Double-layer iron core compact inductive displacement sensor

Abstract

The present invention provides a double-layer iron core type compact inductive displacement sensor. The stator iron core of the sensor has a double-layer tooth portion with an upper and lower layer structure, and the structures of the upper and lower layers are exactly the same, so the molds and lamination process parameters for manufacturing are exactly the same. The present invention effectively solves the technical defect that the traditional sensor process requires secondary lamination of the conventional iron core structure to be combined into an axially radially integrated sensor stator core. The double-layer iron core type compact inductive displacement sensor proposed by the present invention can align two layers of the same iron core and install them on a support seat without secondary lamination, which can greatly reduce the complexity and difficulty of sensor manufacturing.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic bearing inductive displacement sensors, and in particular to a double-layer iron core type compact inductive displacement sensor. Background Art

[0002] Magnetic bearings( Magnetic Bearing , magnetic bearings) use magnetic force to suspend the rotor in the air, so that there is no mechanical contact between the rotor and the stator. Due to its many advantages such as no mechanical friction, long life, no oil pollution, low noise, etc., it is widely used in high-speed rotation fields such as aerospace, flywheel energy storage, and air compressors. Magnetic bearings need to control the suspension state of the rotor, and its active feedback requires a high-sensitivity and high-resolution displacement sensor to determine the rotor position in real time. At present, inductive displacement sensors are widely used in displacement detection of magnetic bearing systems due to their large measurement range, high sensitivity, and high integration.

[0003] The invention patent with publication number CN111623700A provides an inductive displacement sensor for magnetic bearings. Multiple probe groups are evenly distributed along the circumference of the magnetic bearing, and the probes in the multiple probe groups are connected to the sine wave generating circuit and the detection circuit. However, this technical solution has technical defects such as the need for three-layer core structure assembly, complex process, and the direction of the magnetic field lines of the axial measurement probe is perpendicular to the rotor rotating core, which will generate a large amount of eddy current loss in the rotor core, seriously affecting the axial displacement measurement bandwidth.

[0004] like Figure 1 As shown, the current integration method of axial-radial integrated inductive sensors is mainly to simply combine the radial and axial structures together. Since the layout of the axial measuring unit and the radial measuring unit iron cores are different, the current sensor requires a three-layer iron core structure to be stacked for use. It is a special-shaped structure. Therefore, the stacking process and assembly process of the sensor iron core are relatively high, and the cost is also higher.

[0005] The invention patent with the publication number CN115995921A provides an axial-radial integrated magnetic suspension sensor, magnetic suspension motor and turbine motor system. The sensor includes: a plurality of sensor cores, a plurality of sensor cores are staggered and superimposed to form a sensor core assembly, and the sensor core assembly includes a first sensor core and a second sensor core; a coil, the coil is installed on the sensor core assembly; a rotor, located in the annular space of the sensor core assembly, and a measured ring is arranged on the rotor; wherein the combination formed by the first magnetic pole of the first sensor core and the second magnetic pole of the second sensor core and the combination formed by the second magnetic pole of the first sensor core and the first magnetic pole of the second sensor core are calculated to detect the axial displacement of the measured ring, and the combination of the first magnetic pole of the first sensor core and the first magnetic pole of the second sensor core detects the radial displacement of the measured ring. However, the technical solution has the technical defects of large leakage inductance at the staggered magnetic poles, which is not conducive to the sensitivity of the sensor, and low sensitivity of the single tooth measurement axial displacement scheme compared with the double-sided tooth measurement scheme.

[0006] In view of this, it is necessary to design a double-layer iron core compact inductive displacement sensor to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a double-layer iron core type compact inductive displacement sensor. Compared with the traditional special-shaped three-layer iron core structure, it only includes two layers of sensor stator iron core, and the structures of the two layers of iron core are exactly the same, which effectively avoids the process defects existing in the traditional special-shaped three-layer iron core structure, greatly simplifies the sensor iron core manufacturing process, reduces the process complexity, and improves the flexibility of installation.

