Self-inductive displacement sensor, compressor and air conditioner

Abstract

The invention provides a self-inductance type displacement sensor, a compressor and an air conditioner, the self-inductance type displacement sensor comprises a stator core, the stator core is provided with more than two stator teeth which are sequentially arranged along the circumferential direction, each stator tooth is wound with a coil, each stator tooth is matched at the inner side of the stator core to form a stator inner hole, and the stator inner hole is provided with a coil. The stator core is used for sleeving the rotating shaft through the stator inner hole; a stator slot is formed between every two adjacent stator teeth, and each stator slot is kept closed in the axial direction; the self-sensing displacement sensor further comprises a comb tooth structure used for sealing a gap between the inner hole of the stator and the rotating shaft, so that the self-sensing displacement sensor can cover an opening structure through which the rotating shaft passes. According to the invention, an existing displacement sensor and a sealing disc are integrated equivalently, so that compared with the distributed design of the displacement sensor and the sealing disc in the prior art, the integrated design can simplify the installation process and improve the installation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of centrifugal compressor technology, specifically relating to a self-sensing displacement sensor, a compressor, and an air conditioner. Background Technology

[0002] Sensors are tools for information acquisition, the "five senses" of machines, and one of the three pillars of information technology. Sensor technology is the source technology in the information "acquisition-processing-transmission" chain, and a fundamental technology for the automation and intelligence of modern industrial production. Its development level represents a country's level of industrialization. Any operating machinery, as long as it involves motion or mechanical deformation, requires displacement sensors for measurement and control. Furthermore, many non-displacement quantities, such as speed, pressure, angle, angular velocity, and even torque, can be converted into displacement for measurement.

[0003] like Figure 1 and Figure 2 As shown, a centrifugal compressor includes a rotating shaft 3' and an impeller 5' fixed on the rotating shaft 3'. The working fluid is compressed through the impeller 5'. A displacement sensor 100' is installed inside the centrifugal compressor to detect the axial and / or radial displacement of the rotating shaft 3'. Pressure differences exist between the inlet and outlet of the impeller 5' and between the impeller 5' and the motor cavity. Since the rotating shaft 3' and its rotating parts are clearance-fitted with the fixed parts of the centrifuge, the working fluid leaks through the gap between the rotating and fixed parts under the pressure difference, reducing compressor efficiency. To minimize leakage, labyrinth seals are commonly used in engineering. Specifically, the seal at the outlet of the impeller 5' is usually achieved by adding a dedicated sealing disc 13' after the impeller 5'. The sealing disc 13' is fitted onto the rotating shaft 3', and a comb-tooth structure is provided between the sealing disc 13' and the rotating shaft 3' to seal the gap between them. The sealing disc 13' and the displacement sensor 100' are set separately and need to be installed separately, which results in low installation efficiency. Therefore, this problem needs to be solved. Summary of the Invention

[0004] Therefore, the present invention provides a self-sensing displacement sensor, compressor, and air conditioner, which can solve the technical problem that the sealing disc and displacement sensor are separately set in the prior art, requiring separate installation, which leads to low installation efficiency.

[0005] To address the aforementioned problems, this invention provides a self-inductive displacement sensor, comprising a stator core having two or more stator teeth arranged sequentially along the circumference, each stator tooth having a coil wound around it, and each stator tooth engaging with the inner side of the stator core to form a stator inner hole, the stator core being fitted onto a rotating shaft through the stator inner hole; a stator slot is formed between each pair of adjacent stator teeth, and each stator slot remains closed axially; wherein, the self-inductive displacement sensor further includes a comb-tooth structure for sealing the gap between the stator inner hole and the rotating shaft, enabling the self-inductive displacement sensor to cover the opening structure through which the rotating shaft passes.

[0006] In some embodiments, the self-inductive displacement sensor further includes a detection ring for being fixed on the rotating shaft and rotatably fitted into the stator inner hole, wherein the detection ring extends partially into the stator inner hole and is partially located outside the stator inner hole.

[0007] In some embodiments, the comb structure includes a first comb structure disposed on the outer wall of the detection ring.

