core. Similar to most conventional inductive sensors, the configuration design does not obviously increase the process complexity and risk, and only needs to reasonably design the winding method of the stator winding to simultaneously realize the shaft / radial displacement and position measurement, thereby effectively overcoming the technical defects of high cost and low integration of the existing displacement / position sensing measurement technology which needs to rely on a combination of multiple sensors.

[0035] 2. The highly integrated displacement / position composite sensor provided by the present application comprises three-layer special-shaped structure stator cores formed by two different tooth structure designed core laminations, and the stator winding adopts three completely different winding methods, thereby obtaining an axial coil for axial displacement measurement, radial coils for radial X and Y direction displacement measurement, and a position coil for rotor position measurement. That is, the position / speed sensing channel, the axial sensing channel, the X-direction radial sensing channel and the Y-direction radial sensing channel are constructed by different winding structures, thereby integrally realizing the composite sensing function with high integration.

[0036] 3. The highly integrated displacement / position composite sensor provided by the application highly integrates displacement sensors and position sensors, uses a partition plate to effectively isolate the magnetic field, eliminates the negative influence between the sensors by strictly optimizing and limiting the parameters of the partition plate, and uses a sandwich structure rotor core to cooperate with the stator core, thereby realizing the synchronous sensing and measurement of the magnetic bearing displacement and the position (rotation angle).

[0037] 4. The highly integrated displacement / position composite sensor provided by the application, the winding teeth of the independent position coil for measuring the rotation angle (position) of the rotor are arranged in the circumferential direction instead of the axial direction, which can effectively prevent the magnetic force lines from vertically passing through the rotor core to increase the sensor loss, reduce the bandwidth, and cause the technical problems of poor measurement accuracy and unreliable measurement structure, and the signal fusion of the multiple independent position coil groups arranged symmetrically can effectively improve the sensitivity, thereby significantly reducing the interference of the environmental magnetic field. The core coils and circuits for displacement and rotation speed measurement operate independently, and the measurement information can be improved synchronously.

[0038] 5. The highly integrated displacement / position composite sensor provided by the application uses a full-bridge circuit structure to realize displacement measurement, significantly improves the signal-to-noise ratio of displacement detection, and performs superposition processing and data fusion on the multi-channel information of the axial displacement measurement and position information, which is helpful to further improve the signal-to-noise ratio.

[0039] The above description is only a summary of the technical solutions of the application, in order to more clearly understand the technical means of the application, the application can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The structure diagram of the stator core of the highly integrated displacement / position composite sensor provided by the application.

[0041] Figure 2 The schematic diagram of the first stator core S1 in the stator core of the highly integrated displacement / position composite sensor provided by the application.

[0042] Figure 3 The schematic diagram of the second stator core S2 in the stator core of the highly integrated displacement / position composite sensor provided by the application.

[0043] Figure 4 The schematic diagram of the third stator core S3 in the stator core of the highly integrated displacement / position composite sensor provided by the application.

[0044] Figure 5A structure diagram of a stator core of a highly integrated displacement / position composite sensor according to the present application.

[0045] Figure 6 A structure diagram of a rotor core of a highly integrated displacement / position composite sensor according to the present application.

[0046] Figure 7 A structure diagram of a whole of a highly integrated displacement / position composite sensor according to the present application.

[0047] Figure 8 A structure diagram of a typical magnetic force line direction formed by a coil winding and a current direction of a highly integrated displacement / position composite sensor according to the present application.

[0048] Figure 9 A structure diagram of a sensing channel group of a highly integrated displacement / position composite sensor according to the present application.

[0049] Figure 10 A displacement demodulation full bridge circuit of a highly integrated displacement / position composite sensor according to the present application.

[0050] Figure 11 A position demodulation circuit of a highly integrated displacement / position composite sensor according to the present application.

