A sensor device and a detection method for simultaneously detecting displacement changes in multiple degrees of freedom

Abstract

The application relates to a sensor device and a detection method for simultaneously detecting displacement changes of multiple degrees of freedom, and belongs to the technical field of electromagnetic bearing displacement detection. The application solves the problem that a plurality of degrees of freedom sensor devices need to be provided with a fixer to fix the bottom coil. The application comprises a stator assembly and a rotor assembly, the stator assembly is arranged outside the rotor assembly, a plurality of stator subassemblies form the stator assembly, the stator subassembly comprises a first auxiliary magnetic pole, a first winding, a first mounting sheet, a first main magnetic pole, a main winding, a second auxiliary magnetic pole, a second winding, a second mounting sheet and a second main magnetic pole, the first mounting sheet is connected with the first main magnetic pole and the first auxiliary magnetic pole, the first auxiliary magnetic pole is outside the first winding, the second mounting sheet is connected with the second main magnetic pole and the second auxiliary magnetic pole, the second auxiliary magnetic pole is outside the second winding, the first main magnetic pole and the second main magnetic pole form the main magnetic pole, and the main magnetic pole is outside the main winding. The application does not occupy the axial space of the rotor assembly, and has a clever structure and is easy to manufacture.

Description

Technical Field

[0001] This invention relates to a sensor device and detection method for detecting displacement changes, belonging to the field of electromagnetic bearing displacement detection technology. Background Technology

[0002] Currently, in the field of electromagnetic bearing technology, high-precision detection of rotor displacement relies on electromagnetic displacement sensors, specifically eddy current sensors and differential transformer displacement sensors. Both types of sensors can accurately and quickly detect rotor displacement changes, but their drawback is that each sensor can only detect displacement changes in one direction. This necessitates the use of multiple displacement sensors to acquire the dynamic changes of multiple degrees of freedom of the rotor. For example, CN115854844A, an invention entitled "A Multi-Degree-of-Freedom Sensing System for Magnetic Levitation Rotors Based on Eddy Current Shape Detection," uses five sensing coils to measure four degrees of freedom: radial displacement, axial displacement, and rotation. It also implements temperature compensation for the front-stage circuit coils. This non-contact measurement system significantly reduces the number of sensors and lowers measurement costs when measuring the same number of degrees of freedom. However, it measures axial displacement deviation using two sets of windings located below the rotor, requiring a separate fixture to secure the bottom coils, thus complicating the structure.

[0003] Therefore, there is an urgent need to propose a sensor device and detection method for simultaneously detecting multi-degree-of-freedom displacement changes in order to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that multi-degree-of-freedom sensing devices require a separate fixture to fix the bottom coil, resulting in a complex structure. This invention provides a sensor device and method for simultaneously detecting multi-degree-of-freedom displacement changes. A brief overview of the invention is given below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0005] The technical solution of this invention:

[0006] A sensor device for simultaneously detecting multi-degree-of-freedom displacement changes includes a stator assembly and a rotor assembly. The stator assembly is disposed outside the rotor assembly. A plurality of circumferentially arranged stator sub-assemblies form the stator assembly. The stator sub-assembly includes a first auxiliary magnetic pole, a first winding, a first mounting plate, a first main magnetic pole, a main winding, a second auxiliary magnetic pole, a second winding, a second mounting plate, and a second main magnetic pole. The first main magnetic pole is connected to the middle of the first mounting plate, and the first auxiliary magnetic pole is connected to the right side of the first mounting plate. The first winding is fitted outside the first auxiliary magnetic pole. The second main magnetic pole is connected to the middle of the second mounting plate, and the second auxiliary magnetic pole is connected to the left side of the second mounting plate. The second winding is fitted outside the second auxiliary magnetic pole. The first main magnetic pole and the second main magnetic pole are correspondingly arranged to form a main magnetic pole, and the main winding is fitted outside the main magnetic pole.

[0007] Preferably, the number of stator sub-assemblies is four groups, and each group of stator sub-assemblies includes two first windings and two second windings, with one first winding connected to one second winding.