[0008] To achieve the above-mentioned purpose, the present invention provides a double-layer iron core type compact inductive displacement sensor, which is coaxially arranged with a rotatable component and is used to sense the radial position and axial position of the rotatable component. In addition, the double-layer iron core type compact inductive displacement sensor is an axial-radial integrated arrangement, comprising:

[0009] The sensor stator core comprises a yoke and a double-layer tooth portion arranged along the circumference of the inner ring of the yoke; the double-layer tooth portion comprises a plurality of groups of first tooth portions and second tooth portions arranged axially symmetrically (vertically and horizontally);

[0010] A plurality of groups of axial coils, wherein the axial coils for axial displacement measurement are respectively wound along the first tooth portion and the second tooth portion in a predetermined magnetic field line direction and arranged circumferentially, and after winding, the circumferentially adjacent axial coils are connected in series to form an upper axial coil group and a lower axial coil group that are axially symmetrical, respectively;

[0011] Multiple groups of radial coils, which are used for radial displacement measurement in the X and Y directions, are wound around the double-layer tooth portion as a whole in a predetermined magnetic field line direction and are circumferentially symmetrically arranged. After winding, each group of radial coils forms a first radial coil group and a second radial coil group respectively.

[0012] As a further improvement of the present invention, the double-layer iron core type compact inductive displacement sensor further includes a sensor rotor with an air gap arranged between the sensor stator iron core.

[0013] As a further improvement of the present invention, the double-layer iron core type compact inductive displacement sensor further includes a circuit module;

[0014] The circuit module is electrically connected to the axial coil and the radial coil respectively to form an axial induction circuit and a radial induction circuit.

[0015] As a further improvement of the present invention, the circuit module adopts a full-bridge circuit.

[0016] As a further improvement of the present invention, the rotatable component is a magnetic bearing, and the rotor of the magnetic bearing moves coaxially with the sensor rotor.

[0017] As a further improvement of the present invention, the yoke of the sensor stator core is provided with a support seat for mounting the first tooth portion and the second tooth portion, and the support seat and the double-layer tooth portion are detachably connected.

[0018] As a further improvement of the present invention, after the axially symmetrical (vertically symmetrical) upper axial coil group and the lower axial coil group are energized, the directions of the magnetic lines of force formed are arranged in the same manner and are opposite to those of the circumferentially adjacent coil groups;

[0019] After the first radial coil groups arranged adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the coil groups adjacent to each other in the circumferential direction;

[0020] After the second radial coil groups adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the coil groups adjacent to each other in the circumferential direction.

[0021] As a further improvement of the present invention, a plurality of pairs of upper axial coil groups and lower axial coil groups respectively form axial sensing channels; a plurality of pairs of first radial coil groups and second radial coil groups respectively form X-direction radial sensing channels and Y-direction radial sensing channels;

[0022] The axial sensing channel and the radial sensing channel interact with the surface of the rotatable component respectively to detect the relative displacement of the rotatable component.

[0023] In order to achieve the above-mentioned purpose of the invention, the present invention also provides a magnetic bearing system, which includes the above-mentioned double-layer iron core type compact inductive displacement sensor.

[0024] In order to achieve the above-mentioned purpose of the invention, the present invention also provides a motor system, which includes the above-mentioned double-layer iron core type compact inductive displacement sensor, or includes the above-mentioned magnetic bearing system.

[0025] The beneficial effects of the present invention are:

[0026] 1. The double-layer iron core compact inductive displacement sensor provided by the present invention has a double-layer iron core structure with a completely identical double-layer tooth structure, eliminating the traditional three-layer special-shaped structure iron core. Only one stacking shape is required, and its basic shape is similar to the upper and lower layer shapes of the traditional method. Only one stacking process is required, which reduces the process complexity and risk brought by the need for secondary stacking of the three-layer special-shaped structure iron core, saves manufacturing costs, and simplifies the manufacturing process and flow; it effectively overcomes the technical defects of the existing technology of the three-layer special-shaped structure iron core preparation process, such as complex process flow and high preparation cost.