[0051] Reference numerals

[0052] 1 - first Y-direction coil; 2 - second Y-direction coil; 3 - third Y-direction coil; 4 - fourth Y-direction coil;

[0053] 5 - first axial-direction coil; 6 - second axial-direction coil; 5-1 - first upper layer coil; 5-2 - first lower layer coil; 6-1 - second upper layer coil; 6-2 - second lower layer coil;

[0054] 7 - first independent position coil; 8 - second independent position coil;

[0055] 9 - first X-direction coil; 10 - second X-direction coil; 11 - third X-direction coil; 12 - fourth X-direction coil;

[0056] 13 - third axial-direction coil; 14 - fourth axial-direction coil; 13-1 - third upper layer coil; 13-2 - third lower layer coil; 14-1 - fourth upper layer coil; 14-2 - fourth lower layer coil;

[0057] 15 - third independent position coil; 16 - fourth independent position coil;

[0058] 17 - fifth Y-direction coil; 18 - sixth Y-direction coil; 19 - seventh Y-direction coil; 20 - eighth Y-direction coil;

[0059] 21 - fifth axial coil; 22 - sixth axial coil; 21-1 - fifth upper coil; 21-2 - fifth lower coil; 22-1 - sixth upper coil; 22-2 - sixth lower coil;

[0060] 23 - third independent position coil; 24 - fourth independent position coil;

[0061] 25 - fifth X-direction coil; 26 - sixth X-direction coil; 27 - seventh X-direction coil; 28 - eighth X-direction coil;

[0062] 29 - seventh axial coil; 30 - eighth axial coil; 29-1 - seventh upper coil; 29-2 - seventh lower coil; 30-1 - eighth upper coil; 30-2 - eighth lower coil;

[0063] 31 - fifth independent position coil; 32 - sixth independent position coil;

[0064] R1 - first rotor core; R2 - second rotor core; R3 - third rotor core; R4 / S4 - partition; S1 - first stator core; S2 - second stator core; S3 - third stator core;

[0065] R21 - starting portion; R22 - encoding portion. DETAILED DESCRIPTION

[0066] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0068] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0069] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0070] In the description of the embodiments of the application, the term "and / or" is merely used to describe an associated relationship between associated objects, and indicates that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " herein generally indicates that the front and rear associated objects have an "or" relationship.

[0071] In the description of the embodiments of the application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0072] In the description of the embodiments of the application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship shown based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the application.

[0073] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing", and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0074] Please refer to Figures 1 to 7 As shown in the drawings, the application provides a highly integrated displacement / position composite sensor coaxially arranged with a magnetic bearing, for synchronous sensing of radial displacement, axial displacement and rotor rotation angle of the magnetic bearing; the highly integrated displacement / position composite sensor is arranged in a highly integrated manner, and includes a stator core, a rotor core, a partition plate R4 / S4, a stator winding, a circuit module, etc.

[0075] Referring to Figures 1 to 5 As shown in the figure, the stator core is a sandwich structure formed by three layers of stator core laminations arranged in sequence, including a first stator core S1 and a third stator core S3 which are completely identically arranged in the tooth part, and a second stator core S2 sandwiched in the middle; the tooth part of the second stator core S2 is arranged differently from the tooth part of the first stator core S1 or the third stator core S3.

[0076] Referring to Figure 6 As shown in the figure, the rotor core is three layers of rotor core laminations arranged in cooperation with the three layers of stator core laminations; the second rotor core R2 sandwiched in the middle is provided with a non-uniform tooth slot structure cooperating with the tooth part of the second stator core S2; the first rotor core R1 and the third rotor core R3 on both sides are both circular ring structures.

[0077] In some embodiments, the non-uniform tooth slot structure of the second rotor core R2 includes a starting part R21 (i.e. a toothless part, which has the widest width and provides a reference position), and a coding part R22 (i.e. composed of a plurality of equal-width tooth slots, used to provide counting and position calculation for coding).

[0078] Referring to Figures 1 to 7 As shown in the figure, the partition plate R4 / S4 is arranged between the adjacent two layers of laminations of the three layers of stator core laminations and the three layers of rotor core laminations.

[0079] In some embodiments, in order to mechanically protect the core laminations, a partition plate can also be arranged on both sides of the three layers of stator core laminations and the three layers of rotor core laminations, thereby achieving safe and reliable mechanical performance.