[0008] Preferably, a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes further includes a stator housing, the inner wall of which is machined with bosses arranged in a circumferential array, one end of which has side grooves machined on both sides, and the other end of which has connecting grooves machined on both sides, the inner side of which is arc-shaped, and mounting grooves are formed between adjacent bosses, and a set of stator sub-assemblies is correspondingly arranged in one mounting groove, with the two ends of the first mounting plate and the second mounting plate arranged in the connecting grooves.

[0009] Preferably, the stator sub-assembly also includes four slot wedges, each with a wedge-shaped protrusion on both sides and an arc-shaped inner surface. The boss on one side, the first slot wedge, the first auxiliary magnetic pole, the second slot wedge, the main magnetic pole, the third slot wedge, the second auxiliary magnetic pole, the fourth slot wedge, and the boss on the other side are sequentially connected.

[0010] Preferably, the first auxiliary magnetic pole, the first main magnetic pole, the second auxiliary magnetic pole, and the second main magnetic pole are all provided with magnetic pole side grooves on both sides. The inner surfaces of the first auxiliary magnetic pole, the first main magnetic pole, the second auxiliary magnetic pole, and the second main magnetic pole are all arc surfaces. The wedge-shaped protrusions are provided in the magnetic pole grooves or boss grooves. The magnetic pole grooves and boss grooves can cooperate with the wedge-shaped protrusions to realize the connection between magnetic poles and between magnetic poles and bosses. The arc-shaped inner surfaces of the groove wedge, the first auxiliary magnetic pole, the first main magnetic pole, the second auxiliary magnetic pole, the second main magnetic pole, and the boss form a smooth circular surface.

[0011] Preferably, a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes further includes two pressure plates. The boss has a first axial connecting hole in the middle, and the pressure plates have a second connecting hole at the corresponding position of the first connecting hole of the boss. The two pressure plates are located at the upper and lower ends of the boss and connected to the boss, so that the pressure plates press the first mounting plate and the second mounting plate tightly.

[0012] Preferably, the rotor assembly includes a core pressure plate, a rotor core, a rotor bushing, and a shaft. The rotor bushing is coaxially mounted on the outer side of the shaft. The rotor core and the core pressure plate are mounted on the outer side of the rotor bushing. There is a gap between the rotor core and the stator assembly.

[0013] A detection method for simultaneously detecting multi-degree-of-freedom displacement changes employs a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The detection method for simultaneously detecting multi-degree-of-freedom displacement changes includes a radial displacement detection method and an axial displacement detection method.

[0014] Radial displacement detection method: Select a stator core, pass an alternating current through the main winding, and the alternating magnetic flux generated in the main magnetic pole forms a closed loop through the main magnetic pole, yoke, auxiliary magnetic pole, gap, rotor core, and main magnetic pole. The alternating magnetic flux will induce an electromotive force e in the outer first and second windings. a1 With e b1 The sum of the two is the output voltage u1 of the first and second windings on the outer side, and the output voltage u2 of another stator sub-assembly that is 180° apart in the radial direction. The difference between the two output voltages is u. 12 By analyzing the difference u 12 The amplitude and phase of the voltage are used to determine the rotor's offset in the X direction; similarly, the difference between the output voltages of the other two stator components is used to obtain u. 34 By analyzing u 34 The amplitude and phase of the value can determine the rotor's offset in the Y direction; a comprehensive comparison of u 12 with u 34 The radial offset of the rotor can be determined from the data.

[0015] Axial displacement detection method: When the rotor is axially offset, it will cause a change in the radial overlap area between the auxiliary magnetic pole and the rotor assembly, resulting in a change in magnetic permeability, which in turn causes a change in the magnetic flux on the auxiliary magnetic pole, thereby inducing an electromotive force e in the inner first winding and second winding. a2 With e b2 The change in voltage ultimately causes the output voltage u to change. a2 with u b2 The change in the rotor's axial displacement can be determined by comparing the magnitude and phase of the difference between the two values.

[0016] The present invention has the following beneficial effects:

[0017] 1. This invention can simultaneously detect the axial and radial displacement of the rotor assembly through four stator sub-components, eliminating the need for multiple single-degree-of-freedom displacement sensing devices. This saves space and eliminates the need to consider sensor installation and wiring in the system design, greatly reducing development costs. It does not occupy the axial space of the rotor assembly, has a simple and ingenious structure that is easy to manufacture, convenient to maintain, and has low maintenance costs.