[0027] 2. In the double-layer iron core compact inductive displacement sensor provided by the present invention, the teeth of the independent coil for axial measurement are arranged along the circumferential direction rather than up and down in the axial direction, which can effectively prevent the magnetic lines of force from passing vertically through the rotor core, increasing sensor losses and reducing bandwidth. The axial measurement adopts double-tooth sensitivity rather than a single-tooth sensitivity scheme, which has higher sensitivity. It effectively overcomes the technical defect of low sensitivity of the prior art that a single tooth is used to measure axial displacement.

[0028] 3. The double-layer iron core compact inductive displacement sensor provided by the present invention adopts a full-bridge circuit structure, which significantly improves the signal-to-noise ratio of displacement detection, and superimposes multi-channel information of axial displacement measurement to further improve the signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an axial-radial integrated inductive displacement sensor with a traditional three-layer iron core structure.

[0030] Figure 2 A schematic diagram of a double-layer iron core compact inductive displacement sensor provided by the present invention.

[0031] Figure 3 A schematic diagram of the winding direction of the double-layer iron core compact inductive displacement sensor provided by the present invention.

[0032] Figure 4 A circuit structure diagram of the double-layer iron core compact inductive displacement sensor provided by the present invention.

[0033] Reference numerals

[0034] 1-first tooth portion; 2-second tooth portion; 11-first upper coil; 12-second upper coil; 21-first lower coil; 22-second lower coil; 31-third upper coil; 32-fourth upper coil; 41-third lower coil; 42-fourth lower coil; 51-fifth upper coil; 52-sixth upper coil; 61-fifth lower coil; 62-sixth lower coil; 71-seventh upper coil; 72-eighth upper coil; 81-seventh lower coil; 82-eighth lower coil; 1 01-first Y-direction coil; 102-second Y-direction coil; 201-third Y-direction coil; 202-fourth Y-direction coil; 301-third X-direction coil; 302-second X-direction coil; 401-third X-direction coil; 402-fourth X-direction coil; 501-fifth Y-direction coil; 502-sixth Y-direction coil; 601-seventh Y-direction coil; 602-eighth Y-direction coil; 701-fifth X-direction coil; 702-sixth X-direction coil; 801-seventh X-direction coil; 802-eighth X-direction coil. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0037] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0038] See also Figure 2 As shown, the present invention provides a double-layer iron core type compact inductive displacement sensor, which is coaxially arranged with a rotatable component and is used to sense the radial position and axial position of the rotatable component. In addition, the double-layer iron core type compact inductive displacement sensor is an axial-radial integrated arrangement, including: a sensor stator core, multiple groups of axial coils, multiple groups of radial coils, a sensor rotor, a circuit module, etc.

[0039] The sensor stator core has a yoke and a double-layer tooth portion arranged circumferentially along the inner ring of the yoke; the double-layer tooth portion includes multiple groups of first tooth portions 1 and second tooth portions 2 arranged axially symmetrically (vertically and horizontally). The yoke of the sensor stator core is provided with a support seat (not marked in the figure) arranged circumferentially and used to install the first tooth portion 1 and the second tooth portion 2, and the support seat and the double-layer tooth portion are detachably connected.

[0040] The axial coils for axial displacement measurement are respectively wound along the first tooth portion 1 and the second tooth portion 2 and arranged circumferentially. After winding, the circumferentially adjacent axial coils are connected in series to form an axially symmetrical upper axial coil group and a lower axial coil group.

[0041] The radial coils used for radial displacement measurement in the X and Y directions are wound around the double-layer tooth portion as a whole and are circumferentially symmetrically arranged. After winding, each group of radial coils forms a first radial coil group and a second radial coil group respectively.

[0042] The rotatable member is a magnetic bearing, and a rotor of the magnetic bearing moves coaxially with the sensor rotor.

[0043] like Figure 3 As shown, in this embodiment, after the axially symmetrical (vertically symmetrical) upper axial coil group and lower axial coil group are energized, the directions of the magnetic lines of force formed are arranged in the same manner and are opposite to those of the circumferentially adjacent coil groups;

[0044] After the first radial coil groups adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the adjacent coil groups;

[0045] After the second radial coil groups adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the adjacent coil groups.

[0046] The upper axial coil group and the lower axial coil group respectively form axial sensing channels; a plurality of pairs of first radial coil groups and second radial coil groups respectively form X-direction radial sensing channels and Y-direction radial sensing channels.