[0080] Specifically, the material of the partition plate R4 / S4 is a commonly used metal structural part, the thickness of the partition plate R4 / S4 is more than 0.2mm, and the thermal conductivity is relatively close to the thermal conductivity of the core.

[0081] In the present application, the highly integrated displacement / position composite sensor is suitable for a low frequency range, and the low frequency size is set to tens to 200kHz, too low will reduce the measurement bandwidth of the sensor, and too high will cause a large eddy current effect, greatly reducing the measurement sensitivity.

[0082] Referring to Figures 1 to 7 As shown in the figure, the stator winding includes an axial coil for axial displacement measurement, a radial coil for radial X and Y direction displacement measurement, and a position coil for rotor position measurement.

[0083] The position coil is wound around the tooth part of the second stator core S2 in the middle and arranged in the circumferential direction, and after winding, the position coils adjacent in the circumferential direction are connected in series to form an independent position coil group.

[0084] The magnetic field lines formed by energizing the independent position coil group are arranged in a direction in which the magnetic field lines of all the coils are distributed radially along the core and repulsively in a circumferential direction.

[0085] The several pairs of independent position coil groups form position / speed sensing channels, which interact with the surface of the second rotor core R2 of the rotor to detect the rotation angle of the rotor of the magnetic bearing.

[0086] The axial coils are wound along the tooth portions of the first stator core S1 and the third stator core S3 on both sides and arranged circumferentially, and after being wound, the axial coils are connected in series in groups between circumferentially adjacent axial coils to form upper and lower axial coil groups.

[0087] The upper and lower axial coil groups are axially symmetrical, and the magnetic field lines formed by energizing the upper and lower axial coil groups are arranged in the same direction and opposite to circumferentially adjacent coil groups.

[0088] The several pairs of upper and lower axial coil groups form axial sensing channels, which interact with the surface of the magnetic bearing to detect the axial relative displacement of the magnetic bearing.

[0089] The radial coils are wound around the tooth portions of the first stator core S1 and the third stator core S3 on both sides as a whole and arranged axially symmetrically, and after being wound, the radial coils form first and second radial coil groups.

[0090] The first radial coil groups arranged circumferentially adjacent to each other are energized, and the magnetic field lines formed by the first radial coil groups are arranged in a direction opposite to the magnetic field lines formed by the adjacent coil groups.

[0091] The second radial coil groups arranged circumferentially adjacent to each other are energized, and the magnetic field lines formed by the second radial coil groups are arranged in a direction opposite to the magnetic field lines formed by the adjacent coil groups.

[0092] The several pairs of first and second radial coil groups form X-direction radial sensing channels and Y-direction radial sensing channels, respectively, and the radial sensing channels interact with the surface of the magnetic bearing to detect the radial relative displacement of the magnetic bearing.

[0093] In some embodiments, the X-direction radial sensing channels, the axial sensing channels, the position / speed sensing channels, and the Y-direction radial sensing channels are arranged in a circumferential sequence and independently arranged.

[0094] In some other embodiments, the X-direction radial sensing channels, the position / speed sensing channels, the axial sensing channels, and the Y-direction radial sensing channels are arranged in a circumferential sequence and independently arranged.

[0095] Referring to Figure 10 , Figure 11 , the circuit module includes a displacement measurement module and a position / rotation speed measurement module; the displacement measurement module is electrically connected with the axial coil and the radial coil respectively to form an axial induction circuit and a radial induction circuit (displacement demodulation full-bridge circuit); and the position / rotation speed measurement module is electrically connected with the position coil to form a position measurement circuit (position demodulation circuit).

[0096] Embodiment 1

[0097] As shown in Figures 1 to 11 , embodiment 1 provides a highly integrated displacement / position composite sensor.

[0098] As can be seen from Figure 1 , the same group of axial coils for axial measurement are arranged along the circumference, rather than up and down along the axis, which can effectively prevent the magnetic force lines from vertically passing through the rotor core, generate additional eddy current loss, and reduce the measurement sensitivity and bandwidth.

[0099] In the present embodiment, the axial coil includes first to eighth upper axial coils and first to eighth lower axial coils, which are connected in series along the circumference after being wound to obtain four upper axial coil groups and four lower axial coil groups respectively.