[0018] 2. The sequential connection of the inner surfaces of this invention to form a smooth curved surface facilitates the design of the slot wedge size, ensuring uniform air gap when the rotor has no displacement deviation;

[0019] 3. The output signal of this invention can intuitively, quickly, and accurately reflect the rotor displacement change without the need for process processing. Attached Figure Description

[0020] Figure 1 This is a side view of a sensor device that simultaneously detects changes in displacement with multiple degrees of freedom.

[0021] Figure 2 This is an exploded view of a sensor device that simultaneously detects changes in displacement with multiple degrees of freedom.

[0022] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0023] Figure 4 yes Figure 2 Enlarged view of point B in the middle;

[0024] Figure 5 This is a partial schematic diagram of a sensor device that simultaneously detects displacement changes in multiple degrees of freedom;

[0025] Figure 6 This is a three-dimensional cross-sectional view of a sensor device that simultaneously detects changes in displacement with multiple degrees of freedom.

[0026] In the diagram: 1-Stator sub-assembly, 2-First auxiliary magnetic pole, 3-First winding, 4-First mounting plate, 5-First main magnetic pole, 6-Main winding, 7-Second auxiliary magnetic pole, 8-Second winding, 9-Second mounting plate, 10-Second main magnetic pole, 12-Slot wedge, 13-Stator housing, 14-Pressure plate, 15-Core pressure plate, 16-Rotor core, 17-Rotor bushing, 18-Shaft, 121-Wedge-shaped protrusion, 131-Boss, 132-Mounting groove, 133-Connecting groove, 134-Inner side. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0028] Specific implementation method one: Combining Figure 1-6 This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes, comprising a stator assembly and a rotor assembly. The stator assembly is coaxially disposed outside the rotor assembly, with a gap between the stator assembly and the rotor assembly. A plurality of circumferentially arranged stator sub-assemblies 1 form the stator assembly. The stator sub-assembly 1 includes a first auxiliary magnetic pole 2, a first winding 3, a first mounting plate 4, a first main magnetic pole 5, a main winding 6, a second auxiliary magnetic pole 7, a second winding 8, a second mounting plate 9, and a second main magnetic pole 10, as shown below. Figure 4 As shown, a radial first main magnetic pole 5 is fixedly connected to the middle of the first mounting plate 4, and a radial first auxiliary magnetic pole 2 is fixedly connected to the right side of the first mounting plate 4. A first winding 3 is fitted on the outside of the first auxiliary magnetic pole 2. A radial second main magnetic pole 10 is fixedly connected to the middle of the second mounting plate 9, and a radial second auxiliary magnetic pole 7 is fixedly connected to the left side of the second mounting plate 9. A second winding 8 is fitted on the outside of the second auxiliary magnetic pole 7. The first mounting plate 4 and the second mounting plate 9 are arc-shaped plates with the same structure. The first mounting plate 4 and the second mounting plate 9 are arranged axially so that the first main magnetic pole 5 and the second main magnetic pole 10 are correspondingly set to form the main magnetic pole. A main winding 6 is fitted on the outside of the main magnetic pole. The axial length of the main magnetic pole is twice that of the first auxiliary magnetic pole 2 and the second auxiliary magnetic pole 7. The first mounting plate 4 and the second mounting plate 9 can be integrally formed. The main magnetic pole is obtained by symmetrically stacking the upper and lower stator core plates of the upper and lower arranged first main magnetic pole 5 and second main magnetic pole 10. The present invention has the characteristics of simple structure, low development cost, fast response and high response accuracy.

[0029] Specific Implementation Method Two: Combining Figure 1-6This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The stator sub-assemblies 1 consist of four groups, each including two first windings 3 and two second windings 8. One first winding 3 is connected to one second winding 8. The two first windings are arranged radially from the outside inwards, and the two second windings are also arranged radially from the outside inwards. The other first winding 3 and the other second winding 8 are not connected. The two first windings 3 and the two second windings 8 are not connected to each other. When the rotor axially deviates, it causes a change in the induced voltage of the two coils. The voltage values ​​output by the two coils can be directly subtracted to determine the axial deviation. There are four such differences, and the average value is taken to reduce measurement error. This invention can simultaneously detect the axial and radial displacement of the rotor assembly using four stator sub-assemblies, eliminating the need for multiple single-degree-of-freedom displacement sensing devices. This saves space and eliminates the need for sensor installation and wiring design in the system design, greatly reducing development costs. The ingenious structure is easy to manufacture, convenient for maintenance, and has low maintenance costs.