[0008] In some embodiments, the detection ring includes a first lamination and a second lamination stacked together, the first lamination and the second lamination having different outer diameters, and the first lamination and the second lamination are arranged alternately in the axial direction of the stator core, so that the outer walls of each first lamination and the outer walls of each second lamination cooperate to form the first comb tooth structure.

[0009] In some embodiments, the boot portions of each pair of adjacent stator teeth are connected so that each stator slot remains closed on the inner side of the stator hole; and the comb structure includes a second comb structure disposed on the inner wall of the stator hole.

[0010] In some embodiments, the stator core includes a first stator lamination and a second stator lamination stacked together. The stator inner hole includes a first hole segment on the first stator lamination and a second hole segment on the second stator lamination. The first hole segment and the second hole segment have different diameters, and the first stator lamination and the second stator lamination are arranged alternately in the axial direction of the stator core so that the hole walls of each first hole segment and each second hole segment cooperate to form the second comb tooth structure.

[0011] In some embodiments, each of the stator slots is filled with a filler, and each of the stator slots is kept axially closed by the internal filler.

[0012] In some embodiments, the self-inductive displacement sensor is used to be fitted inside the opening structure through the stator core, and the stator core is sealed to the inner wall of the opening structure to cover the opening structure.

[0013] The present invention also provides a compressor comprising the self-inductive displacement sensor described in any one of the above-described embodiments.

[0014] In some embodiments, the compressor is a centrifugal compressor having a compression chamber and a rotating shaft. The compression chamber has an opening on the back side of the impeller, and the opening cooperates with the rotating shaft to form the opening structure. The self-sensing displacement sensor covers the opening structure.

[0015] The present invention also provides an air conditioner comprising the self-inductive displacement sensor described in any one of the above descriptions; or comprising the compressor described in any one of the above descriptions.

[0016] The self-inductive displacement sensor, compressor, and air conditioner provided by this invention have the following beneficial effects: 1. The self-inductive displacement sensor of the present invention has dual functions. On the one hand, it can detect the radial and / or axial displacement of the rotating shaft by utilizing the cooperation between the stator core and the rotating shaft. On the other hand, by keeping each stator slot closed in the axial direction and using a comb-tooth structure to seal the gap between the stator inner hole and the rotating shaft, the self-inductive displacement sensor of the present invention forms a structure similar to an existing sealing disc, thus serving as a sealing disc in existing centrifugal compressors, covering the opening of the compression chamber on the back side of the impeller. In other words, the present invention is equivalent to integrating an existing displacement sensor with a sealing disc. Compared to the distributed design of displacement sensors and sealing discs in the prior art, the integrated design of the present invention simplifies the installation process and improves installation efficiency.

[0017] 2. By stacking stator laminations with different inner diameters to form the second comb tooth structure, the first comb tooth structure can also be stacked with laminations with different outer diameters, thereby eliminating machining processes, facilitating production, improving production efficiency and reducing costs, and also improving product consistency. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1This is a structural diagram of a centrifugal compressor in the prior art; Figure 2 This is a structural diagram of another centrifugal compressor in the prior art; Figure 3 This is a structural diagram of a self-inductive displacement sensor mounted on a rotating shaft according to an embodiment of the present invention; Figure 4 This is a structural diagram of another self-inductive displacement sensor installed on a rotating shaft according to an embodiment of the present invention; Figure 5 This is a structural diagram of another self-inductive displacement sensor installed on a rotating shaft according to an embodiment of the present invention; Figure 6 yes Figure 5 Enlarged view of point A in the middle; Figure 7 This is a schematic diagram of the assembly of a stator core and a coil according to an embodiment of the present invention; Figure 8 yes Figure 7 A sectional view of the middle structure; Figure 9 yes Figure 8 Enlarged view of point B in the middle; Figure 10 This is a structural diagram of the stator core of a self-inductive displacement sensor provided in an embodiment of the present invention; Figure 11 This is a structural diagram of a centrifugal compressor provided in one embodiment of the present invention; Figure 12 This is a structural diagram of another centrifugal compressor provided in an embodiment of the present invention.