[0100] The first upper coil 5-1 and the second upper coil 6-1 are connected in series to form an independent upper axial coil group A1, and the third upper coil 13-1 and the fourth upper coil 14-1 are connected in series to form an independent upper axial coil group A3, the fifth upper coil 21-1 and the sixth upper coil 22-1 are connected in series to form an independent upper axial coil group A5, and the seventh upper coil 29-1 and the eighth upper coil 30-1 are connected in series to form an independent upper axial coil group A7.

[0101] The first lower coil 5-2 and the second lower coil 6-2 are connected in series to form an independent lower axial coil group A2, the third lower coil 13-2 and the fourth lower coil 14-2 are connected in series to form an independent lower axial coil group A4, the fifth lower coil 21-2 and the sixth lower coil 22-2 are connected in series to form an independent lower axial coil group A6, and the seventh lower coil 29-2 and the eighth lower coil 30-2 are connected in series to form an independent lower axial coil group A8.

[0102] The upper axial coil group A1 and the lower axial coil group A2 are symmetrically arranged up and down, the upper axial coil group A5 and the lower axial coil group A6 are symmetrically arranged up and down, the upper axial coil group A3 and the upper axial coil group A4 are symmetrically arranged up and down, and the upper axial coil group A7 and the lower axial coil group A8 are symmetrically arranged up and down.

[0103] In the embodiment, the upper axial coil group A1, the lower axial coil group A2, the upper axial coil group A5 and the lower axial coil group A6 are used as a first axial sensing channel to measure axial displacement. Similarly, the upper axial coil group A3, the upper axial coil group A4, the upper axial coil group A7 and the upper axial coil group A8 are used as a second axial sensing channel to measure axial displacement. Therefore, the sensor has two axial measurement channels and can accurately sense axial displacement.

[0104] The radial coil for radial measurement is wound around the teeth of the first stator core S1 and the teeth of the third stator core S3 as a whole.

[0105] In the embodiment, the radial coil includes first to eighth Y-direction coils and first to eighth X-direction coils, which are connected in series in the circumferential direction after being wound to obtain four Y-direction radial coil groups and four X-direction radial coil groups, respectively.

[0106] The first Y-direction coil 1 and the second Y-direction coil 2 form an independent first radial coil group B1. The third Y-direction coil 3 and the fourth Y-direction coil 4 form an independent second radial coil group B2.

[0107] The fifth Y-direction coil 17 and the sixth Y-direction coil 18 form an independent third radial coil group B3, and the seventh Y-direction coil 19 and the eighth Y-direction coil 20 form an independent fourth radial coil group B4.

[0108] The first X-direction coil 9 and the second X-direction coil 10 form an independent first radial coil group C1, and the third X-direction coil 11 and the fourth X-direction coil 12 form an independent second radial coil group C2.

[0109] The fifth X-direction coil 25 and the sixth X-direction coil 26 form an independent third radial coil group C3, and the seventh X-direction coil 27 and the eighth X-direction coil 28 form an independent fourth radial coil group C4.

[0110] The radial coil groups B1, B2, B3 and B4 are used as a first radial sensing channel to measure Y-direction displacement. Similarly, the radial coil groups C1, C2, C3 and C4 are used as a second radial sensing channel to measure X-direction displacement.

[0111] The position coil for position measurement is wound around the second stator core S2.

[0112] In the embodiment, the independent position coil includes first to eighth independent position coils, which are connected in series in the circumferential direction after being wound to obtain first to fourth position coil groups, respectively.

[0113] The first independent position coil 7 and the second independent position coil 8 form an independent first position coil group P1, the third independent position coil 15 and the fourth independent position coil 16 form an independent second position coil group P2, the fifth independent position coil 23 and the sixth independent position coil 24 form an independent third position coil group P3, and the seventh independent position coil 31 and the eighth independent position coil 32 form an independent fourth position coil group P4.

[0114] Figure 8 The magnetic force lines formed by the independent coil winding and the current direction are opposite between adjacent teeth of the independent coil group, such as the first radial coil group B1, to form an independent magnetic force line loop, and the magnetic force lines are opposite between the independent coil groups, such as the first radial coil group B1 and the second radial coil group B2.