[0030] Specific implementation method three: Combining Figure 1-6This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The device further includes a stator housing 13, a rotating shaft 18 coaxially arranged with the stator housing 13, and stator assemblies disposed inside the stator housing 13. The inner wall of the stator housing 13 is machined with radial bosses 131, arranged in a circumferential array to evenly distribute the stator sub-assemblies 1. One end (inner end) of each boss 131 has axial boss side grooves on both sides, and the other end (outer end) of each boss 131 has... The mounting groove 132 has an axial connecting groove 133, so that both sides of the mounting groove 132 have connecting grooves. The inner surface 134 of the boss 131 is arc-shaped, and a mounting groove 132 is formed between two adjacent bosses 131. A set of stator sub-assemblies 1 are correspondingly arranged in one mounting groove 132. The two ends of the first mounting piece 4 and the second mounting piece 9 are set in the connecting groove 133. The two ends of the first mounting piece 4 are respectively connected to the connecting groove 133 on the left side of one boss 131 and the connecting groove 133 on the right side of the other boss 131. The two ends of the second mounting piece 9 are respectively connected to one boss 131. The connecting groove 133 on the left and the connecting groove 133 on the right of the other boss 131 are connected, that is, the outer surfaces of the first mounting piece 4 and the second mounting piece 9 are attached to the inner wall of the stator housing 13; the stator assembly structure of the present invention has a tooth shape, and is distributed with excitation windings (main windings) and induction windings (secondary windings, i.e., the first winding and the second winding) for measuring the radial and axial directions of the rotor, which are equidistantly distributed along the circumference at 90° intervals. The windings for measuring radial displacement deviation are connected in series on the same iron core structure. There are four sets of windings connected in series, used to measure X+, X-, Y+, and Y-. The other party has three sets of windings, which, although fewer in number, are inconvenient to decouple. The windings used to measure axial displacement deviation do not need to be connected on the same iron core structure. In this way, the output induced voltages of the two sets of windings on the same iron core can be compared to determine the rotor's axial displacement deviation. There are four such windings. In contrast, the existing technology uses two sets of windings to measure axial displacement deviation, resulting in only one comparison data. Moreover, the windings are placed below the rotor and require a separate fixture to fix the bottom coil. Therefore, the present invention has higher measurement accuracy for axial displacement deviation, does not occupy the axial space of the rotor, and has a simpler structure.

[0031] Specific implementation method four: Combination Figure 1-6 This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The stator sub-assembly 1 further includes four slot wedges 12. Figure 1The middle slot wedge 12 is a convex connecting piece. The two sides of the slot wedge 12 have wedge-shaped protrusions 121. The inner side of the slot wedge 12 is arc-shaped. The boss 131 on one side, the first slot wedge 12, the first auxiliary magnetic pole 2, the second slot wedge 12, the main magnetic pole, the third slot wedge 12, the second auxiliary magnetic pole 7, the fourth slot wedge 12, and the boss 131 on the other side are connected in sequence. The first winding 3, the main winding 6, and the second winding 8 are all located on the outside of the slot wedge 12.