[0020] The attached figures are labeled as follows: 1. Stator core; 2. Coil; 3. Shaft; 4. Detection ring; 5. Impeller; 6. Impeller inlet comb teeth; 7. Radial bearing; 8. Motor assembly; 9. Axial bearing; 11. Second comb tooth structure; 12. Stator tooth; 13. Opening; 14. Compression chamber; 41. First comb tooth structure; 51. First impeller; 52. Second impeller; 101. Stator slot; 102. Stator inner hole; 121. Shoe part; 100. Self-inductive displacement sensor; 10a. First self-inductive displacement sensor; 10b. Second self-inductive displacement sensor; 1a. First stator lamination; 1b. Second stator lamination; 2a. First lamination; 2b. Second lamination. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0023] For ease of description, relative regional terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the regional positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that relative regional terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the relative regional descriptions used herein will be interpreted accordingly.

[0024] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0025] See also Figure 3-10As shown, according to an embodiment of the present invention, a self-inductive displacement sensor 100 is provided, which includes a stator core 1. The stator core 1 has two or more stator teeth 12 arranged sequentially along the circumference, and each stator tooth 12 is wound with a coil 2. Each stator tooth 12 fits into the inner side of the stator core 1 to form a stator inner hole 102. The stator core 1 is used to be sleeved on a rotating shaft 3 through the stator inner hole 102. A stator slot 101 is formed between each pair of adjacent stator teeth 12, and each stator slot 101 remains closed in the axial direction. The self-inductive displacement sensor 100 also includes a comb structure for sealing the gap between the stator inner hole 102 and the rotating shaft 3, so that the self-inductive displacement sensor 100 can cover an opening structure through which the rotating shaft 3 passes, such as covering the opening 13 of the compression chamber 14 of a centrifugal compressor on the back side of the impeller 5.

[0026] In the above example, the self-inductive displacement sensor 100 of the present invention has a dual function. On the one hand, it can detect the radial and / or axial displacement of the rotating shaft 3 by utilizing the cooperation between the stator core 1 and the rotating shaft 3. On the other hand, by keeping each stator slot 101 axially closed and using a comb-tooth structure to seal the gap between the stator inner hole 102 and the rotating shaft 3, the self-inductive displacement sensor 100 of the present invention forms a structure similar to an existing sealing disc, thereby serving as a sealing disc in an existing centrifugal compressor, covering the opening 13 on the back side of the compression chamber 14 of the impeller 5. In other words, the present invention is equivalent to integrating an existing displacement sensor with a sealing disc. Compared to the distributed design of displacement sensors and sealing discs in the prior art, the integrated design of the present invention simplifies the installation process and improves installation efficiency.

[0027] The integrated design of the displacement sensor and the sealing disc in this invention can shorten the shaft length, thereby increasing the fixed frequency of the shaft, improving the operating speed of the shaft, expanding the operating range of the shaft, broadening the operating range of the centrifugal compressor, and improving the reliability of the centrifugal compressor.

[0028] In addition, since the axial length of a self-sensing displacement sensor is generally greater than that of an existing sealing disc, the present invention integrates a comb structure into the self-sensing displacement sensor 100, thereby increasing the length of the comb structure, significantly reducing leakage, thereby reducing leakage loss and improving compressor efficiency.

[0029] It should be noted that the aforementioned self-inductive displacement sensor 100 can at least detect the radial displacement of the rotating shaft 3. Specifically, when the rotating shaft 3 undergoes radial displacement, the air gap between the rotating shaft 3 and the stator inner hole 102 changes, which in turn changes the inductance of each coil 2. By detecting the magnitude of the change in inductance of each coil 2, the magnitude of the radial displacement of the rotating shaft 3 can be determined, thus achieving the detection of the radial displacement of the rotating shaft 3. The method of calculating the radial displacement of the rotating shaft 3 by detecting the change in inductance within each coil 2 is existing technology and will not be elaborated upon here.

[0030] In some implementations, such as Figure 3-5 As shown, the aforementioned self-inductive displacement sensor 100 may further include a detection ring 4, which is used to be fixed on the rotating shaft 3 and rotatably fitted in the stator inner hole 102. The detection ring 4 extends into the stator inner hole 102 and is located outside the stator inner hole 102.