[0115] The magnetic force lines of the independent coil group, such as the upper axial coil group A1, are opposite to the adjacent coil groups B2 and P1, and the magnetic force lines of the independent coil groups, such as the upper axial coil group A1 and the lower axial coil group A2, are the same.

[0116] The position coil, such as the first position coil group P1, is opposite to the adjacent coil groups A1 and C1.

[0117] Figure 10 The displacement demodulation full-bridge circuit for the independent coil group of the sensor is formed from Figure 10 As can be seen from the above, the four bridge arms of the circuit structure proposed in the embodiment of the present application are all sensitive to the displacement change, while the traditional half-bridge structure only has two bridge arms sensitive to the displacement change, and the other two are usually fixed resistors, so the sensitivity of the full-bridge circuit is nearly twice that of the current half-bridge circuit, which is beneficial to improve the signal-to-noise ratio of the circuit.

[0118] For the axial measurement circuit, the initial sensitivity is low, so the multi-channel signal addition method is used to obtain the displacement, such as the signals of the axial displacement corresponding voltages Uout1 and Uout2 are superimposed, to further improve the sensitivity of the axial displacement measurement.

[0119] Figure 11 The position demodulation circuit for the independent coil group of the sensor is formed from Figure 11 As can be seen from the above, the series LCR inductance demodulation circuit proposed in the embodiment of the present application, after measuring the inductance of the position coil, based on the position calibration relationship of the inductance value already measured, the position information is calculated reversely.

[0120] As known by those skilled in the art, in other embodiments, different numbers of axial coils and radial coils can also be set according to actual application needs, to obtain different numbers of axial sensing channels, radial sensing channels and position / rotation speed sensing channels. It is not limited to the data settings in the above embodiments.

[0121] Embodiment 2

[0122] Embodiment 2 of the present application provides a magnetic bearing system comprising the highly integrated displacement / position composite sensor described above. In the magnetic bearing system, high-sensitivity synchronous measurement of the radial displacement, axial displacement and rotation angle of the rotor of the magnetic bearing can be achieved by the highly integrated displacement / position composite sensor.

[0123] Embodiment 3

[0124] Embodiment 3 of the present application provides a motor system comprising the highly integrated displacement / position composite sensor provided in Embodiment 1 described above, or comprising the magnetic bearing system provided in Embodiment 2 described above. In the motor system, high-sensitivity synchronous measurement of the radial displacement, axial displacement and rotation angle of the rotor of the magnetic bearing can be achieved by the highly integrated displacement / position composite sensor.

[0125] In summary, the present application provides a highly integrated displacement / position composite sensor, which relates to the technical field of magnetic bearing inductance displacement and position sensors. It is coaxially arranged with the magnetic bearing and used for synchronous sensing of the radial displacement, axial displacement and rotation angle of the rotor of the magnetic bearing. The highly integrated displacement / position composite sensor is highly integrated and comprises a stator core, a rotor core, a partition, a stator winding, a circuit module and the like. The stator core is a three-layer profiled structure stator core composed of core laminations based on two different tooth structure designs. The stator winding adopts three completely different winding methods, thereby obtaining an axial coil for axial displacement measurement, radial coils for radial X and Y direction displacement measurement, and a position coil for rotor position measurement, thereby realizing the composite sensing function with high integration in an integrated manner. The present application effectively solves the defects of high cost and low integration in the prior art in which displacement / position technology needs to rely on a combination of multiple or multiple sensors.

[0126] It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the scope of the technical solutions of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, and other ways constructed by combining part of the components of the embodiments are also included in the scope of the present application.