[0032] Specific Implementation Method Five: Combining Figure 1-6 This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. Axial magnetic pole side grooves are provided on both sides of the first auxiliary magnetic pole 2, the first main magnetic pole 5, the second auxiliary magnetic pole 7, and the second main magnetic pole 10. The inner surfaces of the first auxiliary magnetic pole 2, the first main magnetic pole 5, the second auxiliary magnetic pole 7, and the second main magnetic pole 10 are all arc surfaces. A wedge-shaped protrusion 121 is disposed within the magnetic pole groove or the boss groove. The magnetic pole groove and the boss groove can cooperate with the wedge-shaped protrusion to connect magnetic poles to each other or to the boss. The radii of the arc-shaped inner surfaces of the groove wedge 12, the first auxiliary magnetic pole 2, the first main magnetic pole 5, the second auxiliary magnetic pole 7, the second main magnetic pole 10, and the boss 131 are equal, forming a shape as shown in the diagram. Figure 1 The smooth, circular surface facilitates the design of the slot wedge dimensions, ensuring uniform air gap even when the rotor has no displacement deviation. Figure 5 As shown, the second main magnetic pole 10 is located above the first main magnetic pole 5, and the four slot wedges 12 in each stator sub-assembly are... Figure 4 Taking the arrangement of the stator sub-components as an example, from right to left, they are distinguished as "first...fourth". The wedge-shaped protrusions 121 on both sides of the first slot wedge 12 are located in the lower part of the groove on the side of the boss 131 on the left side and in the groove on the side of the first auxiliary magnetic pole 2 on the right side. The wedge-shaped protrusions 121 on both sides of the second slot wedge 12 are located in the groove on the side of the first auxiliary magnetic pole 2 on the left side and in the groove on the side of the first main magnetic pole 5 on the right side. A boss 131, the inner side of the first slot wedge 12, the first auxiliary magnetic pole 2, the second slot wedge 12, the first main magnetic pole 5, the first auxiliary magnetic pole 2, the first auxiliary magnetic pole 2, the first main magnetic pole 5, the first auxiliary magnetic pole 2, the first auxiliary magnetic pole 2, the first main magnetic pole 2 ... The inner surfaces of the magnetic pole 5 are connected sequentially to form a smooth curved surface. The wedge-shaped protrusions 121 on both sides of the third slot wedge 12 are located in the magnetic pole side groove on the left side of the second main magnetic pole 10 and the magnetic pole side groove on the right side of the second auxiliary magnetic pole 7, respectively. The wedge-shaped protrusions 121 on both sides of the fourth slot wedge 12 are located in the upper part of the magnetic pole side groove on the left side of the second auxiliary magnetic pole 7 and the boss side groove on the right side of the other boss 131, respectively. The inner surfaces of the second main magnetic pole 10, the third slot wedge 12, the second auxiliary magnetic pole 7, the fourth slot wedge 12, and the other boss 131 are connected sequentially to form a smooth curved surface.

[0033] Specific Implementation Method Six: Combination Figure 1-6This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The device further includes two pressure plates 14. A first axial connecting hole is provided in the center of a boss 131. A second connecting hole is provided on the pressure plate 14 at a position corresponding to the first connecting hole of the boss 131. The two pressure plates are located at the upper and lower ends of the boss 131 and connected to it, causing the pressure plates 14 to press against the first mounting piece 4 and the second mounting piece 9. Specifically, bolts are sequentially passed through one second connecting hole, the first connecting hole, and the other second connecting hole before being threaded and tightened with a nut. Mounting plate positioning grooves are machined in the center of both the first mounting piece 4 and the second mounting piece 9. A stator housing positioning groove is machined in the center of the mounting groove 132. A pressure plate positioning groove is machined on the outer side of the pressure plate 14. The mounting plate positioning groove, the stator housing positioning groove, and the pressure plate positioning groove are correspondingly arranged to form positioning grooves. Positioning pins are inserted into the positioning grooves for circumferential limiting.

[0034] Specific implementation method seven: Combination Figure 1-6 This embodiment describes a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes. The rotor assembly includes a core plate 15, a rotor core 16, a rotor bushing 17, and a shaft 18. The rotor bushing 17 is coaxially and tightly mounted on the outer side of the shaft 18. One end (lower end) of the rotor bushing 17 has an annular edge. The rotor core 16 and the core plate 15 are sequentially mounted on the outer side of the rotor bushing 17 from the other end. The rotor core 16, the core plate 15, and the rotor bushing 17 are tightly fitted together. The core plate 15 presses the rotor core 16. The rotor core 16 is a complete circular ring structure. There is a gap between the circular rotor core 16, the core plate 15, and the stator assembly, that is, the first auxiliary magnetic pole 2, the first main magnetic pole 5, the second auxiliary magnetic pole 7, and the second main magnetic pole 10 are not in contact with the rotor assembly.