[0031] In the above example, the detection ring 4 cooperates with the stator core 1, enabling the self-inductive displacement sensor 100 of the present invention to detect both the radial displacement and the axial displacement of the rotating shaft 3. Specifically, when the detection ring 4 cooperates with the stator core 1 to detect the radial displacement of the rotating shaft 3, the radial displacement of the rotating shaft 3 will cause the detection ring 4 to move together, changing the air gap between the detection ring 4 and the stator inner hole 102. This will cause a change in the inductance of each coil 2. By detecting the magnitude of the change in inductance of each coil 2, the magnitude of the radial displacement of the rotating shaft 3 can be determined, thus realizing the detection of the radial displacement of the rotating shaft 3. Similarly, when the detection ring 4 cooperates with the stator core 1 to detect the axial displacement of the shaft 3, the axial displacement of the shaft 3 will cause the detection ring 4 to move together, changing the area of ​​the detection ring 4 relative to the stator inner hole 102. This will also change the inductance of each coil 2. By detecting the magnitude of the change in inductance of each coil 2, the magnitude of the axial displacement of the shaft 3 can be determined, thus realizing the detection of the axial displacement of the shaft 3. It should be noted that the method of calculating the axial displacement and / or radial displacement of the shaft 3 by detecting the change in inductance of each coil 2 is existing technology, and will not be elaborated here.

[0032] In some embodiments, the aforementioned self-sensing displacement sensor 100 is used to detect both the radial and axial displacements of the rotating shaft 3. This enables the self-sensing displacement sensor 100 of the present invention to simultaneously possess both axial displacement detection and radial displacement detection functions, thereby achieving the integration of radial and axial displacement sensors. Compared with the prior art method of separately setting radial and axial displacement sensors on the rotating shaft, the integrated radial and axial displacement sensor method of the present invention solves the problem of limited axial space in conventional axial displacement measurement, enabling accurate determination of the suspension state of the rotating shaft in air suspension bearings or magnetic suspension systems.

[0033] In some implementations, such as Figure 4-5 As shown, the aforementioned comb structure may include a first comb structure 41 disposed on the outer wall of the detection ring 4.

[0034] In the above example, the first comb structure 41 is designed to reduce leakage between the stator inner hole 102 and the rotating shaft 3.

[0035] In some implementations, such as Figure 6 As shown, the aforementioned detection ring 4 may include a first lamination 2a and a second lamination 2b stacked together. The outer diameters of the first lamination 2a and the second lamination 2b are different, and the first lamination 2a and the second lamination 2b are arranged alternately in the axial direction of the stator core 1 so that the outer wall of each first lamination 2a and the outer wall of each second lamination 2b cooperate to form the aforementioned first comb tooth structure 41.

[0036] In the above example, since the first comb tooth structure 41 is formed by stacking laminations of different outer diameters, machining processes are eliminated, making it easier to produce, improving production efficiency and reducing costs, and also improving product consistency.

[0037] It should be noted that both the first lamination 2a and the second lamination 2b mentioned above can be made of silicon steel sheets. The sealing performance of the first comb structure 41 can be adjusted by changing the thickness of the first lamination 2a and / or the second lamination 2b. Alternatively, the sealing performance of the first comb structure 41 can be adjusted by changing the number of both the first lamination 2a and the second lamination 2b.

[0038] In some implementations, such as Figure 10 As shown, the shoe portions 121 of each adjacent pair of stator teeth 12 are connected so that each stator slot 101 remains closed on the side of the stator inner hole 102; and the aforementioned comb structure includes a second comb structure 11 (such as...) disposed on the wall of the stator inner hole 102. Figure 3 (As shown).

[0039] In the above example, by connecting the shoe portions 121 of each pair of adjacent stator teeth 12, each stator slot 101 is kept closed on the side of the stator inner hole 102. This can simulate the inner hole structure of the existing sealing disc. Furthermore, by providing a second comb tooth structure 11 on the hole wall of the stator inner hole 102, it is beneficial to reduce leakage between the stator inner hole 102 and the rotating shaft 3.