Claims

1. A highly integrated displacement / position composite sensor, characterized by: Coaxial with the magnetic bearing, used for synchronous sensing of radial displacement, axial displacement and rotor rotation angle of the magnetic bearing; the highly integrated displacement / position composite sensor is highly integrated, comprising: The stator core is a sandwich structure formed by sequentially arranging and stacking three layers of stator core laminations, comprising a first stator core and a third stator core with completely identical tooth portions, and a second stator core sandwiched in the middle; the tooth portion of the second stator core is different from the tooth portion of the first stator core or the third stator core; The rotor core is three layers of rotor core laminations arranged in cooperation with the three layers of stator core laminations; the second rotor core sandwiched in the middle is provided with a non-uniform tooth slot structure cooperating with the tooth portion of the second stator core; the first rotor core and the third rotor core on both sides are circular ring structures; The partition plate is arranged between the adjacent two layers of the three layers of stator core laminations and the three layers of rotor core laminations; The stator winding comprises an axial coil for axial displacement measurement, a radial coil for radial X and Y direction displacement measurement, and a position coil for rotor position measurement.

2. The highly integrated displacement / position composite sensor according to claim 1, characterized in that: The position coil is wound around the tooth portion of the second stator core in the middle and arranged circumferentially, and after winding, the circumferentially adjacent position coils are connected in series to form an independent position coil group.

3. The highly integrated displacement / position composite sensor according to claim 1, wherein: The axial coil is wound around the tooth portion of the first stator core and the tooth portion of the third stator core on both sides and arranged circumferentially, and after winding, the circumferentially adjacent axial coils are connected in series to form a group, respectively forming an upper axial coil group and a lower axial coil group.

4. The highly integrated displacement / position composite sensor according to claim 1, wherein: The radial coil is wound around the tooth portion of the first stator core and the tooth portion of the third stator core on both sides as a whole and arranged axially symmetrically, and after winding, each group of radial coils forms a first radial coil group and a second radial coil group.

5. The highly integrated displacement / position composite sensor according to claim 1, wherein: The partition plate is made of non-magnetic metal material, and the thickness of the partition plate is greater than 0.1mm; The highly integrated displacement / position composite sensor is suitable for low frequency measurement range of 20kHz to 200kHz.

6. The highly integrated displacement / position composite sensor of claim 1, wherein: The highly integrated displacement / position composite sensor further comprises a circuit module, and the circuit module comprises a displacement measurement module and a position / rotation speed measurement module; The displacement measurement module is electrically connected with the axial coil and the radial coil respectively to form an axial sensing circuit and a radial sensing circuit; the position / rotation speed measurement module is electrically connected with the position coil to form a position measurement circuit.

7. The highly integrated displacement / position composite sensor according to claim 2, wherein: After the independent position coil group is energized, the direction of the magnetic lines of force formed is that the magnetic lines of force of all the coils are distributed radially along the core, and repel each other in the circumferential direction; A plurality of independent position coil groups form a position / rotation speed sensing channel, and the position / rotation speed sensing channel interacts with the surface of the second rotor core of the rotor to detect the rotation angle of the rotor of the magnetic bearing; The non-uniform tooth slot structure of the second rotor core comprises a starting portion provided with no tooth structure for providing a reference position, and an encoding portion for providing counting and position calculation of encoding.

8. The highly integrated displacement / position composite sensor according to claim 3, wherein: After the upper axial coil group and the lower axial coil group are energized, the direction of the magnetic lines of force formed is the same, and opposite to the circumferentially adjacent coil groups. A plurality of pairs of upper axial coil groups and lower axial coil groups form axial sensing channels respectively; the axial sensing channels interact with the surface of the magnetic bearing to detect the axial relative displacement of the magnetic bearing.

9. The highly integrated displacement / position composite sensor according to claim 4, characterized in that: The circumferentially adjacent first radial coil groups form magnetic field lines in the opposite direction to the magnetic field lines formed by the adjacent coil groups when energized; The circumferentially adjacent second radial coil groups form magnetic field lines in the opposite direction to the magnetic field lines formed by the adjacent coil groups when energized; A plurality of pairs of first radial coil groups and second radial coil groups form X-direction radial sensing channels and Y-direction radial sensing channels respectively; the radial sensing channels interact with the surface of the magnetic bearing to detect the radial relative displacement of the magnetic bearing.

10. A magnetic bearing system or an electric machine system, characterized by: A highly integrated displacement / position composite sensor according to any one of claims 1 to 9.

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