[0035] Specific implementation method eight: Combination Figure 1-6This embodiment describes a method for simultaneously detecting multi-degree-of-freedom displacement changes. It employs a sensor device for simultaneously detecting multi-degree-of-freedom displacement changes, comprising a stator core, excitation coils (excitation windings or main windings), induction coils (induction windings), and a rotor assembly or rotor core. The stator core includes a yoke, main magnetic poles, and auxiliary magnetic poles. Two auxiliary magnetic poles are distributed on both sides of each main magnetic pole. The axial length of the main magnetic pole is twice the axial length of the auxiliary magnetic pole. The auxiliary magnetic poles are rotated 180° along the centerline of the main magnetic pole and distributed on both sides of the main magnetic pole, forming the stator core. The flipped secondary magnetic poles do not overlap axially at all. The four stator cores are equidistantly distributed along the circumference at 90° intervals. Each primary magnetic pole has a set of excitation windings, while each secondary magnetic pole has two sets of induction windings. One set of each of the two sets of induction windings placed on the two secondary magnetic poles of a single stator core is used in series, and the remaining set of windings does not need to be connected. A detection method for simultaneously detecting multi-degree-of-freedom displacement changes includes radial displacement detection method and axial displacement detection method; the output signal can intuitively, quickly, and accurately reflect the rotor displacement changes without process processing.

[0036] Radial displacement detection method: Select a stator core with excitation winding L1 (main winding) distributed on the main magnetic pole L, and induction winding l distributed on the auxiliary magnetic poles a and b (first auxiliary magnetic pole and second auxiliary magnetic pole). a1 and l a2 (The first winding on the outer side and the first winding on the inner side), l b1 and l b2 (The outer second winding and the inner second winding), coil l a1 and l b1 In this invention, the rotor assembly does not contain permanent magnets; the excitation source is provided by the excitation coil. Compared to cases where the excitation source is provided by permanent magnets, the excitation magnetomotive force (excitation magnetomotive force) of this invention can be adjusted according to actual working conditions, a function that existing technologies cannot achieve. During normal operation, an alternating current is passed through the main winding (excitation winding L1). The alternating magnetic flux generated in the main magnetic pole forms a closed loop through the main magnetic pole, the yoke (first mounting plate 4, second mounting plate 9), the auxiliary magnetic pole, the air gap, the rotor (rotor core), and the main magnetic pole. Simultaneously, the alternating magnetic flux induces the windings L1 on both sides. a1 With l b1 Induced electromotive force e is generated in a1 With e b1 The sum of the two is l a1 With l b1 The output voltage u1 is generated by the winding of another stator sub-component 1 that is 180° away from this stator sub-component 1 in the radial direction. At the same time, the winding of another stator sub-component 1 that is 180° away in the radial direction will generate an output voltage u2. The difference between the two output voltages is u. 12 By analyzing the difference u 12The amplitude and phase of the voltage are used to determine the rotor's offset in the X direction. Analysis method: When the rotor offsets in the X direction, the gap between the rotor core and the secondary magnetic pole (i.e., the air gap) changes. For example, when offsetting in the X+ direction, the air gap decreases, the magnetic permeability increases, and the amplitude of the alternating magnetic flux in that direction also increases. According to Faraday's principle of induction, the induced voltage in the series winding on the secondary magnetic pole in that direction will also be large, thus increasing the output voltage. Similarly, the output voltage in the X- direction will decrease. The difference between the two output voltages determines the rotor's offset in the X direction. Similarly, the difference between the output voltages of the windings on the other two stator sub-assemblies 1 is used to obtain u. 34 By analyzing u 34 The amplitude and phase of the value can determine the rotor's offset in the Y direction; a comprehensive comparison of u 12 with u 34 The radial offset of the rotor can be determined from the data; a comprehensive method for determining the offset is: u 12 The magnitude of the amplitude determines the offset in the X direction; a positive phase indicates an offset in the X+ direction, and a negative phase indicates an offset in the X- direction, thus determining the rotor's offset coordinates in the X direction. 34 Similarly, the offset coordinates in the Y direction of the rotor can be determined, and the offset coordinates in both directions can reflect the radial offset of the rotor.