[0047] The axial sensing channel and the radial sensing channel interact with the surface of the rotatable component respectively to detect the relative displacement of the rotatable component.

[0048] Example 1

[0049] like Figure 2-4 As shown, Example 1 provides a double-layer iron core type compact inductive displacement sensor.

[0050] from Figure 2It can be seen that the same group of axial coils used for axial measurement are arranged along the circumferential direction rather than up and down along the axial direction, which can effectively prevent the magnetic lines of force from passing vertically through the rotor core, generating additional eddy current losses and reducing the measurement sensitivity and bandwidth.

[0051] In this embodiment, the axial coils include first to eighth upper axial coils and first to eighth lower axial coils. After winding, the coils are connected in series in the circumferential direction to obtain four upper axial coil groups and four lower axial coil groups respectively.

[0052] Among them, the first upper coil 11 and the second upper coil 12 are connected in series to form an independent upper axial coil group A1. Similarly, the third upper coil 31 and the fourth upper coil 32 are connected in series to form an independent upper axial coil group A3. The fifth upper coil 51 and the sixth upper coil 52 are connected in series to form an independent upper axial coil group A5. The seventh upper coil 71 and the eighth upper coil 72 are connected in series to form an independent upper axial coil group A7.

[0053] The first lower layer coil 21 and the second lower layer coil 22 are connected in series to form an independent lower layer axial coil group A2, the third lower layer coil 41 and the fourth lower layer coil 42 are connected in series to form an independent lower layer axial coil group A4, the fifth lower layer coil 61 and the sixth lower layer coil 62 are connected in series to form an independent lower layer axial coil group A6, and the seventh lower layer coil 81 and the eighth lower layer coil 82 are connected in series to form an independent lower layer axial coil group A8.

[0054] The upper axial coil group A1 and the lower axial coil group A2 are symmetrically arranged, the upper axial coil group A5 and the lower axial coil group A6 are symmetrically arranged, the upper axial coil group A3 and the upper axial coil group A4 are symmetrically arranged, and the upper axial coil group A7 and the lower axial coil group A8 are symmetrically arranged.

[0055] In this 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 the first axial sensing channel to measure the 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 the second axial sensing channel to measure the axial displacement. Therefore, the sensor has two axial measurement channels and can realize accurate sensing of the axial displacement.

[0056] The radial coil used for radial measurement is wound around the entire double-layer tooth portion.

[0057] In this embodiment, the radial coils include first to eighth Y-direction coils and first to eighth X-direction coils, which are connected in series in the circumferential direction after winding to obtain four second radial coil groups and four lower first radial coil groups respectively.

[0058] The first Y-direction coil 101 and the second Y-direction coil 102 form an independent second radial coil group R1. The third Y-direction coil 201 and the fourth Y-direction coil 202 form an independent second radial coil group R2.

[0059] The first X-direction coil 301 and the second X-direction coil 302 form an independent first radial coil group R3 , and the third X-direction coil 401 and the fourth X-direction coil 402 form an independent first radial coil group R4 .

[0060] The fifth Y-direction coil 501 and the sixth Y-direction coil 502 form an independent second radial coil group R5 , and the seventh Y-direction coil 601 and the eighth Y-direction coil 602 form an independent second radial coil group R6 .

[0061] The fifth X-direction coil 701 and the sixth X-direction coil 702 form an independent first radial coil group R7 , and the seventh X-direction coil 801 and the eighth X-direction coil 802 form an independent first radial coil group R8 .

[0062] The second radial coil group R1, the second radial coil group R2, the second radial coil group R5 and the second radial coil group R6 are used as the second radial sensing channel to measure the displacement in the Y direction. Similarly, the first radial coil group R3, the first radial coil group R4, the first radial coil group R7 and the first radial coil group R8 are used as the first radial sensing channel to measure the displacement in the X direction.

[0063] Figure 3 It is a typical magnetic field line direction formed by the independent coil winding and the current direction. The magnetic field lines of adjacent teeth of an independent coil group, such as the second radial coil group R1, are opposite to form an independent magnetic field line loop, while the magnetic field lines of adjacent teeth between independent coil groups, such as the second radial coil group R1 and the second radial coil group R2, are opposite.