[0040] In some implementations, such as Figure 9As shown, the aforementioned stator core 1 includes a first stator lamination 1a and a second stator lamination 1b stacked together. The stator inner hole 102 includes a first hole segment on the first stator lamination 1a and a second hole segment on the second stator lamination 1b. The first hole segment and the second hole segment have different diameters, and the first stator lamination 1a and the second stator lamination 1b are arranged alternately in the axial direction of the stator core 1, so that the hole walls of each first hole segment and the hole walls of each second hole segment cooperate to form the aforementioned second comb tooth structure 11.

[0041] In the above example, since the second comb structure 11 is formed by stacking stator laminations with different inner diameters, machining processes are eliminated, making it easier to produce, improving production efficiency and reducing costs, and also improving product consistency.

[0042] It should be noted that both the first stator lamination 1a and the second stator lamination 1b mentioned above can be made of silicon steel sheets. The sealing performance of the second comb structure 11 can be adjusted by changing the thickness of the first stator lamination 1a and / or the second stator lamination 1b. Alternatively, the sealing performance of the second comb structure 11 can be adjusted by changing the number of both the first stator lamination 1a and the second stator lamination 1b.

[0043] In this invention, through the design of the second comb tooth structure 11 on the wall of the stator inner hole 102 and / or the design of the first comb tooth structure 41 on the outer wall of the detection ring 4, when the detection assembly formed by the stator core 1 and the detection ring 4 is sealed at the opening on the back side of the centrifugal compressor's compression chamber, the axial leakage gap of the detection assembly can be made to be only the gap between the stator core 1 and the detection ring 4.

[0044] In some embodiments, when the aforementioned self-sensing displacement sensor 100 includes a detection ring 4, the detection ring 4 is sealed to the rotating shaft 3 to prevent leakage from the opening structure at the junction of the detection ring 4 and the rotating shaft 3.

[0045] In some embodiments, the shoe portions 121 of each of the aforementioned adjacent stator teeth 12 are connected by integral molding, which can improve the connection stability of the shoe portions 121 of adjacent stator teeth 12.

[0046] In order to keep each of the aforementioned stator slots 101 closed in the axial direction, in some embodiments, each of the aforementioned stator slots 101 is filled with a filler, and each stator slot 101 is kept closed in the axial direction by the internal filler.

[0047] In some embodiments, each of the aforementioned stator slots 101 can be filled internally with the aforementioned filler material by potting. Potting improves the filling effect and ensures that the stator slots 101 are completely sealed axially.

[0048] It is understood that the aforementioned filler should be an insulating material, preferably an epoxy resin material.

[0049] In order to enable the aforementioned self-inductive displacement sensor 100 to cover the opening structure through which the rotating shaft 3 passes, in some embodiments, the aforementioned self-inductive displacement sensor 100 is used to be fitted inside the opening structure through the stator core 1, and the stator core 1 is sealed to the inner wall of the opening structure to cover the opening structure.

[0050] In some embodiments, the present invention also provides a compressor that includes a self-inductive displacement sensor 100 of any of the above.

[0051] In some implementations, such as Figure 11-12 As shown, the aforementioned compressor can be a centrifugal compressor, which has a compression chamber 14 and the aforementioned rotating shaft 3. The compression chamber 14 has an opening 13 on the back side of the impeller 5, and the opening 13 cooperates with the rotating shaft 3 to form the aforementioned opening structure. A self-inductive displacement sensor 100 covers this opening structure. Specifically, the self-inductive displacement sensor 100 is fitted onto the opening 13 via a stator core 1, and the outer wall of the stator core 1 is sealed to the inner wall of the opening 13, thereby covering the opening structure with the self-inductive displacement sensor 100.

[0052] In the above example, by utilizing the aforementioned sealing opening structure of the self-inductive displacement sensor 100, the self-inductive displacement sensor 100 of the present invention has a dual function: on the one hand, it functions as a sensor, and on the other hand, it also acts as a sealing disc in the prior art. Thus, compared to the prior art, the present invention eliminates the sealing disc on the original centrifugal compressor shaft, thereby shortening the shaft length, increasing the shaft's fixed frequency, improving the shaft's operating speed, expanding the shaft's operating range, broadening the centrifugal compressor's operating range, and improving the centrifugal compressor's reliability.