[0037] Axial displacement detection method: An alternating current is passed through the excitation winding L1. The alternating magnetic flux generated in the main magnetic pole forms a closed loop through the main magnetic pole, yoke, secondary magnetic pole, air gap, rotor (rotor assembly), and main magnetic pole. That is, the excitation source required for axial and radial detection is the same. When the rotor (rotor assembly) shifts axially, it will cause a change in the radial overlap area between the secondary magnetic pole core and the rotor assembly, resulting in a change in magnetic permeability, which in turn causes a change in the magnetic flux on the secondary magnetic pole, thereby causing the induction winding L1 to shift. a2 and l b2 Induced electromotive force e a2 With e b2 The change in voltage ultimately causes the output voltage u to change. a2 with u b2 The change in the rotor's axial displacement can be determined by comparing the amplitude and phase of the difference between the two values; the output signal can intuitively, quickly, and accurately reflect the rotor displacement change without the need for process processing.

[0038] The comparison method is as follows: Figure 4 For example, assuming there is no offset, the rotor core partially overlaps with both auxiliary magnetic poles 2 and 7 axially. When the rotor shifts upward, the axial overlap area with auxiliary magnetic pole 7 increases, and the magnetic flux of the circuit also increases accordingly, as does the induced voltage. Conversely, the axial overlap area with auxiliary magnetic pole 2 decreases, and the magnetic flux of the circuit also decreases accordingly, as does the induced voltage. Thus, the difference in output voltage generated by the two coils can determine the axial offset.

[0039] The output voltage signal can be used directly and directly correlated with the displacement signal. However, the output voltage of radial detection in the prior art cannot be directly converted into a displacement signal and needs to be decoupled before it can be used. Therefore, the differential transformer of the present invention (i.e., a sensor device that simultaneously detects the displacement changes of multiple degrees of freedom) is more intuitive and faster. As for axial detection, the present invention has four sets of devices for detecting the axial displacement of the rotor, so it is more accurate.

[0040] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sensor device for simultaneously detecting axial and radial displacement changes, characterized in that: It includes a stator assembly and a rotor assembly. The stator assembly is located outside the rotor assembly. Four sets of circumferentially arranged stator sub-assemblies (1) form the stator assembly. Each set of stator sub-assemblies (1) includes two first windings (3) and two second windings (8). One first winding (3) is connected to one second winding (8). The stator sub-assembly (1) includes a first auxiliary magnetic pole (2), a first winding (3), a first mounting plate (4), a first main magnetic pole (5), a main winding (6), a second auxiliary magnetic pole (7), a second winding (8), a second mounting plate (9), and a second main magnetic pole (2). 10) The first mounting plate (4) is connected to the middle of the first main magnetic pole (5), the first mounting plate (4) is connected to the right side of the first auxiliary magnetic pole (2), the first auxiliary magnetic pole (2) is fitted with the first winding (3) on the outside of the first auxiliary magnetic pole (2), the second mounting plate (9) is connected to the middle of the second main magnetic pole (10), the second mounting plate (9) is connected to the left side of the second auxiliary magnetic pole (7), the second auxiliary magnetic pole (7) is fitted with the second winding (8) on the outside of the second auxiliary magnetic pole (7), the first main magnetic pole (5) and the second main magnetic pole (10) are correspondingly arranged to form the main magnetic pole, and the main winding (6) is fitted on the outside of the main magnetic pole.

2. The sensor device for simultaneously detecting axial and radial displacement changes according to claim 1, characterized in that: A sensor device for simultaneously detecting axial and radial displacement changes also includes a stator housing (13). The inner wall of the stator housing (13) is machined with bosses (131). The bosses (131) are arranged in a circumferential array. One end of the boss (131) has side grooves on both sides. The other end of the boss (131) has connecting grooves (133) on both sides. The inner side (134) of the boss (131) is arc-shaped. An installation groove (132) is formed between adjacent bosses (131). A set of stator sub-assemblies (1) is correspondingly arranged in one installation groove (132). The two ends of the first mounting piece (4) and the second mounting piece (9) are arranged in the connecting groove (133).