[0064] The direction of magnetic lines of force of independent coil groups, such as the upper axial coil group A1, is opposite to that of adjacent coil groups R1 and R8, while the direction of magnetic lines of force between independent coil groups, such as the upper axial coil group A1 and the lower axial coil group A2, is the same.

[0065] Figure 4 It is a full bridge circuit composed of independent coils for sensors. Figure 4 It can be seen that the four bridge arms of the circuit structure proposed in the embodiment of the present invention are all sensitive to changes in displacement, while the traditional half-bridge structure has only two bridge arms that are sensitive to changes in displacement, and the other two are usually fixed resistors. Therefore, the sensitivity of the full-bridge circuit is nearly twice that of the current half-bridge circuit, which is beneficial to improving the circuit signal-to-noise ratio.

[0066] For the axial measurement circuit, the initial sensitivity is low, so the displacement is obtained by adding multiple signals. For example, the signals of the voltages Uout1 and Uout2 corresponding to the axial displacement can be superimposed to further improve the sensitivity of the axial displacement measurement.

[0067] Those skilled in the art will appreciate that in other implementations, different numbers of axial coils and radial coils may be provided according to actual application requirements to obtain different numbers of axial sensing channels and radial sensing channels. The data settings are not limited to those in the above embodiments.

[0068] Comparative Example 1

[0069] Comparative Example 1 provides a traditional three-layer iron core inductive displacement sensor.

[0070] In comparative example 1, three types of laminated cores need to be assembled, namely, upper, middle and lower cores. The upper and lower cores have the same shape and are used to sense axial displacement. The middle core has a different structure from the upper and lower cores and is used to sense radial displacement. Its typical process steps include:

[0071] 1) Two types of laminations are produced by wire cutting or stamping, namely upper and lower core laminations and middle core laminations;

[0072] 2) The upper and lower iron cores and the middle iron core are manufactured by gluing and laminating the molds, which involves processes such as gluing, fixing, extruding, and curing;

[0073] 3) Use a method similar to step 2 to paste and solidify the obtained upper and lower iron cores and the middle iron core together, and ensure that the different iron cores are aligned to finally form a complete three-layer iron core structure.

[0074] However, in the present application, only one lamination shape is required, and its basic shape is similar to the upper and lower layer shapes of the traditional method. Only one lamination process is required, such as step 2 mentioned above. Compared with the traditional three-layer core structure of comparative document 1, its preparation process reduces the lamination style, reduces the process complexity and risk brought by the secondary lamination, and saves manufacturing costs.

[0075] The sensor of comparative document 1 and the sensor of embodiment 1 are used to detect the radial and axial displacement of the rotor in the magnetic bearing system.

[0076] Compared with the existing axial radial integrated sensor of comparative example 1, which adopts a special-shaped structure, the double-layer iron core sensor provided by the present invention only requires one lamination shape and process parameters, omitting the steps and processes of secondary lamination, which can greatly reduce the process complexity, reduce costs, and improve manufacturing efficiency. At the same time, the full-bridge circuit structure is adopted, so that the sensitivity of the sensor is nearly doubled. In addition, the sensitivity of the axial output can be further improved by superimposing the two axial output channels, thereby improving the signal-to-noise ratio of the sensor.

[0077] Example 2

[0078] Embodiment 2 of the present invention provides a magnetic bearing system, which includes the above-mentioned double-layer iron core type compact inductive displacement sensor. In the magnetic bearing system, the double-layer iron core type compact inductive displacement sensor can realize high-sensitivity synchronous measurement of radial and axial displacements of magnetic bearing rotors.

[0079] Example 3

[0080] Embodiment 3 of the present invention provides a motor system, which includes the double-layer iron core type compact inductive displacement sensor provided in the above embodiment 1, or includes the magnetic bearing system provided in the above embodiment 2. In the motor system, the double-layer iron core type compact inductive displacement sensor can realize the synchronous measurement of the radial and axial displacements of the magnetic bearing rotor with high sensitivity.