[0053] In some implementations, the aforementioned compressor may be a centrifugal compressor, such as an air-suspended centrifugal compressor or a magnetically suspended centrifugal compressor.

[0054] In some implementations, such as Figure 11-12 As shown, the aforementioned centrifugal compressor also includes a motor assembly 8, a radial bearing 7, and an axial bearing 9, all of which are mounted on the rotating shaft 3. The radial bearing 7 and the axial bearing 9 can both be air-suspended bearings, or both can be magnetically suspended bearings. When both the radial bearing 7 and the axial bearing 9 are air-suspended bearings, the centrifugal compressor is an air-suspended centrifugal compressor. When both the radial bearing 7 and the axial bearing 9 are magnetically suspended bearings, the centrifugal compressor is a magnetically suspended centrifugal compressor.

[0055] In some embodiments, the aforementioned centrifugal compressor further includes an impeller inlet comb 6. The aforementioned impeller 5 includes a first impeller 51 and a second impeller 52. In the first example, as... Figure 11 As shown, the first impeller 51 and the second impeller 52 are distributed at both ends of the rotating shaft 3. The aforementioned self-inductive displacement sensor 100 includes a first self-inductive displacement sensor 10a and a second self-inductive displacement sensor 10b. The first self-inductive displacement sensor 10a corresponds to the first impeller 51, and the second self-inductive displacement sensor 10b corresponds to the second impeller 52. In the second example, as... Figure 12 As shown, the first impeller 51 and the second impeller 52 are distributed at the same end of the rotating shaft 3. The first impeller 51 and the second impeller 52 cooperate to form a two-stage compression, wherein the first impeller 51 is the first-stage impeller and the second impeller 52 is the second-stage impeller. The self-inductive displacement sensor 100 of the present invention is disposed on the back side of the second impeller 52. In this second example, the aforementioned self-inductive displacement sensor 100 may also include a first self-inductive displacement sensor 10a and a second self-inductive displacement sensor 10b. Wherein, the first self-inductive displacement sensor 10a is disposed on the back side of the second impeller 52, the first impeller 51, the second impeller 52 and the first self-inductive displacement sensor 10a are all located on one axial side of the motor assembly 8, and the first self-inductive displacement sensor 10b is located on the other axial side of the motor assembly 8.

[0056] In some embodiments, the present invention also provides an air conditioner that may include the self-inductive displacement sensor 100 described in any one of the above-described embodiments; or include the compressor described in any one of the above-described embodiments.

[0057] For ease of understanding, the overall structure of the present invention will be described below, and its working principle will be explained.

[0058] The aforementioned stator core 1 can be formed by lamination. Specifically, by alternately laminating first stator laminations 1a and second stator laminations 1b with different inner diameters, the aforementioned second comb-tooth structure 11 can be formed on the hole wall of the stator inner hole 102. This eliminates the need for machining the hole wall of the stator inner hole 102. After obtaining the stator core 1, coils 2 are wound on the stator teeth 12, thus obtaining a usable self-inductive displacement sensor 100. To ensure a sealing effect, after the self-inductive displacement sensor 100 is assembled onto the centrifugal compressor, the working fluid on both sides of the self-inductive displacement sensor 100 must flow entirely through the gap between the stator core 1 and the detection ring 4. Therefore, the gap between the coils 2 in the stator slot 101 needs to be sealed. Specifically, potting or other methods can be used to fill the gap between the coils 2 in the stator slot 101.

[0059] This invention, by adding a comb-tooth sealing structure to the self-inductive displacement sensor 100, provides a longer sealing surface after the impeller 5 compared to traditional centrifugal compressors, significantly reducing leakage and thus lowering leakage losses and improving compressor efficiency. Simultaneously, by eliminating the sealing disc on the shaft 3, the shaft length is greatly shortened, increasing the rotor's fixed frequency, widening the operating range of the centrifugal compressor, and improving its reliability. Furthermore, integrating the comb-tooth structure into the self-inductive displacement sensor 100 allows for the stacking of silicon steel sheets of different inner diameters to form the stator core 1, and the stacking of laminations of different outer diameters to form the detection ring 4, eliminating machining processes, facilitating production, improving production efficiency, reducing costs, and enhancing product consistency.