3. The sensor device for simultaneously detecting axial and radial displacement changes according to claim 2 is characterized in that: the stator sub-assembly (1) further includes four slot wedges (12), the two sides of the slot wedges (12) have wedge-shaped protrusions (121), the inner surface of the slot wedges (12) is arc-shaped, and the boss (131) on one side, the first slot wedge (12), the first auxiliary magnetic pole (2), the second slot wedge (12), the main magnetic pole, the third slot wedge (12), the second auxiliary magnetic pole (7), the fourth slot wedge (12), and the boss (131) on the other side are sequentially connected.

4. The sensor device for simultaneously detecting axial and radial displacement changes according to claim 3, characterized in that: The first auxiliary magnetic pole (2), the first main magnetic pole (5), the second auxiliary magnetic pole (7), and the second main magnetic pole (10) are all provided with magnetic pole side grooves on both sides. The inner surfaces of the first auxiliary magnetic pole (2), the first main magnetic pole (5), the second auxiliary magnetic pole (7), and the second main magnetic pole (10) are all arc surfaces. The wedge-shaped protrusion (121) is provided in the magnetic pole groove or the boss groove. The magnetic pole groove and the boss groove can cooperate with the wedge-shaped protrusion to realize the connection between magnetic poles and between magnetic poles and bosses. The arc-shaped inner surfaces of the groove wedge (12), the first auxiliary magnetic pole (2), the first main magnetic pole (5), the second auxiliary magnetic pole (7), the second main magnetic pole (10), and the boss (131) form a smooth circular surface.

5. A sensor device for simultaneously detecting axial and radial displacement changes according to claim 4, characterized in that: A sensor device for simultaneously detecting axial and radial displacement changes also includes two pressure plates (14). The boss (131) has a first axial connection hole in the middle. The pressure plate (14) has a second connection hole at the position corresponding to the first connection hole of the boss (131). The two pressure plates are located at the upper and lower ends of the boss (131) and connected to the boss, so that the pressure plate (14) presses the first mounting piece (4) and the second mounting piece (9).

6. A sensor device for simultaneously detecting axial and radial displacement changes according to claim 5, characterized in that: The rotor assembly includes a core plate (15), a rotor core (16), a rotor bushing (17), and a shaft (18). The rotor bushing (17) is coaxially mounted on the outside of the shaft (18). The rotor core (16) and the core plate (15) are mounted on the outside of the rotor bushing (17). There is a gap between the rotor core (16) and the stator assembly.

7. A detection method for simultaneously detecting axial and radial displacement changes, characterized in that: Using the sensor device for simultaneously detecting axial and radial displacement changes as described in claim 6, a detection method for simultaneously detecting axial and radial displacement changes includes a radial displacement detection method and an axial displacement detection method. Radial displacement detection method: Select a stator core, pass an alternating current through the main winding, and the alternating magnetic flux generated in the main magnetic pole forms a closed loop through the main magnetic pole, the first mounting plate, the second mounting plate, the auxiliary magnetic pole, the gap, the rotor core, and the main magnetic pole. The alternating magnetic flux will induce an electromotive force in the outer first and second windings. e a1 and e b1 The sum of the two is the output voltage of the first and second outer windings. u 1. The output voltage of another stator sub-assembly (1) that is 180° out of radial direction from the stator sub-assembly (1) u 2. The difference between the two output voltages u 12 By analyzing the difference u 12 The amplitude and phase are used to determine the rotor's offset in the X direction; similarly, the difference between the output voltages of the other two stator components (1) is used to obtain... u 34 Through analysis u 34 The amplitude and phase can determine the rotor's offset in the Y direction; a comprehensive comparison u 12 and u 34 The radial offset of the rotor can be determined from the data. Axial displacement detection method: When the rotor is axially offset, it will cause a change in the radial overlap area between the auxiliary magnetic pole and the rotor assembly, resulting in a change in magnetic permeability, which in turn causes a change in the magnetic flux on the auxiliary magnetic pole, thereby inducing an electromotive force in the inner first winding and second winding. e a2 and e b2 The change ultimately causes the output voltage u a2 and u b2 The change in the rotor's axial displacement can be determined by comparing the magnitude and phase of the difference between the two values.

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