[0081] In summary, the present invention provides a double-layer iron core type compact inductive displacement sensor. The iron core of the sensor has a double-layer tooth portion with an upper and lower layer structure, and the structures of the upper and lower layers are exactly the same, so the mold and lamination process parameters are exactly the same. The traditional sensor process requires secondary lamination of the conventional iron core structure to form an axially radially integrated sensor stator core. The sensor proposed in the present invention can align two layers of the same iron core and install them on a support seat without the need for secondary lamination, which can greatly reduce the complexity and difficulty of sensor manufacturing.

[0082] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A double-layer iron core compact inductive displacement sensor, characterized in that: The double-layer iron core type compact inductive displacement sensor is coaxially arranged with the rotatable component and is used to sense the radial position and axial position of the rotatable component. The double-layer iron core type compact inductive displacement sensor is an axial radial integrated arrangement and comprises: The sensor stator core comprises a yoke and a double-layer tooth portion which is arranged circumferentially along the inner ring of the yoke and is completely identical; the double-layer tooth portion comprises a plurality of groups of first tooth portions and second tooth portions which are axially symmetrically arranged; A plurality of groups of axial coils, wherein the axial coils for axial displacement measurement are respectively wound along the first tooth portion and the second tooth portion and arranged circumferentially, and after winding, the axial coils adjacent to each other in the circumferential direction are connected in series to form an upper axial coil group and a lower axial coil group, respectively; Multiple groups of radial coils, the radial coils used for radial displacement measurement in two directions of X and Y are wound around the whole double-layer tooth portion and are arranged symmetrically in the circumferential direction, and after winding, each group of radial coils forms a first radial coil group and a second radial coil group respectively; After the axially symmetrical upper axial coil group and the lower axial coil group are energized, the directions of the magnetic lines of force formed are arranged in the same direction and are opposite to those of the circumferentially adjacent coil groups; A plurality of pairs of upper axial coil groups and lower axial coil groups respectively form axial sensing channels; a plurality of pairs of first radial coil groups and second radial coil groups respectively form X-direction radial sensing channels and Y-direction radial sensing channels; The X-direction radial sensing channel, the axial sensing channel, and the Y-direction radial sensing channel are circumferentially arranged in sequence and are independently arranged.

2. The double-layer iron core compact inductive displacement sensor according to claim 1, characterized in that: The double-layer iron core type compact inductive displacement sensor further comprises a sensor rotor with an air gap arranged between the sensor rotor and the sensor stator iron core.

3. The double-layer iron core compact inductive displacement sensor according to claim 1, characterized in that: The double-layer iron core type compact inductive displacement sensor also includes a circuit module; The circuit module is electrically connected to the axial coil and the radial coil respectively to form an axial induction circuit and a radial induction circuit.

4. The double-layer iron core compact inductive displacement sensor according to claim 3, characterized in that: The circuit module adopts a full-bridge circuit.

5. The double-layer iron core compact inductive displacement sensor according to claim 2, characterized in that: The rotatable member is a magnetic bearing, and a rotor of the magnetic bearing moves coaxially with the sensor rotor.

6. The double-layer iron core compact inductive displacement sensor according to claim 1, characterized in that: The yoke of the sensor stator core is provided with a support seat for mounting the first tooth portion and the second tooth portion, and the support seat and the double-layer tooth portion are detachably connected.

7. The double-layer iron core compact inductive displacement sensor according to claim 1, characterized in that: After the first radial coil groups adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the adjacent coil groups; After the second radial coil groups adjacent to each other in the circumferential direction are energized, the direction of the magnetic force lines formed is opposite to the direction of the magnetic force lines formed by the adjacent coil groups.

8. The double-layer iron core compact inductive displacement sensor according to claim 7, characterized in that: The axial sensing channel and the radial sensing channel interact with the surface of the rotatable component respectively to detect radial and axial relative displacements of the rotatable component respectively.

9. A magnetic bearing system, characterized in that: A double-layer iron core compact inductive displacement sensor comprising any one of claims 1 to 8.

10. A motor system, characterized in that: It comprises the magnetic bearing system described in claim 9, or it comprises the double-layer iron core type compact inductive displacement sensor described in any one of claims 1 to 8.

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