[0060] The self-inductive displacement sensor 100 has a simple stator structure and is easy to assemble, which can greatly reduce the manufacturing cost. When applied to magnetic levitation centrifuges, it can significantly shorten the shaft length and increase the stability of the magnetic levitation system.

[0061] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A self-induction displacement sensor (100), characterized by: The self-induction displacement sensor (100) comprises a stator core (1) having two or more stator teeth (12) arranged in sequence in the circumferential direction, a coil (2) being arranged around each stator tooth (12), each stator tooth (12) being fitted in the inner side of the stator core (1) to form a stator inner hole (102), and the stator core (1) being used to be sleeved on a rotating shaft (3) through the stator inner hole (102); each two adjacent stator teeth (12) form a stator slot (101), and each stator slot (101) is kept closed in the axial direction. The self-induction displacement sensor (100) further comprises a comb structure for sealing the gap between the stator inner hole (102) and the rotating shaft (3), so that the self-induction displacement sensor (100) can cover the opening structure with the rotating shaft (3) passing through.

2. The self-induction displacement sensor (100) according to claim 1, wherein: The self-induction displacement sensor further comprises a detection ring (4) for being sleeved on the rotating shaft (3) and being rotatably sleeved on the stator inner hole (102), the detection ring (4) partially extending into the stator inner hole (102) and partially being located outside the stator inner hole (102).

3. The self-induction displacement sensor (100) according to claim 2, wherein: The comb structure comprises a first comb structure (41) arranged on the outer wall of the detection ring (4).

4. The self-induction displacement sensor (100) according to claim 3, wherein: The detection ring (4) comprises a first lamination (2a) and a second lamination (2b) arranged in layers, the outer diameters of the first lamination (2a) and the second lamination (2a) are different, and the first lamination (2a) and the second lamination (2a) are arranged in sequence and alternately in the axial direction of the stator core (1), so that the outer wall of each first lamination (2a) and the outer wall of each second lamination (2a) cooperate to form the first comb structure (41).

5. The self-induction displacement sensor (100) according to any one of claims 1-4, wherein: The shoe portions of each two adjacent stator teeth (12) are connected, so that each stator slot (101) is kept closed on the side of the stator inner hole (102); and the comb structure comprises a second comb structure (11) arranged on the hole wall of the stator inner hole (102).

6. The self-induction displacement sensor (100) according to claim 5, wherein: The stator core (1) comprises first stator laminations (1a) and second stator laminations (1b) arranged in a stack, the stator inner hole (102) comprises first hole sections on the first stator laminations (1a) and second hole sections on the second stator laminations (1b), the hole diameters of the first hole sections and the second hole sections are different, and the first stator laminations (1a) and the second stator laminations (1b) are alternately arranged in sequence in the axial direction of the stator core (1), so that the hole walls of the first hole sections and the hole walls of the second hole sections cooperate to form the second comb structure (11).

7. The self-induction displacement sensor (100) according to any one of claims 1-4, 6, characterized in that: Each of the stator slots (101) is filled with a filler, and each of the stator slots (101) is kept closed in the axial direction by the filler inside.

8. The self-induction displacement sensor (100) according to any one of claims 1-4, 6, characterized in that: The self-induction displacement sensor (100) is used to be sleeved in the opening structure by the stator core (1), and the stator core (1) is sealingly fitted with the inner wall of the opening structure to cover the opening structure.

9. A compressor characterized by: The self-induction displacement sensor (100) according to any one of claims 1-8.

10. The compressor according to claim 9, characterized in that: The compressor is a centrifugal compressor, the centrifugal compressor has a compression cavity (14) and the rotating shaft (3), the compression cavity (14) has an opening (13) on the back side of the impeller (5), the opening (13) cooperates with the rotating shaft (3) to form the opening structure, and the self-induction displacement sensor (100) covers the opening structure.

11. An air conditioner characterized by comprising: The self-induction displacement sensor (100) according to any one of claims 1-8; or the compressor according to any one of claims 9-10. The self-induction displacement sensor (100) according to any one of claims 1-8; or the compressor according to any one of claims 9-10.

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